The effects of stochastic resonance stimulation on spine proprioception and postural control in chronic low back pain patients

Abstract

STUDY DESIGN.: Spine proprioception and postural control in unstable sitting were compared in 18 chronic low back pain patients using a repeated measures design. OBJECTIVE.: The study objective was to determine if stochastic resonance (SR) stimulation of the paraspinal muscles improves spine proprioception and trunk postural control. SUMMARY OF BACKGROUND DATA.: Decreased spine proprioception and larger postural sway have been found in low back pain patients, although several studies have also shown no differences in spine proprioception. METHODS.: Spine proprioception, measuring subjects' sensitivity to change in position, was assessed in 3 orthopaedic planes. Postural control was assessed using an unstable seat with a hemisphere attached to the bottom. Subjects balanced with eyes closed on the most challenging size hemisphere they could manage while center-of-pressure was recorded with a force plate beneath the seat. Both tasks were performed with SR stimulation randomized at 0%, 25%, 50%, and 90% intensity levels. RESULTS.: No significant differences in spine proprioception were observed between SR stimulation levels for any of the 3 orthopaedic planes. SR stimulation significantly improved postural control, but only in the lateral plane. No differences in postural control were observed between stimulation levels 25%, 50%, and 90% in the lateral plane. There was no correlation between spine proprioception and postural control. CONCLUSION.: Results suggest that SR stimulation to the paraspinal muscles can improve postural control; however, this improvement cannot be attributed to improved spine proprioception based on the current study. People with compromised neuromuscular control or those exposed to unstable environments may benefit from SR stimulation. © 2009, Lippincott Williams & Wilkins.