Date of Award

Summer 2015

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Program/Concentration

Human Movement Sciences

Committee Director

Bonnie L. Van Lunen

Committee Member

Matthew C. Hoch

Committee Member

Joshua T. Weinhandl

Abstract

Primary risk factors for hamstrings strains such as fatigue, previous injury and strength deficits have been identified in the research, yet re-injury rates remain high among the physically active. Sub-acute analysis of the hip, knee and ankle biomechanics following a hamstrings strain have been largely overlooked and may provide additional insight into re-injury risks. It was the aim of this dissertation to explore long-term adaptations in walking and running tasks following a hamstrings strain, and to develop a hip endurance test that could be used in future studies.

Project one used a cross-sectional study with test-retest design to develop and assess a standing hip isometric endurance test. Project two used a case-control design to explore differences in lower extremity muscle activation patterns, kinematics and kinetics during walking gait between individuals with and without a previous hamstrings strain and between previously injured (PIL) and uninjured limbs (UL) of individuals with a previous unilateral hamstrings strain. Project three also used a case-control design to explore lower extremity biomechanics during straight run, and unanticipated cut and deceleration tasks between individuals with and without a history of hamstrings strain.

The findings of project one showed moderate-to-excellent reliability (ICC2,1) for the endurance test in hip flexion, extension, adduction and abduction, and evidence of fatigue. The findings of project two revealed the knee flexors of the PIL were significantly weaker than the UL, but no other differences were found. The findings of project three determined the Hamstring group had significantly lower rectus femoris maximum muscle activation during the straight run compared to Control group.

The outcomes of this dissertation suggest long-term bilateral knee flexor strength deficits exist in those with a history of unilateral hamstrings strain, and individuals with a previous hamstrings strain may have lower rectus femoris maximum muscle activity during straight ahead running compared to those with no history of strain. Additionally, it appears that lower extremity kinematics and kinetics may be unaffected by a previous hamstrings strain. The next step may be to explore the biomechanical measures during unanticipated athletic tasks prior to and following the endurance protocol developed in project one.

DOI

10.25777/sq1g-5v33

ISBN

9781339126432

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