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, moderate emphasis); Semimembranosus (synergist, moderate emphasis); Semitendinosus (synergist, low emphasis); Adductor magnus (synergist, moderate emphasis)
Knee extensionprimary action
Rectus femoris (prime mover, high emphasis); Vastus lateralis (prime mover, high emphasis); Vastus medialis (prime mover, high emphasis); Vastus intermedius (synergist, moderate emphasis)
Ankle plantarflexionprimary action
Gastrocnemius (prime mover, high emphasis); Soleus (synergist, high emphasis)
Hip flexionsecondary action
Iliopsoas (synergist, high emphasis); Rectus femoris (synergist, moderate emphasis); Rectus abdominis (stabilizer, moderate emphasis)