i have an athlete with a lot of potential but i feel like his form holds him back in races. his arm carriage is the exact same from 800-5k (not very much back and forth motion, mostly circles on one arm and the other arm stiff and arms don’t go back nearly at all, even in 400s) and poor knee lift combined with a slight overstride (tight hip flexors or anterior pelvic tilt?) that is improving as he runs more. any tips or cues to help with getting arms back and for higher knee lift?