![]() The navicular bone is also said to be a fulcrum to keep the pull of the deep flexor tendon constant at its insertion on the coffin bone. The navicular bone is compressed by the deep flexor tendon each time the horse moves. ![]() The deep flexor tendon is the main support of the navicular bone as it passes over the navicular bone and attaches to the semi-lunar crest of the coffin bone. For this reason, the sesamoid bones aid in reducing concussion to the fetlock joint the same way that the navicular bone does for the coffin joint-with “yielding articulation.” Another name for the navicular bone is the “distal sesamoid.” The fetlock joint also takes a lot of strain under movement. Reference: Pollitt CC: Color Atlas of the Horse’s Foot. The somewhat elastic collateral ligaments of the navicular bone (which are connected to the long pastern bone ) are what give the navicular bone this function of “yielding articulation.” When the function of the ligaments breaks down, navicular syndrome can develop.Ī)The navicular bone is under strain from the deep flexor tendon when the foot returns to its normal position and breaks over B) The navicular bone is compressed by the short pastern bone (P2) when the foot is loaded. This redirects the force of impact to prevent a direct concussion to the coffin joint and, in turn, the coffin bone. As the horse moves, weight comes down through the leg from the short pastern bone to the navicular bone which then has a slight downward yield, dissipating the concussion to the coffin bone. Major-General Smith also notes that the presence of the navicular bone in the coffin joint increases the surface area of the coffin bone’s articulation surface area to almost as much as the short pastern bone’s articulating surface area. The navicular bone provides this counteraction by yielding under pressure. In his Manual of Veterinary Physiology, Major- General Sir Frederick Smith states, “The joint is the centre of the entire movement of the leg the body rotates over it.” (1921) The incredible amount of force and articulation placed on the joint makes it necessary to have something to counteract shock. The navicular bone is necessary at this joint because of the range of motion and potential concussion that occurs at this site. There is no human counterpart as this joint in humans is the last joint in the finger, just behind the fingernail. The navicular bone in the horse is positioned between the third phanlanx (P3 or coffin bone) and the second phalanx (P2 or short pastern bone) at the coffin joint. The navicular bone acts as a fulcrum to keep the direction of the pull on the deep flexor tendon constant. ![]() To distinguish it from the navicular bone in the ankle, it is now commonly known as the scaphoid-which, interestingly, also means “boat” but in Greek instead of Latin. Older books refer to the bone in the human wrist as a navicular bone. The scaphoid bone in the human’s wrist used to be known as the navicular bone and its placement is comparable to the radial carpal bone in the horse’s knee. In the human, the navicular bone is positioned in the ankle and its placement is comparable to the central tarsal bone in the horse’s hock. The navicular bone in the horse is not in the same place as the human. The bone gets its name because it is shaped like a boat. Why does the horse have a navicular bone? What purpose does it serve? Navicular gets its word origin from the Latin, “navis” meaning boat (think “Navy”). Some conditions are made better by veterinarian-prescribed drugs. The condition is usually treated by the farrier with the application of bar shoes and wedge pads too alleviate pressure to the navicular area. Navicular syndrome or navicular disease often results in heel pain due to a problem associated with the navicular region not just the bone. ![]() navicular syndrome) rather than for its actual function. The navicular bone in the foot of the horse is known more for the problems it can create (i.e. It is attached in the foot via the impar ligament (blue) to the coffin bone (P3) and the collateral ligaments of the navicular bone (black) to the distal end of the long pastern bone (P1). Navicular comes from the latin word “navis” meaning boat because of the bone’s boat-like shape. The navicular bone is a small bone with a big function.
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