Office Chair Feet Hanging in the Air

Office chair feet hanging in the air refers to a sitting posture where the feet do not touch the ground or lack support. This is commonly seen when the seat is too high or when there is no footrest, and it can have significant negative impacts but can be improved through various methods.

Hazards

• Impaired blood circulation: The edge of the seat compresses the blood vessels at the top of the thighs, leading to poor blood circulation in the lower limbs and obstructed blood return. Initially, this manifests as numbness and swelling in the legs and feet. Over the long term, it can cause ischemia and hypoxia in the lower limbs, resulting in frequent leg numbness, varicose veins in the calves in mild cases, and the formation of venous thrombosis in severe cases. If the thrombus breaks off and travels to the lungs, it can even be life-threatening.
• Increased lumbar spine pressure: The hanging posture increases the force on the lumbar spine to 2-3 times that of a normal sitting posture, making it prone to lumbar muscle strain and lumbar disc herniation. Symptoms usually appear within two to three years.
• Decreased knee stability: The knee joint remains in a "semi-flexed hanging state" for a long time, leading to muscle atrophy and ligament laxity in the front of the thighs. This causes an imbalance in the forces acting on the knee joint and a continuous decrease in stability. Data shows that among people who work at a desk for 8 hours a day with a high chair and their feet hanging in the air, the incidence of decreased knee stability is as high as 42%. Among them, 35% of office workers aged 30-45 suffer from chronic knee pain due to improper sitting posture.
• Other impacts: Sitting for a long time can easily cause numbness in the lower limbs and back pain. Children are more likely to have their feet hanging in the air due to their insufficient height, which may affect bone development. The elderly or those recovering from surgery may have difficulty adjusting their posture due to weak lower limb strength, increasing the risk of falls.

Improvement Methods

• Adjust the seat height: After sitting down, the feet should be flat on the ground, with the thighs and calves forming a 90-degree angle and the knee position slightly lower than the hip as the appropriate height. According to height references, those who are 160-165cm tall should choose a seat height of about 40cm, those who are 165-170cm tall should choose 42cm, and those who are over 170cm tall should choose 45cm. If the chair in the company cannot be adjusted in height, a footrest can be used to pad the feet.
• Choose ergonomic furniture: It is recommended that office chairs have adjustable footrests or lumbar supports. The depth of sofas should not be too large to avoid the feet being completely off the ground after sitting down.
• Regular activity and stretching: Get up and move around every 30-40 minutes. Do activities such as tiptoeing, leg lifting, or ankle pumping exercises (repeatedly flexing and extending the feet) to promote blood circulation.
• Solutions for special needs: Children can choose special seats with footrests or match their body proportions with adjustable-height study desks. In home or office environments with limited space, books or hard storage boxes can be used as temporary footrests, with a thickness of 5-10cm being appropriate. Patients with lower limb edema or varicose veins can wear compression stockings when their feet are hanging in the air or use inclined footrests to reduce pressure.