Changes

==='''Asymmetrical gaits'''===  

==='''Asymmetrical gaits'''===  

When the footfalls of a pair of forefeet or hindfeet are unevenly spaced in time, the gait is asymmetrical.  Symmetrical gaits are all some variant of the gallop, which is a general term.  The beat is therefore composed of couplets, separated by pauses, and one foot is a leading foot.  For the horse at least, the leading foot for the forelimbs is conventionally the second foot of the couplet to strike the ground (Fig. 10.11 c: 6th stage).  The leading forelimb is always on the inside of a turn (Fig. 10.12).  A galloping horse changes its lead during the stage when both forelimbs are off the ground (Fig. 10.11: 2nd stage). It may be necessary for a horse to change lead during a jump in order to prepare for a turn immediately on landing.

When the footfalls of a pair of forefeet or hindfeet are unevenly spaced in time, the gait is asymmetrical.  Symmetrical gaits are all some variant of the gallop, which is a general term.  The beat is therefore composed of couplets, separated by pauses, and one foot is a leading foot.  For the horse at least, the leading foot for the forelimbs is conventionally the second foot of the couplet to strike the ground (Fig. 10.11 c: 6th stage).  The leading forelimb is always on the inside of a turn (Fig. 10.12).  A galloping horse changes its lead during the stage when both forelimbs are off the ground (Fig. 10.11: 2nd stage). It may be necessary for a horse to change lead during a jump in order to prepare for a turn immediately on landing.

 

:::::'''Fig 10.11 Forms of asymmetrical gaits'''

:::::'''Fig 10.11 Forms of asymmetrical gaits'''

:::::Dark blue footprint = right footfall.

:::::Dark blue footprint = right footfall.

 

:::::'''Fig 10.12 Limb sequencing at a galloping turn'''

:::::'''Fig 10.12 Limb sequencing at a galloping turn'''

:::::The zebra is turning to its left.  The right forefoot contacts the ground first and the leading (left) limb is on the inside of the turn.

:::::The zebra is turning to its left.  The right forefoot contacts the ground first and the leading (left) limb is on the inside of the turn.

 

==='''Transverse and rotary sequence'''===  

==='''Transverse and rotary sequence'''===  

4.Finally, both extended and gathered suspension occurs in the fast springing gallop of the rabbit, carnivores (Fig. 10.11 d) and some artiodactyls.  

4.Finally, both extended and gathered suspension occurs in the fast springing gallop of the rabbit, carnivores (Fig. 10.11 d) and some artiodactyls.  

    

    

 

:::::'''Fig 10.13 Basic patterns of footfalls in asymmetric gaits'''  

:::::'''Fig 10.13 Basic patterns of footfalls in asymmetric gaits'''  

:::::The canter is a transverse gallop, modified to a three beat gait.

:::::The canter is a transverse gallop, modified to a three beat gait.

The half bound occurs when a spring is made using both hindlimbs together, but the animal lands on one forefoot before the other, as seen in rabbits and hares.   

The half bound occurs when a spring is made using both hindlimbs together, but the animal lands on one forefoot before the other, as seen in rabbits and hares.   

The running jump occurs in with a springing gallop during the stage of extended suspension (Fig. 10.11 d:  4th stage).  In the horse, the jump is not part of a normal gallop.   

The running jump occurs in with a springing gallop during the stage of extended suspension (Fig. 10.11 d:  4th stage).  In the horse, the jump is not part of a normal gallop.   

 

:::::'''Fig 10.14 The running jump of a horse'''   

:::::'''Fig 10.14 The running jump of a horse'''   

The kinetic energy of the horse has been partly stored as elastic energy in the hindlimbs; this energy can subsequently be released to oppose gravity.  The necessity for a concept of elasticity in quadrupedal mechanics cannot be overstated.   

The kinetic energy of the horse has been partly stored as elastic energy in the hindlimbs; this energy can subsequently be released to oppose gravity.  The necessity for a concept of elasticity in quadrupedal mechanics cannot be overstated.   

    

    

 

[[Category:Musculoskeletal System - Anatomy & Physiology]]

[[Category:Musculoskeletal System - Anatomy & Physiology]]