INTER-TRIAL VARIABILITY IN KINEMATIC DESCRIPTORS OF GAIT

  • D.J. Wilson
  • B.K. Smith
  • M. Childers
  • D. Cooke

Abstract

The purpose of this study was to determine the inter-trial variability of kinematic descriptors of human gait. A case study subject with spastic hemiplegic gait following traumatic event was analyzed for kinematic differences pertreatment, 1-week post-treatment and 4-weeks post-treatment. The treatment protocol included a focal dennervation of the spastic gastrocnemius muscle on the affected side of the body. Data was collected via three 60 Hz S-VHS camcorders set at a shutter speed of 11100 second. Each camera was placed at approximately a 30 degree angle with respect to the optical axis of the other two cameras. Ten trials of walking gait at a self-selected pace were recorded for both the affected and unaffected sides for two complete strides. Kinetic data was recorded during a single stance phase simultaneous with the kinematic data. The three views were synchronized using a single pulse from a standard flash unit. The three planer views were transformed to three-dimensional coordinates using a Direct Linear Transformation (DLT) as part of the Ariel Performance Analysis System (APAS). Each joint center location as smoothed individually by selecting the proper cutoff frequency of a double-pass recursive Butterworth filter via an inspection of the joint center's power spectrum. Joint angular displacements of the ankle, knee and hip were compared across the ten trials for each leg individually using a univariate analysis of variance (ANOVA). The pre-treatment and two post-treatment conditions were analyzed separately. Non-significant inter-trial differences were found for each variable and each leg across the data collection periods. Given the proliferation and gait analysis as a clinical tool, as well as a research device for exercise and sport, demonstration of the efficacy and reliability of this analysis is essential.
Section
Coaching and Sports Activities