I was spending quite a bit of time in Jackwood website these day...
He had mentioned a few times how the Portable Power Jumper can improve vertical for him , and even for the program51 author...
the original one is here:
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There is also a less expensive version for people with back injury...
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Being not in the state.. i try to look for alternative for fun..
I did found some copy cat version of the less expensive waist attached version
(notice the ankle connection)..
but since JackW suggested the complete system (rope on the back), I wonder if it is possible to DIY... by using those Foot work ankle warp and additional power rubber band...
$5 USD
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+
$10 USD
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The main problem is, the ankle wrap might be easily slip up on the leg
(what do u guys think?)... unless it is warped from bottom up around the sole..
Another problem is, I have to source a rubber cable with the right length..
but the final or the first question is.... Is this equipment as worthy as jackw suggested... or another waste of $ & time product...