Mainline AA flight attendants have posted online since the beginning of the interwebs that AA fights worker's comp claims for injuries resulting from assisting with passengers' heavy carryon bags, and thus many AA flight attendants enforce a policy of "if you can't lift your bag into the overhead or find another passenger to assist you, it gets a gate-checked tag and it travels down below."

Have no idea if AA routinely fights and/or wins workers' comp cases on this basis, but that's what AA FAs have consistently said online for about 20 years now.