Is Your Office Chair Height Causing Your Low Back Pain?

Young businesswoman sitting at a desk looking over her shoulder
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Although the office chair industry is a booming one, few people stop to learn what they need to know about fitting their seating equipment to their height, frame, or any condition they may have such as back or hip pain. Instead, most ergonomic chair customers base their purchase decisions on color, style, and price.

Here are some tips to adjust your office chair so that it decreases your back and hip pain.

Use Your Chair's Height Adjustment

Rare is the office worker who is interested in tinkering with the controls located at the bottom of the chair seat, but the levers, paddles, and knobs are there for a reason. If nothing else, learning how to adjust the height of your chair may provide a reference for any other workstation adjustment you may need to make.

The height adjustment is the primary way you have to change the angle of your hip joint during sitting. This angle, in turn, affects the position of your pelvis and degree of curve in your lower back, possibly altering the normal alignment of your spine. And the height of your chair also affects certain muscles (quadriceps, psoas, and hamstrings) that play an important role in posture-related back pain.

It's Much More Than the Chair Back Angle

Just think, the angle of your hip joint is something you can control by simply adjusting your chair height.

The hip angle is how close (lots of hip flexion) or how far away (less hip flexion) your trunk is to the top of your thigh when you're sitting in your chair. When you adjust your height, you adjust the degree of flexion at your hip joint.

A recent study measured the load that sitting has on simulated spinal discs.

Researchers concluded that pressure on the spine can be relieved with a more open angle between the trunk and the thigh, that is, the hip joint angle.

Of course, the backrest, seat tilt, and lumbar support features of your chair can help support a pain-free back, and they should be used. But to set yourself up with ​ideal alignment from the beginning, nothing beats getting the correct seat height for your frame.

Getting Your Seat to the Right Height

Another way to understand your hip joint angle is to compare the height of your knees to the height of your hips. This is usually the easiest way to assess if the chair height is right while you are in the process of adjusting it.

When your chair seat is the right height, your feet will be flat on the floor. Your feet should reach the floor without causing pressure at the back of your thighs. If you’ve got a case of dangling feet (which may be due to your own height), place a footrest or thick book under them.

Your knees should be approximately level with, or lower than, your hips. Level, in this case, corresponds to a 90-degree angle between the hip and trunk, which is relatively stress-free on the hips and back.

Risks When Your Chair Is Too High

If you can’t reach your feet to the floor, your chair is probably too high.

The Occupational Safety and Health Administration (OSHA) says this is potentially hazardous because it may lead to your scooting forward and thereby foregoing the support of the backrest. Sitting this way would be considered an awkward posture and a risk factor for work-related musculoskeletal disorders (MSD). Symptoms of an MSD due to awkward sitting posture may include muscle fatigue, swelling, pain, numbness or decreased circulation.

Risks When Your Chair Is Too Low

If your knees are higher than your hips, your chair is probably too low. In this case, your hip joints will have an extreme degree of flexion.

Most people’s backs can’t handle this well because their hip muscles aren’t flexible enough. If you sit with your knees higher than your hips, your position may be responsible for your low back pain.

Sources:

Rohlmann A, Zander T, Graichen F, Dreischarf M, Bergmann G. Measured Loads on a Vertebral Body Replacement During Sitting. Spine Journal. September 2011;11(9):870-875.

Occupational Safety and Health Administration (OSHA). ​Computer Workstations eTool: Chairs. United States Department of Labor.

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