NO ASSOCIATION AMONG GLUTEUS MEDIUS ACTIVITY, HIP ABDUCTION STRENGTH, AND KINEMATIC VARIABLES DURING SINGLE-LEG SQUAT IN YOUNG WOMEN WITH CHRONIC NONSPECIFIC LOW BACK PAIN

Abstract

Background: Chronic nonspecific low back pain (CNSLBP) is the leading cause of long-term pain and disability. There is evidence suggesting a relationship between CNSLBP in adult women and altered hip kinematics and gluteus medius (GM) muscle function. However, this association has been less studied in young women. Objective: To assess the association between lower limb and pelvis kinematics in the frontal plane, and GM strength and electromyographic activity in young women with CNSLBP compared with an age-matched control group of asymptomatic women. Methods: In this cross-sectional study, 32 young women with CNSLBP ([Formula: see text] months of pain; Oswestry index range: 21–40%) and 20 healthy age-matched women were included. The frontal plane projection angle (FPPA) and contralateral pelvis drop (CPD) at the endpoint of the single-leg squat (SLS) test were measured through photogrammetry. Mean GM muscle activity during the SLS and peak isometric GM strength was measured using surface electromyography (sEMG) and hand-held dynamometry, respectively. Results: The Hotelling’s trace showed no significant differences between groups when the variables were considered as a composite ([Formula: see text]; [Formula: see text]). Also, the univariate results showed no individual differences between groups considering each variable separately. Conclusions: The results showed no association between CNSLBP, hip and pelvis kinematics, and GM strength and activity in young women.