The most common and most likely answer to this crossword clue is the 9 letter word BACKSWING
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Buddy explains!

The straight part
We know that "Movement of sportsperson" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case movement of sportsperson = backswing.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does BACKSWING mean?
BACKSWING noun- The preparatory stroke preceding that which produces contact with the target. Normally associated with sports using an implement such as a bat, club, racket or stick.