Background Reports of return to play(8–80%) and subsequent injury(15–30%) are variable following arm injuries in baseball players with no known risk factors.

Objective We aimed to prospectively examine the influence of injury history, return to sport criteria, and baseball participation as risk factors in youth and adolescent baseball players returning to sport following rehabilitation.

Design Prospective cohort study.

Setting Youth through adolescent baseball leagues.

Patients (or Participants) Injured baseball players (n=60;age=15.3±2.5 months) were followed for atleast 1 year (15.8±9.6 months) after returning to sport.

Interventions (or Assessment of Risk Factors) All players' ROM, strength and outcome scores were measured and met predetermined criteria for return to sport. Players were surveyed monthly for participation, competition level, and the development of injuries. All subsequent injuries were verified as overuse time-loss injuries by team athletic trainer, physical therapist, or physician.

Main Outcome Measurements Bivariate correlations were used to evaluate the relationship between injury history, return to sport criteria, and baseball participation. Forward stepwise logistic regression using significant (r>.25; P<0.05) associations with advancing completion level and subsequent injury were then used to calculate odds ratios and 95% confidence intervals (CIs) from the final model (α=0.05).

Results Seven players reported an injury prior to the index injury. Twenty players suffered a subsequent time-loss arm injury. Development of a subsequent arm injury was correlated with previous injury(r=.45; P=0.002) and advancing one competitive level(r=.32; P=0.01). The final regression model revealed that players reporting an prior injury to the index injury were 20.5 (1.8–147.5 95% CI) times greater risk of a subsequent overuse arm injury than in players without a previous injury history.

Conclusions Injury history and advancing competition levels increases the risk of a subsequent arm injury despite achievement of evidence based return to sport criteria. Clinicians should consider counseling and monitoring of youth and adolescent baseball players returning back to sport, especially after multiple arm injuries.