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Related Experiment Video

Updated: Jul 15, 2026

Muscle Imbalances: Testing and Training Functional Eccentric Hamstring Strength in Athletic Populations

Muscle Imbalances: Testing and Training Functional Eccentric Hamstring Strength in Athletic Populations

Published on: May 1, 2018

Patellar tendon load in different types of eccentric squats.

A Frohm¹, K Halvorsen, A Thorstensson

¹Elite Sports Centre, Swedish Sports Confederation, Bosön, Sweden. anna.frohm@telia.com <anna.frohm@telia.com>

Clinical Biomechanics (Bristol, Avon)

|May 15, 2007

Summary

Different eccentric squats significantly alter knee and patellar tendon loading. Decline board squats increase load more than horizontal squats, offering insights for optimizing patellar tendinopathy rehabilitation.

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Area of Science:

Biomechanics
Sports Medicine
Rehabilitation Science

Background:

Patellar tendinopathy rehabilitation effectiveness varies with exercise type.
Mechanical loading differences in patellar tendon exercises are hypothesized to cause these variations.

Purpose of the Study:

To quantify and compare the mechanical load on the knee and patellar tendon during four distinct eccentric squat variations.
To provide biomechanical data that can inform the design of more effective rehabilitation strategies for patellar tendinopathy.

Main Methods:

Subjects performed eccentric squats using free weights (horizontal and decline board) and an eccentric overloading device (Bromsman).
Kinematic data, ground reaction forces, and electromyography (EMG) of three leg muscles were collected.
Inverse dynamics analysis was employed to compute knee joint kinetics.

Main Results:

Decline board squats with free weights resulted in significantly greater eccentric work, patellar tendon force, and specific joint angles compared to horizontal squats.
The Bromsman device induced higher knee joint forces but not work compared to free weight exercises.
EMG activity varied across exercises, with some increases observed on the decline board and with the Bromsman device for specific muscles.

Conclusions:

Distinct eccentric squat variations impose significantly different biomechanical loads on the knee and patellar tendon.
Understanding these loading differences is crucial for explaining varied rehabilitation outcomes and for developing targeted exercise protocols for patellar tendinopathy.