racture in the past 2 years, if caused by injury- Placement of rods or pins for scoliosis- History of a hip or pelvic fracture and/or repair- Brain injury or surgery in the brain tissue- Serious breathing problems such as emphysema, sleep apnea or cystic fibrosis- Cancer: All forms of cancer are not acceptable except any of the followings: - Cured, local skin cancer (basal cell or squamous cell) -