Musculus latissimus dorsi
The latissimus dorsi is a large extrinsic forelimb muscle. It originates from the thoracolumbar fascia (from spinous processes of thoracic and lumbar vertebrae) and the last few ribs, and inserts on the teres major tuberosity of the humerus. Its primary actions are to retract and adduct the forelimb and flex the shoulder joint. When the limb is fixed, it can help draw the trunk forward. It is innervated by the thoracodorsal nerve (roughly C7–C8). It is important in jumping, galloping, and collection work.
Origin: Thoracolumbar fascia from spinous processes of T3-T18 and lumbar vertebrae; last 2-3 ribs
Insertion: Teres major tuberosity of the humerus
Action: Retracts and adducts the forelimb; flexes the shoulder joint
Innervation: Thoracodorsal nerve (C7-C8)
Isolated injury is uncommon. It can be involved in shoulder or back strain, or secondary to other lameness that alters forelimb use.
## Overview Muscles heavily recruited during collected gaits, transitions, and jumping can be strained by the demands of collection. Signs include a shortened forelimb stride, reluctance to canter on
## Overview Saddle pressure damage occurs when the saddle extends too far back or creates focal pressure, compressing muscles such as the caudal latissimus dorsi. It produces white hairs, pressure ma
Reduced forward reach or reluctance to collect after hard work may involve the extrinsic shoulder muscles. Have persistent issues evaluated.
## Overview Muscles heavily recruited during collected gaits, transitions, and jumping can be strained by the demands of collection. Signs include a shortened forelimb stride, reluctance to canter on the affected lead, flinching when palpated behind the shoulder, resistance to lateral work, and flat jumping. ## Causes Overuse during collected work. ## Diagnosis Palpation and observation under saddle. ## Treatment Rest from collected work, physiotherapy, and gradual reintroduction. ## Recovery and Prognosis Good. ## Prevention Progressive development of collection. Signs include: shortened forelimb stride; reluctance to canter on the affected lead; flinching behind the shoulder; resistance to lateral work; flat jumping
## Overview Saddle pressure damage occurs when the saddle extends too far back or creates focal pressure, compressing muscles such as the caudal latissimus dorsi. It produces white hairs, pressure marks, dipping when groomed, cold-backed behavior, and uneven sweat patterns. Trigger points and atrophy can develop. ## Causes Incorrect saddle length or shape. ## Diagnosis Visual marks and palpation of painful or atrophied areas under the saddle. ## Treatment Correct the saddle fit and allow the tissues to recover. Physiotherapy for trigger points. ## Recovery and Prognosis Good. ## Prevention Proper saddle fitting. Signs include: white hairs or pressure marks behind the saddle area; dipping when groomed; cold-backed behavior; uneven sweat pattern
Isolated injury is uncommon. It can be involved in shoulder or back strain, or secondary to other lameness that alters forelimb use.
Reduced forward reach or reluctance to collect after hard work may involve the extrinsic shoulder muscles. Have persistent issues evaluated.
See the Latissimus Dorsi on our interactive 3D horse model. Open 3D Model