Forearm (antebrachii):
- 1- Borders:
- Proximal Border: Located about two fingers' width distal to the elbow fold.
- Distal Border: Positioned approximately 1 cm proximal to the styloid processes of the radius and ulna.
Antebrachial Regions:
- The forearm is subdivided into anterior and posterior compartments.
- Anterior Compartment:
- Contains flexor muscles responsible for wrist and finger flexion, as well as pronation.
- Innervated by the median and ulnar nerves.
- Posterior Compartment:
- Houses extensor muscles involved in wrist and finger extension.
- Innervated by the radial nerve.
- 3.-Longitudinal Lines:
- These lines divide the antebrachium into regions:
- Radial Line: Connects the styloid process of the radius with the lateral epicondyle of the humerus.
- Ulnar Line: Connects the styloid process of the ulna with the medial epicondyle of the humerus.
- 4.Fascia Antebrachii:
- The fascia antebrachii is a continuation of the brachial fascia.
- It is dense, especially in its proximal region.
- Fibers from the superficial antebrachial muscles attach to this thick fascia layer.
- 5. Septa and Compartments:
- The fascia sends two septa toward the radius:
- Anterior radial septum
- Posterior radial septum
- These septa adhere to the bone and to the fascia of the m. supinator proximally.
- The forearm is divided into three osteofibrous compartments:
- Anterior compartment: Contains muscles responsible for flexion and pronation.
- Posterior compartment: Houses extensor muscles.
- Radial compartment: Contains specific muscles.
lateral
- The anterior compartment is further subdivided into superficial and deep fascial spaces by an additional septum.