Each joint action, with the role and emphasis the graph assigns each muscle. These are qualitative anatomical labels, not measured muscle activation.
Shoulder external rotationprimary action
Infraspinatus (prime mover, high emphasis); Teres minor (prime mover, high emphasis); Posterior deltoid (synergist, low emphasis)
Shoulder abductionsecondary action
Medial deltoid (prime mover, moderate emphasis); Supraspinatus (synergist, moderate emphasis); Trapezius (synergist, low emphasis)
Elbow flexionsecondary action
Biceps brachii (synergist, low emphasis); Brachialis (synergist, low emphasis)
Elbow extensionsecondary action
Triceps brachii (prime mover, low emphasis)
Scapula upward rotationsecondary action
Serratus anterior (prime mover, moderate emphasis); Trapezius (synergist, low emphasis); Trapezius (synergist, low emphasis)