Here is a great exercise to coordinate neck stability and core strength. Opposite arm and leg lifts over a ball.
Ok, so we’re going to start in the same position over the ball, keeping the ball entered around your belly button and soft a little bit through your arms maintaining a neutral neck position. Now we’re going to work on opposite arm and leg lifts maintaining good breath and core. So thinking about breathing in as you’re breathing in, breath out, soften your rib cage, engage your core, lift one arm up and then lifting the opposite leg trying to maintain a neutral spine. Breathing in lower down, as you breath our soften your chest, engage your core, lifting the left arm and right leg trying to keep stable through that left hip, maintaining your neck length the whole time. In this position it’s really important to work on that sequencing of the breath, core, moving opposite arm and leg breathing in lower down, while maintaining neutral spine. So work to fatigue, repetitions probably 8-10 in the beginning. You can improve this as you go along when you start to get a little more endurance, take a short break then do 2-3 sets.