• Roland-Morris Low Back Pain and Disability Questionnaire at each visit. [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  
• Quadruple Visual Analog Scale at each visit. [ Time Frame: 5 years ] [ Designated as safety issue: Yes ]
  
• Ware's Short Form-12 (SF-12)at each visit. [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  
• PHYSIOLOGICAL STUDY -All measures at visit 1 (30 weeks) and visit 4 (36 weeks) [ Time Frame: 5 years ] [ Designated as safety issue: Yes ]
  
• Heart rate and blood pressure variability as measured by ECG and power spectral analysis. [ Time Frame: 5 years ] [ Designated as safety issue: Yes ]
  
• BIOMECHANICAL STUDY - All measures taken at visit 1 (30 weeks) and visit 4 (36 weeks) [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  
• Step length as measured by the GAITRite walkway. [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  
• Foot angle of progression as measured by the GAITRite walkway. [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  
• Gait Symmetry as measured by the GAITRite walkway. [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  

• CLINICAL STUDY [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  
• Subject Confidence in Treatment Assessment at visits 1,7,and 9. [ Time Frame: 5 yers ] [ Designated as safety issue: No ]
  
• Meconium staining of the amniotic fluid as recorded on the delivery record. [ Time Frame: 5 years ] [ Designated as safety issue: Yes ]
  
• Other outcomes of pregnancy, labor and delivery including incidence of high-risk status, incidence of pre-term labor, length of labor, use of forceps or suction device, and pain medication use as recorded in the prenatal and delivery record. [ Time Frame: 5 years ] [ Designated as safety issue: Yes ]
  
• PHYSIOLOGICAL STUDY-All measures at visit 1 (30 weeks) and visit 4 (36 weeks) [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  
• Heart rate as measured by ECG. [ Time Frame: 5 years ] [ Designated as safety issue: Yes ]
  
• Arterial pressure as measured by finger photoplethysmographic monitor. [ Time Frame: 5 years ] [ Designated as safety issue: Yes ]
  
• Respiration as measured by a strain gauge belt. [ Time Frame: 5 years ] [ Designated as safety issue: Yes ]
  
• Saphenous vein diameter and flow as measured by surface ultrasound. [ Time Frame: 5 years ] [ Designated as safety issue: Yes ]
  
• Calf muscle EMG as measured by surface electromyographic activity of the gastrocnemius [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  
• Total leg volume as estimated by strain gauge plethysmography. [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  
• Tissue water content as measured by surface dielectric probe. [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  
• Venous flow rate as measured by calf plethysmography. [ Time Frame: 5 years ] [ Designated as safety issue: Yes ]
  
• BIOMECHANICAL STUDY -All measures taken at visit 1 (30 weeks) and visit 4 (36 weeks) [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  
• Gait cadence as measured by the GAITRite walkway. [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  

The osteopathic philosophy of health is built on a model in which basic body functions are coordinated and integrated by the musculoskeletal system. Osteopathic medical students are taught to consider these aspects in assessing, diagnosing, and treating the individual patient. As a treatment method that reflects the osteopathic philosophy, osteopathic manipulative medicine (OMM) is a body-based modality in which the patient is evaluated and treated as a whole to improve physiologic functioning and remove impediments to optimal health and functioning.

During pregnancy, a woman's body is challenged by significant and extensive physiological and biomechanical changes. Some physiological changes, such as increased fluid volume and sympathetic tone, may lead to consequences such as edema, preterm labor, and meconium-staining of the amniotic fluid. The biomechanical state of the woman's body is also drastically affected; as the fetus grows and the uterus expands, the center of gravity shifts forward, rotating the pelvis anteriorly and increasing the lordosis of the low back, and may also affect the motion of the hips and legs. These postural changes also have consequences such as low back pain, decreased functional status, and altered gait. Both these physiologic and biomechanical consequences can have a significant long-term impact on the health of the mother and child.

OMM is theorized to facilitate the body's adjustment to the physiological and biomechanical demands of pregnancy and improve the outcomes of pregnancy, labor and delivery. Clinical case studies report reduced back pain, shorter labor, and fewer incidences of peripartum complications in patients who receive prenatal OMM. However, to date we have found no published systematic investigations of the efficacy of OMM in managing the adverse effects that pregnancy has on a woman's musculoskeletal system, nor have we found any published systematic studies to prove the mechanisms of action of OMM in managing pain, edema, or gait in pregnant patients.

Thus, the overall question that guides this proposal is: to what extent and by what physiological mechanisms does Osteopathic Manipulative Medicine (OMM) affect selected conditions related to pregnancy, labor and delivery? Based on the principles and theories of OMM and the limited previous studies, the hypothesis of this study is that OMM improves clinical outcomes including low back pain, functional status, incidence of meconium-stained amniotic fluid, and complications of labor and delivery, and that the physiological changes related to improved autonomic regulation, peripheral hemodynamic regulation, and biomechanical changes related to gait are, in part, responsible for these clinical benefits.