This lecture covers the correct adjustment of a chair to create an ergonomic workplace. Starting with the seat height, it explains how to maintain a neutral posture by ensuring your feet are flat on the floor and your knees and hips form a 90-degree angle. The instructor demonstrates how to adjust the seat depth, backrest height, and angle to distribute weight evenly and support the lumbar curve. Additionally, the lecture emphasizes the importance of regularly readjusting the chair settings over time.