title: Kinematic analysis of reaching movements of the upper limb after total or reverse shoulder arthroplasty.
abstract: Studies have analyzed three-dimensional complex motion of the shoulder in healthy subjects or patients undergoing total shoulder arthroplasty (TSA) or reverse shoulder arthroplasty (RSA). No study to date has assessed the reaching movements in patients with TSA or RSA. Twelve patients with TSA (Group A) and 12 with RSA (Group B) underwent kinematic analysis of reaching movements directed at four targets. The results were compared to those of 12 healthy subjects (Group C). The assessed parameters were hand-to-target distance, target-approaching velocity, humeral-elevation angular velocity, normalized jerk (indicating motion fluidity), elbow extension and humeral elevation angles. Mean Constant score increased by 38 points in Group A and 47 in Group B after surgery. In three of the tasks, there were no significant differences between healthy subjects and patients in the study groups. Mean target-approaching velocity and humeral-elevation angular velocity were significantly greater in the control group than in study groups and, overall, greater in Group A than Group B. Movement fluidity was significantly greater in the controls, with patients in Group B showing greater fluidity than those in Group A. Reaching movements in the study groups were comparable, in three of the tasks, to those in the control group. However, the latter performed significantly better with regard to target-approaching velocity, humeral-elevation angular velocity and movement fluidity, which are the most representative characteristics of reaching motion. These differences, that may be related to deterioration of shoulder proprioception after prosthetic implant, might possibly be decreased with appropriate rehabilitation.
authors.affiliation: Department of Orthopedic Surgery, Israelitic Hospital, Italian University Sport and Movement, Rome, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Postacchini
authors.affiliation: Department of Physical Medicine and Rehabilitation, Sapienza University, Rome, Italy. Electronic address: marco.paoloni@uniroma1.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Paoloni
authors.affiliation: Department of Orthopedic Surgery, Sapienza University, Rome, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Carbone
authors.affiliation: IRCCS San Raffaele Pisana, Rome, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Fini
authors.affiliation: Department of Physical Medicine and Rehabilitation, Sapienza University, Rome, Italy.
authors.forename: Valter
authors.initials: V
authors.lastname: Santilli
authors.affiliation: Department of Orthopedic Surgery, Sapienza University, Rome, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Postacchini
authors.affiliation: Don Carlo Gnocchi Onlus Foundation, Milan, Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Mangone
mesh_terms: D000368:Aged; D001132:Arm / Q000503:physiopathology; D019643:Arthroplasty, Replacement / Q000379:methods; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009068:Movement; D011434:Proprioception; D012785:Shoulder Joint / Q000503:physiopathology* / Q000601:surgery
keywords: Kinematic analysis; Reaching movements; Reverse shoulder prosthesis; Shoulder biomechanics; Total shoulder prosthesis