Date of Award
5-1967
Document Type
Thesis - Restricted
Degree Name
Master of Science (MS)
Department
Medical
First Advisor
Walter Zeit
Second Advisor
Edward A. Bachhuber
Third Advisor
Mary Pat Murray
Abstract
Knowledge of the ranges of normal muscle force output is essential for identifying the degree of abnormality in many neuro-muscular and musculo-skeletal disorders and also, for assessing strength improvement following therapeutic procedures.
The purpose of this study is to assess the torque output of the medial and lateral rotator muscle groups of the shoulder under static conditions. It is impossible to directly measure the force of contraction of a muscle, or muscle group, in the intact human body. The structure of the human body is such that the line of force of contracting muscles is neither parallel nor perpendicular to the bony segments they exert force upon. Therefore, the resultant force typically can be resolved into components acting at right angles to one another. The component of force which acts parallel to the bony segment of attachment tends to approximate the bones which participate in the formation of the intervening joint. This component is usually termed the stabilizing component. The other component of the resultant contractile force acts perpendicular to the bony segment of its insertion. It is this component of the total contractile force which is effective in producing rotational movement at the intervening joint. Therefore, under static conditions the output of the rotational component of muscular contraction can be measured externally with force-recording devices as the torque produced in an attempt to rotate a segment. As such, the product of the force registered on a scale and the distance from the scale attachment to the axis of motion in the joint is equal to the rotational torque components of the contractile muscle. This study has been designed to identify the ranges of normal viability in torque amplitude for the shoulder rotator muscle groups, and the influence of various gleno-humeral joint positions, successive exertions, and repeated testing sessions on the torque values.
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Recommended Citation
Kloth, Luther C., "Torque Output of the Medial and Lateral Rotator Muscles of the Shoulder" (1967). Master's Theses (1922-2009) Access restricted to Marquette Campus. 5667.
https://epublications.marquette.edu/theses/5667