Office Chair Backrest Depression

Office chair backrest depression can cause both physiological and material damage, as detailed below:

Physiological Damage

• Waist Issues: Some low-cost office chairs lack zoned support in the backrest, with no dedicated lumbar pillow or with the lumbar pillow positioned or sized improperly, leading to a suspended waist or muscle compensation. When the backrest is depressed, this mismatch between the design and human body requirements intensifies. Long-term use can result in a lack of effective support for the waist, continuous pressure on the lumbar discs, and potentially trigger symptoms such as waist soreness and weakness.
• Posture Issues: Excessive sinking of the buttocks, when the seat cushion collapses more than three centimeters, causes the angle between the hip joint and the root of the thigh to be less than ninety degrees, leading to excessive lumbar lordosis. The full weight of the upper body presses on the tailbone and pelvis, and after more than half an hour, symptoms such as waist soreness and weakness, stiffness in the anterior thoracic spine, and a hunched-forward posture may occur.
• Blood Circulation Issues: In a depressed state, 60-80% of the body's weight is concentrated on the tissues surrounding the sciatic nerve, with continuous pressure on the piriformis muscle and the vertebral canal. This can temporarily block nerve conduction sensitivity and, over several months, lead to an increased frequency of lower limb numbness. For those who sit for long periods at a desk, intermittent leg and foot pain may even occur.
• Ischial Region Issues: The filling foam in office chairs can undergo permanent compression deformation over time, completely eliminating the support surface that evenly distributes pressure on the buttocks. The entire body's weight is concentrated on the two pressure points of the ischial tuberosities, and over time, the soft tissues in the ischial region can become sore and painful, pulling the muscles around the lumbar spine into tension and causing lower back pain as well.

Material Damage

Office chair backrest depression often indicates issues with the internal materials, such as foam that is too soft and prone to collapse or a loss of elasticity in the mesh fabric. This not only affects the aesthetic appeal of the office chair but also reduces its lifespan and increases replacement costs. Moreover, a depressed backrest may not return to its original state, and even with simple repairs, it is difficult to achieve the original support and comfort.