Green Apple. Walking uphill will only prove one thing. That is the push must come from the rear foot. Which is as it should. It seems to me that some writters are medal or social or just beginning. The others competition dancers. They are as different as chalk is to cheese. The medal dancer will probably know nothing about bending the knee as the body arrives. That is bending to your own front whether it be the man or the lady going forward or backwards. If I were you i would go to Learn the Dances on the left side of your screen. Then find Forward and Backward Walks. You will see the bending of the knees ( compression ) on frame one. You will se Mid Stride on frame three. If you take frame three for forward and frame three for backwards and place one on the other you will see they are identicle. You won't know which is which. Frame four will show you the flexing of the knees both bending equally. The positioning of the head is not shown. This comes later. Any queries on Latin. It's all here. Best Wishes

Is acceleration mentioned in any technique books?

Inertia and acceleration are to be controlled while walking or dancing. Straight walking steps can be practised slowly by accelerating from 0 m/s to any velocity or decelerating from any velocity to 0 m/s. From inertia view of point for example velocity of 5 m/s is the same as 0 m/s and acceleration from 0 m/s to 1 m/s is the same as acceleration from 5 m/s to 6 m/s, a = 1 m/s**2

There is not any continuous constant velocity. But there are seams of constant velocity when acceleration ends and deceleration begins and when deceleration ends and acceleration begins.

When stopping walking or dance videos frame by frame there are few postures which can be demonstrated being moveless at balance. Others are possible because of controlling of acceleration and inertia. Constant straight velocity does not create any balancing forces.

SQQ. Makes sense to me. I will add this. In our studio we practise to music as soon as possible. I know one young lady who told me that the first time she danced to music was when she did the medal.How crazy is that. Solo practise to your own timing is worse than useless. Obviously you will allow more time than you have on some of the awkward bits. Then one wonders why in practise I can do this fine, but can't when I really need to with the music.

"Inertia and acceleration are to be controlled while walking or dancing."

Perhaps, but only in "legal" ways. You should not allow your body to assume incorrect positions by attempting to achieve unreasonable control over acceleration.

"Straight walking steps can be practised slowly by accelerating from 0 m/s to any velocity or decelerating from any velocity to 0 m/s. From inertia view of point for example velocity of 5 m/s is the same as 0 m/s"

No, this is false - you overlook an extremely important issue: Acceleration in dancing is caused by having the body weight in an unbalanced position, specifically forward of the standing foot. Acceleration is a result of the falling past the foot that occurs in this position.

The slower you are moving, the more time you spend in this unbalanced position, hence the more its acceleration integrates to increased velocity.

The result? You CANNOT slow down a dance figure below its intended speed without CHANGING THE BODY POSITION to prevent the excessive acceleration that would result - usually this means changing body position to one incompatible with closed hold.

"When stopping walking or dance videos frame by frame there are few postures which can be demonstrated being moveless at balance."

Exactly - and the ones that can't be demonstrated stationary can't be demonstrated slowly either, because the acceleration would grow out of control.

"Others are possible because of controlling of acceleration and inertia."

Specifically, those which rise can be demonstrated slowly, because rising actions decelerate.

"Constant straight velocity does not create any balancing forces."

It doesn't create them, but it implies them - constant velocity is of course the result of balanced forces.

"Green Apple. Walking uphill will only prove one thing. That is the push must come from the rear foot."

First, most of the motion is carried over from the previous step. Most of the "push" comes from having the body weight forward of the standing foot. Any muscular "push" from the back foot plays at most a small roll, and only when taking very large steps.

Walking uphill gives you a tool to balance out the acceleration due to being forward of your foot - it lets you practice slowly in a way that you could not otherwise do in a proper body position.

"It seems to me that some writters are medal or social or just beginning. The others competition dancers."

A number of people here are competitors with lacking knowledge of fundamental technique... for example, many are ignorant of the necessary body alignment to enable cosed hold.

"Then find Forward and Backward Walks. You will see the bending of the knees ( compression ) on frame one."

Indeed, you will see it done incorrectly!

The dancer there is making two mistakes: one minor but serious, the other major but trivially corrected. First, the dancer is allowing her hip to lag a slight distance behind her knee as it bends forward. This is not permissable - closed hold required that the hip advance over the bending knee. She's only making the error by a small amount, but the fact that it's shown at all shows the author's misunderstanding of movement in closed hold.

Many are reluctant to keep their hip sufficiently forward over the knee, because doing so will cause the body to accelerte - forcing a commitment to the step incompatible with demonstrating it slowly.

More trivially, she has her moving leg in advance of her body. It should still be parallel to or even behind her standing leg at this point. Fortunately this error is easier to fix, since fixing it does not result in an accelerating body weight position.

Dear Anonymous, Thanks for clarify when the core muscles use in forward walk. I have some question to make clear, please give more teaching tips. Thanks.
I understand moving leg only bears itself gravity. standing food supprot rhe remained major body wiehgt , the hard time is at the moment of half stride. moving heel even off floor transiently while half BD weight is approaching the new standing leg. When flexing the old standing knee, BD should vertically on the supporting point or BT , hip gravity behind the ball and flexing knee but not beyond the heel, moving sliding back to the position without hip tilted , center weight continuously drives away through the heel toward the new standing foot , the stride increasing as a result...
What do you mean about " allowing her hip to lag a slight distance behind her knee '? I thought hip to lag a slight distance behind heel " will make problem because of wrong distribution of body weight to standing foot and floor which affects the generation of kenetic energy and obtain effective stride. Correct me if I am wrong. Thanks.
Ylchen

Dear Anonymous,
I thought , although the standing heel is beneath the hip and spine, but the center weight should be toward the flexing standing knee and standing spot. and partner through the standing thigh. that meants knee and foot are supporting body weight , due to flexing knee and ankle speedly, we got kenetic energy to drive center weight away continuously... due to flexing knee, moving leg sliding back to its limit depending on where the body weight distribution, how much knee flexing , assistance of muscular contraction if needed. Correct me , if I am still wrong.
ylchen.

This is the longest thread ever done on this site. I don't even bother to read most of it. I have no clue who is contributing and their qualifications on what they are writing. There must be some way to attach the manual description with comments. One of the worst things a dancer can experience is wrong or bad information. Once you include it into your muscle memory it is not easy to erase bad information or movements.

Or qualify your self by referring to your previous published dance writings so we would know that you are for real.

I understood and experience how wrong or incompleted information wasted money and time, how hard to erase incorrect muscular memory.
Here is a website for asking and discussing questions and sharing experience or knowledge, althoug its contributing is not as much as dancing college, Alex Moor,Marcus, Luca, it is part of strong fundamental stones where evolution and champion generated. I believed there must be a person who can teach me belong the three persons walking .¤T¤H¦æ, ¥²¦³§Ú®v. I even no care of a dancer or a therapist he/ she is . Relative correct data must be sensible and practicable . It should be completed gradually through upgrate. We absorb other thought or view to get advance. I even don't care of consult a dacner, or a therapist or a student who did good on one step. I much more care of the concept itself , not only the qualification .
ylchen

"First that's an odd definition of balance. But second there is not distribution between moving feet - the weight is entirely on one foot or the other. Plus it's pretty hard to have moving feet (plural) unless you are a quadraped"

If the supporting heel is leaving the floor AST as the other is moving forward then both feet are moving!