Normal range of motion in the knee
Normal ROM in the knee is usually minus 5 to 143 degrees in women and minus 6 to 140 degrees in men.
Flexion is that motion that moves the heel closer to the buttock. Extension is that motion that moves the heel closer to the position where the knee is straight. Hyperextension can be normal or as the result of an injury, and is that motion that moves the knee from fully straight to arching a bit backwards.
Peer-reviewed paperQuote from peer-reviewed paper:
"A minimum range of knee flexion of 90° is essential to daily activities with about 67° required in swing phase, 83° in climbing stairs, 90° in descending stairs, and 93° in rising from a chair."
Citation: Sancheti KH, Sancheti PK, Shyam AK, Joshi R, Patil K, Jain A. Factors affecting range of motion in total knee arthroplasty using high flexion prosthesis: A prospective study. Indian J Orthop. 2013 Jan;47(1):50-6. doi: 10.4103/0019-5413.106901. PMID: 23532488; PMCID: PMC3601234.
Factors affecting normal knee range of motion
Normal range of movement is not the same in everyone. It can depend upon:
What factors limit range of motion in the knee?
Range of motion in the knee can be limited by -
- muscle weakness
- pain
- reflex muscle inhibition
- fluid in the knee (effusion)
- damage to joint structures from injury, eg fractures, ligament damage
- a true mechanical block (eg cyclops lesion, adhesions or scar tissue in the normally-mobile soft tissue areas around the knee)
Forum discussions
- "LOA #2- what is the best thing to do post op"
A discussion about maintaining ROM after a lysis of adhesions procedure to release old scarring of arthrofibrosis.

