That way lies not taking a break at all. That said, good ergonomics are important. Construct a comfortable environment for yourself. If your employer is hesitant to provide what you need, don't just gnash your teeth and keep using bad equipment with stress and resentment from the unfairness of it all. You're the only one who will suffer.
Good posture is vital.
A telltale sign that your equipment is bad is if you are unable to maintain good posture at work. Tilt your body ten degrees, and your muscles have to work to keep you stable. It's especially easy to lean your head forward toward your monitor. The head is, on average, ten percent of the body's weight, about the weight of a bowling ball. Sit up straight.