Date Available


Year of Publication


Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation




Biomedical Engineering

First Advisor

Dr. Babak Bazrgari

Second Advisor

Dr. Robert Shapiro


Prior studies have reported differences in lower back biomechanics during activities of daily living between individuals with and without chronic low back pain (LBP). Nevertheless, the literature on lower back biomechanics of patients with non-chronic LBP is scant. Therefore, the objective of this study, as the first step towards future prospective studies, was to investigate the lower back biomechanics in patients with non-chronic LBP. Case-control studies were conducted wherein measures of lumbo-pelvic coordination during bending and return tasks as well as measures of mechanical demand on the lower back during lifting tasks in the sagittal plane were investigated between patients with non-chronic LBP and matched asymptomatic individuals. Patients were enrolled into the study at the non-chronic stage of their LBP. We found distinct difference in measures of lumbo-pelvic coordination as well as mechanical demands on the lower back between patients with non-chronic LBP and controls. Reduced lumbar range of flexion and slower task pace as well as the more in-phase and less variable lumbo-pelvic coordination observed in patients with non-chronic low back pain, may be the result of a neuromuscular adaptation to reduce the forces and deformation in the lower back tissues and avoid pain aggravation. Such a neuromuscular adaptation, however, resulted in a larger shearing demand on the lower back. Persistent abnormal lumbo-pelvic coordination might play a role in transition to chronic stage or recurrence of LBP. However, such inferences need to be further investigated using prospective studies as well as clinical trials involving a combination of physical and psychological treatments aimed at correction of lumbo-pelvic coordination.

Digital Object Identifier (DOI)