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Three-dimensional deformation and transverse rotation of the human free Achilles tendon in vivo during isometric plantarflexion contraction
journal contribution
posted on 2018-08-03, 00:00 authored by Steven ObstSteven Obst, J-B Renault, R Newsham-West, RS BarrettThree dimensional deformation and transverse rotation of the human free
Achilles tendon in vivo during isometric plantarflexion contraction. J
Appl Physiol 116: 376–384, 2014. First published December 26, 2013; doi:10.1152/japplphysiol.01249.2013.—Freehand three-dimensional
ultrasound (3DUS) was used to investigate longitudinal and biaxial transverse deformation and rotation of the free Achilles tendon in vivo during a voluntary submaximal isometric muscle contraction.
Participants (n ⁼ 8) were scanned at rest and during a 70% maximal
voluntary isometric contraction (MVIC) of the plantarflexors. Ultrasound
images were manually digitized to render a 3D reconstruction
of the free Achilles tendon for the computation of tendon length,
volume, cross-sectional area (CSA), mediolateral diameter (MLD),
anteroposterior diameter (APD), and transverse rotation. Tendon longitudinal and transverse (CSA, APD, and MLD) deformation and
strain at 70% MVIC were calculated relative to the resting condition.
There was a significant main effect of contraction on tendon length
and mean CSA, MLD, and APD (P<5), but no effect on tendon
volume (P ⁼ 0.70). Group mean transverse strains for CSA, MLD,
and APD averaged over the length of the tendon were -5.5%, -8.7%
and 8.7%, respectively. Peak CSA, MLD, and APD transverse strains
all occurred between 40% and 60% of tendon length. Transverse
rotation of the free tendon was negligible at rest but increased under
load, becoming externally rotated relative to the calcaneal insertion.
The relationship between longitudinal and transverse strains of the
free Achilles tendon during muscle-induced elongation may be indicative
of interfascicle reorganization. The finding that transverse rotation
and strain peaked in midportion of the free Achilles tendon may
have important implications for tendon injury mechanisms and estimation
of tendon stress in vivo.
History
Volume
116Issue
4Start Page
376End Page
384Number of Pages
9eISSN
1522-1601ISSN
8750-7587Publisher
American Physiological SocietyPublisher DOI
Peer Reviewed
- Yes
Open Access
- No
Acceptance Date
2013-12-20External Author Affiliations
Griffith University; Département de Génie Mécanique, ParisEra Eligible
- Yes