title: Scapulothoracic and Glenohumeral Kinematics During Daily Tasks in Users of Manual Wheelchairs.
abstract: BACKGROUND
  Rates of shoulder pain in individuals who use manual wheelchairs (MWCs) as their primary means of mobility have been reported to be as high as 70% during activities of daily living. Current prevailing thought is that mechanical impingement of the soft tissues that reside within the subacromial space between the humeral head and coracoacromial arch is a major contributor to the shoulder pain in users of MWCs. The subacromial space size is directly related to the kinematics at the shoulder joint. Yet to be answered are questions about which common daily tasks are characterized by the most potentially detrimental kinematics.
  
  
  OBJECTIVE
  The purpose of this analysis was to quantify and compare potentially detrimental kinematics in three common tasks performed by individuals with spinal cord injury and shoulder pain. These data will add to the body of knowledge and test common assumptions about relative risk of tasks.
  
  
  METHODS
  A cross-sectional study of 15 MWC users with shoulder pain.
  
  
  METHODS
  Electromagnetic surface sensor measures of mean and peak scapulothoracic (ST) internal and downward rotation, anterior tilt, and glenohumeral (GH) internal rotation were compared across propulsion, weight relief, and scapular plane abduction tasks using one-way repeated-measure ANOVA.
  
  
  RESULTS
  Statistical differences were observed between the tasks for all rotations. Mean ST anterior tilt was greater in weight relief and propulsion than during scapular plane abduction (24°, 23°, and 13° of anterior tilt, respectively). Mean GH axial rotation during weight relief was more internally rotated than during propulsion and scapular plane abduction (9°, 26°, and 51° of external rotation, respectively).
  
  
  CONCLUSIONS
  Surface-based measures of kinematics are subject to skin motion artifact, especially in translation which was not addressed in this study.
  
  
  CONCLUSIONS
  Each task presented with specific variables that might contribute to risk of developing shoulder "impingement" and pain. These data may assist therapists in their assessment of movement contributions to shoulder pain in this population, as well as in subsequent treatment planning.
authors.affiliation: Rehabilitation Medicine Research Center, Department of Physical Medicine and Rehabilitation, Mayo Clinic , Rochester, MN , USA.
authors.forename: Kristin D
authors.initials: KD
authors.lastname: Zhao
authors.affiliation: Motion Analysis Laboratory, Division of Orthopedic Research, Mayo Clinic , Rochester, MN , USA.
authors.forename: Meegan G
authors.initials: MG
authors.lastname: Van Straaten
authors.affiliation: Rehabilitation Medicine Research Center, Department of Physical Medicine and Rehabilitation, Mayo Clinic , Rochester, MN , USA.
authors.forename: Beth A
authors.initials: BA
authors.lastname: Cloud
authors.affiliation: Department of Health Sciences Research, Mayo Clinic , Rochester, MN , USA.
authors.forename: Melissa M
authors.initials: MM
authors.lastname: Morrow
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic , Rochester, MN , USA.
authors.forename: Kai-Nan
authors.initials: KN
authors.lastname: An
authors.affiliation: Program in Rehabilitation Science, Department of Physical Medicine and Rehabilitation, University of Minnesota , Minneapolis, MN , USA.
authors.forename: Paula M
authors.initials: PM
authors.lastname: Ludewig
keywords: activities of daily living; kinematics; manual wheelchair users; shoulder pain; spinal cord injury