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- Do physical or imaging changes explain…
Do physical or imaging changes explain the effectiveness of progressive tendon loading exercises? A causal mediation analysis of athletes with patellar tendinopathy
Key Points
- The beneficial effect of progressive exercise for patellar tendinopathy is not mediated through functional changes in strength, range of motion, or jump height.
BACKGROUND & OBJECTIVE
Athletes who use the patellar tendon for repeated elastic energy storage-and-release activities are disproportionately affected by patellar tendinopathy (PT), hence the term “jumper’s knee” (1). Treatment for PT is centered around progressive therapeutic exercise, with the goal of improving exercise tolerance and functional performance (2). Causal mediation analysis (CMA) is a novel statistical method used to evaluate the causal role of multiple mediators in a randomized controlled trial. Mediators are presented as assumptions within a framework of potential outcomes (3).
The authors sought to research whether the effects of a progressive patellar tendon loading exercise program (PTLE) could be attributed to changes in quadriceps muscle strength, dorsiflexion range, jumping performance, tendon thickness, and degree of neovascularization by using a CMA on their 24-week RCT comparing PTLE to a more basic eccentric exercise therapy (EET) program as their control (4).
At this point in time, evidence does not support utilizing imaging or objective measurements of strength, power, and range of motion in the assessment, stratification, and treatment of patellar tendinopathy.
METHODS
- 76 patients (mean age = 24, range 18-35, 76% male) with mostly chronic PT (median symptom duration two years) were randomly assigned to receive either PTLE or EET.