Abstract
This study investigated whether flexion relaxation phenomenon (FRP) can be used as an evaluation technique for low back pain (LBP) independent of age and measurement site. Subjects were comprised of normal young individuals (n=12), young individuals with chronic lower back pain (CLBP) (n=6), normal elderly individuals (n=7), and elderly individuals with CLBP (n=7). Measurements using surface electromyography were conducted at the L2 and L5 levels. Regarding age, FRP occurrence was significantly higher in normal young individuals than the young individuals with CLBP; however, there were no differences observed between normal elderly individuals and elderly individuals with CLBP. In addition, regarding measurement site, FRP occurrence tended to be greater at L2 than L5. Therefore, FRP occurrence can be used for objective evaluation of LBP in young individuals, and the upper lumbar area is favorable for measurement. In elderly individuals, FRP alone is insufficient for accurate evaluation.
