Elbow: The elbow is the point where the long bones of the upper arm connect. Here, the humerus, which is the bone of the upper arm, joins with the ulna (the inner bone of the forearm) and the radius (the outer bone of the forearm), creating a hinge joint. This joint allows the arm to move forward and backward like a hinge and also enables a slight rotation of the forearm. The biceps muscle is primarily responsible for bending the elbow, while the triceps muscle is key in straightening it. Stability of the elbow primarily comes from the ulnar ligament located on the inner side of the elbow. The outer bony part of the elbow is known as the epicondyle, a section of the humerus. Tendons attached to this area can become injured, leading to inflammation or tendonitis, commonly referred to as lateral epicondylitis or tennis elbow. Meanwhile, the inner part of the elbow features a bony prominence called the medial epicondyle of the humerus, where additional muscle tendons attach. Injury to these tendons can also result in inflammation or tendonitis, known as medial epicondylitis or golfer's elbow.