I hear ya....got it all over, worst in hands and knees.and with my arthritis in my back, I just can't twist and bend like I used to.
Another thought... larger louvered and adjustable and maybe 'filtered' vents in gables of cupola....well outer gable of cupola and under run-roof gable of coop itself. They could be kept opened in even badder weather...and could be installed while standing up.