Affiliations: [a] Department of Physical Education, Centro Universitário Tabosa de Almeida – Asces-Unita, Caruaru, Brazil | [b] Associated Graduate Program in Physical Education UPE/UFPB, João Pessoa, Brazil | [c] Department of Physical Therapy, Federal University of Paraíba, João Pessoa, Brazil | [d] Department of Physical Activity, Federal Rural University of Pernambuco, Recife, Brazil | [e] Postgraduate Program in Rehabilitation and Functional Performance, University of Pernambuco (UPE), Petrolina, Brazil
Correspondence:
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Corresponding author: Gabriel de Amorim Batista, Associated Graduate Program in Physical Education, University of Pernambuco, R. Arnóbio Marquês, 310, Santo Amaro, Recife 50100130, PE, Brazil. E-mail: gabriel_amorimbatista@hotmail.com.
Abstract: BACKGROUND: Scapular dyskinesis has been associated with shoulder dysfunctions, and changes in electromyographic (EMG) activity have been reported during the execution of some exercises. OBJECTIVE: To compare upper limb muscles EMG of asymptomatic subjects with and without scapular dyskinesis during bench-press and dumbbell fly exercise performed on different surface stability conditions. METHODS: Twenty-eight physically active men were allocated into two groups: Control group (n= 14) and Dyskinesis group (n= 14). The participants performed six repetitions lasting three seconds of the bench press and dumbbell fly exercises with 50% of one-repetition maximum (1RM) on a bench and a Swiss ball. The EMG activity of the pectoralis major, serratus anterior, upper and lower trapezius, anterior deltoid, biceps and triceps muscles were recorded. RESULTS: No differences were found between groups, regardless of exercise or surface type. Inserting the unstable surface in the supine exercise promoted a slight increase in upper trapezius EMG activity for the control [4.32 (95% CI: 1.04 to 7.60)] and dyskinesis [3.30 (95% CI: 0.34 to 6.27)] groups. CONCLUSIONS: There is no difference in upper limb muscle EMG activity between subjects with and without scapular dyskinesis. In addition, inserting unstable surfaces did not modify EMG activity.
