Why does my knee suddenly give way and now starting to feel painful?

Unless you have had a ligament injury which has made the knee structurally unstable in the past, the main reason why people start to feel their knee giving way especially with instances of going down stairs and suddenly having to place weight through the leg, is weakening of the surrounding muscles around the knee. If you have suffered with some knee pain in the past, pain switches off muscles in the knee thus leading to further weakness. With age too, we lose muscle mass and hence strength. This loss of strength can then lead to little niggles which promote more weakness which then leads to more occurences of pain and more weakness yet again. This is a common spiral seen in the general population. Hence, it is vital to maintain overall leg muscle tone and strength in order to counter the affects of age and/or past injury.

Many injuries can cause instability of the knee, mainly meniscus damage and ligaments damage. It would be very wise to follow-up with a health professional to diagnose the problem and start to manage it.

Well, it could be completely towards posterior cruciate ligament. Sometimes that type of injury, you do not really even notice it until you are doing something like running down the stairs and the suddenly the knee will give way. Then it will be painful. It could be to do with instability of the joint capsule in some way. I would suspect if it is just giving away, and then there is pain afterwards, that would be the posterior cruciate ligament.

Exercise physiologists are not allowed to diagnose so I would not be diagnosing that. I would be referring the client to seeking advice about that with the GP and then perhaps with a physiotherapist.

There are many reasons why your knee may be giving way and beginning to feel painful, that is why a thorough history should be taken in order to get an idea if it is more of an acute injury or an injury of insidious onset. If for example you were playing soccer and twisted your knee during the game, you may have strained particular ligaments around the knee (MCL, LCL, ACL, and PCL) which are responsible for maintaining stability around the knee joint.

If your knee instability and pain has come on gradually over time, it may be that you have patellar femoral pain syndrome which can be caused by many different factors (lower limb alignment, muscle imbalances, hip instability/weakness). Therefore, it is important to see a physiotherapist about the problem so they can do a thoroughly assessment and find out the main cause of the problem. They then will be able to give you self management techniques and specific exercises to address your knee instability and pain.

Can you give us more information on when/where you feel the pain/instability?

What aggravates it? What makes it feel better?

What type of exercise/sport do you do?

As stated above it could be many different factors, from structural damage or biomechanical weakness. More information is needed so we can help!

Matt

My own experience is all I can testify to:

Back in or around 2000 I was involved in a motorcycle/car crash that resulted in some injuries. I still have the small scar on the back of my head to prove it, I had a few stitches. However, the worst injury of all was my knee, which took about a year or so to heal (or so I thought). It was about 10 years later I started noticing my name was randomly unlocking, putting me in serious physical danger of the other knee injury in a fall should I not be able to stop the step within a split second. When I went to see an orthopedic, early arthritis was discovered. Everything else was fine. Since it was arthritis causing my knee to randomly unlock, I could not remain the orthopedics patient for very long at all whatsoever because there was nothing he could do for me. He did however, write a note on a script in my favor to let others know that I have a lifelong issue with arthritis and that I need to use the elevator where I may need to go from the ground level to and upper or lower level of a building. The note also read that there was no expiration, meaning the situation is permanent. I was also able to get my first handicap placard. Another thing is an incident on the same leg during my infancy when my drunken abusive mom tried to bend that same knee backwards. Ever since that very first answer event, I found out at some point that particular knee has never been quite right ever since. I somehow discovered there was a slight difference in that particular join but it didn't slow me down. However, when I had the wreck in 2000, that's when I really had trouble. I just couldn't walk for the longest time, and I think during my healing process I may have done too much too soon to try to force my recovery too fast too soon. I think this contributed to how I got arthritis later on because I was already back on another bike within three days after the accident. Fortunately it was a bike style that didn't require very much knee bending, but I was already working on trying to get back on a crotch rocket. I started working with my need to try to gradually get it to bend enough to where I could once again ride a crotch rocket. I think I went too far too soon and did too much too soon. I think this was detrimental to me in the long run, which may have very likely contributed to the arthritis. Even though it took a while for me to be back in the saddle, I think it was still too soon for my knee to be able to bend that far. This is most likely what may have started the arthritis, and I look back now and regret it because I later started having my knees suddenly unlock and give out without warning. I really don't want to have this happen on the steps or ice, I try my best to avoid these situations. However, when the physical therapist requires you to use steps against your better judgment, this can be a high-risk situation should your knee suddenly start acting up after having to use the steps or even do exercises for steps a certain way. This again is a high-risk situation when you really should be using the elevator or any other handicap lift whether it be a stair lift, pool chair, or the elevator. These handicap tools are installed for a reason including problems like mine. Forcing someone to have to use the steps or do step exercises can actually put a person in danger sure that knee gave out on the steps for instance, this is also a liability issue