A comparison of trapezius muscle activities of different shoulder abduction angles and rotation conditions during prone horizontal abduction

作者：Lim Jin Yong; Lee Jung Seok; Mun Byeong Mu; Kim Tae Ho^*

来源：Journal of Physical Therapy Science, 2015, 27(1): 97-100.

DOI：10.1589/jpts.27.97

• Prone horizontal abduction
• Trapezius muscle activity
• Electromyography

[Purpose] This study examined the differences in the activities of three parts of the trapezius muscle-the upper trapezius (UT), middle trapezius (MT), and lower trapezius (LT)-among three different rotation conditions of the shoulders, while subjects performed prone horizontal abduction (PHA) at 30 degrees, 60 degrees, 90 degrees, and 120 degrees of abduction. [Subjects and Methods] The subjects of this experimental study were 16 healthy male adults. Surface electromyography was used to collect data on the activity of each part of the trapezius. A two-way analysis of variance was used to compare the activities of each area of the trapezius-the UT, MT, and LT-among internal rotation (IR), the neutral position (NP), and external rotation (ER) of the shoulders during PHA with shoulder abduction of 30 degrees, 60 degrees, 90 degrees, and 120 degrees. [Results] Activity of the UT, MT, and LT significantly increased as the shoulder abduction angle increased during PHA. There was a significant difference only in the activity of the LT, with change in shoulder rotation. In addition, the muscle activity of the LT was highest during shoulder IR at 120 degrees. [Conclusion] Although activity of the LT was the highest during IR at 120 abduction, PHA accompanied by ER at an abduction angle of 120 degrees would be effective at eliciting high activity in the LT when PHA is performed. Nonetheless, at an early stage of rehabilitation, PHA accompanied by ER at low abduction angles of 30 degrees and 60 degrees would be desirable to elicit low activity of the UT and high activity of the LT.

• 出版日期2015-1