Descriptive Strength and Range of Motion in Youth Baseball Players

Abstract

Background BackgroundThere are limited studies reporting descriptive strength and range of motion in youth baseball players 12 years of age or younger. Purpose PurposeTo 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). Study Design Study DesignCross-sectional Methods MethodsPatient 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. Results ResultsAll 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). Conclusion ConclusionThese 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.

Periscapular Strength Profile Changes in Collegiate Baseball Pitchers Over the Course of a Season

“…The authors postulate that this effect could be contributing to this increase, or perhaps it could be related to a training effect from the strong eccentric demand placed on the external rotators during the pitching motion, coupled with the ability for eccentric activity to produce greater gains in strength compared to concentric training. 38,39 Last, error in measurement as indicated by the larger standard deviation scores of internal and external rotation strength could be a factor related to this finding. Future studies examining the structure, prescription, and dosing of such strength and conditioning practices during the baseball season may be warranted.…”

Proposed Musculoskeletal Examination of Youth and Adolescent Baseball Players

“…Numerous studies have investigated normative values for shoulder strength and range of motion in the throwing shoulder and their relation to upper extremity injury (30)(31)(32)34). Descriptive profiles of youth baseball players (ages 5 to 12.9 years) have been established for shoulder internal rotation and external rotation passive range of motion, total arc and shoulder internal and external rotation strength at neutral and 90 degrees abduction (34).…”

“…Numerous studies have investigated normative values for shoulder strength and range of motion in the throwing shoulder and their relation to upper extremity injury (30)(31)(32)34). Descriptive profiles of youth baseball players (ages 5 to 12.9 years) have been established for shoulder internal rotation and external rotation passive range of motion, total arc and shoulder internal and external rotation strength at neutral and 90 degrees abduction (34). Recently, differences in shoulder passive range of motion, external rotation, and total range of motion (TRM) or total arc have been identified in youth baseball players (age, 17.2 ± 2.3 years) presenting with neurogenic thoracic outlet syndrome when compared with healthy controls (31).…”

“…A number of studies have looked at factors related to injury in the youth baseball population over the past year ranging in topics from; early sport specialization (ESS) (12)(13)(14)(15)(16), pitch counts (17)(18)(19)(20)(21)(22)(23), prethrowing protocols (24,25), imaging findings (26), to body region-specific inquiries (27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43) in search for opportunities to reduce the risk of injury in this population. We will review a wide range of articles and their relevance to injury risk in this population.…”

Acute effect of upper body vibration on shoulder joint internal and external active position sense in healthy female university students

“…After shoulder joint injury, the internal proprioceptors signal of the joint will be affected; these receptors include the mechanoreceptors of the joint which are responsible for the sensorimotor input and active stability of the joint [6]. The overhead-throwing range at 90 degrees of shoulder abduction may research to 135 degrees from the scapular plane [7], and this range may increase in overhead-throwing athletes to reach 180 degrees due to shoulder joint adaptation [8,9]. Hyper-angulation happened during the overhead throwing shoulder motion.…”