Timothy J Brindle1, Arthur J Nitz, Tim L Uhl, Edward Kifer, Robert Shapiro. 1. Postdoctoral Research Physical Therapist, National Institutes of Health Bethesda, Physical Disabilities Branch, Building 10 Room 65235, 10 Center Drive MCS 1604, Bethesda, MD 20892-1604, USA. Tbrindle@nih.gov
Abstract
STUDY DESIGN: Repeated-measures experiment. OBJECTIVE: To compare measures of end point accuracy (EPA) for 2 feedback conditions: (1) visual and kinesthetic feedback and (2) kinesthetic feedback alone, during shoulder movements, at 3 different speeds. BACKGROUND: Shoulder joint kinesthesia is typically reported with EPA measures, such as constant error. Reporting multiple measures of EPA, such as variable error and absolute error, could provide a more detailed description of performance. METHODS AND MEASURES: Subjects were seated with the shoulder abducted 90 degrees in the scapular plane and externally rotated 75 degrees, with the forearm placed in a custom shoulder wheel. Subjects internally rotated the shoulder 27 degrees to a target position at 48 degrees of shoulder external rotation for both conditions. Motion analysis was used to determine peak angular velocity and 3 EPA measures for shoulder movements. Each EPA measure was compared between the 2 feedback conditions and among the 3 speeds with a separate 2-way analysis of variance. RESULTS: Movements performed with kinesthetic feedback alone, measured by constant error (P<.01), variable error (P<.01), and absolute error (P<.01), were less accurate than movements performed with visual and kinesthetic feedback. Faster movements were less accurate when measured by constant error (P = .01) and absolute error (P<.01) than slower movements. Subjects tended to overshoot the target in the absence of visual feedback; however, movement speed played minimal role in the overshooting. CONCLUSIONS: Multiple measures of EPA, such as constant, variable, and absolute error during simple restricted shoulder movements may provide additional information regarding the evaluation of a motor performance or identify different central nervous system control mechanisms for joint kinesthesia.
STUDY DESIGN: Repeated-measures experiment. OBJECTIVE: To compare measures of end point accuracy (EPA) for 2 feedback conditions: (1) visual and kinesthetic feedback and (2) kinesthetic feedback alone, during shoulder movements, at 3 different speeds. BACKGROUND: Shoulder joint kinesthesia is typically reported with EPA measures, such as constant error. Reporting multiple measures of EPA, such as variable error and absolute error, could provide a more detailed description of performance. METHODS AND MEASURES: Subjects were seated with the shoulder abducted 90 degrees in the scapular plane and externally rotated 75 degrees, with the forearm placed in a custom shoulder wheel. Subjects internally rotated the shoulder 27 degrees to a target position at 48 degrees of shoulder external rotation for both conditions. Motion analysis was used to determine peak angular velocity and 3 EPA measures for shoulder movements. Each EPA measure was compared between the 2 feedback conditions and among the 3 speeds with a separate 2-way analysis of variance. RESULTS: Movements performed with kinesthetic feedback alone, measured by constant error (P<.01), variable error (P<.01), and absolute error (P<.01), were less accurate than movements performed with visual and kinesthetic feedback. Faster movements were less accurate when measured by constant error (P = .01) and absolute error (P<.01) than slower movements. Subjects tended to overshoot the target in the absence of visual feedback; however, movement speed played minimal role in the overshooting. CONCLUSIONS: Multiple measures of EPA, such as constant, variable, and absolute error during simple restricted shoulder movements may provide additional information regarding the evaluation of a motor performance or identify different central nervous system control mechanisms for joint kinesthesia.
Authors: Francesca Marini; Sara Contu; Chris W Antuvan; Pietro Morasso; Lorenzo Masia Journal: Front Hum Neurosci Date: 2017-08-31 Impact factor: 3.169