Assessment of the Effect of Stretching Quadriceps on Pain and Strength in Patello-Femoral Pain Syndrome

Objective: To assess the effect of eccentric, slow speed, submaximal Quadriceps stretching on the pain and strength of patients suffering from the Patello-femoral pain syndrome (PFPS). Materials and methods: Isokinetic evaluation of the Quadriceps strength before and after stretching the injured knee of the pathological group and the dominant knee of the control group, for 27 patients with PFPS and 12 healthy control subjects. The assessment is carried out with contractions at 60°/s and 120°/s in concentric mode and 30°/s in eccentric mode. A pain assessment by an EVA test is made before and after stretching at each speed of the test on the knee tested for both groups. Results: After the Quadriceps stretching we obtained a decrease in pain of -38% (p<0.017) and an increase in strength of +17% for the pathological group. No significant change in the control group. There is a statistical correlation between the decrease in pain and the gain in strength after stretching (p<0.002). Conclusion: We confirm the effectiveness of performing eccentric, slow speed, submaximal Quadriceps stretching on the PFPS. The beneficial effects suggest that a systematic use of the former is advisable in muscle strengthening. These results confirm the necessity of stretching exercises.