Kinematics and kinetics during stair ascent in individuals with Gluteal Tendinopathy.

BACKGROUND: Individuals with gluteal tendinopathy commonly report lateral hip pain and disability during stair ascent. This study aimed to compare kinematics and kinetics between individuals with and without gluteal tendinopathy during a step up task.

METHODS: 35 individuals with unilateral gluteal tendinopathy and 35 pain-free controls underwent three-dimensional motion analysis of stance phase during stair ascent. An analysis of covariance was performed to compare hip, pelvis and trunk kinematic and kinetic variables between groups. A K-means cluster analysis was performed to identify subgroups from the entire group (n=70) based on the characteristics of the external hip adduction moment. Finally, a Newcombe-Wilson test was performed to evaluate the relationship between group and cluster codes and a 3×2 ANOVA to investigate the differences in kinematics between groups and cluster codes.

FINDINGS: Individuals with gluteal tendinopathy exhibited a greater hip adduction moment impulse during stair ascent (ES=0.83), greater internal rotation impulse during the first 50% stance phase (ES=0.63) and greater contralateral trunk lean throughout stance than controls (ranging from ES=0.67-0.93). Three subgroups based on hip adduction moment characteristics were identified. Individuals with GT were 4.5 times more likely to have a hip adduction moment characteristic of a large impulse and greater lateral pelvic translation at heel strike than the subgroup most likely to contain controls.

INTERPRETATION: Individuals with GT exhibit greater hip adduction moment impulse and alterations in trunk and pelvic kinematics during stair ascent. Findings provide a basis to consider frontal plane trunk and pelvic control in the management of gluteal tendinopathy.