EFFECTS OF REHABILITATION ON BACK MUSCLE CONTRACTION PATTERNS OF LOW BACK PAIN PATIENTS

  • W. W. Lu
  • K.D. K. Luk
  • K.M. C. Cheung
  • Y. W. Wong
  • J.C. Y. Leong
Keywords: electromyography (EMG), low back pain (LBP), paraspinal muscles

Abstract

The aims of this study were to conduct a comparative investigation of muscle function between low back pain (LBP) patients and normal subjects, as well as to explore whether intensive rehabilitation can change back muscle contraction synergy. 20 normal subjects and 20 patients with chronic LBP were asked to perform symmetrical and asymmetrical tasks. LBP patients were tested in the weeks immediately before and after 12-week LBP rehabilitation treatment. Tasks include “carrying” weights up and down with a 45° left rotation. Eight channel surface EMG electrodes were placed on the surface of paraspinal muscles. correlation between right and left corresponding muscles as well as between pre- and post-treatment were calculated. Lifting capacity for LBP patients were also measured before and after treatment. EMG profiles showed that the muscle activity strategies varied between normal subjects and LBP patients. The correlation coefficients for spinal muscles have shown very reproducible intra-subject muscle contraction synergies. Unbalanced EMG patterns found in LBP patients under symmetrical tasks were not affected by rehabilitation treatment.