Table 2.

Electromyography electrode positions for the muscles analyzed in this study.

Muscle	Electrodes position
Deltoid	Mid-distance between the acromion and the humeral tuberosity (Hermens et al., 2000)
Upper trapezius	Halfway on the line from the acromion to C7 (Hermens et al., 2000)
Infraspinatus	Halfway and 2 cm below the scapula spine (Allen et al., 2013)
Serratus anterior	On the lateral border of the chest anterior to the latissimus dorsi and posterior to the pectoralis major (Maenhout et al., 2010)
Middle trapezius	At T3 level between the medial border of the scapula and the spine (Hermens et al., 2000)
Lower trapezius	At 2/3 on the line from the scapula spine to T8 (Hermens et al., 2000)
Erector spinae	Approximately 3 cm lateral to the spinous process at L3 level (Fenwick et al., 2009)
External oblique	Approximately 3 cm lateral to the linea semi lunaris (Fenwick et al., 2009)
Reference	Spinous process of C7