Date of Award

8-3-2017

Degree Type

Thesis

Degree Name

M.H.K.

Department

Kinesiology

First Advisor

Andrews, David

Keywords

Biomechanics, Forward Fall Impacts, Shock Attenuation, Soft Tissue, Upper Extremity

Abstract

The purpose of this thesis was twofold: 1) quantify planar (2D) displacement and velocity of, and the amount of shock attenuated by, the forearm soft tissues following a forward fall impact; and 2) compare two massless skin surface marker designs with different uniformity and visual contrast (i.e., single layer, uniform (SLU) design; stacked, non-uniform (SNU) design) in terms of how well they can be tracked over varying skin pigmentation using automated motion capture software. Simulated forward fall impacts were performed by two groups of participants (skin pigmentation: light – 9F, 8M; dark – 9F, 6M) using a torso-release apparatus, in which a high speed camera (5000 f/s) captured planar motion of the right forearm. Automated motion tracking software (ProAnalyst®) was used to quantify displacement, velocity, and shock attenuation capacity of the forearm soft tissue from manually digitized markers. Overall, the greatest mean peak soft tissue displacement (1.47 cm) and velocity (112.8 cm/s) occurred in the distal direction in proximal regions of the forearm where more soft tissue is distributed. Soft tissue displacement and velocity exhibited similar trends, increasing from distal to proximal regions of the forearm, while impact shock accelerations were not attenuated in the forearm, but instead increased by 76%. Apart from proximal rebound distance, soft tissue kinematics between females and males did not significantly differ (p > 0.05). Conversely, the effects of specific tissue masses (i.e., bone mineral content, fat mass, lean mass, and wobbling mass) on tissue kinematics varied between the sexes. Significant differences were found between marker designs for displacement, rebound distance, and velocity (p ≤ 0.05), wherein the SLU design consistently produced higher values than the SNU design.

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