旧題 リフティングとクリーピング





"Lifting" and "creeping" are the common terms used to reflect violations of the two rules of race walking: loss of contact (i.e., you are running) and bent knee (i.e., you are not race walking). No matter what technique you adopt, you want to learn to avoid these two situations early in your race walking career.









A racewalker is said to be "lifting" (i.e., loss of contact) when three or more judges determine, by eye, that the race walker has lost contact with the ground. This situation is most often observed with faster walkers--and often occurs when a racewalker tries too hard to catch, or stay in front of, another walker. While various walking events may take different views on creeping (e.g., ultra events rarely toss you from the course for doing it), ALL walking events strictly enforce the "no flight" rule.




Most writers either suggest that a judge can not detect (by eye) loss of contact that is less than about 25-30 milliseconds, or they suggest that a judge can not detect (by eye) loss of contact that is no more than one frame of a video. Because most video cameras shoot 25 to 30 frames per second, this latter guideline puts the undetectable period at 33-40 milliseconds. Unfortunately, at the 40 millisecond level, if the loss of contact begins just after frame #1 is taken and ends just before frame #3 is taken, the loss of contact captured by a single frame #2 could be as much as 79 milliseconds long.




The bottom line on flying, therefore, is to avoid it altogether OR to keep it very short. Dave McGovern, in his book, The Complete Guide to Racewalking: Technique and Training, suggests that most race walkers can not accurately guage whether, or for how long, they are off the ground. Unless I hear otherwise from someone who should know, I will assume that most race walkers can not learn to fly just for a precise period and, thereby, use it for a tactical advantage. As several writers have noted, if you see the loss of contact side of a judge's paddle, or see your number begin to appear on the Warnings Posting Board, you might want to back off a bit on the throttle.




Dave further notes in his book that walkers are most likely to lose contact




during the acceleration at the start,  スタートの加速期

while passing another walker, 追い抜くとき

during the finishing sprint, ゴール近く

in the middle of a group [where some walkers may try to hide],  集団の中央

while making sharp turns,  鋭い方向転換

while going uphill and downhill, and  上りと下り

while taking aid and refreshments. 補給のとき




First, a little lifting ...





then a little more ...





and then even more.




At some point, the judges begin to notice it ... and you may be in trouble.




In the following three animations, Icabod demonstrates both legal and potentially-illegal patterns of contact. (NOTE: While Walker B's upper body is slightly bobbing up and down, lifting does not always involve such bobbing -- and such bobbing does not always mean a walker is lifting. Lifting is determined solely by watching the walker's feet.)










Walker A is clearly legal.





Walker B is losing contact and

is subject to a lifting call. Lifting

can be hard to see -- especially

with very fast race walkers.





This is also Walker B but

he has been slowed down

so you can more easily

see the loss of contact.





In his book, Dave writes, "The ironic thing is that lifting is not necessarily beneficial to the walker. A bit of simple high school physics, if I may: A body can only accelerate while there is a positive force acting upon it. Once you leave contact with the ground, gravity is the only force acting on you, so you begin to decelerate--you begin to slow down. [¶] Having a strong, propulsive push from behind with the rear foot is great, but the longer it takes the front heel to make contact with the ground after the rear foot leaves the ground, the longer it will take before the next propulsive push. So that "flight phase"--the time when both feet are off the ground--does nothing to help you. Lifting, then, is actually inefficient race walking."




For now, I take exception to Dave's view. Flight significantly increases the length of a walker's step during a period when there is very little friction (like air resistance) to slow the walker down. I sometimes experiment with that grey area that occurs between clearly walking and clearly running, and I know from experience that I can increase speed (or decrease the effort required to maintain the same speed) if I fly for just a tiny fraction of a second during each step. (I am not doing it to "cheat" during race walks. I do it because I think there is an interesting, and untapped, form of pedestrian locomotion that enjoys the benefits of both race walking and running--more speed with hardly any up-and-down motion of the body's center of mass. Such a slightly-bent-knee, "gliding" technique could be most useful for those who have a hard, if not impossible, time straightening their knees.)


 この点に関しては彼に異を唱えたい。飛翔は選手のストライドを大きく伸ばす一方、減速につながるような抵抗をほとんど産み出さない(せいぜい空気抵抗くらい)。ときどき実験として明らかなウォーキングと明らかなランニングの間にあるグレーゾーンを探ってみることがある。その経験から各ステップごとにほんのわずかな飛翔時間があるだけでスピードを上げる(あるいは同じスピードを楽に維持する)ことが可能だ。わたしはずるをしようとしているのではない。すごく面白い課題であり、競歩やランニングの効率を高める( 特に上下動の少ないフォームで)うえで未開発の領域であると思うからだ。このようにかすかに膝が曲がり「滑走する」テクニックは、ひざをまっすぐに保つことに(不可能ではないとしても)苦労する選手たちにも利用できる方法と言える。







A racewalker is said to have a "bent knee" (or be "creeping") when three or more judges determine that the knee of a supporting leg is not straight from the moment of foot contact until the body passes over that leg. This situation is most often observed with newer or slower walkers -- and often occurs when a racewalker tries to go too fast for his or her skills. In the following three animations, Icabod demonstrates both legal and illegal motion of the knees.






Walker A is legal.





Walker B is not legal.

He never straightens the

knee of the supporting leg.





Walker C is not legal.

His knee is bent on contact,

then straightens too late.





While race walking events strictly enforce the "bent knee" rule, ultrawalking events often relax their enforcement of the rule, knowing from experience that most walkers can not maintain straghtened knees for the 1, 2, 3, or even 6 days over which the event lasts. Always check the rules before entering any ultra event.