7 - Analyze Data In a Data Segmentation profile you can select a part of a classified run with a specific average speed range and speed variation. In a Parameter profile you can select specific parameters for analysis and export. You can view the run, 3D and 2D Footprint Intensities, and Footfall Patterns. Here you can view the tables with calculated statistics. Here you can view run statistics grouped by treatment group and time point, and their corresponding charts. A list of research areas where CatWalk XT is an important tool, with special focus on the analysis parameters used by researchers. 7 - Analyze Data

7.1 Select The Data

Using a Data Segmentation profile, you can select one part from each classified run that complies with three criteria (the minimum number of consecutive steps with a specific speed range and maximum allowed speed variation). This is useful, for example, if you have a run in which the animal briefly stopped at the beginning of a run but then continued to walk normally. You can automatically select only the 'good' part of the run for analysis and export with a Data Segmentation profile.

Data Segmentation Profiles

Default data segmentation profile

The default Data Segmentation profile is labeled All Data. It cannot be deleted.

Procedure

1. Do one of the following:

In the Profiles Explorer, right-click Data Segmentation Profiles and select

Add New Profile. Choose Profiles > Data Segmentation Profile > New. 2. Enter the name of the new profile and click OK. 3. In the Profile window, under Select Data, you can set the following: Minimum number of consecutive steps per run - Only the part of the run with the minimum number of consecutive steps which complies with the next two parameters is selected. We advise you to use at least 10 consecutive steps. See also what speed or variation should i choose? on page 95. Average speed should range from (in distance unit/second) - Only the part of the run within the set speed range is selected. The Average Speed is based on the Body Speed of selected steps in a run. The Body Speed for each step cycle is calculated by dividing the distance that animal's body has traveled from one initial contact to the next by the time it took to travel that distance. The Average Speed is different from the Run Average Speed (shown in the Acquisition and Classification screens), which is the average speed of the animal's body during the whole recorded run. Maximum allowed speed variation (in percent) - Only the steps in a run within the set maximum allowed speed variation are selected. 7 - Analyze Data Example - The Average Speed of a run is 22.0 cm/s. The speed of a step cycle of the left front paw in this run is 29.07 cm/sec. The variation then is: ([29.07-22.0] / 22.0) * 100% = 32.1%. Exclude non-compliant runs - When you select this option, runs not compliant with the run criteria in the Experiment Settings are excluded from the data selection. Exclude partially classified runs - When you select this option, runs which have not been completely classified are excluded from the data selection.

Selected Data Overview tab

Shows the result of your data segmentation. The sheet (on the left) shows, per treatment group and time point, the number of Selected Animals / Runs / Steps, the Total number of Animals / Runs / Steps in the experiment and the Percentage of selected Animals / Runs / Steps. You can choose whether you want to see the selected Animals, Runs or Steps by selecting the corresponding option at the bottom. The chart (on the right) is a graphical representation of the selected data. You can choose whether you want time points or treatment groups displayed on the X-axis, by selecting the corresponding option at the bottom. Figure 7.1 Part of the Data Segmentation Profile window. In this example, the Selected Data Overview sheet shows the selected Steps. On the right is the graphical representation of the selection. 7 - Analyze Data

Complete Data Overview tab

In the matrix on the left, the average speed intervals (1 to 10 cm/sec, 1 to 20 cm, 1 to 30 cm/ sec, etc, with centimeters as distance unit) are displayed on rows. The speed variation is displayed in 10%-intervals on columns. Each cell in the matrix shows the resulting number of steps for a specific combination of Average Speed and Maximum Variation in speed based on the Minimum number of consecutive steps you selected. In the Complete Data Overview, you can only change the Minimum number of consecutive steps per run. If you do this, you need to click the Calculate Complete Data Overview button at the bottom to re-calculate the number of selected steps. The 3D-chart shows: On the X-axis: the Average speed range intervals. On the Y-axis, the Maximum allowed speed variation intervals. On the Z-axis, the resulting number of steps per speed / speed variation interval. Figure 7.2 The 3D-chart in the Complete Data Overview tab of a Data Segmentation profile. In this example, the majority of the steps in the runs of this experiment have an Average Speed > 40 cm/s and a Maximum speed variation > 90%. 7 - Analyze Data

What Speed Or Variation Should I Choose?

Minimum number of consecutive steps per run - We recommend to select at least 10 consecutive steps. This generally corresponds to 1 step cycle for each paw (that is, each paw is placed twice on the glass plate). If you select a lower number, a paw might have been placed only once, which means that for this paw some parameters (for example, Swing or Stride Length) cannot be calculated. Average speed should range from ... to ... ([Distance unit]/second) - In the Complete Data Overview tab, the 3D-chart (see Figure 7.2) shows the number of steps in the different Average Speed intervals; this helps you in determining the Average Speed range for your data. Select the widest average speed range possible for your runs if the Average Speed is different for different treatment groups (for example, the experimental animals are on average slower than the control animals). In the 3D-chart in the Complete Data Overview tab, steps with a maximum speed higher than 120 cm/sec (or an equivalent speed in a different Distance unit) are not displayed. However, you can select a maximum average speed of up to 300 cm/sec. Maximum allowed speed variation (percent) - By selecting a low or high speed variation, you allow, respectively, small and large differences in average speed for a run. Example - You have a run with an Average Speed of 25 cm/sec. You have set the Maximum allowed speed variation to 20 percent. The variation is calculated as follows: ([Step speed - Average Speed] / Average Speed) * 100 = speed variation (%). With the values in this example, this means that the step speed can range between 20 and 30 cm/ sec. If you set the Maximum allowed speed variation to 60 percent, the step speed can range between 10 and 40 cm/sec.

Check The Data After Segmentation

While data segmentation is a powerful tool to remove outliers and generate more homogeneous samples which facilitate analysis, is not free of risks. The following figure shows a typical CatWalk XT visualization of paw prints. The subject under study makes a small jump (indicated with the arrow in the Timing view). This jump is typical of the studied phenotype, and should be in the data. However, data segmentation may remove significant part of interesting data because based on increased variation in speed or a number of consecutive regular steps. 7 - Analyze Data Thus, always check the data resulting from data segmentation before running the analysis.

7.2 Select The Analysis Parameters

You can select specific parameters with Parameter profiles. Only selected parameters from the Paw Statistics (see page 106) and Phase Lags (see page 123 and page 126) are displayed in the Run Statistics and in the Group Statistics and Charts, and exported to an Excel file. The default Parameter profile is labeled All Parameters and cannot be edited nor deleted. 1. To create a new Parameter profile, do one of the following: In the Profiles Explorer, right-click Parameter Profiles and select Add New Profile. Choose Profiles > Parameter Profile > New. 2. Type in the name of the Parameter profile and click OK. 3. In the Parameter profile window, you can select or de-select the following: Paws - Select the paws for which you want to display/export the Paw Statistics Parameters. Parameters - Select the Paw Statistics Parameters you want to display/export. Phase Dispersions - Select the paw combinations (Diagonal, Girdle, Ipsilateral) for which you want to calculate Phase Dispersions (see page 123). Couplings - Select the paw combinations (Diagonal, Girdle, Ipsilateral) for which you want to calculate Couplings (page 126). 4. Click OK to make this new Parameter profile active. 7 - Analyze Data

7.3 Visualize The Runs

Procedure

Open the Visualization screen

In the Experiment Tasks window, select View Run Visualizations. Choose Analyze > View Run Visualizations. In the Experiment Explorer: - Right-click a trial and select View Run Visualizations. This option is only available, when the trial contains one or more (partially) classified runs. - Right-click a Run and select View Run Visualizations. This option is only available when the run has been (partially) classified. You can export the Visualizations. See export the run visualizations on page 160.

Visualize a run

1. Under Trial & Run Selection, select a trial and one of the runs in that trial, or click the Previous/Next button to navigate between trials and runs.
2. Replay the run (as described in Review the runs during classification on page 78).
3. Under Visualizations, you can view: 3D Footprint Intensities (see below). 2D Footprint Intensities (see page 99). Footfall Patterns (see page 100). Paws which have not been selected in the currently active Data Segmentation profile, are displayed in gray in the Video window and are not displayed in any of the Visualizations (3D/ 2D Footprint Intensities, Footfall Patterns). You can select another Data Segmentation profile by right-clicking it and selecting Set as Active.

3d Footprint Intensities

Click on the 3D Footprint Intensities tab. The 3D Footprint Intensities tab plots the print intensities of the 4 paws for each individual video frame in which the paws has contact with the glass plate in a 3D-chart. The intensities 7 - Analyze Data range from 0 to 255. The color range used in the 3D-chart is the same as is used in the False Color mode of the footprints in the Classification print view (see page 79). A 3D chart can be rotated in all directions: click a chart, keep the mouse button pressed and drag to rotate the chart. To reset all charts to the original orientation, open another item in the experiment (for example the Trial List) and re-open the Visualization. Figure 7.3 The 3D Footprint Intensities charts. In this example, the Video window shows two paws, right hind (RH) and left front (LF) in gray, which means that these paws were not selected in the current Data Segmentation profile. As a result, these paws are not displayed in the 3D chart. 7 - Analyze Data

2d Footprint Intensities

Click on the 2D Footprint Intensities tab. The 2D Footprint Intensities tab plots the print intensities of each paw print in a single image. The solid red line represents the maximum intensity in a frame, the filled, colored area under the red line represents the mean intensity of the paw (see Figure 7.4). The 2D Footprint Intensities plot displays the prints from left to right irrespective of the animal's actual walking direction. When you right-click the 2D Footprint Intensities plot, you can select on of two options: Save to File. This saves the 2D Footprint Intensities plot to an image file (*.png). Copy to Clipboard. This copies the 2D Footprint Intensities plot to the clipboard. Figure 7.4 The 2D Footprint Intensities. The position of the vertical, dotted hairline corresponds to the position of the animal in the Video window. Left: All steps are selected (Default data profile). Right: Some steps have been excluded in the current Data Segmentation profile and are, therefore, not displayed in the 2D chart. 7 - Analyze Data

Footfall Patterns

Click the Footfall Patterns tab. The Footfall Patterns diagram shows the order in which the paws (represented by colored dots) were placed on the glass plate. The Footfall Patterns are displayed from left to right, irrespective of the animal's actual walking direction. The colors of the dots indicate the following:

Orange - Not taken into account

Orange dots indicate paw placements that are not taken into account when determining a footfall pattern. This often occurs to the first and last paw prints. example In the figure below, the first paw placement, LF, occurs again within a 4-paw sequence (see the fourth dot in the run). A pattern like LF-LH-RF-LF is clearly not a footfall pattern. Therefore, the LF paw placement is ignored and the software starts looking for patterns from the next paw placement. In this case, the next paw placement is LH, which is followed by RF-LF-RH. Together, they form a recognized footfall pattern, indicated with CA. Figure 7.5 The Footfall Patterns diagram (bottom). The dots with the dotted circles correspond to the paws displayed in the Video window (top). 7 - Analyze Data Similarly, paw placements at the end of the run can be excluded. After the last valid pattern LH-RF-LF-RH has been found (see the last CA in the run), three paw placements are left: RF, LH and RH. They form an incomplete pattern, which is excluded from the results.

Blue - Start of a pattern

Paws at the begin of a recognized footfall pattern. It is always followed by three green dots.

Green - Part of a pattern

Paws that are at the second, third and fourth place in a recognized footfall pattern.

Purple - Not part of a pattern

These paw placements are determined as not being part of a footfall pattern. They are usually in the middle of the run, between two valid patterns. In the following example, the paw LF is repeated within a sequence of 4 paw placements (the first and the fourth are indicated with arrows). The sequence LF-LH-RF-LF, indicated with the dotted line rectangle, is not recognized as a valid pattern. So the paw placement LF is marked with a Not part of a pattern dot and the software resumes searching from the next paw placement, in this case LH, which is detected as the start of a CA pattern (LH-RF-LF-RH). 7 - Analyze Data

How Footfall patterns are labeled

Consider a generic footfall pattern found in a run, like LH-RF-LF-RH in the figure below. The starting paw placement LH is marked with a blue dot. Now imagine that this pattern LH-RF-LF-RH is repeated immediately after the first one: LH-RF-LF-RH-LH-RF-LF-RH. Now we can recognize more patterns, for example: If you start from the second placement, RF: RF-LF-RH-LH; If you start from the third placement, LF: LF-RH-LH-RF; If you start from the fourth placement, RH: RH-LH-RF-LF; 7 - Analyze Data etc. This "family" of patterns is marked with the label CA (Cruciate A). The grouping of patterns into "families" is also the reason why Catwalk XT reports only 6 patterns (CA, CB, AA, AB, RA, RB) out of a total of 24 possible combinations. This makes classification independent on which paw comes first in the beginning of a run. The predefined footfall pattern labels are (note that any of the paw prints within a sequence can be the starting point, marked with the blue dot): For Cruciate patterns: - CA, for the paw sequence RF-LF-RH-LH. - CB, for LF-RF-LH-RH. For Alternate patterns: - AA, for RF-RH-LF-LH. - AB, for LF-RH-RF-LH. For Rotate patterns: - RA, for RF-LF-LH-RH. - RB, for LF-RF-RH-LH. When initial contact of two paws coincides in a frame, the paw with the largest surface area in this frame is considered to have been placed first. In the unlikely event that the surface areas of these paws are equal, the following order of placement is used: LF-LH-RF-RH. Paws that are currently visible in the Video window are marked with a dotted circle in the Footfall Patterns diagram (see Figure 7.5).

Export the visualizations

Right-click the Footfall Patterns diagram and choose one of the two options: Save to File. This saves the Footfall Patterns diagram to an image file (*.png). Copy to Clipboard. This copies the Footfall Patterns diagram to the clipboard.

See also

The Regularity Index (%) on page 116. All statistics of Step sequence on page 115. 7 - Analyze Data

7.4 Run Statistics

Procedure

1. Do one of the following: Choose Analyze > View Run Statistics. In the Experiment Explorer, right-click a trial/run and select View Run Statistics. This option is only available, when the trial contains one or more (partially) classified runs.
2. If you want to see the Run Statistics of another trial or run, under Trial &

Run Selection, select a trial and a run, or click the Previous/Next button to

navigate to that trial and run. Under Views, the Print View and the Timing View of the selected run are displayed. 3. Under Statistics, click on one of the tabs to view the corresponding parameter sheet and their statistics. All tabs and their parameters are described below.

Notes

All sheets contain calibrated values, displayed in the Distance Unit selected in the Preferences. By right-clicking individual sheets you can either copy them to the clipboard or export them to Excel. You can export statistics of separate runs (Run Statistics, page 153), grouped per trial (Trial Statistics, page 156) and grouped per experimental group (Group Statistics, page 159). Paw prints displayed in gray are excluded from analysis based on the settings in the Data Segmentation profile currently active. To include all paw prints in the analysis, select the All Data Segmentation profile (page 92).

Summary

The Summary sheet shows a summary for the following parameters categories:

Paw Statistics - The mean and standard deviation (SD) are given for each paw, for the girdle paws (RF-LF and RH-LH) and for the ratio of the girdle paws (RF/LF, LF/RF, RH/LH and LH/RH). See Paw Statistics sheet (page 106) for more details. Step sequence - The total duration of all runs and the total number of categorized footfall patterns are given. For each footfall pattern category the percentage of the total 7 - Analyze Data number of categorized footfall patterns is given. Finally, the Regularity Index is shown, based on all categorized footfall patterns. See Step sequence sheet (page 115) for more details. Base of support - These are the mean values for the front paws and the hind paws. See Base of Support sheet (page 118) for more details. Print positions - These are the mean values for the right paws and the left paws. See Print positions sheet (page 122) for more details. Support - These are the relative duration of contact with the glass plate of all paw combinations. See Support sheet (page 127) for more details. Phase Dispersions - The Mean, AD (Angular deviation), SD (Circular Standard Deviation) and R for all pairs are given, together with the number of Mismatches and occurrences of Anchor-No-Target (ANT), Anchor-Multiple-Targets (AMT) and Target-No-Anchor (TNA). Note that the results are circular statistics. See phase dispersions (page 123) for details. Couplings - The same statistics are given as for Phase dispersions. See Couplings sheet (page 126) for more details.

General

The General sheet displays the following variables: Name - The name of the run. Start Time - The date and time the run was acquired. Run Duration - The duration of the recorded run. Run Average Speed - The average speed of the recorded run. This is the speed of the animal's body in the recorded run. Run Maximum Variation - The maximum variation in walking speed in the recorded run. Frame Rate - The frame rate of the camera. This is always 100 frames per second (fps). Camera Gain - The value of the Camera Gain from the Detection Settings. Green Intensity Threshold - The value of the Green Intensity Threshold from the Detection Settings. X-Unit (mm/pixel) - The horizontal size of a single pixel. Y-Unit (mm/pixel) - The vertical size of a single pixel. Walkway Length - The length of the defined walkway. Walkway Width - The width of the defined walkway. 7 - Analyze Data

Paw Statistics

The Paw Statistics sheet displays parameters that are based on individual paw prints. Choose Analyze > View Run Statistics and under Statistics click Paw Statistics. Which paws/parameters are displayed in this sheet depends on the selection in the currently active Parameter profile (displayed in blue and bold in the Experiment Explorer).

In the Paw Statistics sheet, when you click one of the paw rows:

The Print View highlights the corresponding print. The Timing View shows the corresponding Stand. The Sub Prints View shows the individual prints of the Stand.

Paw

The Paw label based on the current classification.

Initial Contact At (s)

Initial Contact At (s) is the time in seconds since the start of the run at which a paw makes contact with the glass plate.

Stand (s) (or Stance) (s)

Stand (s) or Stance phase is the duration in seconds of contact of a paw with the glass plate. Kloos et al. (2005) (Exp. Neurol. 191: 251-265) showed that rats with a moderate spinal cord injury showed an increase in stand duration of the hind legs compared to pre-operative values. See Application examples > spinal cord injury (page 136).

Stand Index

Stand Index is a measure for the speed at which the paw loses contact with the glass plate. 7 - Analyze Data The formula for Stand Index is: where: a is derived from y = ax + b, that describes a straight line fitted through the values of Print area between the time of maximum contact and the 90% percentile of the stance duration. The value a should be interpreted as "change in print area per video frame". X0 is the max contact area. frame rate is the camera frame rate (usually 100 frames per second). This correction allows to compare results obtained with different frame rates. Stand Index is therefore a function of the change in print area per second. It is always negative because it describes the decrease in print area as shown in the next figure. The more negative the value, the steeper the slope of the line that describes the reduction in the Print area. This means that the subject lifts its paw more quickly.

notes

Index should only be used for smoothly moving animals. The formula of Stand Index includes a/X0 to correct for differences in Print area between paws, subjects etc. Stand Index X 0 - frame rate 7 - Analyze Data Stand Index is only calculated when Stand consists of at least 5 frames and there are at least 3 data points between t(Max area) and the 90% percentile. Stand Index is not calculated when two stances were combined (see page 76) and the Max Contact area was in the first stance. If the 90th percentile of the time interval does not correspond to a video frame, the software interpolates the Print area between the two video frames that include that time.

Max Contact At (s)

Max Contact At (s) is the time in seconds since the start of the run that a paw makes maximum contact with the glass plate. It can be regarded as the point at which the braking phase turns into the propulsion phase during Stand.

Max Contact At (%)

Max Contact At (%) is Max Contact At (s) relative to Stand of a paw. The formula for Max Contact At (%) is: Max Contact At (%) is used in research on spinal cord injury. For example, Hamers et al. (2001) found an increase in Max Contact At (%) for both front and hind paws in rats. This increase was more marked following a contusion injury compared to a transection injury.

Max Contact Area

Max Contact Area is the maximum area of a paw that comes into contact with the glass plate. In other words, it is the Print Area at Max Contact at (s).

Max Contact Max Intensity

This is the maximum intensity at the time of maximum contact of a paw. Intensity ranges from 0 to 255. The intensity of a print depends on the degree of contact between a paw and the glass plate and increases with increasing weight. Therefore, Intensity is a measure of weight put on the glass plate. The parameter is extracted from the print at maximum contact and finding the pixels of highest intensity: Max Contact At Max Contact at (s) - Initial Contact Stand - ·· 7 - Analyze Data The Intensity parameter is used to assess the effects of neuropathic pain, including mechanical allodynia (Vrinten and Hamers, 2003). Vrinten and Hamers found that after a chronic constriction injury, which causes neuropathic pain, Intensity was reduced two weeks after surgery and gradually returned to pre-operative values. This change in Intensity showed a high degree of correlation with Von Frey thresholds.

Max Contact Mean Intensity

This is the mean Intensity of a paw print at Max Contact. Intensity ranges from 0 to 255. See also Mac Contact Max Intensity.

X position

X is the position of the center of the paw print at Max Contact in the horizontal (walking) direction. X is the distance in the Distance Unit from the left side of the walkway to the center of the print. 7 - Analyze Data

Y position

Y is the position of the center of the paw print at Max Contact in vertical direction. Y is the distance in the Distance Unit from the top of the walkway to the center of the print.

Print Length

Print length is the length (horizontal direction) of the complete print. It is displayed in the Distance Unit selected in the Preferences (see page 44). The complete print is the sum of all contacts with the glass plate, as if the animal's paw would have been inked.

Print Width

Print Width is the width (vertical direction) of the complete paw print. It is displayed in the Distance Unit you selected in the Preferences.

Print Area

Print area is the surface area of the complete print (indicated by the hashed area in the figure below). The print area is by definition at least as large as the Max Contact Area. It is displayed in the Distance Unit squared, where Distance Unit can be selected in the Preferences. 7 - Analyze Data

Max Intensity At (s)

Max Intensity At (s) is the time in seconds since the start of the run that the maximum Intensity is measured.

Max Intensity At (%)

Max Intensity At (%) is the same as Max Intensity At (s), expressed in percentage of the duration of Stance phase (Stand). For example: The formula for Max Intensity At (%) is: Max Intensity at Max Intensity At (s) - Initial Contact Stand - 100% 7 - Analyze Data

Max Intensity

Max Intensity is the maximum intensity of the complete paw print, which is obtained by summing up the pixels of all the paw prints detected in the stance phase.

Min Intensity

Min Intensity is the minimum intensity of the complete paw print (see the figure above).

Mean intensity

Mean intensity is the mean intensity of the complete paw print (see in the figure above).

Mean Intensity of the 15 Most Intense Pixels

This is the mean Intensity of the 15 pixels of a paw with the highest intensity.

Swing (s)

Swing (s) or Swing Phase is the duration in seconds of no contact of a paw with the glass plate.

Swing Speed

Swing Speed is the speed (Distance Unit/second) of the paw during Swing. The formula of Swing Speed is:

Stride Length

Stride Length is the distance (in Distance Units) between successive placements of the same paw. Swing Speed Stride Length Swing - 7 - Analyze Data It is obtain by calculating the beeline distance between the center of the paw print of two consecutive placements of the same paw during Max contact. So it is not the difference in the X-coordinates of the two paw print centers. The Stride Length is the length of the segment in the figure below.

Step Cycle (s)

Step Cycle is the time in seconds between two consecutive Initial Contacts of the same paw: The figure below shows an example of Step Cycle, Stand and Swing for a Right Front paw.

Duty Cycle (%)

Duty Cycle (%) expressed Stand as a percentage of Step Cycle:

Toe Spread

For more information on (Intermediate) Toe Spread, Manual Print Length and Paw Angle, see also page 86. Toe Spread is the distance (in Distance Units) between the center of the first and fifth toe of a hind paw. Step Cycle Stand + Swing Duty Cycle Stand Stand + Swing - 100% 7 - Analyze Data

Intermediate Toe Spread

Intermediate Toe Spread is the distance (in Distance Units) between the center of the second and fourth toe of a hind paw (see also page 86).

Manual Print Length

Manual Print Length is the distance (in Distance Units) between the center of the third toe and the heel of a paw.

Paw Angle Body Axis

Paw Angle Body Axis is the smallest angle (in degrees) between the Manual Print Length line and the line representing the orientation of the body axis.

Paw Angle Movement Vector

Paw Angle Movement Vector is the smallest angle (in degrees) between the Manual Print Length line and the line representing the direction of movement of the animal's body.

Single Stance

Single Stance is the duration (in seconds) of ground contact for a single hind paw (Coulthard et al., 2002, 2003). It is used for gait analysis in pain models. In CatWalk XT, Single Stance is the part in the step cycle of a hind paw where the contralateral hind paw does not touch the glass plate (see '3' in Figure 7.6).

Initial Dual Stance

Dual Stance is the duration (in seconds) of ground contact for both hind paws simultaneously (Coulthard et al., 2002, 2003). Dual Stance is used for gait analysis in pain models. In CatWalk XT, a distinction is made between Initial Dual Stance and Terminal Dual Stance. Initial Dual Stance is the first time in a step cycle of a hind paw that the contralateral hind paw also makes contact with the glass plate (see '2' in Figure 7.6).

Terminal Dual Stance

In CatWalk XT, Terminal Dual Stance is the second step in a step cycle of a hind paw that the contralateral hind paw also makes contact with the glass plate (see '4' in Figure 7.6). 7 - Analyze Data Single and Dual Stance values are only calculated if the contralateral hind paw has been placed on the glass plate before and after a step cycle of the other hind paw. Please note that the Terminal Dual Stance for a hind paw is the Initial Dual Stance for the successive step cycle of the contralateral paw.

Body Speed

The Body Speed of a step cycle of a specific paw is calculated by dividing the distance that the animal's body traveled from one initial contact of that paw to the next by the time to travel that distance.

Body Speed Variation

Body Speed Variation (%) is calculated by dividing the absolute difference between the Body speed and the Average Speed of a run by the Average Speed.

Step Sequence

The Step Sequence sheet contains information on the order in which the four paws are placed. The following parameters are displayed in the Step Sequence sheet. Choose Analyze > View Run Statistics and under Statistics click Step Sequence. Figure 7.6 Timing View with a graphical depiction of Single and Dual Stance. 1: Step cycle of the right hind paw RH. 2: Initial Dual Stance of RH, which lasts as long as the contralateral paw, LH, makes contact with the glass plate. Note that from the point of view of LH, 2 is a Terminal Dual Stance. 3: Single Stance of RH. 4: Terminal Dual Stance of RH. Note that from the point of view of LH, 4 is an Initial Dual Stance. 7 - Analyze Data

Step sequence

The Step Sequence lists the order in which the paws were placed on the glass plate. This order determines the footfall pattern that can assigned.

Codes

Each Code corresponds to a particular paw: 1 = Left Hind (LH), 2 = Left Front (LF), 3 = Right Hind (RH), 4 = Right Front (RF). The Codes are used to create the Footfall Patterns diagram (see page 100).

Patterns

This row contains the abbreviations of the assigned footfall patterns (see also Figure 7.6). The colors of the cells correspond to those in the Footfall Patterns diagram (page 100).

Normal Patterns

This is the number of Step Cycles that fall within one of the footfall pattern categories (see Figure 7.6 on page 115).

Accounted Steps

This is the number of steps that was taken into account to determine the footfall patterns.

Regularity Index (%)

The Regularity Index expresses the number of normal step sequence patterns relative to the total number of paw placements. The formula of Regularity Index is: where NSSP is the number of normal step sequence patterns and PP the total number of paw placements (see Figure 7.7). Regularity Index NSSP x 4 PP - 100% 7 - Analyze Data The Regularity Index does not tell whether the subject walks with the same pattern. If the footfall pattern changes during a run (for example, from AA to AB), the Regularity Index is not affected. The Regularity Index (RI) is used in research on spinal cord injury. It is a fractional measure of inter-paw coordination. In healthy, fully coordinated animals its value is 100%. For example, one week after rats were subjected to a transection injury, the RI decreased from 100% (pre- treatment) to approximately 80%. The RI again increased to 90% after 4 weeks (Hamers et al., 2001; see Figure 7.7).

Additional visualizations

In the Step Sequence sheet, when you click a Code or a colored cell, the following occurs: The Print View highlights the corresponding print. The Timing View highlights the start and end time of the stand of that paw. Figure 7.7 A Footfall Patterns diagram. In this example, there are six normal footfall patterns (NSSP). Each patterns begins with a blue dot (in the legend: Start of a pattern) and is followed by three dots. The first paw print and the last three are not taken into account (see page 100 for why that is the case). The number of accounted steps (PP) is 6 * 4 = 24. Therefore, the Regularity Index is (6 * 4)/24 * 100% = 100%. To create footfall pattern diagrams, select Analyze > View Run Visualizations and under Visualizations click the Footfall Patterns tab. See also footfall patterns on page 100. 7 - Analyze Data The Sub Print View shows the individual prints of the Stand. The time between two subsequent prints is 1/100 s.

See also

Footfall patterns on page 100.

Base Of Support

Base of Support is the average distance between either the front paws or the hind paws, measured along the y axis. Choose Analyze > View Run Statistics and under Statistics click Base of Support. 7 - Analyze Data In the Base of Support sheet the following variables/parameters are displayed: Paw - The label of the paw. N - The number of times each paw was placed. Mean (in Distance Unit) - The mean value for the Y position for each paw. SEM (%) - This is the Standard Error of the Mean, expressed as a percentage of the mean Base of Support. At the bottom: Paws - Front paws or Hind paws. N - The total number of times the paw combinations were placed. Base of Support ([Distance Unit]) - The mean distance between either front paws or hind paws. The Base of Support is calculated as follows: The Base of Support parameter is used in research on spinal cord injury. It has been found that as a result of trauma to the spinal cord (either as a result of a transection or contusion), the Base of Support of the front paws is unaffected, but that of the hind paws showed an increase (Hamers et al., 2001).

Other Statistics

In the Other Statistics sheet, the following parameters are displayed:

Duration

This is the duration of the run based on the selected steps in the data selection (see Select the data on page 92). The Duration is different from the Run Duration which the duration of the recorded run.

Average Speed

This is the average speed of the selected steps in the data selection (see Select the data on page 92). The Average Speed is expressed in Distance Units per second. Base of Support Front paws YRF YLF Base of Support Hind paws YRH YLH 7 - Analyze Data

Maximum Variation (%)

This is the Maximum Variation in average speed of the selected steps in the data selection.

Cadence

The Cadence is expressed in steps per second: where steps is the total number of selected steps. The selected steps include the yellow, unaccounted steps in the Footfall Patterns diagram (see page 100), but the steps that are not selected in the current Data Segmentation profile (page 92) are not included.

Number of steps

This is the total number of selected steps in this run. Steps that are not selected in the current Data Segmentation profile are not included.

Sciatic Functional Index

The Sciatic Functional Index (SFI) is a measure for the functional recovery of the sciatic nerve which innervates the hind paws. Therefore, the SFI is only relevant for hind paws. The SFI is calculated differently for rats and mice. The formula used for the calculation of the SFI for rats (Bain et al., 1989): where PL is Manual Print Length, TS is Toe Spread, ITS is Intermediate Toe Spread and the subscripts E and N indicate the Experimental and Normal contralateral hind paws, respectively. The formula used for the calculation of the SFI for mice (Inserra et al., 1998): note Although ITS is not in the formula above, you need to measure the ITS in mice in order to have the SFI calculated! Cadence

steps - 1

Initial contact last Stand Initial contact first Stand - SFI 38.3 PLE PLN PLN - 109.5 TSE TSN TSN - 13.3 ITSE ITSN ITSN - 8.8 SFI 118.9 TSE TSN TSN - 51.2 PLE PLN PLN - 7.5 7 - Analyze Data

Posterior Tibial Functional Index

The Tibial Functional Index (TFI) is a measure for the functional recovery of the tibial nerve which is a branch of the sciatic nerve. The formula used for the calculation of the TFI for rats (Bain et al., 1989): where PL is Manual Print Length, TS is Toe Spread, ITS is Intermediate Toe Spread and the subscripts E and N indicate the Experimental and Normal contralateral hind paws, respectively. The formula used for the calculation of the TFI for mice (Inserra et al., 1998):

Peroneal Functional Index

The Peroneal Functional Index (PFI) is a measure for the functional recovery of the peroneal nerve which innervates the hind paws. The formula used for the calculation of the PFI for rats (Bain et al., 1989): where PL is Manual Print Length, TS is Toe Spread, and the subscripts E and N indicate the Experimental and Normal contralateral hind paws, respectively. The formula used for the calculation of the PFI for mice (Inserra et al., 1998): where TS is Toe Spread and the subscripts E and N indicate the Experimental and Normal contralateral hind paws, respectively. TFI 37.2 PLE PLN PLN - 104.4 TSE TSN TSN - 45.6 ITSE ITSN ITSN - 8.8 TFI 109.9 PLE PLN PLN - 7.2 PFI 174.9 PLE PLN PLN - 80.3 TSE TSN TSN - 13.4 PFI 191.1 TSE TSN TSN - 9.86 7 - Analyze Data

Print

Print displays all non-paw prints (Right Hip, Right Knee, Left Hip, Left Knee, Nose, Abdomen, Tail, Genitalia). For each print is given: Number of Contacts - With the glass plate. Total Duration - Of contact with the glass plate. % - Total Duration of contact with the glass plate expressed as a percentage of the total Duration (time between first selected print and last selected print of the run).

Print Positions

Print Positions is the distance between the position of the hind paw and the position of the previously placed front paw on the same side of the body (ipsilateral) and in the same Step Cycle. A positive value of Print positions indicates that the hind paw is placed behind the front paw. A negative value of Print Positions indicates that the hind paw is placed in front of the front paw. The Print Positions sheet shows the distance (in the selected Distance Units) for the right and left front paws and their respective ipsilateral hind paws. Calculation of Print Positions is based on the X-coordinates of the centers of ipsilateral paws at Max Contact.

Walking direction from left to right

Walking direction from right to left

where FP is one of the front paws and HP is one the hind paws. The last front paw does not have a Step Cycle (and therefore no Print Position) but if the corresponding hind paw starts within the Stance of the front paw, this combination is also used for calculating the Print Position. Print Positions XFP(Max Contact) XHP(Max Contact) Print Positions XHP(Max Contact XFP(Max Contact) 7 - Analyze Data In the Print Positions sheet, when you click one of the front paw rows: The Print View highlights the ipsilateral paws. The Timing View shows the Stand of both ipsilateral paws.

Phase Dispersions

The Phase Dispersions parameter describes the temporal relationship between placement of two paws within a Step Cycle. It is used as a measure of inter-paw coordination.

Calculation

Phase Dispersions is the moment of Initial Contact of a target paw expressed as a percentage of the Step Cycle time of an anchor paw. Phase Dispersions range from -50 to 75% (see Figure 7.8 for a graphical depiction of Phase Dispersions). The formula for Phase Dispersions is: where IC is initial Contact. A positive Phase Dispersions value indicates that initial contact of the target paw occurred after that of the anchor paw. A negative Phase Dispersions value indicates that the target paw preceded the anchor paw. Phase Dispersions can be computed for a total of 12 pairs. However, interchanging target and anchor does not have a large effect since their Phase Dispersions values are normally strongly correlated, so only 6 pairs of paws are displayed. Within diagonal pairs (RF-LH, LF- RH) and ipsilateral pairs (RF-RH, LF-LH), the anchor is always one of the front paws. Within girdle pairs (LF-RF, LH-RH), the anchor paw is always one of the left paws. Which paws/parameters are displayed in the Phase Dispersions sheet depends on the selection in the currently active Parameter profile (displayed in bold and blue in the Experiment Explorer). Phase Dispersions ICtargetm ICanchorn Step cycleanchor - 100% 7 - Analyze Data

Statistics

The following statistics are displayed in the Phase Dispersions sheet for the various paw combinations: Value - This column shows the Phase Dispersions values. An empty cell indicates that Phase Dispersions could not be calculated (see Peculiarities below). Anchor start (A-start) - Initial Contact of the anchor paw. An empty cell indicates that Phase Dispersions could not be calculated (see Peculiarities below). Anchor duration (A-duration) - The duration of Step Cycle of the anchor paw. Figure 7.8 Diagram for the right front paw (RF) and hind paw (RH). Stand for each paw is depicted by a black bar, Swing is shown as a white bar. Initial contact is the point of transition from the white to black bar and also indicated by a vertical, dotted lines. A Step Cycle runs from Initial Contact to the next Initial Contact of that paw which is 0.44 s in (A) and 0.28 s in (B) for the anchor paw. Phase Dispersions is calculated by measuring the timing between Initial Contacts of a paw pair (RF - RH) and expressing it as a percentage of the Step Cycle time of the anchor paw (RF). (A) Initial Contact of the RH, the target paw, occurs 0.22 s after that of the anchor paw (RF), resulting in a Phase Dispersions value of 50% (0.22/0.44 * 100). (B) In this example, the Phase Dispersions value exceeds 75% with the first anchor (0.22/ 0.28 * 100 = 78.6). In such a case the target is assigned to the next anchor resulting in a Phase Dispersions value of -25% (-0.06/0.24 * 100) (Taken from Kloos et al., 2005). 7 - Analyze Data Target start (T-start) - Initial Contact of the target paw. Peculiarities - Displays the abbreviations for a number of potential error conditions that can occur: - ANT - Anchor but no valid target. This is not considered an error with the placement of the first anchor paw, when the target has not been placed yet. - AMT - Anchor with multiple targets. This occurs when the target paw is placed more often than the anchor paw. - TNA - Target no anchor. This is not considered to be an error with the placement of the last target, when the anchor is not placed on the glass plate anymore. Mismatches - This row displays the number of Peculiarities that occurred. Cstat Mean / AD / SD / R - Phase Dispersions and Couplings are more correctly described as a circular variable where a value of 0% (that is, the Target paw starting exactly at the same time as the Anchor paw) is equivalent to a value of 100% (that is, the Target paw starting at the end of the previous step cycle of the Anchor paw). In order to generate meaningful averages, special procedures are followed (see Circular Distributions on page 176). The values derived in this way are labeled as CStat. Mean is the circular mean, expressed as percentage. For Phase Dispersions, it ranges between -50% and +50%. For Couplings, it ranges between 0% and 100%. AD is the Angular Deviation, expressed as percentage. AD is the same as the Standard Deviation in CatWalk 10.6 and earlier versions. See page 179.

SD is the circular Standard Deviation, expressed as percentage. AD and SD are

measures of spread and are calculated with similar formulas. See page 179. R is the length of the vector that represents the mean direction, that is, the mean percentage projected on a circle. It measures the degree of concentration of values around the mean, and is therefore a measure of directedness. R is dimensionless and ranges between 0 (no dominant direction) and 1 (full directedness). In the Phase Dispersions sheet, when you click a row with a target and an anchor pair: The Print View highlights both the target and the anchor paw. The Timing View graphically displays the interval between Initial Contact of the anchor and target paw and the Anchor Duration.

Notes

The values of Phase Dispersions are, by definition, limited in the range -50% to +75% (see Figure 7.8 on page 124). Values between 50% and 75% are equivalent to those between - 50 and -25. Therefore, if the average is greater than 50%, it is expressed as the complementary (negative) value. For example, if the points are around 52%, the CStat Mean reported by CatWalk is -48. 7 - Analyze Data If you are not familiar with circular statistics, take a look at the Excel sheet Calculate

Circular Statistics of Phase Dispersions and Couplings.xlsx in the CatWalk XT

documentation folder. See page 180.

Applications

Kloos et al. (2005) use the Phase Dispersions parameter to study the effect of locomotor and sensory recovery from spinal cord injury (SCI) on inter-paw coordination in rats. In normal animals, for the diagonal paw pairs RF-LH, LF-RH) the target paw typically moves synchronously with the anchor so the Initial Contacts occur simultaneously resulting in a Phase Dispersions value of 0%. Girdle pairs (RF-LF, RH-LH) usually yield a Phase Dispersions value of 50% when walking at a moderate speed. Kloos et al. found that depending on the severity of SCI recovery of inter-paw coordination followed different patterns. See also Application examples on page 135.

Couplings

Couplings describe the temporal relationship between placement of two paws within a step cycle. It is used as a measure of inter-paw coordination. In the Couplings sheet, Couplings values are displayed for all 12 pairs of paws.

Calculation

Couplings are computed the same way as Phase dispersions. However, in the case of Couplings a target can never precede an anchor. Therefore, the value of Couplings ranges between 0 and 100%. 7 - Analyze Data Assuming that the step cycle is constant, Phase Dispersions and Couplings are related to each other. In the following example, if the Phase Dispersion value of a single Anchor-Target pair A-B is - 20% of the step cycle of A (B occurring earlier than A), for Couplings the value is +80% because the previous paw B is taken as an anchor.

Statistics

For a description of the statistics displayed in the Couplings sheet, see phase dispersions on page 124. The main difference between Couplings and Phase Dispersions is that the average of Couplings is always positive in the range 0% - 100%, while the average of Phase Dispersions is in the range -50% to 50%.

Notes

If you are not familiar with circular statistics, take a look at the Excel sheet Calculate

Circular Statistics of Phase Dispersions and Couplings.xlsx in the CatWalk XT

documentation folder. See page 180. See also Circular Distributions on page 176.

Support

The Support sheet shows the following parameters:

Start Time - Displays the start time of the different sections. A section is a time segment in which the same paws make contact with the glass plate. A section starts every time a paw is placed on the glass plate or lifted from the glass plate. Duration - Duration of a section. Support Formula - This is the number of paws that are simultaneously on the glass plate in a section. The Support Formula starts at Initial Contact of the left hind paw after all paws have been placed on the glass plate once. A new Support Formula row is started with the next Step Cycle of left hind. 7 - Analyze Data Footfall Formula - Contains information about which paws are touching the glass plate during each section. For an explanation of the Footfall Formula notation see page 174. Standing on % - This parameter displays the relative duration of simultaneous contact with the glass plate of all combinations of paws. The combinations are: zero paws, a single paw, diagonal pair of paws (RF-LH or LF-RH), lateral paws (RF-RH or LF-LH), girdle paws (RF-LF or RH-LH), three paws and four paws. When you click a Support Formula, the Print View highlights all paws in the section that touch the glass plate, and the Timing View graphically displays the section interval. 7 - Analyze Data

7.5 Group Statistics And Charts

With Group statistics, you can calculate the statistics of parameters, grouped per treatment group*time point combination, and view the corresponding charts.

Procedure

1. Make sure you have selected the right Data Segmentation profile and Parameter profile. Data not selected in these profiles are not included in the results.
2. Choose Analyze > View Group Statistics and Charts.
3. Under Numerical Results, click a category tab to display the results.
4. Under Graphical Results, click a category to view the corresponding parameter charts. See chart settings on page 130.
5. To export group statistics and charts, see page 159.

Notes

If the tab for a parameter contains no results, it means that it is not selected in the currently active Parameter profile. To select another Parameter profile, in the Profiles Explorer, right-click a Parameter profile and select Set as Active. See also Select the analysis parameters on page 96. If your experiment contains one or more runs with missing or corrupt data you get an error message when you try to open the group statistics and charts. In the Experiment Explorer, delete the runs listed in the error message (right-click a run and select Delete. See also page 150).

Statistics Available

To calculate group statistics, CatWalk XT uses the values of trial statistics. example The experimental group Control includes 10 trials for 10 subjects recorded at time point Day 1. The group mean of Print Length for Control - Day 1 is calculated by averaging the 10 per-trial values of Print Length for that group. You can find the per-trial values in the Trial Statistics export file (page 156). The following statistics are available: N - The number of trials in that treatment grouptime point combination. 7 - Analyze Data Mean (for all parameters but Phase Dispersions and Couplings), the arithmetic mean of the parameter for that treatment grouptime point combination. CStat Mean (only for Phase Dispersions and Couplings) - The circular mean of phase lags (CStat) for that treatment group*time point combination. See the circular group mean on page 176. note Values like -49% and +51% may look different in a column chart. However, in the circular domain they are very similar. See page 176.

CStat R (only for Phase Dispersions and Couplings) - The length of the vector

representing the average phase lag for a treatment grouptime point combination. SEM (for all parameters but Phase Dispersions and Couplings) - The Standard Error of the Mean of the parameter. CStat AD (only for Phase Dispersions and Couplings) - The angular deviation of the individual phase lags for a treatment grouptime point combination. CStat SD (only for Phase Dispersions and Couplings) - The circular standard deviation of the individual phase lags for a treatment group*time point combination. See measures of spread around the mean on page 179.

Chart Settings

In the Group Statistics & Charts screen, under Graphical Results, click

In the Chart Settings window, the following settings are available:

Chart Type

Bar Chart - This chart shows the mean value of the parameter as colored bar and the standard error as error bar.

Five Number Summary Chart - A box-whisker chart showing the sample minimum,

lower quartile, median, upper quartile and sample maximum. This chart can be made when at least 4 trials (therefore N≥ 4) are available for that data series. This chart type is not displayed for Phase Dispersions and Couplings.

Horizontal axis

Time Points - Displays the time points on the horizontal axis. Treatment Groups - Displays the treatment groups on the horizontal axis. 7 - Analyze Data

Data Series

Data Series are displayed in the chart legend. You have the same options as under Horizontal axis. If you change the option under Horizontal axis, the option under Data Series changes automatically and vice versa.

Title font size

Select the size in pixels of the font for the chart title (range: 6 - 14).

Bar Chart / Five Number Summary Chart

Chart width - The width of the chart in pixels (including the legend). Chart height - The width of the chart in pixels (including the title). 7 - Analyze Data

Bar width (%) - The percentage of the space

available for that data series occupied by the bar (see the figure on the right). Gap - The gap between bars (in pixels).

Whisker width (%) - The with of the whisker

relative to the bar width.

Circular charts

Chart size - The width and the height of the chart in pixels, including the title and the legend. Range: 100-1000.

Include datapoints - Select this option if you want to have the

per-trial values of variables displayed on the circle. Those data points are used to calculate the group average, which is represented by the vector.

note Data points may overlap on the circle. In that case you

see fewer dots than the actual number of trials in that group. However, the statistics are based on all trials in each group. Split charts by - Select which criterion you want to produce different charts.

Treatment Groups. For example, two treatment groups results in two charts per

variable, one for Control and one for Treated. The time points appear in the legend. Time Points. For example, three time points (d1, d5, d10) results in three charts per variable. The treatment groups appear in the legend.

Time Points and Treatment Groups. This option creates as many charts as those

created with the two option above, taken together. For example, with three time points and two treatment groups, for the variable Phase Dispersions RF->LH: 7 - Analyze Data The first three charts are based on the three time points. The legend shows the groups of subjects. The other two charts show the same data the other way round: one chart for each group of subjects, with the legend showing the three time points.

Note

If a chart is empty, it could be that a five number summary chart is selected, and for that parameter less than four trials are available. To solve this, in the Chart Settings window select Bar chart next to Chart type. To optimize the space needed for charts, reduce the font size for the title, and in the Experiment settings shorten the name of the categories under Treatment Groups and Time Points. That makes the legend smaller.

Interpreting The Circular Charts

Circular charts represent the average (group) values of Phase Dispersions and Couplings.

Vector orientation

The angle formed by the vector represents the average CStat Mean of an experimental group*time point combination, expressed in percentage and plotted on a polar coordinate system.

Vector length

The length of the vector represents the value CStat R for an experimental group*time point combination. It ranges between 0 and 1 and reflects the degree of certainty of the average. The lower the dispersion of the single data points around the average, the longer the vector. 7 - Analyze Data

Data points

If you selected Include datapoints in the Chart Settings (page 130), each dot represents one of the values of Phase Dispersion/Couplings that contribute to the mean. The value N in the table indicates the number of points. However, mind that if one value occurs multiple times, the dot overlap.

Circular scale

The scale of these charts reflects the different definition of the two parameters: -50% to +50% for Phase Dispersions, and o% to 100% for Couplings. For details, see phase dispersions on page 123 and couplings on page 126. Note that for a specific pair Anchor-Target: A value of -50% in a Phase Dispersion chart corresponds to a value of +50% in a Couplings chart. A value of -25% in a Phase Dispersions chart corresponds to a value of +75% in a Couplings chart. However, in practice the average values of Phase Dispersions and Coupling do not always correspond precisely. This is because some values of Phase Dispersions are not calculated when they exceed the limits stated in their definition; for example when a target occurs at more than 75% of the anchor step cycle (see phase dispersions on page 123); however those values are calculated as Couplings. You can check this in the Run Statistics by comparing the tabs Phase Dispersions and Couplings. The two averages, therefore, are not calculated using the same values.

Circular charts options

See chart settings on page 130. 7 - Analyze Data

7.6 Application Examples

This list of applications is not exhaustive. For more applications and publications, please search Google Scholar.

CNS-related changes

Spinal cord injury (CatWalk comes from this field of research) - page 136 Neuropathic pain - page 137 Ischemia / stroke - page 138 Amyotrophic Lateral Sclerosis (ALS) - page 139 Parkinson's disease models - page 141 Cerebellar ataxia - page 139 Motor coordination (cerebellar cortex) - page 140

PNS-related changes

Sciatic nerve injury - page 142

Skeletal and /or musculature changes

Arthritis - page 143

Genetic / toxic

Huntington's disease - page 144 Refsum disease - page 144 Charcot-Marie-Tooth (CMT) - page 144 Leigh disease - page 145 7 - Analyze Data

Spinal Cord Injury

References

Cao, Y., Shumsky, J.S., Sabol, M.A., Kushner, R.A., Strittmatter, S., Hamers, F.P.T., Lee, D.H.S., Rabacchi, S.A. & Murray, M. 2008. Nogo-66 receptor antagonist peptide (NEP1-40) administration promotes functional recovery and axonal growth after lateral funiculus injury in the adult rat. Neurorehabilitation and Neural Repair 22: 262-278. doi:10.1177/ 1545968307308550 Hamers, F.P.T., Koopmans, G.C. & Joosten, E.A.J. 2006. CatWalk-Assisted Gait Analysis in the Assessment of Spinal Cord Injury. Journal of Neurotrauma 23: 537-548. Hou, J., Nelson, R., Nissim, N., Parmer, R., Thompson, F.J. & Bose, P. 2014. Effect of combined treadmill training and magnetic stimulation on spasticity and gait impairments following cervical spinal cord injury (C-SCI). Journal of Neurotrauma 31: 1088-1106. doi: 10.1089/neu.2013.3096. Kloos, A.D., Fisher, L.C., Detloff, M.R., Hassenzahl, D.L. & Basso D.M. 2005. Stepwise motor and all-or-none sensory recovery is associated with nonlinear sparing after incremental

Result

Parameters affected

References

Depending on the severity of SCI, the gait becomes less stable and less coordinated. The animal tries to stabilize the body Base of Support, Intensity, Stand, Phase dispersions depending on severity of SCI Hamers et al. 2006 Kloos et al. 2005 After lateral funiculus injury, gait analysis showed recovery in animals treated with compound Stride Length, Regularity Index, Base Of Support, Run Duration Cao et al. 2008 Effect of locomotor training and/or magnetic stimulation on gait impairments after cervical spinal cord injury Phase Dispersions, Average Speed, Print Area, Stand Index Hou et al. 2014 CatWalk XT analysis and especially its static parameters found highly useful in assessing spontaneous recovery of hindlimb function after severe thoracic spinal cord injury Max intensity, Mean intensity, Max intensity at%, Max contact mean intensity Zheng et al. 2023 7 - Analyze Data

spinal cord injury in rats. Experimental Neurology 191: 251-265. doi: 10.1016/

j.expneurol.2004.09.016. Zheng, G., Zhang, H., Tail, M., Wang, H., Walter, J., Skutella, T., Unterberg, A., Zweckberger, K., Younsi, A. 2023. Assessment of hindlimb motor recovery after severe thoracic spinal cord injury in rats: Classification of CatWalk XT® gait analysis parameters. Neural Regen. Res. 18: 1084.

Neuropathic Pain

References

Hestehave, S., Abelson, K.S.P., Brønnum Pedersen, T. et al. 2020. The influence of rat strain on the development of neuropathic pain and comorbid anxio-depressive behaviour after nerve injury. Scientific Reports 10: 20981 (2020). https://doi.org/10.1038/s41598-020- 77640-8 Moon, E.S., Karadimas, S.K., Yu, W.-R., Austin, J.W. & Fehlings, M.G. 2014. Riluzole attenuates neuropathic pain and enhances functional recovery in a rodent model of cervical spondylotic myelopathy. Neurobiology of Disease 62: 394-406. doi: 10.1016/ j.nbd.2013.10.020.

Result

Parameters affected

References

Rats with a chronic constriction injury of the sciatic nerve, a model of neuropathic pain, minimize contact with the affected paw during locomotion Print Area, Intensity, Duty Cycle. Regularity Index unchanged Vrinten & Hamers 2003 Drug treatment (riluzole) attenuates neuropathic pain and enhances functional recovery in a rat model of cervical spondylotic myelopathy Swing Duration, Swing speed, Mean Intensity Moon et al. 2014 All rat strains displayed similar SNI- specific postural changes with pronation of the affected paw Contact area, Swing duration, Duty cycle, Run speed Hestehave et al. 2020 7 - Analyze Data Vrinten, D.H. & Hamers, F.F. 2003. 'CatWalk' automated quantitative gait analysis as a novel method to assess mechanical allodynia in the rat; a comparison with von Frey testing. Pain 102: 203-209.

Ischemia / Stroke

References

Encarnacion, A., Horie, N., Keren-Gill, H., Bliss, T.M., Steinberg, G.K. & Shamloo, M. 2011. Long-term behavioral assessment of function in an experimental model for ischemic stroke. Journal of Neuroscience Methods 196: 247-257. doi:10.1016/j.jneumeth.2011.01.010. Madinier, A., Quattromani, M.J., Sjölund, C., Ruscher, K. & Wieloch, T. 2014. Enriched housing enhances recovery of limb placement ability and reduces aggrecan-containing perineuronal nets in the rat somatosensory cortex after experimental stroke. PLoS ONE 9: e93121. doi:10.1371/journal.pone.0093121 Qin, L., Jing, D., Parauda, S., Carmel, J., Ratan, R.R., Lee, F.S., Cho, S. 2014. An Adaptive Role for BDNF Val66Met Polymorphism in Motor Recovery in Chronic Stroke. Journal of

Neuroscience 34: 2493-2502. doi: 10.1523/JNEUROSCI.4140-13.2014

Result

Parameters affected

References

Long-term functional deficit after middle cerebral artery occlusion Swing Speed, Intensity, Duty Cycle, Phase Dispersions Encarnacion et al. 2011. After photothrombosis lesion, gait is affected in various ways Average Speed Cadence, Stand and Swing Duration, Support, Maximum Contact Area, Max intensity at Max Contact, Couplings Madinier et al. 2014 Gait analysis reveals impairments in the limbs of both sides after right middle cerebral artery occlusion, and suggests involvement of the contralesional left hemisphere in recovery Regularity Index, Maximum Contact Area, Mean Intensity, Stride Length, Swing speed Qin et al. 2014 7 - Analyze Data

Amyotrophic Lateral Sclerosis (als)

References

Mead, R.J., Bennett, E.J., Kennerley, A.J., Sharp, P., Sunyach, C., Kasher, P., Berwick, J., Pettmann, B., Battaglia, G., Azzouz, M., Grierson, A., Shaw P.J. 2011. Optimised and rapid pre-clinical screening in the SOD1G93A transgenic mouse model of amyotrophic lateral

sclerosis (ALS). PLoS ONE 6: e23244. doi: 10.1371/journal.pone.0023244

Sun, H., Hou, Z., Yang, H., Meng, M., Li, P., Zou, Q., Yang, L., Chen, Y., Chai, H., Zhong, H., Zhuyun Yang, Z., Zhao, J., Lai, L., Jiang, X., Xiao Z. 2014. Multiple systemic transplantations of human amniotic mesenchymal stem cells exert therapeutic effects in an ALS mouse

model. Cell Tissue Research 357: 571. doi:10.1007/s00441-014-1903-z

Vergouts, M., Marinangeli, C., Ingelbrecht, C., Genard, G., Schakman, O., Sternotte, A., Calas, A.-G., Hermans, E. 2015. Early ALS-type gait abnormalities in AMP-dependent protein kinase-deficient mice suggest a role for this metabolic sensor in early stages of

the disease. Metabolic Brain Disease 30: 1369. doi:10.1007/s11011-015-9706-9

Cerebellar Ataxia

Result

Parameters affected

References

Gait parameters describe decline in motor function in a transgenic mouse model of ALS Stand, Stride Length, Duty Cycle, Support on diagonal limbs, Support on 3 limbs Mead et al. 2011 Stem cell treatment improves motor function Stride Length (hindlimbs) Sun et al. 2014 Altered gait in mouse with ALS-related gene n. a. Vergouts et al. 20015

Result

Parameters affected

References

Impaired gait in general as a result of neurological deficits Swing Duration, Stand Duration, Regularity Index Cendelín et al. 2010 7 - Analyze Data

References

Cendelín, J., Voller, J., Vožeh, F. 2010. Ataxic gait analysis in a mouse model of the olivocerebellar degeneration. Behavioural Brain Research 210: 8-15. doi:10.1016/ j.bbr.2010.01.035. Salvi, J., Bertaso, F., Mausset-Bonnefont, A.-L., Metz, A., Lemmers, C., Ango, F., Fagni, L., Lory, P., Mezghrani, A. 2014. RNAi silencing of P/Q-type calcium channels in Purkinje neurons of adult mouse leads to episodic ataxia type 2. Neurobiology of Disease 68: 47-56, doi: 10.1016/j.nbd.2014.04.005. Kyriakou, E.I., van der Kieft, J.G., de Heer, R.C., Spink, A., Nguyen, H.P., Homberg, J.R., van der Harst, J.E. 2015. Automated quantitative analysis to assess motor function in different rat models of impaired coordination and ataxia, Journal of Neuroscience Methods

268: 171-181. doi: 10.1016/j.jneumeth.2015.12.001

Motor Coordination (cerebellar Cortex)

Motor abnormalities measured after suppression of the P/Q-type calcium channels in Purkinje neurons Print Area, Stand, Duty Cycle, Stride Length Salvi et al. 2014 Static and dynamic parameters showed significant differences in three rat models of impaired coordination and ataxia Average Speed, Swing Speed, Stride Length, Phase Dispersions Kyriakou et al. 2016

Result

Parameters affected

References

Reduced motor coordination in mice lacking chloride calcium-gated chloride channels in Purkinje cells Run Speed, Stride Length, Duty Cycle, Swing Speed, Stand, Print Positions, Base of Support, Footfall Patterns, Support on three paws %, Support on diagonal paws, Phase Dispersion variability Neureither et al. 2017 Deterioration of motor performance correlates with the demise of Purkinje cell axons in the cerebellum Stride Length, Stand Duration, Swing Duration, Print Positions Verheijden et al. 2013 7 - Analyze Data

References

Neureither, F., Ziegler, K., Pitzer, C., Frings, S., Möhrlen, F. 2017. Impaired Motor Coordination and Learning in Mice Lacking Anoctamin 2 Calcium-Gated Chloride Channels. Cerebellum (Online). doi:10.1007/s12311-017-0867-4. Verheijden, S., Bottelbergs, A., Krysko, O., Krysko, D.V., Beckers, L., De Munter, S., Van Veldhoven, P.P., Wyns, S., Kulik, W., Nave, K.-A., Ramer, M.S., Carmeliet, P., Kassmann, C.M. & Baes, M. 2013. Peroxisomal multifunctional protein-2 deficiency causes neuroinflammation and degeneration of Purkinje cells independent of very long chain

fatty acid accumulation, Neurobiology of Disease 58: 258-269. doi: 10.1016/

j.nbd.2013.06.006.

Parkinson's Disease Models

Result

Parameters affected

References

Treatment improved motor functions as measured with CatWalk XT Run Average Speed, Regularity Index, Print Area, Swing Speed, Stride Length, Print Positions Tatenhorst et al. 2016 Treatment improves speed of locomotion but impairs forelimb movement Run Duration, Base of Support, Maximum Contact Area, Maximum Intensity, Swing Duration, Swing Speed Vlamings et al. 2016 Behavioral deficits efficiently measured in rat Parkinson models Mean Intensity, Maximum Contact Area (forepaws) Vandeputte et al. 2010 Swaying pattern during locomotion was quantified in rodent models Paw statistics X position and Y position Timotius et al. 2018 Detection of motor deficiencies in a Medial Forebrain Bundle 6-OHDA lesion model of Parkinson's disease Stride Length, Print Position, Step Cycle, Swing phase of the step cycle, Stand index, Phase Dispersion, Print Length, Print Area Boix et al 2018 7 - Analyze Data

References

Boix, J., von Hieber, D., Connor, B. 2018. Gait analysis for early detection of motor symptoms in the 6-OHDA rat model of Parkinson's disease. Frontiers in Behavioral Neuroscience 12: 39. Tatenhorst, L., Eckermann, K., Dambeck, V., Fonseca-Ornelas, L., Walle, H., Lopes da Fonseca, T., Koch, J.C., Becker, S., Tönges, L., Bähr, M., Outeiro, T.F., Zweckstetter, M. & Lingor, P. 2016. Fasudil attenuates aggregation of -synuclein in models of Parkinson's disease. Acta Neuropathologica Communications 4: 39. doi: 10.1186/s40478-016-0310-y Timotius, I.K., Canneva, F., Minakaki, G., Pasluosta, C., Moceri, S., Casadei, N., Riess, O., Winkler, J., Klucken, J., von Hörsten, S., & Eskofier, B. 2018. Dynamic footprint based locomotion sway assessment in -synucleinopathic mice using Fast Fourier Transform

and Low Pass Filter. Journal of Neuroscience Methods 296: 1-11. doi: 10.1016/

j.jneumeth.2017.12.004. Vandeputte, C., Taymans, J.-M., Casteels, C., Coun, F., Ni, Y., Van Laere, K., & Baekelandt, V., 2010. Automated quantitative gait analysis in animal models of movement disorders.

BMC Neuroscience 11: 92. doi: 10.1186/1471-2202-11-92

Vlamings, R., Visser-Vandewalle, V., Koopmans, G., Joosten, E.A.J., Kozan, R., Kaplan, S., Steinbusch, H.W.M., Temel, Y. 2007. High frequency stimulation of the subthalamic nucleus improves speed of locomotion but impairs forelimb movement in Parkinsonian rats. Neuroscience 148: 815-823. doi:10.1016/j.neuroscience.2007.06.043.

Sciatic Nerve Injury

Result

Parameters affected

References

CatWalk gait analysis suitable for the measurement of behavioural recovery after complete rat sciatic nerve injury Paw Print Intensities, Couplings Bozkurt et al. 2008 A review of the most important gait kinematic measures that can be gathered with automated gait analysis systems Costa et al. 2011 7 - Analyze Data

References

Bozkurt, A., Deumens, R., Scheffel, J., O'Dey, D.M., Weis, J., Joosten, E.A., Führmann, T., Brook, G.A. & Pallua, N. 2008. CatWalk gait analysis in assessment of functional recovery after sciatic nerve injury, Journal of Neuroscience Methods 173: 91-98. doi: 10.1016/ j.jneumeth.2008.05.020. Costa, L.M., Simões, M.J., Maurício, A.C. & Varejão, A.S.P. 2009. Chapter 7 Methods and Protocols in Peripheral Nerve Regeneration Experimental Research: Part IV - Kinematic gait analysis to quantify peripheral nerve regeneration in the rat. International Review of Neurobiology 87: 127-139. doi: 10.1016/S0074-7742(09)87007-4. Deumens, R., Jaken, R.J.P., Marcus, M.A.E. & Joosten, E.A.J. 2007. The CatWalk gait analysis in assessment of both dynamic and static gait changes after adult rat sciatic

nerve resection. Journal of Neuroscience Methods 164: 120-130. doi: 10.1016/

j.jneumeth.2007.04.009.

Arthritis

Monoarthritis

Möller, K.Ä., Berge, O.-G., Hamers, F.P.T. 2008. Using the CatWalk method to assess weight-bearing and pain behaviour in walking rats with ankle joint monoarthritis induced by carrageenan: Effects of morphine and rofecoxib. Journal of Neuroscience Methods 174: 1-9. doi: 10.1016/j.jneumeth.2008.06.017. Parameters affected: Print Area, Mean Intensity (as a measure of weight load), Duty Cycle, Regularity Index (all decreased in treated animals).

Osteoarthritis

Ferreira-Gomes, J., Adaes, S. & Castro-Lopes, J.M. 2008. Assessment of movement-evoked pain in osteoarthritis by the knee-bend and CatWalk tests: a clinically relevant study. The Journal of Pain 9: 945-954. Parameters affected: Total Intensity (this was calculated outside CatWalk). CatWalk gait analysis detects a large set of both dynamic and static gait changes after neurotmesis (complete nerve transection) Base of Support, Print Length, Print Width, Stride Length, Maximum Area, Mean Intensity, Stand Duration, Swing Duration, % of normal step sequence patterns, Phase Dispersion (girdles and ipsilateral left side) Deumens et al. 2007 7 - Analyze Data Ishikawa, G., Nagakura, Y., Takeshita, N., Shimizu, Y. 2014. Efficacy of drugs with different mechanisms of action in relieving spontaneous pain at rest and during movement in a rat model of osteoarthritis. European Journal of Pharmacology 738: 111-117. doi: 10.1016/ j.ejphar.2014.05.048. Parameters affected: Maximum Contact Area, Swing Speed. Qin, J., Chow, S.K.-H., Guo, A., Wong, W.-N., Leung, K.-S., Cheung, W.-H. 2014. Low magnitude high frequency vibration accelerated cartilage degeneration but improved epiphyseal bone formation in anterior cruciate ligament transect induced osteoarthritis rat model. Osteoarthritis and Cartilage 22: 1061-1067. doi: 10.1016/j.joca.2014.05.004. Parameters affected: Duty Cycle, Regularity Index.

Genetic/toxic

Huntington's disease

Vandeputte, C., Taymans, J.-M., Casteels, C., Coun, F., Ni, Y., Van Laere, K., & Baekelandt, V., 2010. Automated quantitative gait analysis in animal models of movement disorders. BMC Neuroscience 11: 92. doi: 10.1186/1471-2202-11-92. Parameters affected: Swing speed, Stand.

Refsum disease

Ferdinandusse, S., Zomer, A.W.M., Komen, J.C., van den Brink, C.E., Thanos, M., Hamers, F.P.T., Wanders, R.J.A., van der Saag, P.T., Poll-The, B.T. & Brites, P. 2008. Ataxia with loss of Purkinje cells in a mouse model for Refsum disease. PNAS 105: 17712-17717. doi:10.1073/ pnas.0806066105 Unsteady gait with strongly reduced paw print area for both fore- and hindpaws and reduced base of support for the hindpaws. Parameters affected: Print area, Toe Spread of intermediate toes, Base of Support. Lucas, E.K., Reid, C.S., McMeekin, L.J., Dougherty, S.E., Floyd, C.L., Cowell, R.M. 2014. Cerebellar transcriptional alterations with Purkinje cell dysfunction and loss in mice lacking PGC-1. Frontiers in Cellular Neuroscience 8: 441. doi:10.3389/fncel.2014.00441. Parameters affected: Print Area, Swing speed, Stand Index, Regularity Index.

Charcot-Marie-Tooth (CMT)

Villalón, E., Dale, J.N., Jones, M., Shen, H. & Garcia, M.L. 2015. Exacerbation of Charcot- Marie-Tooth type 2E neuropathy following traumatic nerve injury. Brain Research 1627: 143-153. doi: 10.1016/j.brainres.2015.09.024. 7 - Analyze Data Parameters affected: Print Length and Width, Max Contact Area, Max Intensity, Max Contact at (%), all decreased. Couplings involving the affected limb (LH) decreased or increased depending on the coupling combination. Dale, J.M., Villalon, E., Shannon, S.G., Barry, D. M., Markey, R.M., Garcia, V.B. and Garcia, M.L. 2012. Expressing hNF-LE397K results in abnormal gaiting in a transgenic model of CMT2E. Genes, Brain and Behavior 11: 360-365. doi:10.1111/j.1601-183X.2012.00771.x Parameters affected: Stride Length, Regularity Index, Stand Index (all decreased). Couplings and Phase dispersions increased or decreased depending on which combination was considered.

Leigh disease

de Haas, R., Russel,F.G., & Smeitink, J.A. 2016. Gait analysis in a mouse model resembling Leigh disease. Behav Brain Res, 296: 191-198. See also

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Source: CatWalk XT 10.7 - Reference Manual