title: Shoulder range of motion measures as risk factors for shoulder and elbow injuries in high school softball and baseball players.
abstract: BACKGROUND
  Range of motion deficits in shoulder external rotation (ER), internal rotation (IR), total rotation range of motion (ER + IR), and horizontal adduction (HA) have been retrospectively associated with overhand athletes' arm injuries.
  
  
  OBJECTIVE
  The authors expected the incidence of upper extremity injury in high school softball and baseball players with side-to-side shoulder range of motion deficits to be greater than the incidence of upper extremity injury in players with normal shoulder range of motion.
  
  
  METHODS
  Cohort study (prognosis); Level of evidence, 2.
  
  
  METHODS
  High school softball and baseball players (N = 246) participated. Before the start of the season, passive shoulder ER, IR, and HA were assessed at 90° of abduction with the scapula stabilized. Relative risk (RR) was calculated to examine range of motion measure, by categorical criteria, and risk of upper extremity injury.
  
  
  RESULTS
  Twenty-seven shoulder and elbow injuries (9 softball, 18 baseball) were observed during the season. The dominant shoulder of all injured players and baseball players displayed a significant decrease in HA (P = .05) and IR (P = .04). The dominant shoulder total rotation of injured baseball players displayed a significant decrease (mean difference = 8.0° ± 0.1°; P = .05) as compared with the dominant shoulder of uninjured baseball players. Players who displayed a decrease of ≥25° of IR in the dominant shoulder were at 4 times greater risk of upper extremity injury compared with players with a <25° decrease in IR, especially for baseball players. While we observed a 1.5 to 2 times increased risk of injury for the 10° to 20° loss in rotational range of motion for the overall sample and baseball, the risk estimates were not statistically significant (P > .05).
  
  
  CONCLUSIONS
  There are large mean deficits in shoulder IR and HA between injured and noninjured players, but not in ER or total rotation. Passive shoulder IR loss ≥25° as compared bilaterally was predictive of arm injury. Shoulder range of motion deficits differed between sports and appeared more predictive of injury for baseball players.
authors.affiliation: Proaxis Therapy, Orthopedic Research Foundation of the Carolinas, Greenville, South Carolina, USA. ellen.shanley@proaxistherapy.com
authors.forename: Ellen
authors.initials: E
authors.lastname: Shanley
authors.forename: Mitchell J
authors.initials: MJ
authors.lastname: Rauh
authors.forename: Lori A
authors.initials: LA
authors.lastname: Michener
authors.forename: Todd S
authors.initials: TS
authors.lastname: Ellenbecker
authors.forename: J Craig
authors.initials: JC
authors.lastname: Garrison
authors.forename: Charles A
authors.initials: CA
authors.lastname: Thigpen
mesh_terms: D000293:Adolescent; D001484:Baseball / Q000293:injuries* / Q000502:physiology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D016059:Range of Motion, Articular / Q000502:physiology*; D012307:Risk Factors; D012782:Shoulder / Q000502:physiology; D000070599:Shoulder Injuries; D000092464:Elbow Injuries