Knee effusion, sometimes called water on the knee, occurs when excess fluid accumulates in or around the knee joint. Common causes include arthritis and injury to the ligaments or meniscus, which is cartilage in the knee.
Various things can cause pain in the middle of the bicep, which is the muscle at the front of the upper arm. Muscle strains and bruises, for example, are common causes of bicep pain.
A hyperextended elbow occurs when your elbow joint bends backward more than it should. This condition mostly happens in individuals involved in weight-bearing activities or contact sports.
Shoulders are among the most frequently injured joints in the body, with the main culprit stemming from the rotator cuff, the part of the shoulder that allows you to lift and rotate your arms. Over 3 million Americans each year are affected by rotator cuff problems.