Musculus triceps brachii caput laterale
The triceps brachii has three heads: the long head, the lateral head, and the medial head. The long head is the largest and most superficial, visible as the muscular mass behind the shoulder. It originates from the caudal border of the scapula. The lateral head originates from the deltoid tuberosity and lateral surface of the proximal humerus. The medial head originates from the medial surface of the humerus. All heads insert on the olecranon process of the ulna. Their primary action is to extend the elbow and bear weight during the stance phase. They are innervated by the radial nerve (roughly C7-T1).
Origin: Deltoid tuberosity and lateral surface of the proximal humerus
Insertion: Olecranon process of the ulna
Action: Extends the elbow; bears weight during stance phase
Innervation: Radial nerve (C7-T1)
Triceps dysfunction or atrophy can severely compromise elbow extension and weight bearing. Radial nerve damage can affect the triceps. Relevant in evaluations of elbow function and after trauma. Diagnosis is clinical and with ultrasound or electromyography.
## Overview The triceps absorb large forces when a horse lands from a jump. Strain causes a shortened forelimb stride, reluctance to bear weight after landing, pain behind the shoulder, and refusal o
## Overview Radial nerve paralysis results from damage to the nerve that innervates the extensors of the elbow, carpus, and digit. Common causes are prolonged lateral recumbency during anesthesia or
Inability to bear weight on a forelimb or sudden swelling behind the shoulder after trauma should be evaluated immediately.
## Overview The triceps absorb large forces when a horse lands from a jump. Strain causes a shortened forelimb stride, reluctance to bear weight after landing, pain behind the shoulder, and refusal or stopping at fences. ## Causes Overload on landing. ## Diagnosis Palpation and ultrasound if needed. ## Treatment Rest, anti-inflammatories, and gradual return to jumping. ## Recovery and Prognosis Good. ## Prevention Progressive jumping fitness and appropriate fence heights. Signs include: shortened forelimb stride; reluctance to bear weight after landing; pain behind the shoulder; reluctance to jump or stops at fences
## Overview Radial nerve paralysis results from damage to the nerve that innervates the extensors of the elbow, carpus, and digit. Common causes are prolonged lateral recumbency during anesthesia or humeral fracture. The horse has a dropped elbow, cannot extend the limb, knuckles at the fetlock, and drags the toe. ## Causes Compression during anesthesia or trauma (including humeral fracture). ## Diagnosis Characteristic posture and gait. The limb can bear weight if the elbow and carpus are splinted in pure nerve paralysis. ## Treatment Supportive care, splinting, anti-inflammatories, and time for compressive injuries. Humeral fracture cases have a poor outlook. ## Recovery and Prognosis Good for many post-anesthetic compressive injuries if the limb is protected. Poor if associated with fracture. ## Prevention Proper padding and positioning during anesthesia. Signs include: dropped elbow; inability to extend the elbow and carpus; knuckling at the fetlock; dragging the toe
Triceps dysfunction or atrophy can severely compromise elbow extension and weight bearing. Radial nerve damage can affect the triceps. Relevant in evaluations of elbow function and after trauma. Diagnosis is clinical and with ultrasound or electromyography.
Inability to bear weight on a forelimb or sudden swelling behind the shoulder after trauma should be evaluated immediately.
See the Triceps Brachii (Lateral Head) on our interactive 3D horse model. Open 3D Model