Downs Talmage Jessica, Gilliam Jessica, Chardhari Ajit, Oliver Gretchen D
Sports Medicine and Movement Laboratory, School of Kinesiology, Auburn University, Auburn, Alabama, USA.
Ohio State University, Columbus, Ohio, USA.
Orthop J Sports Med. 2021 Nov 8;9(11):23259671211052022. doi: 10.1177/23259671211052022. eCollection 2021 Nov.
Softball pitching is a whole-body motion that utilizes the kinetic chain to transfer the large amounts of force generated by the lower extremity to the ball. Although the lower extremity is responsible for generating most of the force in softball pitching, limited research has investigated how lower extremity kinematics vary with age.
PURPOSE/HYPOTHESIS: The purpose of this study was to compare lower extremity kinematics between collegiate and youth softball pitchers. It was hypothesized that there would be significant lower extremity kinematic differences between age groups.
Descriptive laboratory study.
Overall, 83 softball pitchers participated in the study: 40 youth and 43 collegiate players. Kinematic data were collected using an electromagnetic motion capture system. All participants threw 3 fastballs to a catcher for a strike at regulation distance. Owing to nonnormally distributed data, Mann-Whitney U tests were used to determine group differences at 5 events during the pitching motion. The alpha level was set a priori at .006.
Collegiate pitchers had significantly higher drive-knee extension angular velocity at the 3-o'clock position than youth pitchers (182.30 ± 145.44 vs -34.66 ± 219.66 rad/s; < .001). Collegiate pitchers also had greater peak drive-knee flexion angle than youth pitchers at the top of the arm circle (37.98° ± 18.09° vs 25.38° ± 17.58°; = .004), while youth pitchers had a significantly more anteriorly shifted center of mass than collegiate pitchers at the top of the arm circle (49.93% ± 5.09% vs 46.47% ± 6.44%; = .003).
The authors found increased drive-knee flexion angle and angular extension velocity in collegiate compared with youth pitchers, although it is unknown if these differences were due to lack of experience or strength. Athletes should work on improving drive-leg mechanics to develop optimal push-off performance.
This information can be applied to develop strength and conditioning programs for softball pitchers. Player performance may be improved through performing exercises to strengthen knee and hip extension musculature and learning to eccentrically load the drive leg to activate the stretch shortening cycle.
垒球投球是一种全身运动，它利用动力链将下肢产生的大量力量传递到球上。尽管下肢在垒球投球中负责产生大部分力量，但关于下肢运动学如何随年龄变化的研究有限。
目的/假设：本研究的目的是比较大学和青少年垒球投手的下肢运动学。假设年龄组之间下肢运动学会有显著差异。
描述性实验室研究。
共有83名垒球投手参与了该研究：40名青少年和43名大学生球员。使用电磁运动捕捉系统收集运动学数据。所有参与者向捕手投出3个快球，在规定距离进行击球。由于数据呈非正态分布，使用曼-惠特尼U检验来确定投球动作中5个事件的组间差异。α水平预先设定为0.006。
大学投手在3点位置的驱动膝伸展角速度显著高于青少年投手（182.30±145.44对-34.66±219.66弧度/秒；P<.001）。大学投手在手臂环绕顶点处的驱动膝屈曲峰值角度也大于青少年投手（37.98°±18.09°对25.38°±17.58°；P = .004），而青少年投手在手臂环绕顶点处的重心比大学投手显著更靠前（49.93%±5.09%对46.47%±6.44%；P = .003）。
作者发现与青少年投手相比，大学投手的驱动膝屈曲角度和伸展角速度增加，尽管这些差异是否由于缺乏经验或力量尚不清楚。运动员应致力于改善驱动腿力学以发展最佳蹬离表现。
该信息可应用于制定垒球投手的力量和体能训练计划。通过进行加强膝和髋伸展肌肉组织以及学习对驱动腿进行离心加载以激活拉长缩短周期的练习，运动员的表现可能会得到改善。
