Efficacy of strengthening exercises for osteoarthritis (Part I): A meta-analysis

Abstract

Objective: Osteoarthritis (OA) is highly prevalent among older adults and is associated with increased pain, loss of strength and joint range of motion (ROM), as well as to an overall decrease in functional status. Therapeutic strength exercises are recommended as part of the standard intervention programme for the patient with OA in an effort to control pain and improve functional and health status. The purpose of this meta-analysis is to review the strength and quality of evidence supporting the effectiveness of therapeutic strengthening exercises for improving a variety of measured outcomes relevant for OA. Methods: A systematic review was conducted, following a protocol of methods recommended by the Cochrane Collaboration. Trials were identified by a literature search of Medline, EMBASE, and the Cochrane Controlled Trials Register. Only randomised controlled trials using strengthening exercises as an intervention and treating clients with OA were eligible. Twenty-two trials were included with 2325 patients undergoing various forms strengthening exercises (e.g. isometric, isotonic, isokinetic, concentric, concentric/eccentric, dynamic). The exercises were implemented either in stand-alone format or in combination with other exercises, such as stretching and ROM. Interventions were either facility-based, home-based or a combination of the two. Results: Evidence is provided for the inclusion of strengthening exercises in the rehabilitation programme for the patient with OA. Improvements were found for strength, pain, function and quality of life (QOL). Important components of the exercise programme that influence outcome include: (i) the combination of joint-specific strengthening with general strength, flexibility and functional exercises; (ii) progression of the exercise programme; and (iii) level of client self-reliance to sustain the programme. There is no evidence that the type of strengthening (i.e. isometric, isotonic or isokinetic) has an important impact on programme outcome. However, evidence is provided that the control of pain may be a dominant mechanism by which strengthening exercise produces beneficial effects for the patient with OA. Conclusion: Strengthening exercises alone have some effects on improving pain and functional outcomes in clients with OA. However, in order to maximise the effectiveness of strengthening exercise for these clients, it is necessary to combine strengthening exercises with a more complete exercise programme including ROM, stretching, functional balance and aerobic exercises.