A Preliminary Study of Patellar Tendon Torques during Jumping

Click name to view affiliation

Niell Elvin City College of New York

Search for other papers by Niell Elvin in
Current site
Google Scholar
PubMed
Close
,
Alex Elvin University of the Witwatersrand

Search for other papers by Alex Elvin in
Current site
Google Scholar
PubMed
Close
,
Cornie Scheffer University of Stellenbosch

Search for other papers by Cornie Scheffer in
Current site
Google Scholar
PubMed
Close
,
Steven Arnoczky Michigan State University

Search for other papers by Steven Arnoczky in
Current site
Google Scholar
PubMed
Close
,
Edwin Dillon University of Stellenbosch

Search for other papers by Edwin Dillon in
Current site
Google Scholar
PubMed
Close
, and
P. J. Erasmus University of Stellenbosch

Search for other papers by P. J. Erasmus in
Current site
Google Scholar
PubMed
Close
Restricted access

The etiology of patellar tendinopathy (jumper’s knee) has been attributed to a significant increase in patellar tendon torques associated with jumping. While some investigators have suggested that patellar tendon torques are greater during takeoff, little is known about the relative magnitudes of patellar tendon torques during takeoff and landing. We hypothesized that peak patellar tendon torques are greater in jump takeoff than in landing, and that there is a linear correlation between jump height and peak patellar tendon torque. Seven asymptomatic, recreational male athletes each performed a series of 21 jumps ranging from low to maximal height. A calibrated fiber-optic sensor, implanted transversely within the patellar tendon was used to measure the knee torque during takeoff and landing. There was no significant difference in the peak patellar tendon torque experienced during takeoff and landing within individuals. There was a moderate correlation (r = .64) between maximum takeoff patellar tendon torques and jump height. There was a weak correlation (r = .52) between maximum landing patellar tendon torques and jump height. There was a moderate correlation (r = .67) between maximum 60°/s isokinetic extension torque and maximum jump height. The lack of a strong correlation between jump height and patellar tendon forces during takeoff or landing suggests that these forces may be technique dependent. Therefore, modifying takeoff and/or landing techniques could reduce patellar tendon force and potentially lessen the incidence of patellar tendinopathy.

Niell Elvin is with the Department of Mechanical Engineering, City College of New York, New York, NY. Alex Elvin is with the Department of Civil and Environmental Engineering, University of the Witwatersrand, Johannesburg, South Africa. Scheffer is with the Department of Mechanical Engineering and Mechatronics, University of Stellenbosch, Stellenbosch, South Africa. Arnoczky is with the Laboratory for Comparative Orthopedic Research, Michigan State University, East Lansing, MI. Dillon is with the Department of Orthopaedic Surgery, University of Stellenbosch, Stellenbosch, South Africa. Erasmus is with the Department of Orthopaedic Surgery, University of Stellenbosch, Stellenbosch, South Africa.

  • Collapse
  • Expand