title: Distance between rotator cuff footprints and the acromion, coracoacromial ligament, and coracoid process during dynamic arm elevations: Preliminary observations.
abstract: BACKGROUND
  The objective of this study was to provide preliminary measures of the distance between the supraspinatus, infraspinatus, and subscapularis footprints and the acromion, coracoacromial ligament, and coracoid process, during dynamic arm elevations through the entire range-of-motion.
  
  
  METHODS
  Two healthy men performed maximum adduction, flexion, abduction, and extension with the arm internally, neutrally, and externally rotated. The distance between each rotator cuff footprint and the acromion, coracoacromial ligament, and coracoid process was measured from glenohumeral kinematics obtained from markers fitted to intracortical pins combined with the scapular and humeral 3D geometry obtained from CT-scan.
  
  
  RESULTS
  All footprints moved to be less than 10 mm to the acromion, coracoacromial ligament and coracoid process. They got closer to the acromion than to the other parts of the coracoacromial arch. The acromion-supraspinatus and acromion-infraspinatus distances were minimal during abduction and flexion. The acromion-subscapularis distance was minimal when the arm was in external and neutral rotation during both adduction and flexion.
  
  
  CONCLUSIONS
  The present study provides benchmark results of the distance between the rotator cuff footprints and the coracoacromial arch that may guide future clinical research. Pressure transducers should be positioned throughout the coracoacromial arch to provide comprehensive assessment of the compression undergone by the rotator cuff tendons. Common shoulder examination tests, that require flexion and internal rotation movements, may be refined since the supraspinatus footprint was the closest to the coracoacromial arch during abduction. Larger scale investigations may be needed to identify more accurate shoulder examination tests.
authors.affiliation: Département de kinésiologie, Université de Montréal, 2100, boul. Édouard-Montpetit, Montréal, QC, H3T 1J4, Canada; Centre de recherché du CHU Ste Justine, 3175 Chemin de la Côte-Sainte-Catherine, Montréal, QC, H3T 1C4, Canada. Electronic address: fabien.dalmaso@gmail.com.
authors.forename: Fabien
authors.initials: F
authors.lastname: Dal Maso
authors.affiliation: Département de kinésiologie, Université de Montréal, 2100, boul. Édouard-Montpetit, Montréal, QC, H3T 1J4, Canada; Centre de recherché du CHU Ste Justine, 3175 Chemin de la Côte-Sainte-Catherine, Montréal, QC, H3T 1C4, Canada.
authors.forename: Yoann
authors.initials: Y
authors.lastname: Blache
authors.affiliation: Centre de recherché du CHU Ste Justine, 3175 Chemin de la Côte-Sainte-Catherine, Montréal, QC, H3T 1C4, Canada; Ecole Polytechnique de Montréal, 2900 boul. Édouard-Montpetit, Montréal, QC, H3T 1J4, Canada.
authors.forename: Maxime
authors.initials: M
authors.lastname: Raison
authors.affiliation: Karolinska Institutet, Solnavägen 1, 171 77 Solna, Sweden; The Swedish School of Sport and Health Sciences, Lidingövägen 1, 114 33 Stockholm, Sweden.
authors.forename: Anton
authors.initials: A
authors.lastname: Arndt
authors.affiliation: Département de kinésiologie, Université de Montréal, 2100, boul. Édouard-Montpetit, Montréal, QC, H3T 1J4, Canada; Centre de recherché du CHU Ste Justine, 3175 Chemin de la Côte-Sainte-Catherine, Montréal, QC, H3T 1C4, Canada.
authors.forename: Mickaël
authors.initials: M
authors.lastname: Begon
mesh_terms: D000174:Acromion / Q000033:anatomy & histology* / Q000502:physiology; D000328:Adult; D001132:Arm / Q000033:anatomy & histology* / Q000502:physiology*; D000070597:Coracoid Process / Q000033:anatomy & histology* / Q000502:physiology; D006801:Humans; D008023:Ligaments, Articular / Q000033:anatomy & histology* / Q000502:physiology; D008297:Male; D016059:Range of Motion, Articular / Q000502:physiology*; D017006:Rotator Cuff / Q000033:anatomy & histology* / Q000502:physiology
keywords: Acromiohumeral distance; Coracoacromial arch; Intracortical pins; Subacromial impingement syndrome