Influence of Upper Trapezius Fibers on Hand-behind-back Motion Elicited Using Electrical Stimulation

Takanao SHIRAI, Tomohito IJIRI, Toshiaki SUZUKI
2021 Rigakuryoho Kagaku  
Purpose] Scapular anterior tilt and downward rotation are important in the hand-behind-back motion. The purpose of this study was to investigate the effect of the hand-behind-back motion when the upper trapezius muscle fibers involved in the scapular anterior tilt and downward rotation can not be relaxed. [Participants and Methods] The upper trapezius fibers of 20 healthy adults were electrically stimulated reproducing a state in which relaxation is not possible, and they performed
more » ... ack motion as well as the hand-behind-back motion without the electrical stimulation. Shoulder joint abduction, extension, internal rotation, scapular anterior tilt, upward rotation, and hand-behind-back motion distance were compared. [Results] Electrical stimulation caused prolongation of the hand-behind-back motion distance, decrease in the scapular anterior tilt angle, and increase in the upward rotation angle. [Conclusion] The results suggest that the muscle tone of the upper trapezius fibers and scapular motion are important in hand-behind-back motion.
doi:10.1589/rika.36.433 fatcat:r2spcn53ebamtp4nhl3yswh7ja