Originally Posted by kuprum

Depends on the condition of the back and the age of the body.

Soft mattresses are necessary for body weight up to 55 kg, diseases of the lumbar spine.

Medium-hard models are suitable for body weight 55-90 kg, problems with thoracic and cervical spine.

Stiff beds are good with body weight over 90 kg, osteochondrosis, problems with posture.