I believe this video is showing the hip joint movement but not suggesting ski without knee joint and ankle joint flex.
PSIMAN—The Movie on Vimeo
Look at this PSIA video demonstrator has a lot of knee and ankle flex. It's a suprise if any one ski like the robot with stiff knee & ankle.


PSIA-AASI Go With A Pro: Carving with Control - YouTube
taichiskiing 寫:Of course, those hinges of PSIMAN which hold it together serve as joints; what is neat about this device is the silver pin's ability to swing back and forth, and side to side, which under the influence of gravity, becomes "automatic" leads the turns, after the initial push, it moves downward, the slope causes the simple hinges tilt to one side to maintain the structure's balance, which causes the skis to be set on edges, following the edges, PSIMAN turns! The initial force of the turn is gravity/地心吸引力 + "centripedal force"/向心力, as centripetal force generates an opposite force "centrifugal force"/離心力, which slows down the pin movement and slows down the turn; when "centripedal force"/向心力 and "centrifugal force"/離心力 equal to each other, the gravity takes over, PSIMAN moves downward again, so the process of skiing continues until the initial energy is exhausted by frictions. It "illustrates" the "pricinples" and the "mechanism" of the modern carving turn, mainly, angulation and edging, "Tipping." The flex of PSIMAN's knees is actually showing the best skiing knee postions for we human.
PSIMAN—The Movie on Vimeo
Of course, human has muscles and bones, we don't ski like a robot; nevertheless, the reasons and ways we make a lot knee and ankle flex/movements, as well as various muscle tensions, is to maintain the "turning pressure" that demonstrated by PSIMAN. The PSIA demonstrator shows only a refinements.
PSIA-AASI Go With A Pro: Carving with Control - YouTube
So, are you decided to come back to the human realm?
:)
IS
Good for you, at least you understand what is good sking now.


the human realm will automatic come back when you stop your 很有成就的太極烏嘴.taichiskiing 寫: So, are you decided to come back to the human realm?
:)
IS

