Achilles Tendon Loading During Heel-Raising and -Lowering Exercises.
BACKGROUND
Achilles tendinopathies are common injuries during sport participation, although men are more prone to Achilles tendon injuries than women. Heel-raising and -lowering exercises are typically suggested for Achilles tendon rehabilitation.


OBJECTIVE
To compare the estimated Achilles tendon loading variables and the ankle range of motion (ROM) using a musculoskeletal model during commonly performed heel-raising and -lowering exercises.


METHODS
Controlled laboratory study.


METHODS
University biomechanics laboratory.


METHODS
Twenty-one healthy men (age = 21.59 ± 1.92 years, height = 178.22 ± 8.02 cm, mass = 75.81 ± 11.24 kg).


METHODS
Each participant completed 4 exercises: seated heel raising and lowering, bilateral standing heel raising and lowering, bilateral heel raising and unilateral lowering, and unilateral heel raising and lowering.


METHODS
A repeated-measures multivariate analysis of variance (α = .05) was used to compare Achilles tendon stress, force, and strain and ankle ROM for each exercise. Kinematic data were recorded at 180 Hz with 15 motion-analysis cameras synchronized with kinetic data collected from a force platform sampled at 1800 Hz. These data were then entered in a musculoskeletal model to estimate force in the triceps surae. For each participant, we determined Achilles tendon stress by measuring cross-sectional images using ultrasound.


RESULTS
Peak Achilles tendon loading was lowest when performing the seated heel-raising and -lowering exercise and highest when performing the unilateral heel-raising and -lowering exercise. Loading was greater for the unilateral exercise or portions of the exercise that were performed unilaterally.


CONCLUSIONS
Bilateral and seated exercises with less weight-bearing force resulted in less Achilles tendon loading. These exercises may serve as progressions during the rehabilitation process before full-body weight-bearing, unilateral exercises are allowed. Ankle ROM did not follow the same order as loading and may need additional monitoring or instruction during rehabilitation.
La Crosse Institute for Movement Science, Physical Therapy Program, Department of Health Professions, University of Wisconsin-La Crosse.
Andrew
A
Revak
La Crosse Institute for Movement Science, Physical Therapy Program, Department of Health Professions, University of Wisconsin-La Crosse.
Keith
K
Diers
La Crosse Institute for Movement Science, Physical Therapy Program, Department of Health Professions, University of Wisconsin-La Crosse.
Thomas W
TW
Kernozek
La Crosse Institute for Movement Science, Physical Therapy Program, Department of Health Professions, University of Wisconsin-La Crosse.
Naghmeh
N
Gheidi
La Crosse Institute for Movement Science, Physical Therapy Program, Department of Health Professions, University of Wisconsin-La Crosse.
Christina
C
Olbrantz
D000125:Achilles Tendon / Q000000981:diagnostic imaging / Q000293:injuries*; D000842:Ankle / Q000502:physiology; D001696:Biomechanical Phenomena; D003430:Cross-Sectional Studies; D005081:Exercise Therapy / Q000379:methods*; D006365:Heel / Q000502:physiology; D006801:Humans; D008297:Male; D009068:Movement; D011187:Posture; D014463:Ultrasonography; D016474:Weight-Bearing; D055815:Young Adult
kinematics; kinetics; rehabilitation; strain; therapeutic exercise