The muscular anatomy of a horse is a complex system that helps to move the bones and joints of the animal. The muscles of the horse are divided into two main categories: voluntary muscles, which the horse can control, and involuntary muscles, which work automatically.

The voluntary muscles of the horse are responsible for movement and are divided into two main groups: skeletal muscles, which are attached to the bones and move them, and smooth muscles, which are found in the organs and blood vessels and control involuntary movements.

The skeletal muscles of the horse are responsible for moving the bones and joints and are divided into several groups, including the shoulder muscles, the neck muscles, the back muscles, the hindquarters muscles, and the leg muscles.

The shoulder muscles of the horse are responsible for moving the shoulder blade and upper arm bone, and they help to support the weight of the animal. The neck muscles of the horse allow the animal to move its head and neck and are important for balance and coordination. The back muscles of the horse help to support the spine and allow the animal to move its body. The hindquarters muscles of the horse are responsible for moving the hind legs and are important for propulsion. The leg muscles of the horse allow the animal to move its legs and are important for balance and support.

The smooth muscles of the horse are found in the organs and blood vessels and are responsible for involuntary movements. These muscles work automatically to keep the horse healthy and are found in the heart, the digestive system, and the respiratory system.

Overall, the muscular anatomy of a horse is essential for movement and is closely linked to the skeletal system to allow the animal to run, jump, and perform other activities.