Movement is brought about by the coordinated movement of the different body parts. During locomotion, the limbs are moved in a repetitive and regular sequence.
Movement with change in location
- Movement with change in location of the animal is known as “locomotion”. The movement may be forward, backward or sideward. In principle, in all these type of movement, there is a shift in change of the position of centre of gravity forward, sideward or backward depending upon the type of movement. Generally in domestic animals, the most common form of locomotion is forward movement. Lateral and backward movements are occasionally performed in certain situations like playing, fighting or when they overcome any obstruction on their way.
- Forward movement is brought about by the extension of all the joints of one limb and it is pressed against the ground (thrust). If the extended limb does not slip, then the force directed against the ground will be converted into a forward thrust. This is in turn transmitted to the trunk via the pelvis. Form the trunk, the thrust is transmitted to the opposite forelimb, which is then lifted off the ground and swing forwards. Immediately afterwards, the hind limb which has initiated the thrust is also placed forwards. In the meantime, the joint of other limb has begun their extension, shifting the thrust to the opposite forelimb. Normally in a slow moving gait, there will be regular shifting of centre of gravity from left to the right of the midline resulted in forward movement. This will be accompanied by rhythmic sideward movement of the trunk, head and tail. These rhythmic movements of head and tail contribute much to the maintenance of equilibrium during locomotion.
- Walk: Walk is the slowest form of forward locomotion. It is four-beat gait. The sequence of hoof beat will be as follows: 1. Left hind → 2. Right fore → 3. Right hind → 4. Left fore limb. During walk, two feet are always in contact with the ground, there is no suspension period. Three types of walk are recognised: the quick walk, normal walk and shortened walk. In horse, the step length in walk is 1.3 to 1.8 meter and the speed is 6 – 7 Km/hour.
- All domestic animals normally walk backwards with so much of reluctance. Because their locomotor apparatus is well suited only for forward walk and it has to spend more energy while walk backwards. A horse while walking backwards, spend 3 ½ of times more calories than it does when walking forward. To initiate backward walk, the thrust has to come from forelimb and it has to be transmitted to the hind limb via the trunk.
- Factors that cause hindrance for backward walking are:
- The forelimb musculature is poorly developed
- The forelimb is attached to the trunk only by synsarcosis
- The hind limb cantilever is rigidly attached with the trunk
- The lumbar region is poorly developed
- The position of centre of gravity of the body is not favourable for backward movement
- Trot: Trot is a two-beat gait in which fore and hind feet hit the ground together. The right forelimb and left hind limb move together as do the left forelimb and right hind limb.
- Trot is a faster gait than the walk. It is used by the all domestic animals; particularly the horse and dog can trot for longer time. The step-length of the horse while trotting is 2 to 2.3 meter and the speed is 14 – 18 Km / hour. Eskimo dog can pull sledges at 4 meter / second over a distance of 75 Km and at 6.5 meter / second over 11 Km.
- Pace: Pace is a modified two-beat gait which produces a greater speed without alterations in the sequence of limb movements. It is seen only in some of the large ungulates like Giraffes and Camel. In elephants and large bears it is the natural form of gait during faster locomotion.
- The characteristic feature of pace is simple “sagittal synchronism”. This means that the limbs of one side work together. Thus the movement of an animal in pace has been compared with that of two people walking in step, one behind the other.
- Gallop :The gallop is the fastest four-beat gait encountered in animals. In the horse, the step-length varies between 4.35 to 8 meters and the speed of 5 -9 meter / second at the middle gallop and 12 to 14 meter/ second at the racing gallop.
Movement with change in location
- Some movement occur without change in location of the animal like sitting, lying down, rolling and rising. In this type of movement, there may or may not be a shift in change of the position of centre of gravity.
