Insertional achilles tendinopathy associated with altered transverse compressive and axial tensile strain during ankle dorsiflexion.
The purposes of this case-control study (N = 20) were to examine the effects of insertional Achilles tendinopathy (IAT) and tendon region on tendon strain in patients with IAT compared to a control group without tendinopathy. An ultrasound transducer was positioned over the Achilles tendon insertion during dorsiflexion tasks, which included standing and partial squat. A non-rigid image registration-based algorithm was used to estimate transverse compressive and axial tensile strains of the tendon from radiofrequency ultrasound images, which was segmented into two regions (superficial tendon and deep). For transverse compressive strain, two-way mixed effects ANOVAs demonstrated that there were interaction effects between group and tendon region for both dorsiflexion tasks (Heel lowering, p = 0.004; Partial squat, p = 0.008). For axial tensile strain, the IAT group demonstrated a main effect of lower tensile strain than the control group (Standing, p = 0.001; Partial squat, p = 0.033). There was also a main effect of greater tensile strain in the superficial region of the tendon compared to the deep during standing (p = 0.002), but not during partial squat (p = 0.603). Reduced transverse compressive and axial tensile strains in the IAT group indicate altered mechanical properties specific to the region of IAT pathology. Additionally, patterns of compressive strain are consistent with the theory of calcaneal impingement contributing to IAT pathology. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:910-915, 2017.
Department of Physical Therapy and Rehabilitation Science, University of Iowa, 2116 Westlawn, Iowa City, 52245, Iowa.
Ruth L
RL
Chimenti
Department of Biomedical Engineering, University of Rochester, Rochester, New York.
Mary
M
Bucklin
Department of Orthopaedic Surgery, University of Rochester, Rochester, New York.
Meghan
M
Kelly
Department of Orthopaedic Surgery, University of Rochester, Rochester, New York.
John
J
Ketz
Department of Orthopaedic Surgery, University of Rochester, Rochester, New York.
Adolph Samuel
AS
Flemister
Department of Surgery, University of Rochester, Rochester, New York.
Michael S
MS
Richards
Department of Biomedical Engineering, University of Rochester, Rochester, New York.
Mark R
MR
Buckley
D000125:Achilles Tendon / Q000473:pathology*; D000328:Adult; D000368:Aged; D000465:Algorithms; D000842:Ankle / Q000502:physiology*; D016022:Case-Control Studies; D054459:Elasticity Imaging Techniques; D005260:Female; D006365:Heel; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D011846:Radio Waves; D013180:Sprains and Strains / Q000473:pathology*; D052256:Tendinopathy / Q000473:pathology*; D013708:Tendon Injuries / Q000473:pathology*; D013718:Tensile Strength; D014159:Transducers; D014465:Ultrasonics; D014463:Ultrasonography
Achilles tendonitis; heel lift; tendon mechanics; ultrasound elastography