The elbow is a stable joint that moves in two directions; it bends and extends (it is affected with forearm rotation). The joint itself is made up of 2 bones, but discussing the elbow 3 bones are commonly mentioned.
The upper arm bone
This is the bone on the pinky side of the arm. It cups the humerus creating the elbow joint.
This is the bone on the thumb side of the bone. The upper end, by the elbow, is rounded which allows the forearm to rotate.
Ulnar Collateral Ligament
This ligament holds the ulna to the humerus. There are 3 separate bands that form this ligament.
Radial Collateral Ligament
This ligament holds the radius to the ulna.
This ligament holds the head of the radius in place.
There are several muscles that have attachments to the elbow. We will look at the major muscles and the muscles that form groups.
The biceps is located on the front side of the arm and attaches from the shoulder and upper arm bone to the forearm (below the elbow) and when contracted bends the arm.
The triceps are located on the back of the arm and attached from the shoulder and upper arm bone and attaches to the elbow and when contracted straightens the arm.
These are a group of individual muscles on the inside of the forearm and come together attaching to the inside of the elbow. These muscles are used for gripping and curling the wrist. Tendonitis sometimes develops here; golfers and throwing athletes are more prone to developing tendonitis due to the mechanics of their sports.
These are a group of individuals muscles on the outside of the forearm and come together attaching to the outside of the elbow. These muscles are used for opening the hand (extending the fingers) and extending the wrist. This is the most common site for developing tendonitis (tennis elbow).
There are 5 major nerves that run down the shoulder to the hand. We will mention 3 of the 5 for they are most common in elbow/forearm and hand injuries.
The median nerve runs from the neck down to the palm side of the hand (thumb, first finger and 1/2 of the middle finger). This nerve is involved in carpal tunnel syndrome. These nerves innervate the forearm flexors.
The ulnar nerve runs from the neck down to the palm of the hand (pinky, ring finger and 1/2 of the middle finger). This nerve is also known as the “funny bone”. As it travels down the arm, it curves around the inside of the elbow; at that point it is close to the surface of the skin and isn’t covered by muscle so can be accidentally bumped or hit causing numbness and tingling down the arm and into the hand. This nerve innervated muscles on the pinky side of the hand/forearm.
The radial nerve runs from the neck down the back side of the forearm to the hand (thumb, first finger, middle finger and 1/2 of the ring finger). This nerve innervates the muscles that extend the fingers and the wrist.
Bursas are fluid filled sacs that are located in areas to help reduce friction. The main bursa of the elbow is called the Olecranon Bursa. It is located at the point of the elbow. This is often injured when someone falls and/or hits the end of their elbow.