 This study compares three treatments for low back pain that started during pregnancy. The study hypothesizes that exercise, spinal manipulation, and a mind-body technique called neuroemotional technique NET equally affect pain intensity and disability associated with pregnancy-related low back pain. The study also hypothesizes that pain intensity and disability levels do not influence maternal heart rate variability a measure of stress and intrauterine attachment a measure of relationship quality. Ten women will additionally provide blood and salivary oxytocin samples during pregnancy and periodically for three months after birth. These women and their babies will also be videotaped playing for 5 minutes at 2 weeks, 6 weeks, and 3 months postpartum. 