Characterizing patellar tendon loading during the landing phases of a stop-jump task

Area of Science:

• Biomechanics
• Sports Medicine
• Knee Injury Research

Background:

• Overuse knee injuries, particularly patellar tendinopathy, are linked to excessive extensor mechanism loading during repetitive landings.
• Identifying landing mechanics that maximize patellar tendon load is essential for injury prevention strategies.

Purpose of the Study:

• To compare the patellar tendon force (F(PT)) generated during horizontal versus vertical landing tasks.
• To determine which landing type imposes the greatest load on the patellar tendon.

Main Methods:

• Sixteen male athletes performed stop-jump tasks involving horizontal and vertical landings.
• Ground reaction forces and 3D kinematics were measured.
• Patellar tendon force (F(PT)) was calculated using net knee joint moments and the patellar tendon moment arm.

Main Results:

• Horizontal landings produced significantly higher patellar tendon force (F(PT)) and loading rates compared to vertical landings.
• Posterior ground reaction forces were also elevated during horizontal landings.
• Vertical ground reaction forces (F(V)) did not correlate with F(PT), indicating their inadequacy as a sole measure of tendon load.

Conclusions:

• Horizontal landing tasks induce greater patellar tendon loading than vertical landings.
• Findings suggest that F(V) alone is insufficient to assess patellar tendon stress.
• This research provides a basis for investigating landing strategies in athletes with patellar tendinopathy.