Nakaji Ross M, Ellenbecker Todd S, McClenahan Kevin M, Roberts Lianna M, Perez Chase, Dickenson Scott B
Los Gatos Orthopedic Sports Therapy, Inc.
Rehab Plus Sports Therapy Scottsdale.
Int J Sports Phys Ther. 2021 Feb 1;16(1):195-206. doi: 10.26603/001c.18815.
There are limited studies reporting descriptive strength and range of motion in youth baseball players 12 years of age or younger.
To establish normative data for external (ER) and internal (IR) rotation range of motion (ROM), total arc range of motion (TROM), and isometric rotator cuff strength in youth baseball players, and to compare between the dominant throwing arm (D) to the non-dominant arm (ND).
Cross-sectional.
Patient population included 50 (5 to 12-year-old) uninjured, healthy athletes. ROM measurements were performed preseason using a goniometer for IR and ER in the supine position with the shoulder in 90 degrees of abduction (abd) with scapular stabilization. Isometric strength measurements for IR and ER were collected in both neutral and 90 degrees (deg) of abduction with the use of a hand-held dynamometer and recorded in pounds (lbs) utilizing a "make" test. Descriptive statistics were obtained for all measures.
All data were analyzed as a single group (average age: 9.02). No significant difference in average total arc of PROM (ER+IR=Total Arc) on the D side compared to the ND side (136.7 ± 12.7 deg vs. 134.3 ± 12.3 deg). There were statistically significant differences between ER ROM (102.2 ± 7.7 deg vs. 96.8 ± 7.4 deg) and IR ROM (34.4 ± 9.0 deg vs. 37.5 ± 9.5 deg) between D versus ND arms (p= .000, .006 respectively). Mean ER strength in neutral (13.6 ± 3.4 and 12.8 ± 3.6 lbs) and 90 deg abduction (12.3 ± 3.4 and 12.5 ± 4.3 lbs) did were not significantly different between D and ND arms, respectively. Mean IR strength in neutral (18.0 ± 6.0 and 15.7 ± 4.7 lbs) and 90 deg abd (16.4 ± 5.6 and 15.0 ± 5.7 lbs) was significantly greater in the D arm vs ND arm, respectively (p=.000, .001).
These data can provide descriptive information for clinicians who treat very young baseball players. These data show sport specific adaptations occur at very young ages (5-12) and are similar to prior reports on adolescent, high school and professional baseball players regarding upper extremity ROM and rotator cuff strength.
关于12岁及以下青少年棒球运动员的描述性力量和活动范围的研究有限。
建立青少年棒球运动员外旋（ER）和内旋（IR）活动范围（ROM）、总弧活动范围（TROM）以及等长旋转袖带力量的规范数据，并比较优势投掷手臂（D）和非优势手臂（ND）之间的差异。
横断面研究。
患者群体包括50名（5至12岁）未受伤的健康运动员。在赛季前，使用角度计在仰卧位测量ROM，肩部外展90度（abd）并稳定肩胛骨，测量IR和ER。使用手持测力计在中立位和外展90度（deg）时收集IR和ER的等长力量测量值，并使用“制造”测试以磅（lbs）记录。获得所有测量的描述性统计数据。
所有数据作为一个单一组进行分析（平均年龄：9.02）。与ND侧相比，D侧的PROM平均总弧（ER + IR =总弧）无显著差异（136.7±12.7度对134.3±12.3度）。D臂和ND臂之间的ER ROM（102.2±7.7度对96.8±7.4度）和IR ROM（34.4±9.0度对37.5±9.5度）存在统计学显著差异（分别为p =.000，.006）。D臂和ND臂在中立位（13.6±3.4和12.8±3.6磅）和90度外展（12.3±3.4和12.5±4.3磅）时的平均ER力量分别无显著差异。D臂在中立位（18.0±6.0和15.7±4.7磅）和90度abd（16.4±5.6和15.0±5.7磅）时的平均IR力量分别显著大于ND臂（p =.000，.001）。
这些数据可以为治疗非常年轻的棒球运动员的临床医生提供描述性信息。这些数据表明，特定于运动的适应性在非常年轻的年龄（5 - 12岁）就会出现，并且与先前关于青少年、高中和职业棒球运动员上肢ROM和旋转袖带力量的报告相似。
3级。
