Each joint action, with the role and emphasis the graph assigns each muscle. These are qualitative anatomical labels, not measured muscle activation.
Shoulder extensionprimary action
Latissimus dorsi (prime mover, high emphasis); Teres major (prime mover, high emphasis); Posterior deltoid (synergist, moderate emphasis)
Shoulder horizontal abductionsecondary action
Posterior deltoid (synergist, moderate emphasis); Latissimus dorsi (synergist, low emphasis); Infraspinatus (synergist, low emphasis); Teres minor (synergist, low emphasis)
Elbow flexionsecondary action
Biceps brachii (synergist, high emphasis); Brachialis (synergist, moderate emphasis); Brachioradialis (synergist, low emphasis)
Scapula retractionsecondary action
Trapezius (synergist, moderate emphasis); Rhomboids (synergist, moderate emphasis)
Spine extensionsecondary action
Erector spinae (stabilizer, high emphasis); Multifidus (stabilizer, moderate emphasis)