Resident University of Rochester University of Rochester Rochester, NY, US
Disclosure(s):
Gabrielle Santangelo, MD: No financial relationships to disclose
Introduction: The CoE theory explains how the body attempts to maintain balance with minimal energy expenditure. No previous work has investigated the role of the lower extremity with patient’s CoE. This study aims to evaluate the effect of the lower extremity on patient’s Cone of Economy (CoE) in two degenerative lumbar conditions and introduce a novel assessment of seated balance using the traditional CoE measurements.
Methods: This is a prospective, single-center cohort study examining the cone of economy (CoE) in patients with either operative single level lumbar stenosis or single level foraminal stenosis with radiculopathy compared to controls. Functional balance tests were performed in the standing and seated position approximately one week before surgery and recorded by 3D motion capture. The data were analyzed with a one-way analysis of variance (ANOVA) to determine differences between groups CoE outcomes and for each position.
Results: Sixty-one lumbar degenerative (LD) surgical candidates, consisting of 27 stenosis (LS) and 27 radiculopathy (LR) patients, and 35 healthy controls were enrolled. The standing CoE was significantly different increased in the LD group compared to the control group (p < 0.001). The seated head and pelvic sway in coronal plane were significantly higher in the LD group versus controls (p=0.005, p< 0.0001, respectively). Between the seated LS and LR groups, there was increased sway in the head and pelvis in the stenosis group (p=0.049, p=0.008, respectively). The difference of total sway of the head, pelvis and CoM in the seated versus standing position were significant to p< 0.001 in all measures between the LD and control groups.
Conclusion : Using two degenerative lumbar conditions compared with controls, we demonstrate that the lower extremities play a critical role in CoE derangements in focal degenerative lumbar conditions. This also serves as a proof-of-concept study that can be applied to adult spinal deformity cohorts.