The main objective of this study is to measure the effect induced by combined muscle contraction of the Quadriceps and rectus femoris (by neuromuscular reprogramming) on pain phenomena and on the short-term recovery of muscle power. The goal to be achieved for these patients is to reduce the pain phenomena and to modify voluntarily and actively the orientation of their functional mechanical axes.

Evaluation of isokinetic quadriceps strength before and after stretching the injured knee and the healthy knee for 27 patients with FPPS and 12 healthy control subjects (matched). No pathology on the contralateral knee. The evaluation is carried out at 60°/s concentric 120°/s concentric and 30°/s eccentric contraction by an isokinetic dynamometer. After performing the isokinetic tests and evaluating the pain (by EVA), specific contraction work of the quadriceps of the injured knee according to an identical protocol for each patient was performed (3 times).

Our results show a significant effect of these contraction exercises on the pain phenomena of patients in the short-term. We obtained after quadriceps contraction a significant decrease in pain −38% and an increase in the strength of +17% for the pathological group. No significant change in the control group. There is a statistical correlation between the decrease of pain and recovery of strength after stretching. This significant decrease in pain associated with an increase in force parameters in only eccentric contraction.

We confirm the effectiveness of quadriceps stretching with slow eccentric contraction in the care of FPPS. These beneficial effects are in favor of a systematic use with muscle building. These results are in favor of a new therapeutic care by using this kind of stretching. The management of stiffness and neurophysiological components that are directly associated with these phenomena of stiffness during the onset of this syndrome, encourages therapists to continue.