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

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSION

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.