Wei-Chen Peng1, Yi-Ping Chang1, Yuan-Hung Chao1, S N Fu2, Christer Rolf3, Tiffany Tf Shih4, Sheng-Chu Su5, Hsing-Kuo Wang6. 1. School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Center of Physical Therapy, National Taiwan University Hospital, Taipei, Taiwan. 2. Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong. 3. Department of Orthopaedics, Clintec, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden. 4. Department of Medical Image, National Taiwan University Hospital, Department of Surgery, College of Medicine, National Taiwan University, Taiwan. 5. Department of Business Administration, Hwa Hsia Institute of Technology, Taipei, Taiwan. 6. School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Center of Physical Therapy, National Taiwan University Hospital, Taipei, Taiwan. Electronic address: hkwang@ntu.edu.tw.
Abstract
BACKGROUND: Functional deficits are found in ankles that have sustained an Achilles rupture. 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. 5.0cm) and thickness (1.7 vs. 1.9cm), lower stiffness of the GM tendon and aponeurosis (174.1 vs. 375.6N/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.
BACKGROUND: Functional deficits are found in ankles that have sustained an Achilles rupture. 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. 5.0cm) and thickness (1.7 vs. 1.9cm), lower stiffness of the GM tendon and aponeurosis (174.1 vs. 375.6N/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.
Authors: Jennifer A Zellers; Ryan T Pohlig; Daniel H Cortes; Karin Grävare Silbernagel Journal: Knee Surg Sports Traumatol Arthrosc Date: 2019-07-02 Impact factor: 4.342
Authors: Jennifer A Zellers; Marianne Christensen; Inge Lunding Kjær; Michael Skovdal Rathleff; Karin Grävare Silbernagel Journal: Orthop J Sports Med Date: 2019-11-25