Study design: Case-series study with pre- vs. post-test measurements design.
Background: Strength training programs emphasizing eccentric muscle actions have received much attention in the treatment of tendinopathies. The current study reports on the efficacy of a novel strength training paradigm using inertial eccentric-concentric resistance to treat chronic patellar tendinopathy. Case description: Ten athletes with chronic patellar tendinopathy (15 tendons) volunteered for the study. Subjects completed a 6-week training program employing a leg press flywheel ergometer. Pre and post measurements assessed lower limb maximal strength and vertical counter-movement-jump (CMJ) height. Surface electromyography (SEMG) analysis of paraspinal, rectus femoris, biceps femoris and medial gastrocnemius muscles were collected. All measurements were performed one week before and after the training period. Clinical measures of pain and tendon function were assessed by means of a visual analogue scale (VAS) and a patellar tendinopathy questionnaire (VISA) at baseline, post-training and follow-up (12 wk). The Wilcoxon signed-rank test was employed for data comparisons.
Results: Eccentric strength increased after training (90%, p < 0.05). Similarly, VAS and VISA scores improved after training as well (60% and 86%, respectively, p < 0.01). There were no changes in CMJ height.
Conclusion: Short-term training using inertial eccentric overload, resulted in improved muscle function and reduced subjective pain in long-lasting patellar tendinopathy.