Question: When I ride my hands bounce up and down at all the gaits. Not a lot but enough so I am not riding horses to the best of my ability and knowledge. I can keep the horse on the bit but in the posting trot every time I go up my hands come up too.Holding a strap doesn't help. Trying to make my hands go down as I go up doesn't help. What can I do?
Basically if you are stiff in mid-back or in the upper chest and shoulders and the shoulder blades don't slide well over the rib cage your hands will be tied to the movement of your torso and hence they will not be independent. Basically an independent seat means that the movement of your pelvis and spine are independent of the movement of your shoulders, which you can think of as part of your arm. The pelvis sits on and moves with the horse's motion, The 'S' shaped, neutral spine ideally moves up and down in a wave-like motion all the way to the balanced head. The shoulder blades, when independent, hang and slide over the ribs that are moving with the spine, adjusting to the horse's motion. The arms then are not hooked to tightly held shoulders but an extension of relaxed, supple controlled shoulders, This gives freedom and light motor control of the arms and hands--hence they can be quiet.
In the above drawing from Albinus on Anatomy, you can see the musculature of the shoulder and how it is part of the arm. If you imagine your arm like a wing, with muscles that overlay the stabilizing muscles of the torso, you can get a sense of the independent hand. If the arm/shoulders muscles are held tightly to the underlying support you have co-dependent hands and seat. When differentiated in the movement between torso and shoulders, you will feel like you could write your name or juggle while you ride.
Riders who haven't quiet learned to go with the motion of the horse with a neutral spine, proportionate muscle tone and an adjustable torso try to hold somewhere to stop the assault on the spine. They feel like the horse is moving against them and they brace, and often this is in the musculature that holds the shoulders to the torso or in the mid-back or thoracic spine. This is not a sign of weakness but a sign of poor use of the big muscles of the lower torso, chest-breathing, and an inability to find the appropriate ratio of spinal stabilization and movement that allows the joints to move so the body can adjust to the horse.
There are many ways to inhibit the independence of the shoulders. The photos below show three ways of holding the shoulders and a last photo of sitting in balance, with hanging shoulders. From the outside it is not always easy to tell if someone is in balance and even from the inside it is not--but the horse will tell you when you are not riding with a neutral spine.
The torso is stabilized through coordinated use of the muscles (abdominal bracing--the tone you'd have if someone were about to sock you in the tummy or if you cough deep in your belly). The rider then, uses the large muscles of the lower torso in a coordinated way to protect the lumbar spine from excessive movement outside of neutral, while moving with the horse. When the movement through the spine is stopped somewhere, the spine will go up and bring the shoulders with it.
You can experience the feeling of hanging, sliding shoulders if you lie on your back and bend your knees and then push and pull with your feet in small, quick motions (think jello torso!). If you push through your spine so you jiggle all the way up to your head, you'll feel your shoulders slide because you are resting on them and your ribs will move with the spine and glide over them.
All the "fixes" in the world won't help much if you don't learn the capacity to move with appropriate organization and tone of the large muscles and allow all of your joints to give a little when you move with the horse or when the horse moves against you, which it feels like it is doing when you stiffen. If you have held joints that don't participate in going with the movement of the you'll have stiffness and bouncing hands--especially at the sitting trot, but at other gaits too.
In the posting trot every rider does need to learn to open the elbows every time they come up in the trot so the hands stay at the same distance from the horse's neck when the rider is up or down. This is similar to learning to open and close the knee joint without moving the lower leg. Still, the relaxed shoulders will allow the motion to be smooth while tight shoulders will make it jerky.
And really, this type of movement is good for everyday life so it's not just about the way you ride, but about the way you move through life!