Is the following a unit turn?
The reason for the question is I keep having a hard time talking about "unit turn" vs "hip and shoulder turn, separation, etc". For example, in the pic above I would say Murray basically has no (very little) hip turn or shoulder turn at this point. But we are trying to turn our torso and arms as a unit, hence the term "unit turn".
I have been thinking of the following as the "unit turn", but I think I should just refer to it as something else ... "backswing", ???
Talking tennis is much harder than playing tennis.
You are deriving instructions from a simple phase of very few words. Often the words are not even accurately descriptive, much less instructive. The stokes needs much more information to describe them. Spending time squeezing meaning from so few words, that were first used after a visible eye observation, is an approach that will very often be misleading. I've done a lot of that in the past.
What makes more sense -
Use the words to identify a broad subject or part of the stoke.
'shoulder turn', 'unit turn', 'separation', '
pronation' (as in tennis usage') and then use the words to identify what you want to discuss in high speed videos or for more scientific accurate purposes using 3D motion capture systems. Make the pictures the primary definition - For example, 'see the
separation of the hip's line and the shoulder's line labeled in this picture'.
You can also use clearly defined terms that have been developed by decades or centuries of academic study, for example, the defined names for the joint motions and the anatomical names for body parts. Definitions and illustrations are available on the internet and in books. Currently a Tower of Babel exists made of tennis stroke terms.
For complicated subjects - like the details of tennis strokes, that is, biomechanics - researchers always use defined terms, if available, as defined terms don't require explanations each time they are used by an individual. And everybody hearing or reading the terms understands the same definition. Communication is faster, clearer and the chance of misunderstandings in much reduced. Widely used tennis terms are often very poorly defined. Mushy terms. Hard to pin down terms. Typical tennis terms. But some have been developed by researchers and illustrated with pictures, for example
'separation' can be Googled and ITF presentations found that show it. They are pretty good if readers look them up.
Is there a definition of unit term by any tennis authority? One clue is if the terms can be Googled? ?
Maybe the ITF could define some tennis terms that have a considerable usage in 2018.
For the Murray pictures, they are during practice and some parts of the strokes, 'separation', may not be used during warm ups or practice but only for aggressive stokes. Aggressive strokes, when the player is not pressured, are best to show their best techniques.
