How to assess knee strength

Assess function at the knee 

  • Ask the person to stand up out of a chair, walk three meters up and back 


If the person is unable to independently perform this movement with full strength, assess all individual knee movements on both sides using the MRC muscle power test.


Note: If a person is having difficulty with transfers, a full assessment of transfers and mobility should also be conducted. 


Assess function at the knee by asking the person to stand up out of a chair and walk three meters up and back
 

Read on to learn how to assess strength of individual movements at the knee.

How to assess knee flexion strength 


Positioning of person: 

  • For grade 0-2 (gravity eliminated): person in side-lying with side being tested on top 
  • For grade 3-5: person in prone position, with knee extended 


Clinician positioning and handling: 

  • For grade 0-2: support the leg at the ankle and knee joint. to test the opposite side, move to the other side of the bed. 
  • For grade 3-5: clinician on the test side. Support the ankle. Apply resistance behind lower leg 


Instructions for person: 

  • ‘Please bend your foot towards your buttock’


Watch these videos to learn how to assess knee flexion strength:

Assess knee flexion strength grade 0-2 
 

Assess knee flexion strength grade 3-5 
   


How to assess knee extension strength 


Positioning of person: 

  • For grade 0-2 (gravity eliminated): person in side-lying with side being tested on top, knee bent to 90 degrees 
  • For grade 3-5: person in seated position, with knee bent to 90 degrees, upper legs supported 


Clinician positioning and handling: 

  • For grade 0-2: support the leg at the ankle and knee joint. To test the opposite side, move to the other side of the bed.
  • For grade 3-5: clinician kneeling on the test side. Support the ankle. Apply resistance backwards at front of lower leg 


Instructions for person: 

  • ‘Please straighten your leg and kick your foot out’


Watch these videos to learn how to assess knee extension strength:

Assess knee extension strength grade 0-2
    

Assess knee extension strength grade 3-5
         


Activity

Activity Practice performing each of the muscle strength assessments with a colleague for: 

  • Knee flexion 
  • Knee extension 

Practice assessing in gravity eliminated and against gravity positions. 

Time: 5 minutes 

Post any questions on the discussion forum.

Congratulations, you have now learnt how to assess muscle strength for the knee. 

Learning how to properly assess muscle strength for each movement will take time so we encourage you to practice assessing each movement in your own time as well as in this module.