Achilles tendinitis occurs when the band of tissue that connects the calf muscles at the back of the lower leg to the heel bone, the Achilles tendon, becomes inflamed. This condition is a result of overuse from intense exercise, jumping, running, and other activities that strain the tendon and calf muscles.
Patellar tendinitis is an inflammation of the tendon connecting the kneecap (patella) to the shinbone (tibia). Commonly called jumper's knee, patellar tendinitis is also referred to as patellar tendinopathy and patellar tendinosis.
Plantar fasciitis is the most common cause of heel pain. It is sometimes incorrectly referred to as a "heel spur". It is not the bone formation that causes the pain but, instead, this condition.