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Faculty Advisor(s)

Joseph Day PT, PhD


Background/Purpose: Individuals with upper extremity pathology often present with altered scapular motion and muscle performance. There are few clinical tools that are capable of collecting specific and efficient data on alterations in scapular motion and even fewer studies have looked at variations in scapular acceleration. The primary purpose of this study was to determine the effectiveness of wireless accelerometers for detecting changes in acceleration in individuals with and without scapular dyskinesis.

Methods: Twenty-seven subjects, mean age 24 (SD1.49). Healthy subjects were visually screened for scapular dyskinesis. Subjects were positioned in a standardized standing posture and anatomical references were marked on the scapula for the wireless accelerometer (MyoResearch 3D DTS). After the accelerometer was secured, subjects performed five repetitions of standing scaption from 0-140. Linear scapular accelerations along three orthogonal axes (x, y, and z) were collected during arm elevation and lowering. For the first 9 subjects, the entire process was repeated 1-2 days later. Data was synthesized in order to reflect changes in acceleration from the resting position. Intraclass correlation coefficients (ICC 3, k) were used to determine the between-day intra-rater reliability. An independent t-test was used to determine the difference in average axis acceleration between those with and without dyskinesis. A one-way multivariate analysis of variance (MANOVA) was used to determine differences in acceleration between those with and without dyskinesis for each accelerometer axis while adjustments were made for multiple comparisons.

Results: There was good intra-rater reliability for the x and y axes (ICC>.80). There was a significant increase in overall acceleration of the scapula in those with dyskinesis (P=.039). There was also a significant increase in acceleration across the x-axis for those with dyskinesis (P=.003).

Conclusion: Wireless accelerometers are a reliable tool for quantifying scapular motion in healthy individuals with and without dyskinesis. In a healthy population with dyskinesis, the overall magnitude of scapular acceleration was greater when compared to a healthy group without dyskinesis.

Clinical Relevance: Dyskinetic subjects present with increased scapular acceleration in elevation implicating potential muscle imbalances that need to be further investigated in future research.

Publication Date



Physical Therapy | Rehabilitation and Therapy


Platform presented at the Combined Sections Meeting of the American Physical Therapy Association, Denver, CO, February 2020.

Scapular Acceleration during Upper Extremity Elevation in Healthy Individuals with and without Scapular Dyskinesis