Revista Brasileira de Medicina do Esporte
Print version ISSN 1517-8692
HALLAL, Camilla Zamfolini; MARQUES, Nise Ribeiro and GONCALVES, Mauro. Electromyographic ratio of shoulder stabilizer muscles during performance of exercises with oscillatory poles. Rev Bras Med Esporte [online]. 2011, vol.17, n.1, pp. 31-35. ISSN 1517-8692. http://dx.doi.org/10.1590/S1517-86922011000100006.
Shoulder pain and dysfunction processes are very common and demand great attention from the professionals who work with training and rehabilitation of this joint. Excessive activation of the upper trapezius muscle (UT) combined with decreased activation of the lower trapezius (LT) have been proposed as a contributing factor to shoulder injuries. Several equipments are used in training and rehabilitation of these muscles like elastic bands, free weights and recently, oscillatory poles. Despite having been used in clinical and sports context, little is known about their effects on the recruitment of shoulder stabilizers. Thus, the objective of the present study was to determine the activation ratio between UT and LT in different exercises performed with an oscillatory pole. 12 young (20.4 ±2.0 years) and physically fit females participated in this study. EMG signal of UT and LT was collected during 3 different exercises performed with oscillatory pole. The EMG signal analysis was done with Root Mean Square (RMS) values by the calculation of the ratio between the muscles UT and LT for each exercise. Statistical analysis was carried out with ANOVA for repeated measures and post hoc of Bonferroni tests, considering significant p<0.05. Exercise III showed lower ratio between UT and LT (0.722), followed by exercises I and II, respectively (0.876 and 0.995). CONCLUSION: The use of oscillatory pole in exercises performed with single hand grip, sagittal plane and with the pole perpendicularly to floor are recommended for training and rehabilitation of scapular stabilizer muscles since these promote lower activation of UT than LT
Keywords : shoulder rehabilitation; muscular balance; scapula; eletromyography.