There is a normal lordosis in the upper (cervical) spine and the lower (lumbar) spine. People with scoliosis develop additional curves to either side of the body, and the bones of the spine twist on each other, forming a C or an S shape in the spine. Scoliosis is about two times more common in girls than boys. It can be seen at any age, but it is most common in those over about 10 years of age. Scoliosis is hereditary in that people with scoliosis are more likely to have children with scoliosis; however, there is no correlation between the severity of the curves from one generation to the next.
The final rule requires that employers inspect walking-working surfaces regularly and as needed and correct, repair, or guard against hazardous conditions; and Training (Â§1910.30).
Once you've confirmed you have adequate floor space, you can focus on the size of your running deck -- the actual moving platform component of your treadmill. If you intend to use the machine for walking and you are of average height, your track should be a least 50 inches long by 16 inches wide. If you'll be jogging or running, you will want more room to stride and move your arms, so a track of at least 55 inches long by 20 inches wide is in order.