Date of Award

Summer 1993

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Human Movement Sciences

Committee Director

Charles W. Jackson

Call Number for Print

Special Collections LD4331.E44 H66

Abstract

The purpose of this study was to determine if variations in cam profiles cause differences in muscle contraction as measured by surface EMG, knee joint angular displacement, and torque. There were seven hypotheses tested. The ten subjects were adult male volunteers (18-24 years) who participated in a counterbalanced treatment design study testing three variously shaped cams over five lifting tests. The results indicated that for the EMG data, the cam and lifts effect had significant Wilk's values. For the cam effect the consistent cam had the highest millivolt value. For the lift effect, the pre 1 rep max had the highest millivolt value. Results for the angular displacement demonstrated a significant Wilk's value for the cam effect only. The easy cam had the greatest degrees of displacement. Of the torque analysis, only the concentric torque showed significance at the 0.05 level. This study supports the earlier findings that the consistent cam efficiently loaded the muscle at more points in the range of motion and was able to maneuver throughout a greater arc in this same range than the easy or hard cams. However, even though the preliminary data showed differences in speed of movement, it could not be determined if there were actual differences in the amount of work produced by the cams.

Rights

In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).

DOI

10.25777/zfvr-pj74

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