Achilles Tendon Loading During Heel-Raising and -Lowering Exercises

Area of Science:

• Biomechanics
• Sports Medicine
• Rehabilitation Science

Background:

• Achilles tendinopathies are prevalent sports injuries, particularly in men.
• Heel-raising and -lowering exercises are standard for Achilles tendon rehabilitation.

Purpose of the Study:

• To compare Achilles tendon loading and ankle range of motion (ROM) during common heel exercises using a musculoskeletal model.
• To evaluate the biomechanical demands of different heel-raising and -lowering exercises.

Main Methods:

• Controlled laboratory study involving 21 healthy men.
• Participants performed seated, bilateral standing, and unilateral heel raising/lowering exercises.
• Musculoskeletal modeling, motion capture, and ultrasound were used to estimate Achilles tendon stress, force, strain, and ankle ROM.

Main Results:

• Peak Achilles tendon loading was lowest during seated exercises and highest during unilateral exercises.
• Unilateral exercises or portions thereof resulted in significantly greater tendon loading.
• Ankle ROM did not correlate directly with loading levels across exercises.

Conclusions:

• Seated and bilateral exercises, with reduced weight-bearing, impose less Achilles tendon load.
• These exercises can be used as progressive steps in rehabilitation before advancing to unilateral, full weight-bearing exercises.
• Ankle ROM requires careful monitoring during rehabilitation as it may not parallel tendon loading progression.