Each joint action, with the role and emphasis the graph assigns each muscle. These are qualitative anatomical labels, not measured muscle activation.
Hip extensionprimary action
Gluteus maximus (prime mover, high emphasis); Biceps femoris long head (synergist, high emphasis); Semimembranosus (synergist, moderate emphasis); Semitendinosus (synergist, moderate emphasis); Adductor magnus (synergist, moderate emphasis)
Knee extensionprimary action
Vastus lateralis (prime mover, high emphasis); Vastus medialis (prime mover, high emphasis); Vastus intermedius (synergist, moderate emphasis); Rectus femoris (synergist, moderate emphasis)
Ankle plantarflexionsecondary action
Gastrocnemius (synergist, high emphasis); Soleus (synergist, high emphasis)
Spine extensionsecondary action · resisted
Rectus abdominis (stabilizer, moderate emphasis); Transverse abdominis (stabilizer, moderate emphasis); Erector spinae (stabilizer, moderate emphasis)