With some back conditions, specific positions are known to help manage symptoms. These positions are known as biases. There are three types of biases: flexion, extension and non-weight bearing.
If your back feels better and your symptoms abate when you bend forward, your injury or condition has a flexion bias. Spinal stenosis, which is a condition that narrows the space in the intervertebral foramen as well as other areas of the vertebral column, has a flexion bias. Bending makes more space in the intervertebral foramen so that the nerve that's there can pass through without being touched or pressured by the nearby misshapen bone. Other conditions with a flexion bias include spondylosis and spondylolisthesis.
For injuries and condition with a flexion bias, symptoms tend to increase when your back is extended (arched).