Impacts of myosin heavy chain phenotypes on recovery of leg extension force after ACL-reconstructed knee

• Main Authors: Tetsuo Kobayashi (Author), Yuji Ogura (Author), Satoshi Kishiro (Author), Mitsutoshi Kurosaka (Author), Toshinori Yoshihara (Author), Ryo Kakigi (Author), Naoki Minakawa (Author), Kenji Uehara (Author), Tomohiro Suzuki (Author), Katsumasa Goto (Author), Hisateru Niki (Author)
• Format: Book
• Published: Japanese Society of Physical Fitness and Sports Medicine, 2023-05-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

It is well known that myosin heavy chain (MyHC) phenotypes impact skeletal muscle function. Anterior cruciate ligament (ACL) tear, a common sport injury, induces skeletal muscle atrophy around the injured knee. However, the interrelationship between MyHCs and the functional recovery of ACL reconstruction surgery (ACL-R) remains unclear. The purpose of this study was to investigate the interrelationship between MyHC phenotypes and the functional recovery of leg extension force in patients with ACL-R. Under a clinical setting, 27 patients with ACL-R participated in this study. ACL-R in each patient was carried out using a semitendinous (ST) tendon autograft. During ACL-R, a small muscle sample was dissected from the ST tendon of each patient. MyHC phenotypes in the muscle sample were evaluated using SDS-PAGE. The leg extension force was evaluated 1 day before and then 3, 6, and 12 months after ACL-R. Based on the dominant (>40%) MyHC isoforms in the ST muscle, patients were classified into 4 groups as follows: Groups I, IIa, IId/x, and Even (E: all MyHC isoforms less than 40%). There is a positive correlation between the relative content of MyHC II (IIa + IId/x) and the leg extension force before ACL-R. Functional recovery of knee in subjects with ACL-R was facilitated in patients having the dominant MyHC IIa. This study suggests that the analysis of MyHC phenotypes in ST muscle dissected during ACL-R is a clinically useful index for the functional assessment of the knee in subjects with ACL injury.

Item Description

2186-8131
2186-8123
10.7600/jpfsm.12.77