Resistance training for people with hip or knee osteoarthritis

Some of the Elf’s older friends have started to develop osteoarthritis (OA) in their hips and knees and have been asking the Elf about it. Here are some of their questions. Would exercise strengthen their muscles? Would stronger muscles help them in their everyday activities?

The authors of a recent systematic review evaluated the effect of current rehabilitation programs for improving muscle strength in people with hip or knee OA. Let’s see what they found.

Here’s what they did

The authors searched seven databases (up to Feb 2013) for randomized controlled trials evaluating lower limb strength outcomes of exercise-based interventions for participants with hip or knee OA using voluntary contractions with a minimum duration of 6 weeks. Quality of evidence was assessed using Grading of Recommendation, Assessment, Development and Evaluation approach.

Here’s what they found

Forty RCTs were included – 39 for OA knee and only 1 for OA hip
77% involved resistance based exercise programs compared wth control
Low-intensity resistance programmes at short term (ST) follow-up – high quality evidence
- improved knee extension strength (SMD 0.47, 95% CI 0.29 to 0.66)
- improved flexion strength (SMD 0.74, 95% CI 0.56 to 0.92)
- these effects were not sustained in the intermediate or long term
High-intensity resistance programmes at short term follow up – moderate quality evidence
- large effect for knee flexion and extension strength (SMD = 0.76, 95% CI 0.47, 1.06).
- this effect was sustained at intermediate term follow-up (SMD = 0.80, 95% CI 0.44, 1.17).
Few studies reported on outcomes at long term follow-up

The authors concluded

When compared to a control group, high-intensity resistance exercise demonstrated moderate quality of evidence for large and sustained improvements for knee muscle strength in knee OA patients.

The Musculoskeletal Elf’s view

This review opens up a number of issues. Firstly it is very interesting to note that OA hip receives very little attention in the literature compared with OA knee. From the reports of the studies included in this review it appears that the severity of OA was not quantified. This could have important implications on the data obtained and conclusions drawn from these studies. Perhaps a stratified selection process could be employed in future studies with an a priori subgroup analysis for severity of OA.

Furthermore these studies focussed on strength outcomes alone. It would perhpas be more useful for people with OA if these studies examined the effects of strength training on functional outcomes.

What do you think?

Are strength outcomes approriate or should the focus be on function?
Do you think severity of OA should be recorded and accounted for in analysisof these types of studies?

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