Activity – Vastus Muscles (Vastus lateralis, intermedius and
medialis)
In this activity we will use the "3 Rules of Muscles" to determine the joint actions of the Rectus
Femoris. An (TFL). Answer the questions below:
Quadriceps - Vastus muscle with Rectus Femoris removed on left - http://www.criticalbench.com/muscles/quadriceps-anatomy.jpg
Knee Joint Actions Word Bank
Action
Plane
Flexion
Extension
Sagittal
Sagittal
© 2014 Brent Brookbush
1. What joint does this muscle cross?
Knee
2. Since this vastus muscles course up and down, in-front of this joint, what joint action is
this muscle group responsible for?
Knee Extension
3. Critical Thinking: Will hip extension contribute to a stretch for the vastus lateralis,
intermedius and medialis? Adding hip extension to a "quadriceps" stretch targets which
muscle?
Hip extension will not affect the vastus muscles, but it may improve a stretch with
the intent of lengthening the rectus femoris.
4. Re-write your answers into one succinct table?
Vastus Muscles
o Joints crossed: Knee
o Actions: Knee Extension
Check your answers!
© 2014 Brent Brookbush