Date of Award
Doctor of Physical Therapy (DPT)
Electromyography -- methods; Movement Disorders -- physiopathology; Scapula -- physiopathology; Case Reports
Introduction and Purpose. The purpose of this case study was to examine the differences in muscle activation between the upper trapezius, middle trapezius, lower trapezius and serratus anterior in a participant with scapular dyskinesia.
Methods. EMG activity was recorded using a Noraxon TeleMyo DTS telemetry unit with a sampling rate of 1 kHz. EMG data was recorded during three different speeds of shoulder abduction. Four scapular muscles were monitored bilaterally during the experiment. The muscles that were monitored included the upper trapezius, middle trapezius, lower trapezius and serratus anterior. The subject was also captured on video using the NiNox 125/250 FPS camera system.
Results. In comparing UE ratios of EMG activity, it appears that the left lower trapezius showed more EMG activity than the right lower trapezius. The left serratus anterior showed decreased activity relative to the trapezius muscle activity. The decreased activity in the left serratus anterior would help explain the scapular winging that occurred in the subject during shoulder elevation .
Conclusion. The results of this study indicate that the subject showed increased EMG activity in the left lower trapezius and decreased in the left serratus anterior that might explain the scapular dyskinesia. The use of EMG and video may be a useful diagnostic tool for clinicians to identify specific muscle firing patterns.
Garcia, Daniel; Roppel, Trevor; Scheresky, Mekenzie; and Omdahl, Shane, "EMG of Serratus Anterior, Upper, Middle, and Lower Trapezius during Glenohumeral Abduction in a Participant with Scapular Dyskinesia: A Case Study" (2019). Physical Therapy Scholarly Projects. 666.