title: Kinematic evaluation of patients with total and reverse shoulder arthroplasty during rehabilitation exercises with different loads.
abstract: BACKGROUND
  Following shoulder arthroplasty, any well-planned rehabilitation program should include muscle strengthening. However, it is not always clear how different external loads influence shoulder kinematics in patients with shoulder prostheses. The objective of this study was to describe shoulder kinematics and determine the contribution of the scapulothoracic joint to total shoulder motion of patients with total and reverse shoulder arthroplasties and of healthy individuals during rehabilitation exercises (anteflexion and elevation in the scapular plane) using different loading conditions (without external load, 1 kg and elastic resistance).
  
  
  METHODS
  Shoulder motions were measured using an electromagnetic tracking device. A force transducer was used to record force signals during loaded conditions using elastic resistance. Statistical comparisons were made using a three-way repeated-measures analysis of variance with a Bonferroni post hoc testing.
  
  
  RESULTS
  The scapula contributed more to movement of the arm in subjects with prostheses compared to healthy subjects. The same applies for loaded conditions (1 kg and elastic resistance) relative to unloaded tasks. For scapular internal rotation, upward rotation and posterior tilt no significant differences among groups were found during both exercises. Glenohumeral elevation angles during anteflexion were significantly higher in the total shoulder arthroplasty group compared to the reverse shoulder arthroplasty group.
  
  
  CONCLUSIONS
  Differences in contribution of the scapula to total shoulder motion between patients with different types of arthroplasties were not significant. However, compared to healthy subjects, they were. Furthermore, scapular kinematics of patients with shoulder arthroplasty was influenced by implementation of external loads, but not by the type of load.
authors.affiliation: Physical Education School, Exercise Research Laboratory, Federal University of Rio Grande do Sul, Porto Alegre, Brazil. joellytoledo@hotmail.com
authors.forename: Joelly Mahnic
authors.initials: JM
authors.lastname: de Toledo
authors.forename: Jefferson Fagundes
authors.initials: JF
authors.lastname: Loss
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Janssen
authors.forename: Jan W
authors.initials: JW
authors.lastname: van der Scheer
authors.forename: Tjarco D
authors.initials: TD
authors.lastname: Alta
authors.forename: W Jaap
authors.initials: WJ
authors.lastname: Willems
authors.forename: DirkJan H E J
authors.initials: DH
authors.lastname: Veeger
mesh_terms: D000328:Adult; D000368:Aged; D000886:Anthropometry; D001178:Arthroplasty; D001696:Biomechanical Phenomena; D004548:Elasticity; D006801:Humans; D007595:Joint Prosthesis; D008875:Middle Aged; D010003:Osteoarthritis / Q000534:rehabilitation* / Q000601:surgery*; D016059:Range of Motion, Articular; D012399:Rotation; D012540:Scapula / Q000033:anatomy & histology / Q000601:surgery; D012782:Shoulder / Q000033:anatomy & histology / Q000601:surgery*; D000070599:Shoulder Injuries; D013314:Stress, Mechanical; D013718:Tensile Strength