Investigating the Effects of Knee Flexion during the Eccentric Heel-Drop Exercise
File(s)
Published version
Author(s)
Weinert-Aplin, RA
Bull, AMJ
McGregor, AH
Type
Journal Article
Abstract
This study aimed to characterise the biomechanics of the widely
practiced eccentric heel-drop exercises used in the management
of Achilles tendinosis. Specifically, the aim was to quantify
changes in lower limb kinematics, muscle lengths and Achilles
tendon force, when performing the exercise with a flexed knee
instead of an extended knee. A musculoskeletal modelling approach
was used to quantify any differences between these
versions of the eccentric heel drop exercises used to treat Achilles
tendinosis. 19 healthy volunteers provided a group from
which optical motion, forceplate and plantar pressure data were
recorded while performing both the extended and flexed knee
eccentric heel-drop exercises over a wooden step when barefoot
or wearing running shoes. This data was used as inputs into a
scaled musculoskeletal model of the lower limb. Range of ankle
motion was unaffected by knee flexion. However, knee flexion
was found to significantly affect lower limb kinematics, intersegmental
loads and triceps muscle lengths. Peak Achilles load
was not influenced despite significantly reduced peak ankle
plantarflexion moments (p < 0.001). The combination of reduced
triceps lengths and greater ankle dorsiflexion, coupled
with reduced ankle plantarflexion moments were used to provide
a basis for previously unexplained observations regarding
the effect of knee flexion on the relative loading of the triceps
muscles during the eccentric heel drop exercises. This finding
questions the role of the flexed knee heel drop exercise when
specifically treating Achilles tendinosis
practiced eccentric heel-drop exercises used in the management
of Achilles tendinosis. Specifically, the aim was to quantify
changes in lower limb kinematics, muscle lengths and Achilles
tendon force, when performing the exercise with a flexed knee
instead of an extended knee. A musculoskeletal modelling approach
was used to quantify any differences between these
versions of the eccentric heel drop exercises used to treat Achilles
tendinosis. 19 healthy volunteers provided a group from
which optical motion, forceplate and plantar pressure data were
recorded while performing both the extended and flexed knee
eccentric heel-drop exercises over a wooden step when barefoot
or wearing running shoes. This data was used as inputs into a
scaled musculoskeletal model of the lower limb. Range of ankle
motion was unaffected by knee flexion. However, knee flexion
was found to significantly affect lower limb kinematics, intersegmental
loads and triceps muscle lengths. Peak Achilles load
was not influenced despite significantly reduced peak ankle
plantarflexion moments (p < 0.001). The combination of reduced
triceps lengths and greater ankle dorsiflexion, coupled
with reduced ankle plantarflexion moments were used to provide
a basis for previously unexplained observations regarding
the effect of knee flexion on the relative loading of the triceps
muscles during the eccentric heel drop exercises. This finding
questions the role of the flexed knee heel drop exercise when
specifically treating Achilles tendinosis
Date Issued
2015-06-01
Date Acceptance
2015-04-08
Citation
Journal of Sports Science and Medicine, 2015, 14 (2), pp.459-465
ISSN
1303-2968
Publisher
University of Uludag
Start Page
459
End Page
465
Journal / Book Title
Journal of Sports Science and Medicine
Volume
14
Issue
2
Copyright Statement
© Journal of Sports Science and Medicine
Subjects
Science & Technology
Life Sciences & Biomedicine
Sport Sciences
Achilles
tendinosis
tendinopathy
rehabilitation
MIDPORTION ACHILLES TENDINOPATHY
SURAE MUSCLE-ACTIVITY
LOWER-LIMB
FOLLOW-UP
TENDINOSIS
FORCE
Publication Status
Published