Asking horses to move faster than their natural cadence is likely to cause some bad side effects. Aside from overloading the fore limb (see "Slow Down") another is damage to the hind limb joints.  When the forelimbs are on the ground too long, too far back, the hind limbs have to adapt to avoid striking the front. They have many options, to the outside of the fore, to the inside, or behind,) but all of them will interfere with the synchronization of the joint rotations (see Asynchronous Joint Rotations). Unfortunately repeating these motions creates a new pattern of movement that becomes habit. To correct this requires creating healthy locomotion patterns know as CPG's (see Central Pattern Generators). This calls for many many repetitions of healthy kinematics to create CPG's.