i think that we are very lucky to do this thing that we do; like no other.
One of the reasons is the amount of lessons in our standard DdRT; and how we get a 2:1 effect (-friction) from it.
This counter-intuitive point; gives many lessons on maximizing your power; by using the usually wasted part of it. Most systems are more 'open' systems; of 3 or more 'force points' (my own term; so their might/probably is better expression of it). Usually; there is output(on load), pivot/machine and input(effort); like where 1 man lifts a climber thru pulley. But, skinning this down to 2 points; closes the system more; allowing less waste/escape of useful force. Notice that 2 points is the minimal system; as part of the promise of the equal and opposite law in physics (yin/yang in philosophy).
Friction on support limits us to less than 2:1; so hip thrusting decreases friction, to bring closer to 2:1 efficiency; 2:1 from the pressure of the hand pull down, not the 1:1 of the hip thrust. Hip thrusting can take a lot of energy though; so can be less efficient for that (t)reason. It is better if the thrust (like a kip in gymnastics); is timed also with a pull of pressure/effort (not just an easy pull of the free slack); to get the 2:1 effect of the handpull; with less friction reduction+ hip thrust force. More efficiency can be had with better timing of the legs falling back down after the thrust and that serving the hands back up high for another well timed pull and thrust together; so you get kinda a continuous rocking motion IMLHO. But this takes real good timing, and very good stomach muscles(to be stiff enough for falling legs to pivot chest/arms back up with full efficiency). Even though this can be seen as mechanically efficient, it takes one in real good shape and stamina for it to be ergonomically efficient; but visually very gracefull to see someone do it very well with the timing of a dance!
Anytime we have a pivot to change directions; we have the capacity to have our normal input force; AND a means of capturing it's equal and opposite (usually wasted/ terminating on anchor outside the system) and fold it back into the work effort (instead of running away from the work effort!). When we do this; we close the system more and thus conserve more of the present forces into the equation/load output.
The ways to do this, and it's presents are so deceptively simple and discreet; that they can be passed by; or not even noticed even if used. So much so; that though i maid some of the ways up to use this 30 years ago as the little guy trying to keep up with real grain fed farm boys 3x my size; it is only in the last 10 years or so; that i figured out what i was doing; and how to expound on that and exploit it in nearly everything, purpose-fully; with full intention and faith as maximum.
Loop around ball hitch was one of the first ways i tripped over this. i took a lot of flack for it; but also stopped a lot of guys bigger than me from laughing very suddenly as i pulled them over. i'd also stand on something in truck or trailer that needed compressed down; and tie rope to the load or top sheet, loop down and around reese or round pipe bumper and then pull up on it. So, i had massive 120 on load, the push down through my feet from the pull up on the rope and the pull down of the hitchpoint; with the pipe bumper as the reverse to capture the equal and opposite. Soon i found that the input of pressing down with legs, was better than pulling up with arms; and even sudden impact helped. But i didn't know what i was doing; or how much; just that it worked... soon i could train the bigger guys (that would listen) to do my tricks; once i figured out what to do thru own body.
Leveraging options
2Handing a pulley system can give 4x effort + body wieght from a "3:1"/ZRig; and 8xeffort+bodyweight forces from a "5:1". Both by the ability to input the distance force quotient at 2 points into the system; rather than 1. A partial downside to this is increased anchor loading. Whereby; a 3:1, usually gives 3x effort, at a cost of 'only' 2x effort on the anchor/pivot; and a 5:1 gives 5x effort with only 4x effort loading on the anchor; because these are more 'open' systems a final 1x effort is in your pull hand, and not on the anchor. But, as we 'close' the system more; to just it's equal and opposites/2 end points not 3; the 4x effort output of the "3:1" also gives 4x effort on the anchor, as well as the 8x effort output of the "5:1" also places the equivalent 8x effort on the anchor. Just as, the climber being lifted doesn't have loading on the anchor equal to the load/output; but the climber self lift does. Here the climber being lifted gives more loading on the anchor instead of less like the pulley/compression jigs; because the final leg to effort input goes to an anchor as a redirect and not to the load as a pull on the load. Even Super Bob (our 13 year old) now does these things Naturally.
The elusive magic of a Spanish Burton(example P); uses this principal; as well as my own "Mayhem Puzzle"(example S) on my Pulley Sheet. As well as this Olde Ship's Rig with the inset pulley system; taking 2 pulls on the main pulley system in a more closed system kinda way; rather than having 1 end on an anchor and just pulling the tail of the larger pulley system with the smaller pulley system (like most people would do).
Though i show this mainly with pulleys as the reverse capture of the equal and opposite, it works the same mechanics with a stiff lever and you working 1 hand on either side of the pivot lever. Or standing on the roll too side of a tire, and placing 1 hand on the opposite/roll form side of the tire; with axle as pivot/reverse capturing the 'run away' equal and opposite force. Input force with hand lift; gives 2x arm effort + bodyweight; but input with leg push, gives 2x leg force + bodyweight! don't get hurt, jump off after initiating roll! works on logs too; with same warning!
Now older and with bad back; i find the maximizing puts less stress on whole body; and (for me) it is best to use the reverse/capture 'arm to arm'; meaning missing leg force; but also conducting the equal and opposite force from arm to arm like electricity; and not just doing a lift with 'open system' like normal people; whereby arm lifts and the equal and opposite force trails down through back to legs on ground(like an electrical path seeking equal/opposite +/-; ground). Route the equal and opposite arm to arm; like elctricity, and not thru back to ground. Use the '2Handing' for more force easier; and not route thru back.
i know i've tossed out a lot; sum of ye have seen this 'hogwash' before. Many shake their heads; i know well. But, think and connive in these terms; it will do wonders for you, my brothers; it is truly some of the best i have to give!
