Contacting the base is a common injury mechanism for base runners in softball, with ankle sprains being the most common type of injury, but it is not known how the base affects lower extremity mechanics. The purpose of this study was to analyze lower extremity biomechanics while rounding a base. Sixteen recreationally active females with previous softball experience completed two base rounding conditions. A base was securely placed on the force place for the with base (WB) condition, and an outline of the base was taped on the force plate for the no base (NB) condition. Three-dimensional right-leg hip, knee, and ankle kinematics and kinetics were measured during the stance phase of the base rounding and analyzed using statistical parametric mapping (SPM). The WB condition resulted in decreased hip abduction (p = 0.034), increased dorsiflexion (p = 0.012), and decreased inversion (p < 0.001) angles. Increased hip extension (p < 0.001) and hip abduction (p = 0.016) moments were exhibited during the WB condition. Decreased hip abduction (p = 0.026), ankle plantarflexor (p < 0.001), and ankle eversion (p < 0.001) moments were also exhibited in the WB condition. The base acts as a lateral banking surface, reducing variables associated with ankle sprains, and likely assists in propelling base runners to the next base without injury.

接触底座是垒球垒手常见的伤害机制，踝关节扭伤是最常见的伤害类型，但尚不知道底座如何影响下肢的力学。这项研究的目的是在四舍五入的同时分析下肢的生物力学。十六名具有先前垒球经验的休闲运动女性完成了两个基本的四舍五入条件。将基座牢固地放置在有基座（WB）条件下的受力位置上，并将基座的轮廓粘贴在无基座（NB）条件下的测力板上。在基本四舍五入的站立阶段测量了三维右腿臀部，膝盖和踝关节的运动学和动力学，并使用统计参数映射（SPM）进行了分析。WB条件导致髋关节外展减少（p = 0.034），背屈增加（p  = 0.012）和反 倾角减小（p <0.001）。 在WB情况下 ，髋关节伸展时间增加（p <0.001）和髋关节外展（p = 0.016）。 在WB情况下 ，髋关节外展（p = 0.026），踝plant屈（p  <0.001）和踝关节外翻（p <0.001）力矩也减少。基部充当侧向倾斜表面，减少与脚踝扭伤相关的变量，并可能有助于将基部跑步者推向下一个基部而不会造成伤害。