title: Upper limb kinematics after arthroscopic and open shoulder stabilization.
abstract: BACKGROUND
  Shoulder joint stability mediated by proprioception is often quantified by arm repositioning tests (i.e., static end-position accuracy), overlooking ongoing movement quality. This study assessed movement quality by adopting smoothness-related kinematic descriptors. We compared performance of healthy controls with that of patients in arthroscopic shoulder stabilization and open shoulder stabilization groups. We hypothesized that arm kinematics after arthroscopic intervention would more closely resemble healthy movements compared with patients after open shoulder stabilization surgery.
  
  
  METHODS
  Healthy controls (N = 14) were compared with patients after arthroscopic shoulder stabilization (N = 10) and open shoulder stabilization (N = 12). Right-hand dominant subjects (the affected side in patients) performed 135 unconstrained 3-dimensional pointing movements toward visual targets (seen through pinhole goggles; i.e., no arm vision). Arm kinematic data were recorded and offline analyzed to obtain hand tangential velocity profiles further used to compute the acceleration-to-movement time ratio, peak-to-mean velocity ratio, and number of velocity peaks ("symmetry," "proportion," and "fragmentation" features, respectively). Parametric and nonparametric statistics were used for comparisons (P ≤ .05).
  
  
  RESULTS
  Control and arthroscopic shoulder stabilization groups presented similar acceleration-to-movement time ratio and peak-to-mean velocity ratio. Both groups differed from the open shoulder stabilization group (P = .001). Distributions of velocity peaks for control and arthroscopic shoulder stabilization groups were similar, whereas open shoulder stabilization and control subjects differed significantly (P = .028).
  
  
  CONCLUSIONS
  Movement quality mediated by proprioception in arthroscopic shoulder stabilization patients matches that of healthy controls, whereas performance in open shoulder stabilization patients seems inferior compared with that in healthy controls, as assessed by smoothness-related measures (less symmetrical, more fragmented movements).
authors.affiliation: Department of Orthopedic Surgery, Sheba Medical Center, Tel Hashomer, Israel; Department of Physical Therapy, Stanley Steyer School of Health Professions, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Ofir
authors.initials: O
authors.lastname: Uri
authors.affiliation: Department of Orthopedic Surgery, Sheba Medical Center, Tel Hashomer, Israel.
authors.forename: Moshe
authors.initials: M
authors.lastname: Pritsch
authors.affiliation: Department of Orthopedic Surgery, Sheba Medical Center, Tel Hashomer, Israel.
authors.forename: Ariel
authors.initials: A
authors.lastname: Oran
authors.affiliation: Department of Physical Therapy, Stanley Steyer School of Health Professions, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. Electronic address: dlieberm@post.tau.ac.il.
authors.forename: Dario G
authors.initials: DG
authors.lastname: Liebermann
mesh_terms: D000328:Adult; D001182:Arthroscopy; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology* / Q000601:surgery; D008297:Male; D009068:Movement; D011434:Proprioception; D012783:Shoulder Dislocation / Q000503:physiopathology* / Q000601:surgery; D012785:Shoulder Joint / Q000503:physiopathology* / Q000601:surgery; D055815:Young Adult
keywords: Arm kinematics; arthroscopic Bankart repair; open capsular shift; shoulder stabilization