The effect of stabilization instruction on lumbar acceleration

Objective. To determine the effect of trunk stabilization instruction on lumbar acceleration. Background. There is a paucity of information showing the impact of stabilization training and instruction on lumbar motion. Neuromuscular activation patterns have been implicated as an etiological factor in low back disorders. Knowledge of the short-term alterations in lumbar motion control, as assessed by acceleration, is an important first step to understanding the impact of trunk stabilization programs. Methods. A calibrated, uniaxial accelerometer was positioned over the L4 spinous process of subjects (n=33) to record anterior/posterior acceleration during 10 repetitions of lower and upper limb movements (hip flexion/extension and biceps curl) before and after standardized stabilization instruction. Results. Each repetition exhibited four stereotypical phases of acceleration. Instruction resulted in a substantial reduction in peak lumbar acceleration magnitude (P<0.01) for all movement phases for both exercises (hip flexion 39.5%, biceps curl 30.8%). Lumbar peak accelerations for the biceps curl were substantially higher than peak accelerations for hip flexion (P<0.05). Conclusions. This study demonstrated that stabilization instruction results in immediate alteration of kinematics (global reduction of limb movement-induced lumbar acceleration) during upper and lower body movements. Reduced lumbar acceleration levels would arise from a change in the motor control strategy of trunk musculature due to instruction.