An ergonomic footrest is designed to keep your feet supported and comfortable, ease leg problems and lessen lower back issues. If one's feet are not resting on the floor, we tend to perch at the front edge of the seat. This is not ideal as it places significant pressure on the lower back and on the back of the legs. A foot rest ensures that your feet are anchored, allowing you to sit all the way back in your chair, and letting the chair take some of the stress and strain off your back.
When setting yourself up at your workstation, your chair needs to be raised to the correct height to reach your keyboard comfortably with your hips slightly higher than your knees. If you have done this and your feet are dangling in the air, you need a footrest!