Title

Ankle and Midtarsal Joint Kinematics During Rearfoot and Non-rearfoot Strike Walking

Author

Elijah Kuska

Date of Award

1-1-2019

Degree Name

M.S. in Mechanical Engineering

Department

Department of Mechanical and Aerospace Engineering and Renewable and Clean Energy

Advisor/Chair

Advisor: Allison Kinney

Second Advisor

Advisor: Joaquin Barrios

Abstract

Toe walking is often considered an undesirable gait deviation seen in pathological populations. The heterogeneous nature within and between these populations make it difficult to understand the biomechanics of pathological toe walking. Thus, previous studies have often analyzed healthy individuals performing non-habitual toe walking in hopes to understand this gait abnormality. Studies have found biomechanical deviations in kinematics, muscle activity levels, and kinetics between heel-toe and toe walking. However, these findings have focused primarily on sagittal plane discrete metrics of more proximal joints. Because toe walking involves increased activity of the distal foot, and these joints are often thought to have multi-planar tendencies, we believe further investigation is needed. The purpose of this study was to examine biomechanical differences in rearfoot strike walking (RFSW) and non-rearfoot strike walking (NRFSW). We hypothesized that previously seen increased ankle plantarflexion would be accompanied by increased ankle inversion and adduction, commonly referred to as supination, during NRFSW, and the MT joint would supinate with the ankle because of their parallel axes. Twenty-four healthy females walked overground with both walking patterns. Motion capture, electromyography (EMG), and force plate data were collected. A validated multi-segment foot model was used along with mean difference waveform analyses to study differences in the walking conditions during stance. Most differences occurred in early stance. NRFSW exhibited increased ankle supination at IC compared to RFSW, indicating ankle supination is needed for forefoot contact. Increased supination creates increased pronation excursion and pronation is a mechanism for shock absorption. This advantageous phenomenon was apparent in NRFSW as the loading rate was reduced despite a larger peak vertical ground reaction force and would not have been found if waveform analyses were not performed. The MT joint only exhibited increased plantarflexion similar to the ankle but this suggests both ankle and MT joints must plantarflex to land and remain in a toe walking posture. This finding emphasized the important of multi-planar, distal joint, and waveform analyses during gait, especially in relation to pathological toe walking populations.

Keywords

Biomechanics, Toe walking, Ankle biomechanics, Midtarsal biomechanics, Waveform analysis, Multi-segment foot

Rights Statement

Copyright 2019, author

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