Upper Extremity Range of Motion and Pitching Profile of Baseball Pitchers in Japan

Shoulder Strength and Range of Motion Between Collegiate Pitchers and Position Players in Baseball

Baseball is a sport that places excessive strain on the shoulder complex caused from repetitive overhead throws. In the sport of baseball, shoulder strength and range of motion (ROM) are paramount for success on the field. The purpose of this study was to determine strength and ROM differences between collegiate baseball pitchers and position players. It was hypothesized that pitchers would have higher strength and ROM values, due to the volume of throwing a pitcher performs. A total of nine collegiate baseball pitchers and position players (n = 18) volunteered for the study (age = 20.94 ± 1.21 years, height = 183.42 ± 4.74 cm, and mass = 89.56 ± 10.76 kg). Shoulder strength was measured using a Humac Norm isokinetic dynamometer at 180ºsec-1 and 300ºsec-1 and ROM was measured using a goniometer. All participants completed a five-minute warm-up at 50 rpm on an upper body ergometer. Following the warm-up, passive internal and external ROM were measured for the throwing (dominant) arm. No statistical differences were found in external ROM (p = 0.319), internal ROM (p = 0.258), external peak torque @180ºsec-1 (p = 0.467), internal peak torque @180ºsec-1 (p = 0.156), external peak torque @300ºsec-1 (p = 0.225), or internal peak torque @300ºsec-1 (p = 0.137). The findings indicate similar isokinetic strength and flexibility in the throwing shoulder of collegiate athletes who perform repeated overhead throwing motions. Thus, in this study the player's baseball position (pitchers vs. position player) did not influence throwing shoulder strength and ROM characteristics.

Upper Extremity and Hip Range of Motion Changes Throughout a Season in Professional Baseball Players

BACKGROUND

Loss of upper and lower extremity range of motion (ROM) is a significant risk factor for injuries in professional baseball players.

PURPOSE/HYPOTHESIS

The purpose was to determine changes in ROM in professional baseball players over the course of a single season and their careers. We hypothesized that pitchers and position players would lose ROM, specifically total shoulder motion (total ROM [TROM]) and hip internal rotation (IR), over the course of a season and their careers.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Upper and lower extremity ROM measurements were recorded during pre-, mid-, and postseason on all professional baseball players for a single organization between 2011 and 2018. ROM measurements were compared for pitchers and position players over the course of the season and their careers. Also, ROM measurements over the pre-, mid-, and postseason were compared between pitchers and position players.

RESULTS

A total of 166 professional baseball players (98 pitchers, 68 position players) were included. Pitcher hip external rotation (ER; P < .001), IR (P = .010), and TROM (P < .001) for lead and trail legs decreased over the course of the season. Pitcher shoulder ER (P = .005), TROM (P = .042), and horizontal adduction (P < .001) significantly increased over the course of the season. Position player shoulder flexion (P = .046), hip ER (P < .001, lead leg; P < .001, trail leg), and hip TROM (P = .001; P = .002) decreased over the course of the season. Position player shoulder ER (P = .031) and humeral adduction (P < .001) significantly increased over the course of the season. Over the course of pitchers' careers, there was decreased shoulder IR (P = .014), increased shoulder horizontal adduction (P < .001), and hip IR (P = .042) and hip TROM (P = .027) for the lead leg. Position players experienced loss of hip TROM (P = .010, lead leg; P = .018, trail leg) over the course of their careers. Pitchers started with and maintained more shoulder ER and gained more shoulder TROM over a season as compared with position players.

CONCLUSION

Pitchers and position players saw overall decreases in hip ROM but increases in shoulder ROM over the course of the season and career.

Preseason shoulder range of motion screening and in-season risk of shoulder and elbow injuries in overhead athletes: systematic review and meta-analysis

Objective

To characterise whether preseason screening of shoulder range of motion (ROM) is associated with the risk of shoulder and elbow injuries in overhead athletes.

Design

Systematic review and meta-analysis.

Data sources

Six electronic databases up to 22 September 2018.

Eligibility criteria

Inclusion criteria were (1) overhead athletes from Olympic or college sports, (2) preseason measures of shoulder ROM, (3) tracked in-season injuries at the shoulder and elbow, and (4) prospective cohort design. Exclusion criteria were (1) included contact injuries, (2) lower extremity, spine and hand injuries, and (3) full report not published in English.

Results

Fifteen studies were identified, and they included 3314 overhead athletes (baseball (74.6%), softball (3.1%), handball (16.1%), tennis (2.0%), volleyball (2.0%) and swimming (2.2%)). Female athletes are unrepresented (12% of the overall sample). Study quality ranged from 11 to 18 points on a modified Downs and Black checklist (maximum score 21, better quality). In one study, swimmers with low (<93°) or high (>100°) shoulder external rotation were at higher risk of injuries. Using data pooled from three studies of professional baseball pitchers, we showed in the meta-analysis that shoulder external rotation insufficiency (throwing arm <5° greater than the non-throwing arm) was associated with injury (odds ratio=1.90, 95% confidence interval 1.24 to 2.92, p<0.01).

Conclusion

Preseason screening of shoulder external rotation ROM may identify professional baseball pitchers and swimmers at risk of injury. Shoulder ROM screening may not be effective to identify handball, softball, volleyball and tennis players at risk of injuries. The results of this systematic review and meta-analysis should be interpreted with caution due to the limited number of studies and their high degree of heterogeneity.

PROSPERO registration number

CRD42017072895.

Current Workload Recommendations in Baseball Pitchers: A Systematic Review

BACKGROUND

Several recommendations have been made regarding pitch counts and workload for baseball players of different levels, including Little League, high school, collegiate, and professional baseball. However, little consensus is found in the literature regarding the scientific basis for many of these recommendations.

PURPOSE

The primary purpose of this study was to summarize the evidence regarding immediate and long-term musculoskeletal responses to increasing pitching workload in baseball pitchers of all levels. A secondary purpose of this review was to evaluate the extent to which workload influences injury and/or performance in baseball pitchers.

STUDY DESIGN

Systematic review.

METHODS

We performed a systematic search in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for studies addressing physiologic and/or pathologic musculoskeletal changes in response to a quantifiable pitching workload. We included studies examining the effects of pitching workload on performance, injury rate, and musculoskeletal changes in Little League, high school, collegiate, and professional baseball players.

RESULTS

We identified 28 studies that met our inclusion and exclusion criteria: 16 studies regarding Little League and high school pitchers and 12 studies regarding collegiate and professional pitchers. The current evidence presented suggests that increased pitching workload may be associated with an increased risk of pain, injury, and arm fatigue in Little League and high school pitchers. However, little consensus was found in the literature regarding the association between pitching workload and physiologic or pathologic changes in collegiate and professional pitchers.

CONCLUSION

Evidence, although limited, suggests the use of pitch counts to decrease injury rates and pain in Little League and high school baseball pitchers. However, further research must be performed to determine the appropriate number of pitches (or throws) for players of different ages. This systematic review reported conflicting evidence regarding the use of pitch counts in college and professional baseball. Future high-quality research is required to determine the role, if any, of pitch counts for collegiate and professional pitchers.

Effects of a six-week weighted-implement throwing program on baseball pitching velocity, kinematics, arm stress, and arm range of motion

BACKGROUND

Weighted-baseball training programs are used at the high school, collegiate, and professional levels of baseball. The purpose of this study was to evaluate the effects of a six-week training period consisting of weighted implements, manual therapy, weightlifting, and other modalities on shoulder external rotation, elbow valgus stress, pitching velocity, and kinematics.

HYPOTHESIS

A six-week training program that includes weighted implements will increase pitching velocity along with concomitant increases in arm angular velocities, joint kinetics, and shoulder external rotation.

METHODS

Seventeen collegiate and professional baseball pitchers (age range 18-23, average: 19.9 ± 1.3) training at Driveline Baseball were evaluated via a combination of an eight-camera motion-capture system, range-of-motion measurements and radar- and pitch-tracking equipment, both before and after a six-week training period. Each participant received individualized training programs, with significant overlap in training methods for all athletes. Twenty-eight biomechanical parameters were computed for each bullpen trial, four arm range-of-motion measurements were taken, and pitching velocities were recorded before and after the training period. Pre- and post-training period data were compared via post-hoc paired t tests.

RESULTS

There was no change in pitching velocity across the seventeen subjects. Four biomechanical parameters for the holistic group were significantly changed after the training period: internal rotational velocity was higher (from 4,527 ± 470 to 4,759 ± 542 degrees/second), shoulder abduction was lower at ball release (96 ± 7.6 to 93 ± 5.4°), the shoulder was less externally rotated at ball release (95 ± 15 to 86 ± 18°) and shoulder adduction torque was higher (from 103 ± 39 to 138 ± 53 N-m). Among the arm range of motion measurements, four were significantly different after the training period: the shoulder internal rotation range of motion and total range of motion for both the dominant and non-dominant arm. When the group was divided into those who gained pitching velocity and those who did not, neither group showed a significant increase in shoulder external rotation, or elbow valgus stress.

CONCLUSIONS

Following a six-week weighted implement program, pitchers did not show a significant change in velocity, joint kinetics, or shoulder external rotation range of motion. When comparing pitchers who gained velocity versus pitchers who did not, no statistically significant changes were seen in joint kinetics and shoulder range of motion.