Jumper's knee or lander's knee? A systematic review of the relation between jump biomechanics and patellar tendinopathy.

Patellar tendinopathy (jumper's knee) is a common injury in sports that comprise jump actions. This article systematically reviews the literature examining the relation between patellar tendinopathy and take-off and landing kinematics in order to uncover risk factors and potential prevention strategies. A systematic search of the Pubmed, Embase and Amed databases was performed to identify studies that reported kinematics of sport specific jumps in relation to patellar tendinopathy. A quantitative analysis was performed on 4 indentified studies. Differences were found only between controls and asymptomatic subjects with patellar tendon abnormalities. Most differences were found during horizontal landing after forward acceleration. A synthesis of the literature suggests that horizontal landing poses the greatest threat for developing patellar tendinopathy. A stiff movement pattern with a small post-touchdown range of motion and short landing time is associated with the onset of patellar tendinopathy. Accordingly, employing a flexible landing pattern seems to be an expedient strategy for reducing the risk for (re-) developing patellar tendinopathy. Together, these findings indicate that improving kinetic chain functioning, performing eccentric exercises and changing landing patterns are potential tools for preventive and/or therapeutic purposes.