Jumper's knee is more of a generic term for what's called patella tendonitis and patella is your formal word for your kneecap, so it's an overuse injury, because of the word tendonitis. That's an inflammation injury. The pain is usually experienced just below the kneecap, at the level just below the kneecap or as well as the tendon that runs from the kneecap down to the tibia, where it attaches, it's called the tibial tubercle, so it's just below the knee. You don't have to be involved in any jumping sport. That's one of the big misconceptions.
You just have to be involved in sports or recreation, usually and it's usually a situation where there's too much work load on the muscles and it's causing an overuse problem or there's an actual skeletal alignment issue that you don't know about, maybe from the hip or to the knee, so you're doing the normal amount of work, but it's poor efficiency because the hip is out of alignment or the knee is out of alignment. But one way or the other, you're going to get this pain just below the knee.
The activity that patient's usually experience the pain in, is usually when they're asked to load their leg and asked the quad to work in an eccentric manner meaning it's lengthening while it's contracting. The classic one is going to be going downstairs or walking downhill. When patients are complaining of walking downstairs or downhill, they're lowering their quad in a lengthening manner and this is where we know as therapists that we're probably dealing with a patella tendonitis injury.
Once you've been diagnosed with it or have the problem, if it's very sharp and painful you're going to want to rest of course, and maybe use some ice or anti-inflammatories, followed by a series of strengthening exercises for your quads and hamstrings and some stretching techniques, as well. It's a very treatable thing. We see it all the time in the clinic. It tends to be in the younger population in general.
They do very well with a month or two of therapy and even in the gym setting you get by. Just make sure you understand the first few days and weeks are very important to take care of the pain and range of motion first, before doing things too hard at the gym, so patella tendonitis and jumper's knee are synonymous with one another and it's a very common problem.