title: Prospective multifactorial analysis of preseason risk factors for shoulder and elbow injuries in high school baseball pitchers.
abstract: OBJECTIVE
  To prospectively identify preseason physical factors for shoulder and elbow injuries during the season in high school baseball pitchers.
  
  
  METHODS
  The study included 105 high school baseball pitchers [median age 16 (15-17) years]. The range of motion of the shoulder (90° abducted external and internal rotation) and elbow (extension/flexion), shoulder muscle strength (abduction and prone internal and external rotation), shoulder and elbow laxity, horizontal flexion, and scapular dyskinesis were assessed. After the season, the participants completed questionnaires regarding shoulder and/or elbow injuries, with injury defined as an inability to play for ≥1 week due to elbow/shoulder problems. The results of two groups (injured and noninjured) were compared using t tests and Chi-square analyses. Stepwise forward logistic regression models were developed to identify risk factors.
  
  
  RESULTS
  Twenty-one injuries were observed. In univariate analysis, 90° abducted internal rotation and total arc of the dominant shoulder and the ratio of prone external rotation in the dominant to nondominant sides in the injured group were significantly less than those in the noninjured group (P = 0.02, 0.04, and 0.01, respectively). In logistic regression analysis, 90° abducted internal rotation in the dominant shoulder and prone external rotation ratio were significantly associated with injuries (P = 0.02 and 0.03, respectively).
  
  
  CONCLUSIONS
  A low prone external rotation ratio and decreased 90° abducted internal rotation in the dominant shoulder in the preseason were significant risk factors for shoulder and elbow injuries in high school baseball pitchers. The results may contribute to reduce the incidence of these injuries.
  
  
  METHODS
  II.
authors.affiliation: Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, 3-39-22 Showa, Maebashi, Gunma, 371-8511, Japan. hshitara@gunma-u.ac.jp.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Shitara
authors.affiliation: Department of Physical Therapy, Takasaki University of Health and Welfare, 37-1 Nakaorui, Takasaki, Gunma, 370-0033, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, 3-39-22 Showa, Maebashi, Gunma, 371-8511, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yamamoto
authors.affiliation: Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, 3-39-22 Showa, Maebashi, Gunma, 371-8511, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Shimoyama
authors.affiliation: Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, 3-39-22 Showa, Maebashi, Gunma, 371-8511, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Ichinose
authors.affiliation: Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, 3-39-22 Showa, Maebashi, Gunma, 371-8511, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Tajika
authors.affiliation: Department of Orthopaedic Surgery, National Hospital Organization Takasaki General Medical Center, 36 Takamatsu, Takasaki, Gunma, 370-0829, Japan.
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Osawa
authors.affiliation: Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, 3-39-22 Showa, Maebashi, Gunma, 371-8511, Japan.
authors.forename: Haku
authors.initials: H
authors.lastname: Iizuka
authors.affiliation: Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, 3-39-22 Showa, Maebashi, Gunma, 371-8511, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Takagishi
mesh_terms: D000293:Adolescent; D001134:Arm Injuries / Q000453:epidemiology*; D001484:Baseball / Q000293:injuries*; D006801:Humans; D008297:Male; D009068:Movement; D015999:Multivariate Analysis; D053580:Muscle Strength / Q000502:physiology; D018482:Muscle, Skeletal; D011446:Prospective Studies; D016059:Range of Motion, Articular / Q000502:physiology; D012307:Risk Factors; D012399:Rotation; D012540:Scapula; D012574:Schools; D012782:Shoulder / Q000502:physiology; D000070599:Shoulder Injuries / Q000453:epidemiology*; D000092464:Elbow Injuries
keywords: Baseball; High school pitcher; Multifactorial analysis; Prospective; Risk factor