When you think of Waltz, the first thing that comes to mind is a swooping up and down dance motion. The primary characteristic of Slow Waltz is rise and fall, but the primary characteristic of Viennese Waltz is sway. There is no time for rise and fall in Viennese Waltz. The concept of rise and fall can be confusing if it is not precisely defined.
The definition of rise and fall in ballroom dancing is the vertical up and down movement of the body. In Smooth and Standard dancing, the body is defined as from the hip sockets and up. This is important because rise and fall is developed through the feet (ankles), the legs (knees) and the body (stretching). The ankles provide vertical movement through the balls of the feet. The legs provide vertical movement through the straightening of the knees. The stretching of the body provides additional vertical movement.
A typical description of forward steps in Slow Waltz used by many instructors as well as students is "heel, toe, toe". A better description would be "heel, ball, ball". Toes imply being on your toes like a ballerina, where in fact you are on the balls of your feet. Make sure that you as a student know what definition your instructor is using. Let's analyze these three steps more precisely. The general rule is to move from "heel to heel" and "ball to ball". In order to accomplish this movement there must be a transition from "heel to ball" and "ball to heel".
The foot movement "heel, ball, ball" is achieved as follows:
As stated above, vertical movement is achieved through the feet, the legs and the body. The rise is created by lifting vertically through the ankle, leg and body (all at the same time). In general, Bronze American Style Slow Waltz implements immediate rise on the second step (rising on 2). Silver American Style Waltz and above implements delayed rise (rising at the end of 2). Immediate rise creates a swinging, pole vaulting action and delayed rise allows the body weight to be on top of the foot so vertical movement is more controlled and deliberate. There are times in Silver Waltz where you want "leg swing" and other times where you want controlled vertical movement. An example would be that a "Forward Hover" requires delayed rise for stability and that hovering action and an "Open Left Turn" requires "leg swing".
Rise and fall are executed differently. The fall is accomplished by lowering through the ankle first (ball to flat), then lowering through the knee. Lowering through the ankle first provides stability and closes the feet. Then the lowering through the knee, allows the free leg to move in anticipation of the next step. This lowering through the knee on 1 is part of the lead that allows the follower to respond to the start of the movement.
The basic movement in Slow Waltz is: travel horizontally on 1 (power), travel vertically on 2 and 3 (rise and fall). Horizontal movement must be minimized during rise and fall for balance and control. It feels to me like "power and glide". Power on the 1 step and glide along on the power during 2 and 3 while rising and falling. In my opinion all, of the good stuff happens during the rising portion of the movement. This is where the hovering action happens. This is where turns are executed. This is where the partnership stretching happens, etc. Almost all of the really good feeling stuff happens on rise.
Foxtrot has a very similar movement in the ankles and knees. Technically, however, Foxtrot has no rise and fall. The big difference is that the Foxtrot body has no vertical movement. The ankle rise and fall is absorbed in the knees. The legs act as shock absorbers to keep the body from going up and down. Some instructors refer to this as rise and fall. Students, when your instructor talks about rise and fall, make sure you understand exactly what he/she is trying to communicate.
As stated in the first paragraph, Viennese Waltz does not have rise and fall (movement of the body vertically). There is, however, ankle rise and leg swing resulting in sway.
The foot movements of a forward "1, 2, 3, Left Turn" element is "heel, ball, flat" and is achieved as follows:
The 2nd step creates sway and there is no rise because the body never gets on top of the 2nd steps "ball".
As you can see from the above, "rise and fall" is a complicated action and can be a potential communication problem. As a characteristic of a dance (i.e. Waltz), "rise and fall" refers to movement of the body vertically. Rise and fall can also refer to ankle, knee and body actions. As always, obey "rule number one": "Know what you are doing".