I am a new pole vaulter, and one of the exercises we've been doing is the V-up, touching your toes to your hands and further while hanging from a pull-up bar. My coach says most everyone should be able to do this, but for some reason, I struggle with getting my legs past parallel with the ground. I have scapular winging and I do not if that may have anything to do with it. I have been trying to perform this exercise for a couple of days, but I don't know how to build up the strength to perform it properly, and often just make a few attempts, failing, before stopping. How can I properly build up the strength to perform this exercise?
Disclaimer: I don't know what scapular winging is, and if you think you have an actual physical issue that prevents this movement, check with a medical expert.
This movement involves two main contractions. Of course neither is isolated, but at different parts of the move, different muscles are the primary mover.
The first primary contraction is from your hip flexors, and this is how you get your legs to about parallel.
From there your abdominals must contract to pull your hips up to achieve the remaining range of motion. For many (myself included) this is the most challenging part of the movement. So it could be your sticking point, or maybe you were just missing this cue. A possible progression could be leg raises on the floor, but lifting your hips off the floor to simulate the fuller range of motion.