Most high school baseball pitchers are using weighted ball throwing programs to increase ball velocity: crosssectional analysis of US high school pitchers.

Background: Weighted-ball velocity training programs are popular but may be associated with increased injury risk. The purpose of this study was to determine the current frequency of these programs, as well as their association with range of motion, strength, velocity, injury, and utilization in high school baseball pitchers. Methods: This was a multicenter, prospective, community-based study including high schools from the Northeastern, Southeastern, Midwestern, and Western regions of the United States. Preseason pitchers were surveyed about their use of weighted ball velocity programs and history of injury. Preseason pitchers underwent standardized physical examinations and pitch velocity was measured. During a single high school season, pitch counts and injury incidence were prospectively collected. Results: In total, 115 pitchers were recruited, of whom 63% had participated in a weighted ball program. There were no differences in range of motion or strength between groups who used weighted balls and those who did not. Pitchers that utilized weighted ball programs demonstrated a higher average fastball velocity (114.26 vs. 106.22 km/h [71 vs. 66 mph]; P < .001) as well as peak fastball velocity (115.87 vs. 109.44 km/h [72 vs. 68 mph]; P = .001) compared to those that did not use weighted ball programs. Pitchers that utilized weighted ball programs were no more likely to be single-sport athletes (44%) than those who were multisport athletes (49%, P = .667). Within the group who had used a weighted ball program 29% (13/45) reported a history of injury and within the group who had not used a weighted ball program 25% (10/40) reported a history of injury (P = .687). As only a single injury occurred in the entire cohort, comparison of injury rates could not be completed. Conclusion: In this prospective study, the majority of high school pitchers reported using weighted ball programs to increase velocity, and these programs were associated with increased average and peak velocity compared to pitchers who did not use weighted ball programs. There were no significant differences in injury history between the 2 groups. Further study is necessary to understand the injury risk associated with weighted ball programs.

Rheumatoid arthritis is associated with increased symptomatic acromial and scapular spine stress fracture after reverse total shoulder arthroplasty.

BACKGROUND: The purpose of this study was to determine factors associated with early symptomatic acromial and scapular spine fractures in patients who underwent reverse total shoulder arthroplasty (RTSA). METHODS: We retrospectively evaluated all RTSAs performed by the senior author between 1/1/2013 and 6/1/2019. We evaluated patient demographics including gender, age, prevalence of comorbidities including osteoporosis, inflammatory arthritis, diabetes, and endocrine disorders such as hypothyroidism. We also evaluated preoperative and 2-week postoperative radiographs for center of rotation medialization (CORM) as distance between the center of the humeral head or glenosphere and the line of the deltoid, and distalization via the acromial-greater tuberosity distance (AGT). We evaluated inter- and intra-rater reliability via intraclass correlation coefficients. RESULTS: We included 335 RTSAs with a minimum of 3 months of follow-up in the analysis. Reliability was acceptable with all intraclass correlation coefficients> 0.75. Symptomatic acromial and scapular spine stress fractures were significantly more common in those with inflammatory arthritis than those without (18% vs. 5%, P = 0.016). The rate of fracture was highest in patients with rheumatoid arthritis (24% vs. 5.2%, P = 0.003). There was no statistically significant association between symptomatic fractures and preoperative CORM or AGT (P = 0.557, P = 0.528) or postoperative CORM or AGT (P = 0.56, P = 0.102). There also was no statistically significant correlation between symptomatic stress fracture and patient age, gender, BMI, smoking, osteoporosis, gout, medical comorbidity, or previous shoulder surgery. CONCLUSION: In this retrospective analysis of postoperative RTSA, symptomatic acromial and scapular stress fractures were significantly more common in patients with rheumatoid arthritis and thus precautions should be taken in these patients.