Janet Baraclough.. expounded:

Professionals wear kevlar trousers precisely because that accident can
happen so easily.
Inexperienced people can very easily misjudge the speed of cut, and the
weight, balance and impetus of the saw as it comes free.The OP has
already told us that her arms get tired easily.

Janet, I know many professional tree men and they don't wear special
pants. It may be the norm where you live, but it certainly isn't
around here. My husband is an experienced woodsman and knows no one
who has that type of pant. Chaps, perhaps, but only professionals who
cut for a living might use them. It's a personal preference.
Knowledge is the best defense, knowledge and experience.

--
Ann, Gardening in zone 6a
Just south of Boston, MA
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