How can I improve my jumping position?

[paddypat123]

Hi,
My jumping position is really bad and I have noticed it in lots of photos. I kinda just do it naturally but I have noticed that I really hunch my back over. Are here any physical exercises I can do to improve it!? Thanks for your help Xx

 

[FlyingCircus]

Do you have any photos?
Might be easier to offer advice then