This is one of the early rides after Lacey came back from retirement-injury-blindness. I rode bareback with just a halter, so that things were as simple as possible. I would just walk around the arena a few times, to rebuild fitness and balance.
I used a lot of in-hand exercises while she was coming back into work, so that she could learn to coordinate her body and build balance, and to stretch and loosen her muscles and joints without the added weight of a rider.
Schooling in-hand is also a good way to teach a young horse the basics before he is backed, or to teach new concepts to a mature horse.
Mobilising the jaw is one of the first steps. The tongue is connected to the lower muscles of the neck and to the upper limb of the forelegs, via the hyoid apparatus. So a relaxed mouth is a mobile mouth and vice versa. And, as such, a relaxed/mobile mouth should lead to a relaxed horse.
Philippe Karl outlines the exercises for teaching the horse to mobilize the jaw with biomechanically sound actions. Rather than putting the pressure on the bars of the horse’s lower jaw, causing pain (the bony surface of this toothless section of the jaw can be very sharp and is covered by only a thin layer of tissue), the bit is lifted slightly into the soft and pliable corners of the lips. With slight pressure, the horse will eventually begin to chew and move his tongue, and the pressure should then be released.
Soon, just a slight upward action of the hand can remind the horse to mobilise his tongue and relax his mind and body. All good things for stiff and/or nervous horses.