Purpose: Although high patellar tendon loading is believed to be the primary causative factor for patellar tendinopathy, research investigating factors that affect patellar tendon loading during landing is scarce. Therefore, the purpose of this study was to identify whether factors previously associated with the development of patellar tendinopathy, and selected variables characterizing landing technique, could predict patellar tendon loading incurred by volleyball players when landing from a jump.
Methods: Ten highly skilled male, 20 skilled male, and 20 skilled female volleyball players performed a lateral stop–jump movement. Sex, skill level, quadriceps strength, quadriceps extensibility, and trunk moment of inertia were recorded. Landing kinematics (250 Hz) and kinetics (1500 Hz) were collected, and peak patellar tendon force and patellar tendon force loading rate were calculated. Backward multiple regression analyses identified which risk factors or landing technique variables were predictors of patellar tendon loading.
Results: Multiple regression analyses were able to estimate and predict 52% (F4,49 = 14.258, P < 0.001) and 70% (F4,49 = 29.329, P < 0.001) of the peak patellar tendon force and the patellar tendon force loading rate variance, respectively. The present study revealed that male volleyball players with greater quadriceps strength, who displayed increased ankle dorsiflexion velocity and trunk flexion velocity during landing, were predicted to incur higher patellar tendon loading.
Conclusions: As frequent application of high patellar tendon loading has previously been identified as a causative factor for developing patellar tendinopathy, interventions designed to decrease ankle dorsiflexion velocity and trunk flexion velocity at landing, particularly in male players with strong quadriceps muscles, may be effective in reducing patellar tendon loading and, in turn, patellar tendinopathy prevalence in this population.
1Biomechanics Research Laboratory, School of Health Sciences, University of Wollongong, Wollongong, AUSTRALIA; 2AIS Movement Science, Australian Institute of Sport, Canberra, AUSTRALIA; and 3ARC Centre of Excellence in Electromaterials Science and Intelligent Polymer Research Institute, University of Wollongong, Wollongong, AUSTRALIA
Address for correspondence: Julie R. Steele, Ph.D., Biomechanics Research Laboratory, Northfields Avenue, University of Wollongong, Wollongong, NSW 2522, Australia; E-mail: firstname.lastname@example.org.
Submitted for publication May 2012.
Accepted for publication November 2012.