Freehill Michael T, Rose Michael J, McCollum Katherine A, Agresta Cristine, Cain Stephen M
Department of Orthopaedic Surgery, Stanford University School of Medicine, Stanford, California, USA.
Department of Orthopaedic Surgery, University of Michigan School of Medicine, Ann Arbor, Michigan, USA.
Orthop J Sports Med. 2023 Mar 21;11(3):23259671231151450. doi: 10.1177/23259671231151450. eCollection 2023 Mar.
Pitch count recommendations are used to reduce injury risk in youth baseball pitchers and are based chiefly on expert opinion, with limited scientific support. Furthermore, they only account for pitches thrown against a hitter and do not include the total number of throws on the day a player pitched. Currently, counts are recorded manually.
To provide a method using a wearable sensor to quantify total throws per game that is compliant with Little League Baseball rules and regulations.
Descriptive laboratory study.
Eleven male baseball players (age, 10-11 years) from an 11U (players 11 years and younger) competitive travel team were evaluated over a single summer season. An inertial sensor was placed above the midhumerus of the throwing arm and was worn during baseball games across the season. A throw identification algorithm capturing all throws and reporting linear acceleration and peak linear acceleration was used to quantify throwing intensity. Pitching charts were collected and used to verify actual pitches thrown against a hitter in a game versus all other throws identified.
A total of 2748 pitches and 13,429 throws were captured. On the day a player pitched, he averaged 36 ± 18 pitches (23%) and 158 ± 106 total throws (pitches in game as well as all warm-up pitches and other throws during game). In comparison, on a day a player did not pitch, he averaged 119 ± 102 throws. Across all pitchers, 32% of all throws were low intensity, 54% were medium intensity, and 15% were high intensity. The player with one of the highest percentages of high-intensity throws did not pitch as their primary position, while the 2 players who pitched most often had the lowest percentages.
Total throw count can be successfully quantified using a single inertial sensor. Total throws tended to be higher on days a player pitched compared with regular game days without pitching.
This study provides a fast, feasible, and reliable method to obtain pitch and throw counts so that more rigorous research on contributing factors to arm injury in the youth athlete can be achieved.
投球次数建议用于降低青少年棒球投手的受伤风险，主要基于专家意见，科学依据有限。此外，这些建议仅考虑了面对击球手投出的球数，未包括球员投球当天的总投球数。目前，投球数是手动记录的。
提供一种使用可穿戴传感器来量化每场比赛总投球数的方法，该方法符合少年棒球联盟的规章制度。
描述性实验室研究。
在一个夏季赛季对来自一支11岁及以下（11U）竞技巡回赛球队的11名男性棒球运动员（年龄10 - 11岁）进行评估。将一个惯性传感器放置在投球手臂的肱骨中部上方，球员在整个赛季的棒球比赛中都佩戴该传感器。使用一种捕捉所有投球并报告线性加速度和峰值线性加速度的投球识别算法来量化投球强度。收集投球图表，用于验证比赛中面对击球手实际投出的球数与识别出的所有其他投球数的情况。
总共捕捉到2748次投球和13429次投掷。在球员投球的当天，他平均投出36 ± 18次投球（占23%）和158 ± 106次总投掷（比赛中的投球以及所有热身投球和比赛期间的其他投掷）。相比之下，在球员不投球的日子里，他平均投出119 ± 102次投掷。在所有投手中，32%的投掷为低强度，54%为中等强度，15%为高强度。高强度投掷百分比最高的球员之一并非主要担任投手位置，而投球最频繁的2名球员的高强度投掷百分比最低。
使用单个惯性传感器可以成功量化总投掷次数。与不投球的常规比赛日相比，球员投球当天的总投掷次数往往更高。
本研究提供了一种快速、可行且可靠的方法来获取投球数和投掷次数，从而能够对青少年运动员手臂受伤的影响因素进行更严格的研究。
