Final answer:
A dental assistant's stool incorporates lumbar support to help maintain good posture by matching the curvature of the spine and ensuring the center of gravity is aligned with the hips, thus preventing back strain and disk damage.
Step-by-step explanation:
The ergonomic feature of a dental assistant's stool that helps avoid lower back pain caused by leaning over during dental procedures is referred to as lumbar support. Lumbar support is designed to match the curvature of the spine, thereby ensuring that someone is sitting with good posture. Good posture is defined as having one's center of gravity directly above the pivot point in the hips. This alignment helps to prevent back strain and damage to disks because it reduces the amount of stress placed on the lower back muscles and the intervertebral disks.
Most of our muscles are attached close to joints, which makes maintaining proper alignment vital for musculoskeletal health. Additionally, lumbar support in a dental assistant's stool may be complemented by other ergonomic features such as adjustable height and tilt, as well as foot rests, all contributing to the comfort and health of the dental assistant during long procedures.