Open versus closed kinetic chain exercises in patellofemoral pain - A 5-year prospective randomized study

Background: Today, no clinical studies have been undertaken to examine the long-term effects of an open kinetic chain or closed kinetic chain program. Hypothesis: The long-term follow-up results after a conservative exercise protocol are significantly worse than the short-term results. The long-term effect of closed kinetic chain training is significantly better compared to the effect of open kinetic chain training. Study Design: Prospective randomized clinical trial. Methods: Sixty patients were randomized into a 5-week conservative program, consisting of only closed kinetic chain exercises or only open kinetic chain exercises. Assessment of muscular characteristics, subjective symptoms, and functional performance was evaluated in this study at the time of initial physical examination, at the end of the treatment period, and 5 years later. Results: At the 5-year follow-up, both groups demonstrated maintenance of good subjective and functional outcomes achieved immediately after the conservative treatment. No significant difference between both groups was observed at the 5-year follow-up for the majority of the examined parameters. However, on 3 of the 18 visual analog scales, the open kinetic chain group showed significantly less complaints compared to the closed kinetic chain group. Conclusions: On the basis of these results, the authors conclude that both open kinetic chain and closed kinetic chain programs lead to an equal long-term good functional outcome.