Take a walk? Procrustes would sometimes do it (7,4,4)

I believe the answer is:

stretch ones legs

'take a walk?' is the definition.
(I've seen this before)

I don't understand how the remainder of the clue works.

(Other definitions for stretch ones legs that I've seen before include "as Procrustes might do" , "stroll" , "Go for a short walk" , "Take a walk for exercise" , "Take a short walk" .)

I've seen this clue in The Times.

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