Validity and reliability of the CatWalk system as a static and dynamic gait analysis tool for the assessment of functional nerve recovery in small animal models

Abstract

IntroductionA range of behavioral testing paradigms have been developed for the research of central and peripheral nerve injuries with the help of small animal models. Following any nerve repair strategy, improved functional outcome may be the most important evidence of axon regeneration. A novel automated gait analysis system, the CatWalk™, can measure dynamic as well as static gait patterns of small animals. Of most interest in detecting functional recovery are in particular dynamic gait parameters, coordination measures, and the intensity of the animals paw prints. This article is designed to lead to a more efficient choice of CatWalk parameters in future studies concerning the functional evaluation of nerve regeneration and simultaneously add to better interstudy comparability.MethodsThe aims of the present paper are threefold: (1) to describe the functional method of CatWalk gait analysis, (2) to characterize different parameters acquired by CatWalk gait analysis, and to find the most frequently used parameters as well as (3) to compare their reliability and validity throughout the different studies.ResultsIn the reviewed articles, the most frequently used parameters were Swing Duration (30), Print Size (27), Stride Length (26), and Max Contact Area (24). Swing Duration was not only frequently used but was also the most reliable and valid parameter. Therefore, we hypothesize that Swing Duration constitutes an important parameter to be chosen for future studies, as it has the highest level of reliability and validity.ConclusionIn conclusion, CatWalk can be used as a complementary approach to other behavioral testing paradigms to assess clinically relevant behavioral benefits, with the main advantage that this system demonstrates both static and dynamic gait parameters at the same time. Due to limited reliability and validity of certain parameters, we recommend that only the most frequently assessed parameters should be used in the future.

The course of recovery of locomotor function over a 10‐week observation period in a rat model of femoral nerve resection and autograft repair

“…Comparison of our work with publications on gait analysis in rats with segmental sciatic nerve injury is difficult, as there are major differences regarding distance from lesion to target organ, method of repair, and, most importantly, length of the nerve gap (Kappos et al, ). However, besides these considerations, we were able to report almost full functional regeneration at 10 weeks after segmental nerve damage, in contrast to the sciatic nerve defect model as published by various authors (Hare et al, ; Irintchev, ; Lee et al, ; Perussi Biscola, Politti Cartarozzi, Ferreira Junior, Barraviera, & Leite Rodrigues de Oliveira, ).…”

“…Linear regression analysis to evaluate correlations between the CatWalk data and electrophysiologic measurements revealed that only Print Length and the amplitude of the electrophysiological measurements showed statistically significant correlation. Other authors have published their findings on such correlation analysis between functional data and electrophysiology in the past, indicating that both do not necessarily correlate (Kappos et al, ). However, Print Area and amplitude as well as Print Length and CMAP revealed correlation close to statistically significant levels.…”

Automated Gait Analysis to Assess Functional Recovery in Rodents with Peripheral Nerve or Spinal Cord Contusion Injury

“…At least three compliant runs are needed in which the animal must cross the walkway steadily without hesitation 27 .…”

“…It is also routinely used to assess locomotor function in rats with central nervous injuries, e.g., stroke 25 or spinal cord contusion 26 . The method's advances lie in the great amount of comparable data and its possibility to record a plethora of parameters related to gait 27 . This paper aims to provide researchers interested in animal models of PNI and spinal cord injury (SCI) with a detailed and hands-on guideline to assess locomotor function in such models.…”

Metformin Enhances Functional Recovery of Peripheral Nerve in Rats with Sciatic Nerve Crush Injury

“…Without disturbing the nerve, wounds were closed or subjected to sciatic injury from distal to notch. A smooth hemostat (tip width 1 mm) was used to deform the nerve for 2 min, and the crush area was marked with 9-o nylon suture, as previously described [20]. Nerve-injured mice were randomly grouped into M and saline groups.…”