Sudden knee pain is common in contact sports, particularly those that involve twisting. It’s usually caused by a sprain, strain or tendonitis.

Runner’s knee is caused by overuse of the knee; symptoms include soreness and discomfort beneath or to one side of your kneecap; it can also cause a grating sensation in your knee.

Treatments include resting the knee, icing the spot, providing some support, elevating the knee, wearing arch support, trying acupuncture and as a last resort surgery.