Coupon-clipper

I read in a book:
She suffered agonies from coupon-clipper's thumb.
Can anyone help me about its meaning?

Advertising coupons must be cut out of the advertisement before they can be redeemed at the store. A coupon-clipper would be someone who cuts out a lot of coupons with scissors. Excessive use of any tool can lead to soreness, a blister, or even a repetitive stress disorder. She has hurt herself by constant over-use of her scissors.