Thanks for the reply the information was really useful. I think I will go see the GP as i've started doing more competitive sport but it slightly feels like I can't trust it 100%. When I did the injury i completly wrecked my knee - snapped the cruciate, strained the medial ligament and also damaged some of the cartalige - do you think this might be what is making it so stiff and sore. They took the graft from the hamstrings. Although my knee never locks if I put my foot down slightly wrong when walking it will make it jolt and causes pain down the front of the shin.