Dose-response effects of medical exercise therapy in patients with patellofemoral pain syndrome: a randomised controlled clinical trial.

OBJECTIVES

To evaluate two different therapeutic exercise regimens in patients with patellofemoral pain syndrome (PFPS).

DESIGN

Multicentre, randomised controlled clinical trial.

SETTING

Three primary healthcare physiotherapy clinics.

PARTICIPANTS

Forty-two patients with PFPS were assigned at random to an experimental group or a control group. Forty participants completed the study.

INTERVENTIONS

Both groups received three treatments per week for 12 weeks. The experimental group received high-dose, high-repetition medical exercise therapy, and the control group received low-dose, low-repetition exercise therapy. The groups differed in terms of number of exercises, number of repetitions and sets, and time spent performing aerobic/global exercises.

MAIN OUTCOME MEASURES

Outcome parameters were pain (measured using a visual analogue scale) and function [measured using the step-down test and the modified Functional Index Questionnaire (FIQ)].

RESULTS

At baseline, there were no differences between the groups. After the interventions, there were statistically significant (P<0.05) and clinically important differences between the groups for all outcome parameters, all in favour of the experimental group: -1.6 for mean pain [95% confidence interval (CI) -2.4 to -0.8], 6.5 for step-down test (95% CI 3.8 to 9.2) and 3.1 for FIQ (95% CI 1.2 to 5.0).

CONCLUSION

The results indicate that exercise therapy has a dose-response effect on pain and functional outcomes in patients with PFPS. This indicates that high-dose, high-repetition medical exercise therapy is more efficacious than low-dose, low-repetition exercise therapy for this patient group.