Since most of us spend at least a third of our lives lying down, a good quality mattress goes a long way in avoiding a whole host of musculoskeletal problems later in life. In addition, a quality mattress will help you get a good night's sleep, which most health practitioners agree is essential to a well-balanced, healthy life-physically and emotionally.

A quality mattress allows you to maintain the same natural spinal alignment that you have while standing. It can be an innerspring, foam, flotation (waterbed), or air mattress. The most important thing is choosing a mattress that offers you the most support and comfort.

Mattress criteria

• Comfort - Before buying a mattress, "test drive" it by laying down on it in several positions you normally sleep in. It will pay dividends down the road and help ensure that your spine's natural curve is supported. "Orthopedic" mattresses are generally a marketing gimmick and nothing more.
• Durability - This criterion applies both to the "guts" of the mattress as well as its covering. Ensure that the manufacturer guarantees the mattress at least 8 to 10 years.
• Firmness - Softness and firmness are generally a matter of personal preference and have little to do with a good night's sleep or avoiding back problems. Overly firm mattresses don't support the body evenly, while overly soft mattresses tend to sag, preventing your spine from maintaining its proper alignment.
• Foundation - The foundation, or box spring, absorbs the brunt of the stress and weight of your mattress and helps extend the useful life of your mattress. It is advisable to buy a new box spring when you replace your old mattress, and ensure that the box spring, or foundation, is suited for the type of mattress you are buying.

Replace your bed if:

• The mattress is worn a frayed, or the box spring creaks.
• The mattress sags, is out of shape or doesn't return to its shape after you lie down on it.
• You are constantly waking up sore or irritable, which could be a sign that your body isn't getting the support it needs during sleep.

Best sleep positions

Believe it or not, the position in which you sleep can make a big difference in your waking disposition, and help you avoid skeletal, muscular, or nerve problems down the road.

Here's why: One of the best positions is on your side, with knees slightly bent and a pillow between your knees. Place a pillow under your knees if you are a back sleeper; this helps maintain the curve in your lower back. If you are a stomach sleeper and sleep with your head on an oversized pillow, it sometimes forces your lower back to curve excessively, putting pressure on your diaphragm and lungs.