Gluteal muscle recruitment during level, incline and stair ambulation in healthy subjects and chronic low back pain patients

Purpose. The purpose of this first evaluation was to directly compare myoelectrical patterns of gluteus maximus activity during different walking tasks (level and 10 degrees incline) and a stair climb task in healthy men and men with chronic low back pain (CLBP). Methods: Neuromusclar activity of the gluteus maximus of twelve male CLBP (age = 53.4 +/- 7.7 yr) patients and twenty sex-matched control subjects (age = 32.6 +/- 5.1 yr) was compared during level walking (1.25 m/s), graded treadmill ambulation (10%, 1.25 m/s) and stair climbing. EMG-recordings were carried out on one randomly selected body side in each group Results: Compared to level ambulation, incline walking and stair ascent induced a significant (P < 0.01) increase of about 25% respectively 50% of gluteus maximus activity in the healthy cohort. CLBP patients in contrast demonstrated an average increase of about 35% in incline walking and stair climbing along with an extended stance phase activity during stair ascent. Discussion: The findings sufficient that low back disorders are associated with changes of the level and duration of gluteus maximus activity under different gait conditions. The alterations may point toward a compensatory recruitment pattern to accomplish a certain degree of lumbo-pelvic stabilization. More study is needed on the behaviour of CLBP patients in different provocative tests and functional rehabilitation programs.