Hind foot

The foot (pes, hind foot, hind paw) skeleton is made up of the tarsals, the metatarsals, and the digits, or toes. The tarsus contains from five to seven bones. The most prominent tarsal bone is the calcaneus, or heel bone, which projects backward and upward, beyond the ankle joint, to receive the Achilles tendon of the gastrocnemius and soleus muscles. Primates and bears stand and walk with their heels on the ground; this is called plantigrade locomotion. Most four-legged animals stand and walk with only the tips of their toes on the ground and their heels raised quite high up off the ground, never touching the heel to the ground while walking; this is called digitigrade locomotion.

ALL LEFT REAR LIMB

OUTSIDE VIEW < FRONT

HEEL

Drawing Anatomy Foot

BEAR

WALKS ON SOLE OF FOOT

HORSE

WALKS ON TIPTOE

WALKS ON TOES

BEAR

WALKS ON SOLE OF FOOT

(FROM SPECIMENS)

NUCHAL LIGAMENT

Nuchal Ligament

(AFTER ELLEÜBERGER)

Bank1 Sensor Location Pontiac FirebirdAnimal Anatomy Muscles Tail

FIRST TAIL VERTEBRA

Cartilaginous Joints Horse Pelvis

PELVIS

HORSE

NUCHAL LIGAMENT

(AFTER ELLEÜBERGER)

the weight of the head. Muscles pull the head down; the nuchal ligament, along with muscles, helps raise it.

In the horse, the rear end of the nuchal ligament attaches to the tip of the spinous process of the fourth thoracic vertebra, and in the ox, to the first thoracic vertebra. This makes the neck of the horse appear relatively longer and its trunk shorter, whereas in the ox the neck appears shorter and the trunk longer. In the horse, the nuchal ligament can be seen on the surface. An elongated fat pad and the mane run along its upper surface. Covered by muscle and not directly visible in the ox, the presence of the nuchal ligament can be detected by the taut upper profile of the neck, between the head and the shoulder. In carnivores, the nuchal ligament is thin and has no effect on the surface. It can be seen and felt on the top of the back of the neck in humans when the head is tipped down.

The sacrotuberal ligament is a sheet-like ligament in the horse and ox, and cordlike in the dog and feline. It connects the sacrum and the first one or two tail vertebrae to the ischiatic tuberosity of the pelvis. The rear part of its posterior edge can occasionally be seen in the ox and the dog, passing downward and backward toward the ischiatic tuberosity.

The metatarsals and digits of the hind limb are similar to those in the forelimb, with some notable differences. In the horse, the single metatarsal of the hind limb is longer that the metacarpal of the forelimb. Dogs may have a very rudimentary first metatarsal; occasionally, especially in the larger breeds, a couple of attached small phalanges form a much reduced digit, complete with a claw, called the dewdaw. Cats often have a tiny, rudimentary first metatarsal only, or may have a fully developed dewdaw. Because these first digit bones are usually either absent or quite small and insignificant, carnivores are typically seen to have five digits in front (with a reduced first digit) and four in the back.

Primates have two phalanges in the big toe, and the usual three in the other four digits. The big toe is the thickest toe, and is opposable (it can touch the other four toes) in monkeys and apes, but not in humans.

Ligaments

The thick, strong, elastic, nuchal ligament is made up of the cordlike funicular part and the sheetlike lamellar part. The funicular part consists of a double cable (lying side-by-side) that connects the back of the skull to the top of the rib cage. The lamellar part lies deep in the neck. The elasticity of the nuchal ligament assists in lifting and then supporting

SACROTUBERAL LIGAMENT

FIRST TAIL VERTEBRA

SACROTUBERAL LIGAMENT

SACRUM

FIRST TAIL VERTEBRA

SACROTUBERAL LIGAMENT

SACRUM

FIRST TAIL VERTEBRA

PELVIS

HORSE

PELVIS

PELVIS

FEMUR

SACROTUBERAL LIGAMENT

PELVIS

LEFT SIDE 4 FRONT

(AFTER NICKEL)

Joints and Motion A joint is the place where two bones articulate, or touch, and usually move against one another. The articular surfaces are usually covered with lubricated cartilage. Motion takes place at joints. The motion may be slight, for instance, at the joint where a rib articulates with its vertebra or among the small wrist bones, or the motion may be extensive, such as at the hip joint, where the thigh bone can be flexed forward, extended backward, abducted outward, adducted inward, and rotated. Some joints have virtually no motion, such as where the pelvis articulates with the sacrum, or between the various bones of the skull. Bones are held together at joints by ligaments. They permit only the desired movement to take place while restricting undesired movement. Muscles and their tendons pull on the bones and create movement.

Flexion takes place when two bones are brought closer together, as when bending the elbow joint so the radius comes closer to the humerus (decreasing the angle between the two bones). Extension takes place when two bones are moved further apart, as when straightening the elbow so that the radius moves away from the humerus (increasing the angle between the two bones). Abduction involves moving a bone away from the centerline of the body, whereas adduction brings the bone toward it.

Rotation takes place when a bone is rotated around its long axis. Rotation occurs in the radius when the forearm is pronated and supinated—the upper end of the radius rotates in place on the outside of the elbow while its lower end glides around the lower end of the ulna. This motion takes place only in animals with a complete ulna and with a radius that is capable of rotation around the ulna, such as felines and primates. Rotation also takes place at the joint between the first and second neck vertebrae (the atlas and axis), permitting the head to rotate side-to-side without participation of the other neck vertebrae.

In four-legged animals, motion in the limbs is primarily flexion and extension, for the purpose of locomotion. Abduction, adduction, rotation, and gliding take place to a lesser degree.

The illustrations show the most important, most conspicuous movements of the skeleton. The degree of motion illustrated is based on photographs of animals in action. The left side of the body is illustrated. In most cases the horse is used, and these movements are similar in the various species. Other animals are illustrated where appropriate. Each limb illustration shows only one joint moving, for the sake of demonstrating that particular joint. However, in some species, some joints always move in conjunction with others, which will account for the skeleton appearing unnatural (impossible) in some of the illustrations. For example, in the horse, the ankle joint must flex when the knee joint is flexed, and conversely, the two joints extend simultaneously.

Animal Knee Joint

SPINE AND SKULL STANDING

SPINE AND SKULL FLEXED

SPINE AND SKULL FLEXED

Outside Skull Anatomy

SCAPULO-THORACIC |0INT HORSE

LEFT SIDE < FRONT

Animal Skeleton Illustration

ELBOW JOINT

HORSE

LEFT FRONT LIMB OUTSIDE VIEW

< FRONT

(METACARPOPHALANGEAL JOINT IS USUALLY FLEXED WHEN THE (WRIST WOULD ALSO BE ELBOW JOINT FLEXED WHEN THE ELBOW IS FLEXED) JOINT IS FLEXED)

RADIUS IN PRONATION AND SUPINATION

LION

LEFT FRONT LIMB FRONT VIEW -4 INSIDE

Pronation Dog Paw
PRONATION

WRIST JOINT HORSE

LEFT FRONT LIMB

Bones The Horse Front LimbCanine Anatomy Phalanges Metaphalangeal

(METACARPOPHALANGEAL JOINT IS OFTEN FLEXED WHEN THE WRIST JOINT IS FLEXED)

FLEXED

(METACARPOPHALANGEAL JOINT IS OFTEN FLEXED WHEN THE WRIST JOINT IS FLEXED)

FLEXED

TOE JOINTS HORSE

LEFT FRONT LIMB OUTSIDE VIEW ■* FRONT

Horse Front LimbMetatarsophalangeal JointPrimate Knee Joint

(METATARSOPHALANGEAL JOINT IS USUALLY FLEXED WHEN THE KNEE JOINT IS FLEXED)

Drawing Equine Hock
FLEXED

(ANKLE/HOCK JOINT WOULD ALSO BE FLEXED WHEN THE KNEE JOINT IS FLEXED)

(METATARSOPHALANGEAL JOINT IS USUALLY FLEXED WHEN THE KNEE JOINT IS FLEXED)

KNEEIOINT HORSE

LEFT REAR LIMB OUTSIDE VIEW < FRONT

(METATARSOPHALANGEAL JOINT IS USUALLY FLEXED WHEN THE ANKLE JOINT IS FLEXED)

Metatarsophalangeal Joint

(KNEE JOINT WOULD ALSO

BE FLEXED WHEN THE ANKLE JOINT IS FLEXED)

FLEXED

(KNEE JOINT WOULD ALSO

BE FLEXED WHEN THE ANKLE JOINT IS FLEXED)

(METATARSOPHALANGEAL JOINT IS USUALLY FLEXED WHEN THE ANKLE JOINT IS FLEXED)

FLEXED

STANDING

ANKLE (HOCK) JOINT

HORSE

LEFT REAR LIMB OUTSIDE VIEW

Joints Hind Limb AnimalToe Joints AnatomySkeleton Hind Leg Horse

TOE JOINTS

HORSE

LEFT REAR LIMB OUTSIDE VIEW

The skeletal muscles of the body are the organs of voluntary motion, and by their contraction they produce movement, stabilize body segments, or lock the joints as required.

These muscles attach to the skeleton and create most of the surface form of an animal. The two most common types of muscles are the volumetric muscles, with full volumes, like the triceps, calf muscles, or long narrow forearm muscles, and the sheet muscles, like the thin latissimus dorsi or the trapezius. The volumetric muscles create most of the body's forms. The sheet muscles cover the volumetric muscles and bone, whose forms may be either seen underneath or concealed. Sheet muscles can also produce form directly, especially at their edges where they appear in relief. A muscle belly is the total fleshy mass of a single muscle. It may consist of one or more heads, which are distinct muscle forms that usually begin separately yet have a single insertion after they fuse together.

Muscle fibers attach either directly to the skeleton or cartilage, or by means of a tendon, which may be cable-like or sheet-like. Muscles also attach to the surface of other muscles. Fascia is a connective tissue which, among other things, forms dense, fibrous, sheets that surround the individual muscles, the limbs, and the body as a whole, forming sheaths around them. Fascia holds the muscles in position, and yet allows adjacent muscles to glide past one another as they contract. Fascial surfaces also provide attachment areas for muscles.

When a muscle contracts and shortens, its origin and insertion get closer together and the belly becomes thick and full. When stretched, it becomes thin and elongate. One can think of the muscles of the body as a cluster of balloons attached to a rigid skeleton, all covered with a thin skin. Regardless of whether they are volumetric and bulging, or sheetlike and flattened, they all produce convex forms. This yields a complex, undulating surface created by a series of adjacent, yet distinct, anatomical forms.

Not all surface forms conform to the delineations of the muscles as described in an anatomy book. When a muscle pulls on its tendon or on a wide or narrow fascial sheet that lies on top of other muscles, the tension across the surface can create new forms by separating the underlying muscle belly into two or more forms. For example, the tensor fasciae latae muscle of the leg will pull on a narrow band of fascia on the outer surface of the thigh and compress the underlying vastus lateralis muscle, creating a vertical furrow. Also, a single muscle belly can at times separate into several basically parallel bundles as it contracts.

It is important to understand the shape and location of each muscle and muscle group in relationship to the skeleton, as well as how muscles change when they are contracted. This understanding is the basis of artistic anatomy.

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Responses

  • gertha
    What part of the hindfoot does a dog walk on?
    9 years ago
  • Almaz
    What will you do if the tarsals of the dog is moved?
    2 years ago
  • Robert
    What is the function of the dewdaw?
    2 years ago
  • tauno mikkola
    How to draw dog hind foot?
    2 years ago
  • Hagosa
    What is hind foot animal?
    1 month ago

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