3 Clinical Trials for Various Conditions
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.
The goal of this clinical trial is to evaluate how different exercise programs alter bone density, structure, and strength in adults. It will also collect data on hormones, factors released from skeletal muscle, and body composition. The main questions it aims to answer are: * Do exercise programs that are frequent with high-impact loading will cause greater improvements in bone health? * What changes in hormones, factors released from skeletal muscle, and body composition contribute to bone adaptations? Researchers will compare different exercise groups to see if the type of exercise influences bone adaptation compared to a recreationally active control group. Participants are asked to: * complete questionnaires, 5 blood draws across the study (3 at rest, 2 after strenuous exercise), dual energy x-ray absorptiometry (DXA) scans (to assess bone mineral density and body composition), high resolution tibial scans to assess bone structure and geometry, and physical performance testing. * attend up to 7 testing visits. * (for those randomized to the exercise training intervention) participate in exercise training sessions for 6 months.
This study will evaluate the effects of a novel, non-pharmacologic intervention for the prevention of deleterious changes in bone density and strength in adolescents with anorexia nervosa (AN), a disease commonly treated with extended periods of bed rest and immobilization. The primary focus of the trial is to conduct a prospective short-term intervention to prevent an uncoupling of bone turnover in inpatients hospitalized for AN, and to determine the long-term effects of a biomechanical intervention on skeletal health in ambulatory adolescents with AN.