ABSTRACT
BACKGROUND: Shoulder strength measured with a handheld dynamometer (HHD) and the Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST) are clinical tools that have been used to measure athlete's performance and track their progress. PURPOSE: The specific aims of this study were to describe baseball (BB) and softball (SB) players isometric strength measures and their performance on the CKCUEST; examine the relationships between strength and the CKCUEST; compare isometric strength measures of the throwing and non-throwing arms; and compare the strength and the CKCUEST measures between BB and SB players. STUDY DESIGN: Observational cohort study. METHODS: Participants included 50 DIII BB and 24 DIII SB players. Shoulder strength for the internal and external rotators were measured using a HHD and the CKCUEST was performed. The CKCUEST score and power were calculated. Descriptive statistics and paired t-tests were used to compare throwing and non-throwing shoulder strength. Independent t-test was used to compare BB and SB players shoulder strength and the CKCUEST measures. RESULTS: The BB players demonstrated significant strength differences between the throwing and non-throwing shoulders and the internal rotators were significantly stronger than the external rotators (p < 0.05), while the strength ratio of the internal and external rotators was not different between arms (p=0.87). The SB players demonstrated no significant strength differences between the throwing and non-throwing shoulders for the internal and external rotators or the strength ratio of the rotators (p > 0.05). There were no significant differences between the strength of the internal and external rotators of the non-throwing shoulder (p=0.075) or the throwing shoulder (p=0.096). The BB players throwing and non-throwing shoulders produced significantly more internal and external force than the SB players (p < 0.001), however, the internal/external rotators strength ratio were similar (p=0.32, p=0.30). The CKCUEST power had inverse and significant correlations (p=0.006, p=0.003) with SB players internal and external rotators, respectively. The CKCUEST power was significantly different between BB and SB players (p < 0.001). CONCLUSION: This study presented shoulder rotator strength and CKCUEST reference values for DIII BB and SB players. BB players demonstrated more strength but overall, less symmetry compared to SB players. CKCUEST power may be considered for the evaluation of athletes. LEVEL OF EVIDENCE: Level III.
ABSTRACT
BACKGROUND: Adaptive changes may occur to the throwing shoulder of overhead athletes that can influence range-of-motion (ROM). Shoulder ROM characteristics of Division III softball (SB) and baseball (BB) players are unique. HYPOTHESIS/PURPOSE: To report the passive ROM characteristics of Division III SB and BB players and identify similarities and differences between these two populations. STUDY DESIGN: Descriptive, observational research on measurement. METHODS: Participants included healthy Division III BB (n = 50) and SB (n = 24) players. Passive shoulder internal rotation (IR) and external rotation (ER) ROM were measured in the supine position with the arm in 90 ° of abduction and the scapula stabilized. Descriptive statistics and frequency distributions were used to describe ROM. Paired and independent t-tests were also used to compare throwing and non-throwing shoulder ROM for athletes of each sport and to compare the shoulder ROM of SB and BB players, respectively. RESULTS: The IR and ER ROM for BB players throwing shoulders (IR 54.1 ± 10.9 °; ER 94.1 ± 9.1 °) were significantly different (p < 0.001) from their non-throwing shoulders (IR 63.3 ± 11.1 °; ER 87.6 ± 9.2 °) while SB players were not (p = .06 & .08, respectively). Compared to the BB players, the throwing shoulder of SB players demonstrated statistically significantly higher IR ROM (p < .001, mean difference = 11.8 °, 95% CI: 6.4-17.2 °) as well as higher total range of motion (TRM) (p < .001, mean difference = 14.4 °, 95% CI: 8.6-20.2 °) when compared to BB players. Glenohumeral internal rotation deficit (GIRD) was significantly higher in BB players when compared to SB players (p = .042, 95% CI: .2-10.8 °). There were no significant differences in IR, ER, TRM, GIRD and ER gain between SB or BB pitchers and all other field positions (p > .05). CONCLUSIONS: SB players have more ROM and bilateral symmetry when compared to BB players. TRMD occurred more often than GIRD in BB players, indicating that they did not adaptively gain the same amount of ER while losing IR. The throwing shoulder ROM characteristics of both SB and BB players in this study were not influenced by the player's position (pitcher vs. field player). LEVEL OF EVIDENCE: Level III.
