Knowledge Base

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.

Data Points

If you selected Include datapoints in the Chart Settings, 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, if one value occurs multiple times, the dots overlap.

Circular Scale

The scale of these charts reflects the different definition of the two parameters: -50% to +50% for Phase Dispersions, and 0% to 100% for Couplings.

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. 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.

Application Examples

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

CNS-Related Changes

• Spinal cord injury
• Neuropathic pain
• Ischemia / stroke
• Amyotrophic Lateral Sclerosis (ALS)
• Parkinson's disease models
• Cerebellar ataxia
• Motor coordination (cerebellar cortex)

PNS-Related Changes

• Sciatic nerve injury

Skeletal and/or Musculature Changes

• Arthritis

Genetic / Toxic

• Huntington's disease
• Refsum disease
• Charcot-Marie-Tooth (CMT)
• Leigh disease

Spinal Cord Injury

The following table summarizes results, parameters affected, and references for spinal cord injury research using CatWalk XT.

• Depending on the severity of SCI, the gait becomes less stable and less coordinated. The animal tries to stabilize the body. Parameters affected: 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. Parameters affected: 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. Parameters affected: 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. Parameters affected: Max Intensity, Mean Intensity, Max Intensity at%, Max Contact Mean Intensity. (Zheng et al. 2023)

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 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

• Rats with a chronic constriction injury of the sciatic nerve, a model of neuropathic pain, minimize contact with the affected paw during locomotion. Parameters affected: 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. Parameters affected: 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. Parameters affected: Contact Area, Swing Duration, Duty Cycle, Run Speed. (Hestehave et al. 2020)

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. 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
• 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.