Ergonomic Design: The ergonomic office chair has an "S" backrest ergonomic design back and adjustable lumbar support to fit the natural curve of the lower back and take the pain of spinal away from your body. The high back of this home office chair can be adjusted up and down by 4". Flexible Adjustments Functions: Our ergonomic office chair features a multi-stage height-adjustable headrest, lumbar support, and 3D armrests for a customized fit. The ergonomic office chair can be tilted from 90° to 120° to 135°,and the cushion can be adjusted back and forth.