Lateral Meniscus/Fibular Collateral Ligament area pain...

Hello, I am a 22 year old athletic male with knee area pain symptoms.

The symptoms began last Monday (5 days ago) as I was walking a short distance (about 2 miles).

To begin with it just felt like a small irritation in the knee joint. I play badminton at county standard and I'm regularly on court, Monday night was no exception. The pain got noticeably worse within the first few hours but by the time I started playing harder it seemed to have disappeared.

However, when I finished playing, I could barely lift my leg to step forward as it was so painful.

Interestingly, by midday Tuesday the pain had completely disappeared. I also played Wednesday night and all I felt was that slight irritation (almost the same as when it started on Monday). Since Wednesday I haven't played at all, and today I went for a run... as I went downhill I felt it go again, but this time very sudden and sharp, almost as if someone had wedged a stone behind my knee. I could feel an irritation beforehand as I left the house, the acute pain didn't start until I reached the top of the hill.

I cannot seem to pinpoint the pain exactly, hence I can't find any good explanations through Google, but I believe it's coming from the Collateral Ligament or Collateral Meniscus area.

There is no pain when I relax the leg muscles (I can move my leg in all directions using my hands, without causing any symptoms to occur), and there is no pain when the leg is fully extended or fully bent.

However, there is severe pain as soon as I lift my leg to walk or step forward. The pain is especially strong walking downhill or downstairs - it seems to occur only when I contract the hamstrings to lift the lower leg during a step motion. The pain is there when I walk on level surface too, so unless I walk with a straight leg, the pain is there whenever I make the step motion.

There is no swelling or "pain on contact". I tried to push my fingers in all areas around my knee and felt nothing to confirm a knock/strike related injury.

I really need to play tomorrow, and my doctor is away until next Friday, so I would really appreciate any advice I could get. I don't necessarily want to see another doctor, but if it turns out to be something serious then I will make an appointment or even drop by the hospital.

I really don't think this is a MCL/LCL sprain (I've been doing a lot of research this afternoon), since the symptoms really don't match... but I'm no medical professional and could likely be wrong. Please advise.