Effect of low back pain on the kinematics and joint coordination of the lumbar spine and hip during sit-to-stand and stand-to-sit

Study Design. Experimental study to describe lumbar spine and hip joint movements during sit-to-stand and stand-to-sit. Objectives. To examine differences in the kinematics and joint coordination of the lumbar spine and hips during sit-to-stand and stand-to-sit between healthy subjects and patients with subacute low back pain (LBP). Summary of Background Data. There is a paucity of information on the coordination of movements of lumbar spine and hips during sit-to-stand and stand-to-sit. The effect of LBP, with or without nerve root signs, is largely unknown. Methods. A three-dimensional real-time electromagnetic tracking device was used to measure movements of the lumbar spine and hips during sit-to-stand and stand-to-sit. Sixty subacute LBP participants with or without straight leg raise signs and 20 healthy asymptomatic participants were recruited. The kinematic patterns of lumbar spine and hips were analyzed. Coordination between the two joints was studied by relative phase angle analysis. Results. The mobility of the spine and hips was significantly limited in back pain subjects. It was observed that LBP subjects employed various strategies to compensate for the limited motions at the hips and lumbar spine. The contribution of the lumbar spine relative to that of the hip was found to be reduced for subjects with LBP. The lumbar spine-hip joint coordination was significantly altered in back pain subjects, in particular, those with positive straight leg raise sign. Conclusion. Back pain was related to changes in the kinematics and coordination of the lumbar spine and hips during sit-to-stand and stand-to-sit. Assessment of back pain patients should include kinematic analysis of the hips as well as the spine.