You might need to work on your elbows for a very long time. Elbows are often not something that we worry about, but when it comes down to it, there are many factors that go into having still upper arms but flexible elbows. Good control of your elbows play a key role in developing and then keeping a supple yet effective connection with the horse's mouth.
Quite a lot of flexibility is required from the joint; the opening and closing of the elbow, in relation to your horse's movement is something that can only be achieved through enough practice to develop muscle memory. Of course, different disciplines have somewhat different requirements. For example, jumping requires a reaching forward of the arm in order to give the horse's neck plenty of room to extend over a jump. In dressage, the elbows need to stay fairly stationary and supple without coming off the body.
We'll focus on dressage elbows here. Put simply, your upper arm should hang vertically along your torso. In theory, it shouldn't be ahead of the body, nor behind the body. Here's the tough part: it should stay there.
When done correctly, it looks like nothing. But there are a lot of factors involved in keeping vertical, supple elbows. If you squeeze your elbows too tightly, your arms become rigid and the hands end up being too wide. If you turn your wrists down, your elbows come off the body ("chicken elbows"). 🙂
If you reach too far forward, your elbows straighten too much and your balance is compromised. If you hold your elbows sideways off your body, they move with the horse's gait and the hands "bounce".
The elbows are easy to forget about because after you've developed some muscle memory, they will feel like they are vertical when in fact, they aren't. It helps to have a ground person describe what your elbows are doing while the horse is moving, so you can learn to feel them and know when you need to change something.
You'll have to ride with awareness, noticing your forearm and hand positions, and then relate them to the elbows. Feel for the elbows on your sides, notice how tight or loose they are and focus on opening and closing them as needed in the movement of the horse. Use these specific tips and get feedback when you can!
