[Last Edited: 24/08/26]
What Causes my Knee to Lock?
If your knee has been getting stuck or you're experiencing difficulty moving your knee and getting the full range of movement you could have a problem or injury to your cartilage.
Cartilage in the knee is referred to as the meniscus. There are two rims of the cartilage of the tibia that are shaped like horseshoes, they are wedge-shaped too like the edge of a cycling velodrome. Once you have that mental picture you can see how the femoral condyles (think big knuckles) sit in these horseshoes for shock absorbency, stability and movement. Whether the knee is bending or straightening, the condyles must be able to glide over the meniscus surface to create the movement.
Falls, sporting injuries and twisting can cause tears in the cartilage or the surfaces can become rough over time with ageing. These changes to the surface of the meniscus means that the movement of the joint can become limited. It can often feel like a free movement suddenly becomes stuck or blocked. You may find you even have to grab your leg to free it up or move into a different position for the movement to continue. Tears in the surface of the meniscus get in the way and stop the gliding motion of the joint.
Knee movement can also be blocked by 'loose bodies’ in the knee joint, floating in the synovial joint fluid (natural joint lubrication). This can happen from injuries, where something has torn and left floating free whether from the meniscus or from patella cartilage or even something else in the joint. Once floating around they can interrupt the smooth movement, so blocking or knee locking can be more intermittent or occasional.
With the knee movement locking, exercises can improve joint flexibility and reduce the locking frequency. Alternatively, a keyhole surgery can be performed to clear the debris and loose bodies in the joint restoring unblocked movement and normal activity. If the knee hasn't been able to move through its normal range in some time it may be that other structures (muscles and tendons) may have tightened up, people can also experience change to their walking habits so they limp or do things differently. It can take quite a bit of practice to get this back to normal again.
A word about what a support can and cannot do here. A knee that genuinely locks is being blocked by something physical inside the joint, and no support will move a torn flap of meniscus or a loose body out of the way. What a support does is add a firm, steady feeling around the knee, which some people find helps their confidence walking and on stairs while they are waiting to be seen or working through their exercises. That is a real thing, and it is a different thing from fixing the cause.
A knee that locks, or that you have to manoeuvre to free, is worth getting looked at rather than managing at home - especially if it happened after a twist or a fall, if the knee swelled up, or if it will not take your weight. A GP or physiotherapist can tell you whether it needs imaging, exercises, or something else entirely.
The Essential Wellness knee support is a strong all-rounder, adjustable at three points, with a cushioned ring that sits around the kneecap. People wear it for the steadier feeling it gives while they are on their feet.
