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.

Inclusion criteria

for patients with sLSS

• age > 30 years
• BMI < 35kg/m2
• diagnosed symptomatic lumbar spinal stenosis
• clinical symptoms for at least 6 months
• intermittent neurogenic claudication with limitations of their walking ability due to symptoms in the lower back and or in one or both legs
• unsuccessful conservative treatment
• confirmation of the LSS through MRI
• Inclusion criteria for age-matched healthy control subjects
• age > 30 years
• BMI < 35kg/m2
• Inclusion criteria for young healthy control subjects
• 18 years ≤ age ≤ 30 years
• BMI < 35kg/m2

Exclusion criteria

for patients with sLSS

• inability to provide informed consent
• previous spine surgery
• use of walking aids
• other neurologic disorders affecting gait
• MRI incompatibility
• Exclusion criteria for age-matched healthy control subjects
• inability to provide informed consent
• previous spine surgery
• history of claudications
• use of walking aids
• other neurological or orthopaedic conditions that may affect gait
• MRI incompatibility
• Exclusion criteria for young healthy control subjects
• inability to provide informed consent
• previous back injury; previous spine surgery
• use of walking aids
• current injury of any kind