Load distribution within the contracting hamstring muscles: relevance to strain injuries in sport

2017 Fiscal Year Annual Research Report

• Project/Area Number: 17F17412
• Research Institution: Waseda University
• Principal Investigator: 川上 泰雄 早稲田大学, スポーツ科学学術院, 教授 (60234027)
• Co-Investigator(Kenkyū-buntansha): EVANGELIDIS PAVLOS 早稲田大学, スポーツ科学学術院, 外国人特別研究員
• Project Period (FY): 2017-11-10 – 2020-03-31
• Keywords: injury / hamstrings / fatigue / elastography / in vivo

Outline of Annual Research Achievements

The proposed research is to better understand the mechanisms of hamstring strain injuries. The specific aims are: 1) to examine the load distribution between the individual hamstring muscles at different levels of muscle activation and contraction modes (concentric, isometric, and eccentric), 2) To examine the effect of neuromuscular fatigue on load distribution between hamstring muscles at different contraction modes and 3) to clarify the detailed three-dimensional architecture of muscle fibers, tendons and aponeuroses of the hamstrings in vivo and examine the muscle-tendon interactions during dynamic contractions. During the FY2017 and 2018, the first two aims of the research plan are being addressed. To date, extensive pilot work has been completed which has informed the design of the research protocol.

Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

The lengthy pilot tests (more than two months) were necessary to optimize the procedures and protocols for the experiments. The ultrasonographic device become out of order during the pilot tests and took one month to recover. Now the participants recruitment has already been completed and the data collection has commenced.

Strategy for Future Research Activity

In the remaining FY2018, the data collection for the first two aims will be completed (mid-July) followed by the data analysis, which is expected to last until late October/early November. The final months of the current FY will be dedicated on preparing manuscripts for the publication of the findings. In addition, the design and pilot work for the third and final research study will commence.