Equiami experts - help/advice needed please

[cornwallexracers]

I've been advised by my equine chiropractor to begin lunging my horse in a pessoa type aid. After much consideration and reading reviews on here I bought an equiami. I tried it yesterday and its definitely set up right, have watched the instruction dvd over and over!! but the back piece seems very low above hocks and seems to me at least to catch every so often and looks uncomfortable being just rope. The only way I can get the back piece up higher is to shorten it right up which then pulls the loop right back on the d ring on the roller so there is no free back & forth movement and this then seems to restrict the front piece. Any advice as to what I can do, at the moment the only way I can seem to keep it in place is to tighten it up, but this pulls the front piece back, then he comes behind the vertical rather than working long and low, defeating the point of using it..

Thanks in advance!

 

[DD265]

Can you make an "S" in the rope lower down, secured with electrical tape? Or these things usually have a sheepskin-type band for the back end - is there an adjustment in there?