Shoulder Strength and Range of Motion in Healthy Collegiate Softball Players

Abstract

Context: Shoulder range of motion (ROM) and strength are key injury evaluation components for overhead athletes. Most normative values are derived from male baseball players with limited information specific to female softball players. Objective: To determine between-limb differences in shoulder ROM and strength in healthy collegiate softball players. Design: Descriptive laboratory study. Setting: University research laboratory and collegiate athletic training room Participants: Twenty-three healthy collegiate softball players (age=19.9 ± 1.2y; height=170.5 ± 4.3cm; mass=78.4 ± 11.3kg). Interventions: Outcome measures included shoulder ROM (internal [IR] and external rotation [ER]), isometric strength (IR, ER, flexion, abduction [135 degrees], and horizontal abduction), and a measure of dynamic strength (Upper Quarter Y Balance Test [UQYBT]). Main Outcome Measures: Paired sample t-tests were used to determine between limb differences for each outcome measure. Results: Participants had significantly more ER ROM (12° more) and significantly less IR ROM (12° less) on the dominant arm, relative to the non-dominant arm. There were no significant differences between limbs for any of the isometric strength measures or for the UQYBT reach directions. Conclusions: While female collegiate softball players demonstrated typical changes in ER and IR ROM in the dominant arm, they demonstrated relatively symmetrical performance across strength measures, which contrasts with previous studies using male baseball players.

Athletic Shoulder Test Differences Exist Bilaterally in Healthy Pitchers

“…Only one other study has used the ASH test to examine shoulder strength in throwing athletes and found no significant differences bilaterally. 9 Potential explanations for the conflicting results may lie in the positioning utilized for the modified version of the ASH test and from player types. Biaggi et al 9 examined subjects in supine positioning rather than prone as the ASH test is typically performed and included players from all fielding positions, rather than pitchers alone.…”

“…9 Potential explanations for the conflicting results may lie in the positioning utilized for the modified version of the ASH test and from player types. Biaggi et al 9 examined subjects in supine positioning rather than prone as the ASH test is typically performed and included players from all fielding positions, rather than pitchers alone. This study utilized pitchers only and the prone position for the purpose of isolation of shoulder strength in dedicated OH throwing-specific athletes.…”

“…While data has been published evaluating rugby and softball players with the ASH test, data does not yet exist for baseball pitchers performing the test. 8,9 Baseball pitchers exhibit well-documented adaptations in shoulder strength and function (such as humeral and glenoid retroversion, posterior capsular tightness, increased labral forces, humeral head translation, capsular expansion, decreased internal rotation and increased external rotation ROM) in the dominant arm and core/hips when compared to the non-dominant side that other athletes do not. [10][11][12] As such, any test measuring upper extremity strength should be sensitive to the adaptations that the OH athlete's shoulder undergoes.…”

Inter-limb differences in upper quarter mobility/stability are not associated with performance in competitive swimmers

“…Usually, the YBT–UQ is recorded for both sides, thus inter-limb differences (i.e., asymmetry) can be detected as well as their association with athletic performance ( 7 ). In the first case, most of the available studies did not detect side differences in swimming ( 5 , 8 , 9 ) or in other sports like baseball ( 10 , 11 ) and softball ( 10 , 12 ). However, these studies were almost exclusively performed with adult athletes, which limits the transferability of the findings to young athletes due to growth, maturation, and development processes ( 13 ).…”