Evaluation and treatment of anterior knee pain using eccentric exercise

Various authors have indicated that muscle imbalances might lead to knee pain and the potential for knee injury during sports. However, few reports have been published to substantiate such a hypothesis. But in all of the existing studies, only concentric torque measurements were evaluated. The purpose of the present study was to document any torque deficiencies which might be present during eccentric exercise in patients with knee pain. Of 130 patients with various knee disorders, 41 demonstrated a suppression in torque production during the eccentric exercise and generally in the portion of the range of movement between 30 degrees and 60 degrees of knee flexion (P less than 0.05). These individuals fit the criteria for anterior knee pain syndrome and demonstrated remarkable improvement after training 3 times/wk at concentric-eccentric exercises of the knee extensors at various speeds (30 degrees, 60 degrees, and 90 degrees . s-1) on a computer-controlled dynamometer (KIN/COM). In some cases, the pain as well as their torque deficiency was relieved after only 2 wk of training, most others were relieved after 2 to 4 wk of training.