Abstract
Statement of Purpose
It is well known that individuals with a history of low back pain (hLBP) exhibit altered movement patterns that are caused by changes in neuromuscular control. Postural disturbance provides an effective method for creating these differentiable movement patterns. This study has explored the response of the lower limb and spine to a translational perturbation similar to that experienced on public transport in healthy volunteers and those with hLBP.
Methods
Healthy volunteers (n=16) and subjects with hLBP (n=10) were subjected to 31 identical postural disturbances at varying time intervals while standing atop a moving platform. Skeletal kinematics and muscle activation were recorded using a 10-camera Vicon system (Oxford, UK) and Myon electromyography (EMG) at the trunk (lumbar, lower thoracic, and upper thoracic segments), pelvis, thigh, calf, and foot. Joint angles were calculated using Body Builder (Vicon) and a unilateral seven-segment custom model.
Results
Examination of the total range of joint motion (RoM) exhibited during the trial demonstrated similar RoM at the knee and hip (p=0.90 and 0.97 respectively), but less RoM for the hLBP group at the ankle and lumbar spine (p=0.21 and 0.38, respectively). EMG signals revealed higher muscle activation of the lower limbs from the hLBP cohort compared to healthy controls, yet greater activation at the gluteal and oblique muscles in the control group.
Conclusions
In the presently small cohorts, trends demonstrate that differences in postural strategies exist between the healthy and hLBP cohorts, yet further testing of LBP patients will further clarify targets for rehabilitation.
