Individuals with gluteal tendon repair display similar hip biomechanics to those of a healthy cohort during a sit-to-stand task.

BACKGROUND: Gluteal-tendon repair (GTR) is reported to be effective for relieving pain and improving clinical function in patients with gluteal-tendon tears. The sit-to-stand (STS) task is an important activity of daily living and is often used to assess functional capacity in clinical populations. Understanding if and how STS performance is altered in individuals with gluteal tendon repair may be an effective marker of GTR outcomes as well as a possible therapeutic target for post-operative rehabilitation. RESEARCH QUESTION: Do biomechanical parameters during STS differ between age- and sex-matched participants with and without gluteal-tendon repair? METHODS: 27 participants with a GTR and 29 healthy participants performed the STS task. Data were acquired using the three-dimensional motion capture system and forceplates. Outcomes of interest were task duration, rate of force development, trunk, pelvis, and hip joint angles, moments and powers. Differences were assessed using Generalised linear multivariate models and statistical parametric mapping. RESULTS: GTR patients performed the STS movement significantly slower (1.4+/- 0.40 s) compared to controls (1.1+/ -0.2 s) with a significantly lower rate of force development (35.1+/- 5.7 N/kg/ms vs 30.3+/- 8.5 N/kg/ms). There were no group differences for hip, pelvis, or trunk angle over the movement cycle or for maximal or minimal values. Furthermore, there were no significant differences detected in hip joint kinetics. However, there appeared to be substantial between-subject variability indicating different patient-specific movements patterns. SIGNIFICANCE: Individuals with a GTR performed the STS task about 20 % slower than healthy controls with a lower rate of force development. The individual variations indicate that participants likely employed different movement strategies to achieve STS. While the lack of differences between groups could suggest that GTR helps restore function and corrects the proposed underlying aetiology, it is possible that the STS task was not sufficiently challenging to discriminate between groups.

People after gluteal tendon repair have gait characteristics which are similar to those of a healthy cohort.

BACKGROUND: Gluteal-tendon repair is reported to be effective for relieving pain and improving function in patients with gluteal-tendon tears. However, post-operative three-dimensional gait analysis has never been conducted in gluteal-tendon repair patients. Thus, our primary aim was to investigate how biomechanical gait parameters differ between age- and sex-matched participants with and without gluteal-tendon repair. METHODS: Vicon motion analysis technology was used to measure gait characteristics of 25 gluteal-tendon repair participants and 29 matched healthy comparison group participants. A generalised linear multivariate model was used to compare external hip-adduction moment, range of movement in hip adduction and internal rotation, pelvic obliquity, trunk lean, stride length and velocity of both cohorts throughout stance. FINDINGS: There were no differences between the groups in external hip adduction moment, pelvic obliquity and range of movement in hip adduction and internal rotation. Gluteal-tendon repair participants had a shorter stride length (P = 0.031) and reduced walking velocity (P = 0.015). Ipsilateral trunk lean was reduced in gluteal-tendon repair participants at the first-peak external hip-adduction moment (P = 0.016), mid-stance minimum external hip-adduction moment (P = 0.029) and second-peak external hip-adduction moment (P = 0.006). INTERPRETATION: There were no differences between the gluteal-tendon repair and comparison groups for external hip-adduction moment and pelvic obliquity. This suggests that gluteal-tendon repair may restore hip control in stance. Slower walking speed, reduced stride length and decreased ipsilateral trunk lean may reflect persistence of pre-operatively developed gait adaptations. Future studies of gait biomechanics before and after gluteal-tendon repair would be needed to substantiate this theory.