Elasticity of the forearm flexor-pronator muscles in youth baseball players with elbow injuries

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K17610
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Orthopaedic surgery; Sports science
• Research Institution: Akita University
• Principal Investigator: Saito Akira 秋田大学, 医学系研究科, 助教 (90591751)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 野球肘 / 前腕屈筋・回内筋群 / 円回内筋 / 尺側手根屈筋 / 超音波エラストグラフィ / 離断性骨軟骨炎

Outline of Final Research Achievements

The elasticity of the forearm flexor-pronator muscles in youth baseball players was evaluated using ultrasound elastography. The elasticity of the pronator teres muscle of the throwing arm was significantly higher in baseball players with osteochondritis dissecans of the humeral capitellum than in healthy palyers. In players with medial elbow injuries, the elasticity of pronator teres muscle of both the throwing and non-throwing arms was higher as compared to that of healthy players.
In the flexor carpi ulnaris muscle, the elasticity of the throwing arm was significantly higher in baseball players with medial elbow injuries than in healthy players. In addition, the elasticity of that muscle was correlated with practice time per week.
The elasitcity of these muscles are probably reflect repetitive elbow valgus stress by throwing. These findings may contribute to an acurate evaluation and prevention of elbow injuries in youth baseball players.

Free Research Field

リハビリテーション科学関連、スポーツ科学関連

Academic Significance and Societal Importance of the Research Achievements

成長期野球肘において前腕屈筋・回内筋群の硬さは臨床上たびたび経験するが、本研究成果はこれらの関係を初めて科学的に証明した。円回内筋の硬さにおいては離断性骨軟骨炎と野球肘内側障害において、その特徴が異なることから発症メカニズム解明につながる可能性がある。また尺側手根屈筋の硬さも野球肘内側障害おける特異的な変化である他、オーバーユースと関連することが明らかとなり、筋の硬さに影響する因子を明らかにすることができた。
これらの知見は、臨床において成長期野球肘の正確な評価や予防のための一助になると考えられる。