The elbow joint is a complex hinge joint connecting the upper arm (humerus) to the forearm (radius and ulna), enabling crucial arm movements. It functions primarily as a hinge, allowing flexion (bending) and extension (straightening) of the arm, but also incorporates a pivot action for forearm rotation.
Structure of the Elbow Joint
The elbow joint isn't a single joint, but a complex of three articulations working together:
- Humeroulnar Joint: A hinge joint formed between the trochlea of the humerus and the trochlear notch of the ulna. This is the primary joint responsible for flexion and extension.
- Humeroradial Joint: A gliding joint between the capitulum of the humerus and the head of the radius. This contributes to flexion and extension and works in conjunction with the radioulnar joints.
- Proximal Radioulnar Joint: A pivot joint between the head of the radius and the radial notch of the ulna. This allows the forearm to rotate, pronating (palm down) and supinating (palm up). [Source: Multiple sources including
https://teachmeanatomy.info/upper-limb/joints/elbow-joint/,https://www.kenhub.com/en/library/anatomy/elbow-joint, andhttps://www.ortho.wustl.edu/content/patient-care/3151/services/shoulder-elbow/overview/elbow-arthroscopy-information/the-anatomy-of-the-elbow.aspx]
The ends of these bones are covered with articular cartilage, providing a smooth surface for movement. Strong ligaments, such as the ulnar collateral and radial collateral ligaments, stabilize the joint. [Source: https://www.ortho.wustl.edu/content/patient-care/3151/services/shoulder-elbow/overview/elbow-arthroscopy-information/the-anatomy-of-the-elbow.aspx]
Function of the Elbow Joint
The primary function of the elbow is to provide a stable yet highly mobile connection between the upper arm and forearm, facilitating a wide range of movements essential for daily activities:
- Flexion: Bending the forearm towards the upper arm.
- Extension: Straightening the forearm.
- Pronation: Rotating the forearm to turn the palm downwards.
- Supination: Rotating the forearm to turn the palm upwards. [Source:
Your elbow hinges to bend and straighten your arm. It's also a pivot joint. Pivot joints rotate in place without moving out of their original position. Your elbow pivoting is what lets you turn your forearm over to move your palm up and down.andhttps://www.kenhub.com/en/library/anatomy/elbow-joint]
These movements are facilitated by numerous muscles in the upper arm and forearm, working in coordination. [Source: https://www.ncbi.nlm.nih.gov/books/NBK536975/ and https://www.ncbi.nlm.nih.gov/books/NBK551630/]
The elbow joint's stability is crucial for tasks requiring precision and force. The structure and function of the elbow enable us to perform everyday actions such as lifting, carrying, writing, and manipulating objects.
