Assessment of hip abductor muscle strength. A validity and reliability study.

Background: Hip abductors are the most important muscles around the hip joint. It is therefore essential to assess their function in a valid and reliable way. Since the optimal body posture for the assessment of hip abductor strength is unknown, we tested the validity and reliability of unilateral hip abductor strength assessment in three different body positions.

Asymmetry in quadriceps rate of force development as a functional outcome measure in TKA.

Quadriceps muscle strength is an important predictor of functional abilities in patients having TKA. However, because several daily activities are characterized by a limited time to generate force, it has been suggested that rate of force development (RFD) could better predict functional difficulties than maximal strength. We therefore hypothesized the side-to-side asymmetry would be larger for RFD than for maximal strength, and RFD asymmetry relates to subjective symptoms and/or functional daily living activities.

Spatiotemporal parameters of gait after total hip replacement: anterior versus posterior approach.

The objective of this preliminary study was to examine possible differences in gait characteristics between subjects operated by way of a direct anterior approach and a posterior approach for primary total-hip arthroplasty, and age-matched healthy controls. Fifty-one subjects walked over an instrumented mat at two different speeds (self-selected comfortable and faster than normal) and spatiotemporal gait parameters were calculated using a validated methodology. Despite excellent clinical and radiographic scores, and irrespective of surgical approach, patients demonstrated an impaired walking performance (lower velocity and shorter step lengths) during fast walking, but not at the self-selected comfortable speed compared with healthy controls.