title: Relation between glenohumeral internal rotation deficit and valgus laxity of the elbow in high school baseball pitchers.
abstract: BACKGROUND
  There are few literatures describing the association between glenohumeral internal rotation deficits (GIRD) and valgus laxity of the elbow on the throwing side of high school pitchers with and without a history of elbow symptom.
  
  
  METHODS
  The passive range of motion of glenohumeral internal and external rotation on bilateral side shoulders was measured in 75 high-school baseball pitchers during the preseason. Using ultrasonography, the width of the ulnohumeral joint of the elbow was measured at 30° of flexion, both at rest and with valgus stress in the pitching side. Comparisons of glenohumeral internal rotation deficits and the difference between the width of ulnohumeral joint space with and without valgus stress on the throwing side were made between 75 high-school pitchers with and without a history of elbow symptom.
  
  
  RESULTS
  Participants with a history of elbow symptom exhibited a greater difference between the width of ulnohumeral joint with and without valgus stress in the throwing side than participants with no history of elbow symptom (P<0.05). No difference in glenohumeral internal rotation deficits was found in participants with and without a history of elbow symptom. In all participants, significant association was found between glenohumeral internal rotation deficits on the pitching side and the difference from the width of the ulnohumeral joint with and without valgus stress (P=0.04, r=0.23).
  
  
  CONCLUSIONS
  Elbow valgus instability was associated with elbow joint pain in high-school pitchers. Although GIRD was not significantly different between the two groups, GIRD and elbow valgus instability might be related to the throwing side in high-school pitchers.
authors.affiliation: Department of Orthopedic Surgery, Gunma University, Graduate School of Medicine, Maebashi, Japan - tajika@gunma-u.ac.jp.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Tajika
authors.affiliation: Department of Physical Therapy, Takasaki University of Health and Welfare, Maebashi, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Department of Orthopedic Surgery, Gunma University, Graduate School of Medicine, Maebashi, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yamamoto
authors.affiliation: Department of Orthopedic Surgery, Gunma University, Graduate School of Medicine, Maebashi, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Shitara
authors.affiliation: Department of Orthopedic Surgery, Gunma University, Graduate School of Medicine, Maebashi, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Ichinose
authors.affiliation: Department of Orthopaedic Surgery, National Hospital, Organization Takasaki General Medical Center, Maebashi, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Shimoyama
authors.affiliation: Department of Orthopedic Surgery, Gunma University, Graduate School of Medicine, Maebashi, Japan.
authors.forename: Noboru
authors.initials: N
authors.lastname: Oya
authors.affiliation: Department of Orthopedic Surgery, Gunma University, Graduate School of Medicine, Maebashi, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Sasaki
authors.affiliation: Department of Orthopedic Surgery, Gunma University, Graduate School of Medicine, Maebashi, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Takagishi
mesh_terms: D000222:Adaptation, Physiological; D000293:Adolescent; D001484:Baseball; D001696:Biomechanical Phenomena; D017885:Collateral Ligaments / Q000000981:diagnostic imaging; D004550:Elbow / Q000503:physiopathology*; D004551:Elbow Joint / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D007564:Japan; D007593:Joint Instability / Q000150:complications / Q000000981:diagnostic imaging; D008297:Male; D010146:Pain / Q000150:complications / Q000503:physiopathology; D016059:Range of Motion, Articular / Q000502:physiology*; D012399:Rotation; D012574:Schools; D000070599:Shoulder Injuries; D012785:Shoulder Joint / Q000000981:diagnostic imaging / Q000503:physiopathology*; D014463:Ultrasonography; D000092464:Elbow Injuries