Each joint action, with the role and emphasis the graph assigns each muscle. These are qualitative anatomical labels, not measured muscle activation.
Spine extensionprimary action · resisted
Rectus abdominis (prime mover, high emphasis); Transverse abdominis (stabilizer, high emphasis); External oblique (stabilizer, moderate emphasis); Internal oblique (stabilizer, moderate emphasis)
Spine rotationsecondary action · resisted
External oblique (stabilizer, moderate emphasis); Internal oblique (stabilizer, moderate emphasis); Multifidus (stabilizer, low emphasis)
Hip flexionsecondary action
Iliopsoas (synergist, moderate emphasis); Rectus femoris (synergist, moderate emphasis)
Shoulder flexionsecondary action
Anterior deltoid (synergist, moderate emphasis); Serratus anterior (stabilizer, moderate emphasis)