Morphomechanical alterations in the medial gastrocnemius muscle in patients with a repaired Achilles tendon: Associations with outcome measures

Wei Chen Peng, Yi Ping Chang, Yuan Hung Chao, Siu Ngor Fu, Christer Rolf, Tiffany TF Shih, Sheng Chu Su, Hsing Kuo Wang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

22 Citations (Scopus)


This study sought to evaluate and compare the morphomechanical characteristics of the medial gastrocnemius muscle in the legs of participants within six months of a unilateral Achilles repair to determine any correlations between those characteristics and objective outcomes and self-reported functional levels. Methods Fifteen participants were assessed via measurements of muscle morphologies (fascicle length, pennation angle, and muscle thickness) in a resting state, the mechanical properties of the proximal aponeurosis of the medial gastrocnemius muscle, the pennation angle during ramping maximal voluntary isometric contractions (MVIC), the heel raise test, and the Taiwan Chinese version of the Lower Extremity Functional Scale (LEFS-TC) questionnaire. Findings Compared with the non-injured legs, the repaired legs showed a lower muscle fascicle length (mean 4.4 vs. 5.0 cm) and thickness (1.7 vs. 1.9 cm), lower stiffness of the GM tendon and aponeurosis (174.1 vs. 375.6 N/mm), and a greater GM pennation angle (31.2 vs. 28.9°) during 90% MVIC (all p ≤ 0.05). Correlations were found between the morphomechanical results and maximal heel raise heights or the LEFS-TC score, and between the symmetry ratios of the fascicle lengths and the LEFS-TC score. Interpretation There are decreases in fascicle length, muscle thickness and mechanical properties in the medial gastrocnemius muscles of the participants within the first six months after an Achilles repair. These morphomechanical alterations demonstrate associations with functional levels in the lower extremities and indicated the need for early mobilization of the calf muscles after the repair.
Original languageEnglish
Pages (from-to)50-57
Number of pages8
JournalClinical Biomechanics
Publication statusPublished - 1 Mar 2017


  • Achilles rupture
  • Aponeurosis
  • Muscle morphology
  • Tendinous tissue
  • Viscoelasticity

ASJC Scopus subject areas

  • Biophysics
  • Orthopedics and Sports Medicine


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