Suzuki Keita, Nagai Satoshi, Iwai Koichi, Furukawa Takuo, Takemura Masahiro
Sports Research and Development Core, University of Tsukuba, Tsukuba, Japan.
Department of Physical Therapy, Faculty of Health Sciences, Tsukuba International University, Tsuchiura, Ibaraki, Japan.
BMJ Open Sport Exerc Med. 2021 Mar 17;7(1):e000949. doi: 10.1136/bmjsem-2020-000949. eCollection 2021.
Tacklers need to decide where to place their head based on the evasive manoeuvres of the ball-carrier and positional relationship with the ball-carrier before tackle. Therefore, it is difficult for tacklers to improve incorrect head placement at the moment of contact. Moreover, the characteristics prior to tackle have a relationship with the tackler's head placement. However, how situations lead to incorrect head placement remains unknown. The aim of this study was to identify pre-contact situations that lead to incorrect head placement by using decision tree analysis.
Tackles leading to concussions were used to identify events that provoked injury using the video recordings of matches. Injury-free tackle was used as a control. All tackles were classified according to head placements and coded from seven pre-contact factors configured aspect of both tacklers and ball-carriers.
Three situations that led to incorrect head placement were identified. Evasive manoeuvres implemented by the ball-carrier significantly contributed to the head placement at the time of contact.
Our findings suggest that tacklers should keep their heads up to identify the movements of the ball-carrier, which might lead to tackling the head on the correct side at the moment of tackling and decrease the risk of tackler-related concussions.
擒抱者需要根据持球者的躲避动作以及擒抱前与持球者的位置关系来决定头部的位置。因此，擒抱者很难在接触瞬间改善不正确的头部位置。此外，擒抱前的特征与擒抱者的头部位置有关。然而，何种情况会导致不正确的头部位置仍不清楚。本研究的目的是通过决策树分析确定导致不正确头部位置的接触前情况。
利用比赛录像记录，将导致脑震荡的擒抱动作用于识别引发损伤的事件。将无损伤擒抱动作作为对照。所有擒抱动作均根据头部位置进行分类，并根据擒抱者和持球者的七个接触前因素配置方面进行编码。
确定了三种导致不正确头部位置的情况。持球者实施的躲避动作对接触时的头部位置有显著影响。
我们的研究结果表明，擒抱者应抬起头来识别持球者的动作，这可能会导致在擒抱瞬间在正确的一侧擒抱头部，并降低与擒抱者相关的脑震荡风险。
