Development of a new index for quantifying muscle elongation using ultrasonography

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K21223
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0909:Sports sciences, physical education, health sciences, and related fields
• Research Institution: Kansai Medical University
• Principal Investigator: Nakao Sayaka 関西医科大学, リハビリテーション学部, 助教 (30967253)
• Project Period (FY): 2022-08-31 – 2024-03-31
• Keywords: 超音波診断装置 / ストレッチング / 筋輝度

Outline of Final Research Achievements

We investigated whether echo intensity of the gastrocnemius muscle would change with muscle elongation by passive ankle angle change. To evaluate echo intensity, B-mode images were scanned longitudinally using ultrasonography. The echo intensity was determined as the average grayscale values of the region of interest (RoI). Grayscale analysis was performed using two RoIs: one that included as much of the muscle as possible, and a rectangular one with size and depth identical for all images captured from all participants. The results indicated that echo intensity increased with muscle elongation via passive ankle dorsiflexion. The echo intensity of the longitudinal images, calculated using the RoI that included as much of the muscle as possible, may be useful for quantifying muscle elongation.

Free Research Field

リハビリテーション科学

Academic Significance and Societal Importance of the Research Achievements

各筋の効果的なストレッチング方法の開発や効果検証のため、個別の筋の伸張量を非侵襲的に定量化できる指標が必要である。本研究の結果、筋伸張に伴い腓腹筋の輝度が増加することが、若年男性だけでなく、元々筋内脂肪が多く輝度が高いとされる女性においても明らかとなった。本研究の成果は、一般的な超音波診断装置でも算出可能な輝度を新たな筋の伸張量の指標として利用できる可能性を示すものであり、臨床現場での応用につながる可能性が考えられる。