2 Clinical Trials for Various Conditions
Low back and posterior pelvic pain are common in pregnant females. Previous studies have demonstrated disability and it is estimated that all women experience some degree of musculoskeletal discomfort during pregnancy. Borg-Stein et. al. found 25% of pregnant females have temporarily disabling symptoms. There is demonstrated controversy over the mechanism of low back pain in pregnancy. The biomechanical theory implies that the enlarging uterus causes the maternal center of gravity to move anteriorly causing stress on the low back. Jensen et. al. demonstrated that weight gain correlated with biomechanical changes. The changes were measured by weight gain in segmental regions of the body and in principal moments of inertia from the sit to stand movement. Literature does not demonstrate a specific correlation between weight gain and the biomechanical changes of sway rate, lumbosacral angle and center of gravity. These three measurements may have a correlating effect on the underlying cause of low back pain in pregnant women. This study aims to determine the correlation between weight gain of pregnant females and the biomechanical changes of sway rate, lumbosacral angle and center of gravity. The change in weight over the last two trimesters will be correlated with the sway rate, lumbosacral angle and center of gravity. The degree of symptomatic low back pain as measured by the Oswestry Low Back Pain Scale will also be correlated with the sway rate, lumbosacral angle and center of gravity.
Stress fractures are a common and debilitating injury for a variety of athletes however current evidence does not clearly allow easy prediction of athletes at risk for a first fracture. Animal and some preliminary human evidence suggest that assessment of bone strength, muscle size and running mechanics may be primary risk factors for stress fractures. The investigators study will help determine which, if any, of these modifiable risk factors could help identify athletes at risk for stress fracture. Competitive female distance runners will be recruited for this study. Participants will placed into a stress fracture or control group based on stress fracture history. Dual energy x-ray absorptiometry (DXA) and peripheral Quantitative Computed Tomography (pQCT) will be used to assess bone structure and strength. Running mechanics will be assessed during a 30-40 minute fatiguing run. A treadmill with an embedded force plate and high speed video will be used to assess changes in running mechanics throughout the run. The purpose of this project will be to 1. explore differences in volumetric bone mineral density (vBMD), bone geometry, and muscle cross sectional area (MCSA) using pQCT 2. explore changes in load (GRFs) and running mechanics that occur during a fatiguing run in runners with and without a history of stress fracture.