title: Quantifying acromiohumeral distance in overhead athletes with glenohumeral internal rotation loss and the influence of a stretching program.
abstract: BACKGROUND
  Loss of internal rotation range of motion (ROM) on the dominant side is well documented in athletes performing overhead sports activity. This altered motion pattern has been shown to change glenohumeral and scapular kinematics. This could compromise the subacromial space and explain the association between glenohumeral internal rotation deficit (GIRD) and subacromial impingement.
  
  
  OBJECTIVE
  First, to quantify acromiohumeral distance (AHD) and compare between the dominant and nondominant side in overhead athletes with GIRD of more than 15°. Second, to investigate the effect of a sleeper stretch program on ROM and AHD.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Range of motion was measured with a digital inclinometer and AHD was measured with ultrasound in 62 overhead athletes with GIRD (>15°) at baseline. Differences between sides were analyzed. Athletes were randomly allocated to the stretch (n = 30) or control group (n = 32). The stretch group performed a 6-week sleeper stretch program on the dominant side. Change of range of motion and AHD were measured and analyzed in both groups after 6 weeks.
  
  
  RESULTS
  The dominant side showed a significant internal rotation deficit (-24.7° ± 6.3°) and horizontal adduction deficit (-11.8° ± 7.4°) and the dominant side AHD was significantly smaller with the arm at neutral (-0.4 ± 0.6 mm) and at 45° (-0.5 ± 0.8 mm) and 60° (-0.6 ± 0.7 mm) of active abduction compared with the nondominant side. After stretching, significant increase of internal rotation (+13.5° ± 0.8°), horizontal adduction (+10.6° ± 0.9°) ROM and AHD (+0.5 to +0.6mm) was observed at the dominant side of the stretch group compared with prestretching measurements. No significant change of AHD was seen in the nondominant side of the stretch group and in both sides of the control group.
  
  
  CONCLUSIONS
  The AHD, a 2-dimensional measure for subacromial space, was found to be smaller on the dominant side in athletes with GIRD and was found to increase after a 6-week sleeper stretch program.
  
  
  CONCLUSIONS
  These findings might provide insight into the relation between GIRD and subacromial impingement but future studies are needed to determine clinical implications.
authors.affiliation: Department of Physiotherapy and Rehabilitation Sciences, Ghent University, De Pintelaan 185, 9000 Ghent, Belgium. annelies.maenhout@ugent.be
authors.forename: Annelies
authors.initials: A
authors.lastname: Maenhout
authors.forename: Valerie
authors.initials: V
authors.lastname: Van Eessel
authors.forename: Lieselot
authors.initials: L
authors.lastname: Van Dyck
authors.forename: Aagje
authors.initials: A
authors.lastname: Vanraes
authors.forename: Ann
authors.initials: A
authors.lastname: Cools
mesh_terms: D000174:Acromion / Q000033:anatomy & histology* / Q000503:physiopathology; D000293:Adolescent; D001484:Baseball; D001696:Biomechanical Phenomena; D001837:Body Weights and Measures; D005081:Exercise Therapy; D005260:Female; D006801:Humans; D006811:Humerus / Q000033:anatomy & histology* / Q000503:physiopathology; D008297:Male; D016059:Range of Motion, Articular; D012399:Rotation; D019534:Shoulder Impingement Syndrome / Q000503:physiopathology / Q000628:therapy*; D012785:Shoulder Joint / Q000503:physiopathology; D055815:Young Adult