B
Bar Shoe: Characterized by a closed (rather than open) heel.
Beat: The number of beats associated with a gait refers to the number of individual footfalls that occur before the sequence repeats. Two feet striking the ground surface simultaneously generate a single beat.
Bilateral Lameness: Altered movement manifesting on both (right and left) sides of the horse.
Biomechanical Lameness: Altered movement(s) made in an attempt to accommodate restricted or exaggerated action of one or more parts of the horse’s anatomy (usually the limbs). Many forms of biomechanical lameness have no inflammatory component and accordingly do not hurt.
Biomechanics: The structure and function of biological systems.
Breakover: The action of the hoof as it pivots over the toe to lift and move the respective limb forward.
Bursa: A synovial sack that facilitates tendon movement over bone via lubrication.
C
Caudal: Toward the tail. Refers to anatomy of the head and body parts above the carpi (knees) in the forelimbs and tarsi (hocks) in the hind limbs. “The pelvis is caudal to the neck.”
Centerline: An imaginary line that splits the horse into right and left halves (see also Midline).
Central Neurologic Lameness: Altered movement stemming from abnormal function of the brain and/or spinal column.
Cervicothoracic: The region adjoining the neck and chest.
Chronic: Of long or indefinite duration. “This horse has a chronic lameness; it first developed last year.”
Circumduction: The circular or conical movement of a limb relative to the horse’s body. During protraction, the circumducting limb moves away from the midline before moving back toward it, thus tracing a semicircle. This gait deficit is most often associated with neurologic disease in the horse.
Collagen Fibers: Small, inelastic reticular fibrils comprised of insoluble protein. Collagen fibers are found in skin, bone, ligaments, tendons, and cartilage, and comprise nearly one-third of all body protein.
Collateral: On either side. “The medial (inside) and lateral (outside) collateral ligaments of the fetlock joint function to maintain stability.”
Collection: A movement performed by the horse in which more weight is assumed by the hind limbs relative to the forelimbs.
Columnar: A pattern of muscle tissue in which individual fiber bundles (called fascicles) run parallel to the long axis of the structure and its respective tendon. This pattern allows for extensive range of motion but generates nominal force.
Compensating Limb: The limb that “takes the brunt” of the primary problem associated with another limb. “The horse’s left front limb often serves as the compensating limb for the right hind limb.”
Concentric Muscle Action: Contraction or shortening of muscle fibers.
Contraction: The process of becoming shorter or shrinking.
Contralateral: Located on the other side of the horse. “The right front limb is contralateral to the left front and left hind limbs.”
Contralateral Counterpart: The comparable limb located on the other side of the horse. “The right hind limb is the contralateral counterpart to the left hind limb.”
Contralateral Limb: A limb located on the other side of the horse. “The left front limb is contralateral to the right front and right hind limbs.”
Correct Lead: Leading with the inside forelimb while turning or circling.
Cranial: Toward the head. Refers to body parts above the carpi (knees) in the forelimbs and tarsi (hocks) in the hind limbs. “The neck is cranial to the pelvis.”
Cross-Firing: Striking the forelimb with the opposite (diagonal) hind foot. Occurs in pacers.
D
Daisy Cutter: A horse that demonstrates a flat stride with very little elevation of the limbs during protraction.
Descending Movement: Downward motion of one or more body parts.
Desmitis: Inflammation of ligament tissue.
Desmopathy: Ligament disease.
Diagonal Gait: A method of movement in which the forelimb and hind limb on opposite sides of the horse mimic each other in action.
Diagonal Pair: The pair of limbs that mirror each other in action. “The left hind and right front limbs comprise one diagonal pair and the right hind and left front limbs comprise the other.”
Diarthrodial Joint: A freely-movable joint characterized by the presence of a fibrous capsule, synovial membrane, lubricating (synovial) fluid and fibro- or hyaline cartilage layers which line opposing bony surfaces.
Differential List: A distinguishing list of diseases or conditions that present similar symptoms or clinical signs.
Distal: Toward the free (lower) end of the limb. “The foot is distal to the fetlock joint.”
Distal Tarsitis: Inflammation associated with the lower joints of the horse’s tarsus (or hock).
Dorsal: Toward the front of the limbs (below the levels of the carpus and tarsus) and toward the upper aspect of the head, neck, back, and pelvis. “The horse’s withers are dorsal to the ribs.”
Dorsal Plane: Passes through the head, body, or limb parallel to its dorsal surfaces.
Dorsal Subluxation: Abnormal repositioning or dislocation of a limb structure in a forward direction or a body structure in an ascending direction.
Dorsiflexion: Bending of the spine in a way that moves either end away from the ground surface.
Dorsolateral: Toward the front and outside of the lower limb (below the levels of the carpus and tarsus). “The outside toe quarter is dorsolateral to the center of the navicular bone.”
Dorsomedial: Toward the front and inside of the limb (below the levels of the carpus and tarsus). “The inside toe quarter is dorsomedial to the center of the navicular bone.”
Drifting:
