CRD summary

The authors assessed the efficacy of aerobic walking and home-based quadriceps strengthening exercises in reducing pain and disability in patients with knee osteoarthritis. Both interventions were found to be more effective than no exercise. However, the findings were based on poor-quality trials which may compromise the validity of the conclusions. Direct comparisons between the two interventions are warranted.

Authors' objectives

To assess the efficacy of aerobic walking and home-based quadriceps strengthening exercises in reducing pain and disability in knee osteoarthritis.

Searching

MEDLINE, EMBASE, CINAHL, PEDro and the Cochrane Controlled Trials Register were searched from 1966 to 2003 for studies published in English; the search terms were reported. The reference lists from retrieved studies and reviews were screened for further eligible studies. Abstracts alone were excluded.

Study selection

Assessment of study quality

The Jadad scale was used to assess the validity of the studies. This scale measures randomisation, double-blinding, and withdrawals and drop-outs, and gives a score between 0 and 5. Two reviewers independently assessed the validity of the studies.

Data extraction

Two reviewers independently extracted the data from the studies. Such data included the mean pain scores and reported disability, with standard deviations, at baseline and final follow-up to enable the calculation of the mean change for each trial arm. This was then used to calculate the mean difference and 95% confidence interval (CI) for each trial.

Methods of synthesis

Results of the review

Thirteen RCTs were included. Three studies assessed aerobic walking (n=156), nine assessed home-based quadriceps strengthening exercises (n=1,709) and one assessed both aerobic walking and home-based strengthening exercises (n=439).

The Jadad scores ranged from 1 to 3 (out of 5), with none of the trials reporting to be double-blinded.

Pain was reduced significantly more with aerobic exercise than with no exercise (WMD 0.52, 95% CI: 0.34, 0.70; 4 RCTs, n=449). Participants in the aerobic exercise group reported less disability than those in the no exercise group (WMD 0.46, 95% CI: 0.25, 0.67; 2 RCTs, n=385). No statistically significant heterogeneity was detected for either analysis.

Pain was reduced significantly more with home-based quadriceps strengthening exercises than with no exercise (WMD 0.32, 95% CI: 0.23, 0.42; 11 RCTs, n=2,004). One study, with a large effect size, was excluded from this meta-analysis due to concomitant medication and a sham exercise programme delivered in the control group. Participants in the quadriceps strengthening exercise group reported less disability than those in the no exercise group (WMD 0.32, 95% CI: 0.23, 0.41; 11 RCTs, n=2,004). No statistically significant heterogeneity was detected for either analysis.

Authors' conclusions

Both aerobic walking and home-based quadriceps strengthening exercise are effective in reducing pain and disability in people with knee osteoarthritis, and appear equally effective when an indirect comparison is made.

CRD commentary

The research question and inclusion criteria were clearly stated. The search for studies was comprehensive, although there was no attempt to search for non-English language studies, which may introduce language bias. The data extraction and quality assessment were carried out in duplicate, thus reducing the potential for error and bias. However, it was unclear whether the same methods were employed at the study selection stage. Validity was assessed using appropriate criteria, and the results of the assessment were discussed. The decision to combine the studies in meta-analyses, grouped according to outcome and intervention, seemed appropriate, although there was no information on the outcome measures used in the different studies. The conclusions follow from the data presented, however, the poor-quality trials may compromise the reliability of the findings.

Implications of the review for practice and research

Practice: Offering patients the choice between two effective interventions has the potential to improve adherence and hence outcome.

Research: Direct comparisons between aerobic walking and home-based quadriceps strengthening exercises are required to identify the relative efficacies.

Funding

Arthritis Research Campaign, ICAC grant number D0593.

Bibliographic details

Roddy E, Zhang W, Doherty M. Aerobic walking or strengthening exercise for osteoarthritis of the knee: a systematic review. Annals of the Rheumatic Diseases 2005; 64(4): 544-548. [PMC free article: PMC1755453] [PubMed: 15769914]

Original Paper URL

http://ard.bmj.com/cgi/content/full/64/4/544

Other publications of related interest

Zhang WY, Li Wan Po A. Analgesic efficacy of paracetamol and its combination with codeine and caffeine in surgical pain: a meta-analysis. J Clin Pharmacol Ther 1996;21:261-82.

This additional published commentary may also be of interest. Schattner A. Review: both aerobic and home-based quadriceps strengthening exercises reduce pain and disability in knee osteoarthritis. ACP J Club 2005;143:71.

Indexing Status

Subject indexing assigned by NLM

MeSH

Disability Evaluation; Exercise; Exercise Therapy; Humans; Osteoarthritis, Knee /physiopathology /rehabilitation; Pain /prevention & control; Randomized Controlled Trials as Topic; Treatment Outcome; Walking

AccessionNumber

12005009813

Database entry date

31/10/2006

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.