Date of Award

2019

Degree Name

Biomechanics

College

College of Health Professions

Type of Degree

M.S.

Document Type

Thesis

First Advisor

Dr. Steven Leigh, Committee Chairperson

Second Advisor

Dr. Suzanne Konz

Third Advisor

Dr. Mark Timmons

Abstract

Overarm throwing athletes utilize the kinetic chain, which allows forces generated by the lower body to be transmitted to the throwing arm in a proximal-to-distal sequence. Efficient force transmission from the lower body to the throwing arm can improve performance and reduce risk for injury. The purpose of this thesis was to explore the relationship between the lower trunk (pelvis) maximum angular momentum and the joint resultant forces at the shoulder during the overarm throwing motion of baseball athletes. I hypothesized that there would be a negative correlation between the maximum angular momentum about the superior-inferior axis of the lower trunk during the arm cocking phase and the throwing shoulder joint anterior shear force at ball release, and that there would be a negative correlation between the maximum angular momentum about the superior-inferior axis of the lower trunk during the arm cocking phase and the throwing shoulder joint compressive force at ball release. Two high-speed video cameras were used to record twenty-four competitive male baseball players executing an overarm throw. The videos were digitized, and 3D landmark coordinates were obtained using the Direct Linear Transformation procedure. Lower trunk angular momentum, shoulder joint compressive force, and shoulder joint anterior shear force were calculated from the 3D landmark coordinates and anthropometric data. Bivariate correlations were computed to determine if an association existed between maximum lower trunk angular momentum and shoulder joint anterior shear force at release or shoulder joint compressive force at release. There was no association between lower trunk maximum angular momentum and shoulder joint anterior shear force (r = 0.149, p = 0.244). There was also no association between lower trunk maximum angular momentum and shoulder joint compressive force (r = 0.222, p = 0.149). The lack of association between the lower trunk maximum angular momentum and shoulder joint forces may indicate that this relationship is not determinative of overarm throwing technique. An alternative explanation is that the subjects exhibited inefficient mechanics and an improper timing sequence of the kinetic chain. Future work should investigate the sequencing of force transmission between the lower body and upper body.

Subject(s)

Biomechanics.

Sports -- Physiological aspects.

Athletes -- Physiology.

Baseball| -- Physiological aspects.

Download

Share

COinS