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Published on: February 10, 2015
Reliability of Inertial Sensors for Measuring Scapular Kinematics in Individuals With Shoulder Pain and Scapular
Felipe Augusto da Silva Oliveira1, Laís Regina de Holanda Santos2, Hitalo Andrade da Silva3
1Graduate Program of Rehabilitation and Functional Performance, University of Pernambuco (UPE), Petrolina, PE, Brazil.
Context:
Scapular dyskinesis is frequently associated with subacromial pain syndrome (SAPS), and clinicians increasingly use inertial sensors as a portable, low-cost option to assess scapular kinematics. However, the reliability of these measurements in individuals with SAPS and scapular dyskinesis remains unclear. This study aimed to report the reliability of scapular kinematic variables obtained using inertial sensors during arm elevation and lowering in individuals with SAPS and scapular dyskinesis.
Design:
Test-retest study.
Methods:
Fifty-two adults with unilateral SAPS for at least 3 months and clinically diagnosed scapular dyskinesis performed arm elevation and lowering in the scapular plane across 2 sessions separated by 48 to 72 hours. Five inertial sensors (Xsens) recorded 3-dimensional scapular upward rotation, internal rotation, and scapular tilting at 30°, 60°, 90°, and 120° of humeral elevation on both limbs. Within- and between-day reliability were quantified using intraclass correlation coefficients, standard error of measurement, and minimal detectable change.
Results:
Within-day reliability was excellent, with intraclass correlation coefficients ranging from .91 to .97 for all scapular angles. Between-day reliability ranged from .63 to .89 across movements and angles, with higher values on the dominant side and at lower elevation angles. Standard error of measurement values ranged from 0.67° to 4.55°, and minimal detectable change values from 1.87° to 12.61°, indicating low-to-moderate measurement error.
Conclusions:
Inertial sensors provide reliable within- and between-day measurements of scapular kinematics during arm elevation and lowering in individuals with SAPS and scapular dyskinesis, particularly on the dominant limb and at lower elevation angles, supporting their use as a clinical assessment tool.
