Objective: To investigate the reliability of a clinically applicable method of dynamometry to assess and monitor hip abductor muscle strength in older persons.
Design: Bilateral isometric hip abductor muscle strength measured with a handheld dynamometer, patients supine with the contralateral hip positioned directly against a wall for stabilization. Reliability determined by comparing intra-assessor and inter-assessor results and comparison to a criterion standard (stabilized dynamometer with patients in the standing position).
Setting: UniSA Nutritional Physiology Research Centre.
Participants: Twenty-one patients older than 65 years were recruited from the Royal Adelaide Hospital.
Main outcome measures: Intraclass correlation coefficients (ICCs), bias, and limits of agreement calculated to determine reliability.
Results: Intra-assessor and inter-assessor ICCs were high (0.94 and 0.92-0.94, respectively). There was no intra-assessor bias and narrow limits of agreement (±2.4%). There was a small inter-assessor bias but narrow limits of agreement (0.6%-0.9% and ± 2.3%, respectively). There was a wide variation comparing results to the criterion standard (±5.0%-5.2% limits of agreement), highlighting problems attributed to difficulties that the test population had with the standing position used in the criterion standard test.
Conclusions: Testing older persons' hip abductor muscle strength while in the supine position with optimal pelvic stabilization using a handheld dynamometer is highly reliable. While further studies must be done to assess patients with specific pathologies, this test has potential application to monitor and evaluate the effects of surgical interventions and/or rehabilitation protocols for a variety of conditions affecting hip abductor function such as hip fractures and arthritis.
Keywords: fragility fractures; gait disorders; occupational therapy; osteoporosis; physical medicine and rehabilitation; physical therapy.