Chair Ergonomics Tips
You want to position your chair slightly more than 90 degrees. Basically, you want your hips higher than your knees. We know of pilots that sit with their knees higher than their hips.
If the knees are higher than your hips, you will contract your major hip flexor muscle...called the Psoas Major. This will cause lower back pain.
This muscle attaches to ALL the low back discs and low back spinal bones. When contracted, it will compress your discs and your low back spinal bones.