main agonists

M. deltoideus, Pars spinata
Mm. rhomboidei
M. Trapezius
Pars descendens
Pars transversa
Pars ascendens

synergists

M. Latissimus dorsi
M. teres minor/major

Description:

Hold EMLA by both handles, elbows shoulder high, upright body position, basic stomach tension, hold with maximal force for 5 sec.