A platform rides up and down the frame side leg guide channels in response to the raising and lowering of the lower arms such that a one foot rise in the platform results in {HEAD ~ a three foot rise} in the platform relative to {TAIL ~ ground levcel} 
relative to
A platform rides up and down the frame side leg guide channels in response to the raising and lowering of the lower arms such that a one foot rise in the platform results in { HEAD ~ a three foot rise } in the platform relative to { TAIL ~ ground levcel }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL