please help

background: im 17 years old been riding since i could walk didnt start jumping till i was 12 but comeyed competivly in showing classes here in ireland up til the and only jumped for fun and continue to competing showing now but i bought a 4 yr old 15 2  in april this year for eventing in the future and have been getting him started jumping small fences up to 90cm and some xc schooling however i have been having issues with lower leg hands and strides :(

<lj-cut>


and a video
and ignore most of the xc it was his first time in 6 months http://www.youtube.com/user/LifeOfRiding?feature=mhum#p/u/5/c_BazS5Ialw