Article Title



J. Stoewer1, E. Foch2, M.B Pohl1

1University of Puget Sound, Tacoma, WA; 2Central Washington University, Ellensburg, WA

Restricted passive range of motion (PROM) of hip extension has been anecdotally linked with low back pain. A potential mechanism for this may be that restrictions in passive hip extension prevents the hip from fully extending during running. As a consequence, the pelvis may undergo anterior tilt to allow the thigh to extend, thus, resulting in greater loading of the lumbar spine. However, it is currently unclear whether restricted passive hip extension has any bearing on hip and pelvis biomechanics during running. PURPOSE: To determine whether runners who differ in passive hip extension also demonstrate differences in hip extension and anterior pelvic tilt during running. METHODS: Participants included 9 healthy runners (3 males, 6 females) between the ages of 18-28. Passive hip extension was measured using the Thomas Test. Kinematic data during running was collected using a 3D motion capture system. Subjects were split into three groups (tight, normal, & flexible) using tertiles based on their Thomas Test score. Both hip extension and anterior pelvic tilt during running were then compared between groups using Cohen’s effect sizes (ES). RESULTS: The tight group exhibited the least amount of hip extension during running with a large effect size (ES=0.84) when compared to the flexible group (Table 1). The tight group exhibited the greatest amount of anterior pelvic tilt with large effect sizes when compared to both the normal (ES=0.80) and flexible (ES=2.34) groups. CONCLUSION: Limited passive hip extension was linked with alterations in running biomechanics including reduced hip extension and greater anterior pelvic tilt. These kinematic alterations could potentially place greater loading the lumbar spine.

Table 1.docx (12 kB)
Table 1

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