Author ORCID Identifier

Year of Publication


Degree Name

Master of Science in Biomedical Engineering

Document Type

Master's Thesis




Biomedical Engineering

First Advisor

Dr. Babak Bazrgari


Abnormal lumbar movement has been observed in individuals who have a history of low back pain (LBP). Affected individuals display a reduction in lumbar spine rotation during trunk movement tasks, while pelvic rotation increases to compensate. Reduced lumbar contribution to forward bending is associated with increased compressive forces and increased shearing demand of the task on the lower back. This abnormal lumbo-pelvic coordination (LPC) can persist beyond LBP symptom alleviation and may contribute to further occurrences or more severe cases of LBP. This study serves as a first step in investigating if abnormal LPC can be corrected with a hip orthosis by examining the effects of the device on the LPC of healthy individuals. Twenty participants without presence or history of LBP were recruited to participate in a repeated measures study, completing trunk motion tasks with and without a hip orthosis. In a random order, participants completed forward bending and backward return, lateral bending to the left and right, and axial twisting to the left and right. Thoracic, lumbar, and pelvic rotation along with lumbar-thoracic ratio (LTR) were calculated for each of the movement tasks. Thoracic rotation (total trunk movement) was not significantly altered (p > 0.05, F=0.633) by the application of the hip orthosis. LTR was significantly increased (p < 0.001, F=2.96) with the orthosis by 32%, 22%, 12%, 4%, and 12% for axial twisting left, axial twisting right, lateral bending left, lateral bending right, and forward bending, respectively. This indicates lumbar contributions were increased by physically restricting the pelvis. The effects of a hip orthosis should be further investigated in LBP patients to verify correction of an abnormal LPC.

Digital Object Identifier (DOI)