Three-dimensional motion analysis for comprehensive understanding of gait characteristics after sciatic nerve lesion in rodents

Junichi Tajino,Momoko Tanima,Hiroshi Kuroki,Tomoki Aoyama,Akihiro Nakahata,Shoki Yamaguchi,Hirotaka Iijima,Wataru Kiyan,Akira Ito

doi:10.1038/s41598-018-31579-z

Abstract

Rodent models of sciatic nerve lesion are regularly used to assess functional deficits in nerves. Impaired locomotor functions induced by sciatic nerve lesion are currently evaluated with scoring systems despite their limitations. To overcome these shortcomings, which includes low sensitivity, little significance, and the representation of only marginal components of motion profiles, some additional metrics have been introduced. However, a quantitative determination of motion deficits is yet to be established. We used a three-dimensional motion analysis to investigate gait deficits after sciatic nerve lesion in rats. This enabled us to depict the distorted gait motion using both traditional parameters and novel readouts that are specific for the three-dimensional analysis. Our results suggest that three-dimensional motion analysis facilitates a comprehensive understanding of the gait impairment specifically, but not limited to, a sciatic lesion rat model. A broad application of these methods will improve understanding and standardized motor assessment.

Highlights

Animal models are widely used to study nerve damage
We explored a set of metrics using 3D gait characteristics reconstructed from a multi-camera recording of their walking
We evaluated ankle stance angle (ASA, ankle angle at midstance) as a spatial parameter, as previously described[17]. We suggested these additional spatial parameters as follows: ankle to the ground (AtG), ankle angle to the ground at midstance; metatarso-ankle distance (MAD), distance between the ankle and metatarsophalangeal joint (MTP) markers at midstance; AoA, toe angle at the final segment of the swing phase[18]

Summary

Introduction

Animal models are widely used to study nerve damage. To address the functional deficits as consequences of these nerve lesion, motion analysis of animals is common and supposed to represent the characteristics of neural malfunctions[1,2,3]. Among the impairments induced by sciatic nerve lesions including antalgic, sensory, and paretic aspects, animal gait kinematic assessment principally has advantages to represent motor paralysis[12,13,14]. It could overcome the short comings and reinforce the significances of the sciatic functional index (SFI), which is still the gold standard for the sciatic nerve lesion model[15]. We examined 3D reconstructions in order to make full use of the 3D assessment apparatus and provided suggestions for novel parameters

Methods

Results

Conclusion