Increased gluteus medius activation during sustained walking in chronic low back pain: A compensatory strategy for...

Chronic low back pain (CLBP) is associated with neuromuscular adaptations that may alter hip muscle activation and lumbopelvic control during gait. The gluteus medius (Gmed) plays a critical role in lumbopelvic control; however, its activation patterns and their relationship with center of pressure (COP) behavior during gait in individuals with CLBP remain unclear OBJECTIVE: To compare Gmed activation and center of pressure (COP) displacement during sustained walking (10-minute test) between individuals with and without CLBP.

Twenty-six participants (13 CLBP, 13 controls) matched for sex, height, weight, and BMI walked barefoot on a treadmill at a self-selected speed. Surface electromyography (EMG) recorded Gmed activation, normalized to percent maximal voluntary isometric contraction (%MVIC). COP displacement in the anterior-posterior (A-P) and mediolateral (M-L) directions was collected using a pressure-sensing treadmill. Group differences were evaluated using mixed repeated-measures ANOVA, with significance set at p < 0.05.

The CLBP group demonstrated significantly greater Gmed activation during minutes 8-9 (p = 0.041, η² = 0.163) and 9-10 (p = 0.014, η² = 0.226) of the 10-minute walking test. No significant group differences were observed for COP displacement in either direction (p > 0.05).

Individuals with CLBP exhibit increased gluteus medius activation during sustained walking while maintaining comparable COP-derived postural control, suggesting reliance on a neuromuscular compensation strategy rather than mechanical alterations in postural control. Rehabilitation programs may benefit from emphasizing motor control retraining and improving neuromuscular efficiency to address these compensatory patterns.