Effect of Muscle Fatigue on Spinal Imbalance and Motion in Lumbar Spinal Stenosis

Symptomatic lumbar spinal stenosis (sLSS) is a common syndrome affecting the human spine characterized by age related degeneration of the lumbar discs and facet joints resulting in pain, limited function and compromised quality of life. In a healthy spine, global and local spinal loads during static posture and dynamic motion will have minimal effects on the spinal canal. However, spinal loads altered by the presence of sLSS may result in further narrowing of the spinal canal and compression of the neural elements or in overloading of the already degenerated lumbar segments possibly eliciting typical pain symptoms. This study assesses spinal imbalance and motion in patients with sLSS and elicits fatigue via back exercises and compares spinal imbalance and motion before and after the fatigue exercise and compares these to healthy controls, allowing to associate sLSS-specific motion patterns to paraspinal muscle fatigue. Additional data generated using magnetic resonance tomography allows detecting and assessing differences in muscle degeneration between sLSS patients and healthy controls. Radiological images from the spine in upright position using EOS, a specialized low-dose x-ray unit will be obtained to allow the calculation of the actual clinical global and local spinal imbalance. Furthermore, this study investigates the outcome of the decompression surgery during a second study visit scheduled 1 year postoperatively. The data obtained here are pilot data that will be critical for designing a larger clinical trial and produce important information for adapting musculoskeletal spine models to simulate spinal imbalance and motion and further defining meaningful outcome parameters.