Overground vs. Treadmill Running: Do Runners Use the Same Strategy to Adjust Stride Length and Frequency While Running at Different Velocities?

Running speed is determined by stride frequency and stride length. As running speed is adjusted, runners make greater adjustments in stride length at slower speeds with a shift to stride frequency adjustments at the faster speeds. The relationship between stride frequency and stride length is largely based on overground research which leads to the purpose of this study to analyze whether the connection of stride frequency and stride length will adjust similar due to changes in running velocity during overground and treadmill running. The protocol was recently approved by The Institutional Review Board and data collection is currently in progress; - thus the following present abstract does not contain data. In order to compare runner’s gait pattern responses to velocity changes, two wearable technologies (Garmin Fenix2, Garmin, Kansas, USA; runScribe, Scribe Lab, San Francisco, USA) designed to measure stride length and stride frequency will be utilized. Subjects will run at a variety of velocities overground and then on the treadmill with speeds ranging from slow, preferred, and fast. The main dependent variables will be stride frequency and stride length. The null hypothesis is: The relationship between stride length and stride frequency is similar while running overground and on a treadmill at different velocities. The results of this study will be helpful to runners as well as development of wearable technology used to quantify run metrics

3-Dimensional Scanning to Determine Body Volume and Composition With and Without a Wetsuit

Wetsuits are designed to improve swimming performance by providing increased buoyant forces, reduced drag forces, and compressive forces on the body. Recently, 3-D scanning technology (2015 Structure Scanner, Occipital) has been used to measure body volume, and may provide an alternative method to obtaining body composition. Purpose: Therefore, the purpose of this study is to use 3-D scanning to measure and compare body volume with and without a wet suit. Combined with mass, volume from 3-D scanning will provide density calculations for body composition analysis. A secondary purpose of this study is to measure the difference in body composition with and without a wetsuit. Methods: The Institutional Review Board has recently approved the study and data collection has started; therefore, no data are presented in this abstract. Participants will be 3-D scanned with and without a wetsuit (Company), followed by BodPod (COSMED) measurements with and without the wetsuit. Following measurements, the 3-D scan will be used to calculate volume using MeshLab Software (Company). 2x2 mixed-factor ANOVA will be run to analyze the differences between wetsuit conditions, and between measurement methods (3D Scan vs BodPod). By comparing measurements of body volume and calculations of body composition with and without a wetsuit, the validity of the 3-D scanning technique will be determined and this might lead to the development of empirically determined wetsuit fit criteria

Understanding the Effect of Body Weight on Muscle Activity During Unilateral Hopping

Running can be described as a series of bilateral single-legged jumps and landings. Interestingly, single-legged jumps and landings are qualitatively more difficult unilaterally than bilaterally known as bilateral deficit syndrome (BDS). For example, one leg will produce less mechanical energy while jump squatting unilaterally than it would produce if both legs worked synchronously. The analysis of dynamic conditions under different levels of body weight support of the hopping movement may prove useful to understanding the bilateral deficit. Purpose: To compare muscle activity of the lower extremity during single-legged hopping at different levels of body weight support. Methods: The research study was recently approved by the Institutional Review Board and data collection has begun. Therefore, no data are presented in the abstract at this time. Subjects will be equipped with electromyography (EMG) leads to measure muscle activity of the rectus femoris, semitendinosus, medial gastrocnemius, and tibialis anterior. Subjects will be asked to perform 5 trials of hopping forwards at a preferred speed (PS) for 1 minute at varying levels of body weight (80%, 70%, 60%, 50%, 40%). EMG data of all four muscles will be compared across the separate body weight control conditions

Activity Restriction Among Women With a Short Cervix

OBJECTIVE: To estimate determinants of and outcomes associated with activity restriction among women with a short cervix. METHODS: This was a secondary analysis of a randomized trial of 17-a hydroxyprogesterone caproate for prevention of preterm birth among nulliparous women with singleton gestations and cervices less than 30 mm by midtrimester ultrasonography. Women were asked weekly whether they had been placed on pelvic, work, or nonwork rest. "Any activity restriction" was defined as being placed on any type of rest. Factors associated with any activity restriction were determined and the association between preterm birth and activity restriction was estimated with multivariable logistic regression. RESULTS: Of the 657 women in the trial, 646 (98%) responded to questions regarding activity restriction. Two hundred fifty-two (39.0%) were placed on any activity restriction at a median of 23.9 weeks (interquartile range 22.6-27.9 weeks). Women on activity restriction were older, more likely to have private insurance, less likely to be Hispanic, had a shorter cervical length, and were more likely to have funneling and intra-amniotic debris. Preterm birth at less than 37 weeks of gestation was more common among women placed on activity restriction (37% compared with 17%, P,.001). After controlling for potential confounding factors, preterm birth remained more common among those placed on activity restriction (adjusted odds ratio 2.37, 95% confidence interval 1.60-3.53). Results were similar for preterm birth at less than 34 weeks of gestation. CONCLUSION: Activity restriction did not reduce the rate of preterm birth in asymptomatic nulliparous women with a short cervix

Activity Restriction Among Women With a Short Cervix

OBJECTIVE: To estimate determinants of and outcomes associated with activity restriction among women with a short cervix. METHODS: This was a secondary analysis of a randomized trial of 17-a hydroxyprogesterone caproate for prevention of preterm birth among nulliparous women with singleton gestations and cervices less than 30 mm by midtrimester ultrasonography. Women were asked weekly whether they had been placed on pelvic, work, or nonwork rest. "Any activity restriction" was defined as being placed on any type of rest. Factors associated with any activity restriction were determined and the association between preterm birth and activity restriction was estimated with multivariable logistic regression. RESULTS: Of the 657 women in the trial, 646 (98%) responded to questions regarding activity restriction. Two hundred fifty-two (39.0%) were placed on any activity restriction at a median of 23.9 weeks (interquartile range 22.6-27.9 weeks). Women on activity restriction were older, more likely to have private insurance, less likely to be Hispanic, had a shorter cervical length, and were more likely to have funneling and intra-amniotic debris. Preterm birth at less than 37 weeks of gestation was more common among women placed on activity restriction (37% compared with 17%, P,.001). After controlling for potential confounding factors, preterm birth remained more common among those placed on activity restriction (adjusted odds ratio 2.37, 95% confidence interval 1.60-3.53). Results were similar for preterm birth at less than 34 weeks of gestation. CONCLUSION: Activity restriction did not reduce the rate of preterm birth in asymptomatic nulliparous women with a short cervix

Activity Restriction Among Women With a Short Cervix

OBJECTIVE: To estimate determinants of and outcomes associated with activity restriction among women with a short cervix. METHODS: This was a secondary analysis of a randomized trial of 17-a hydroxyprogesterone caproate for prevention of preterm birth among nulliparous women with singleton gestations and cervices less than 30 mm by midtrimester ultrasonography. Women were asked weekly whether they had been placed on pelvic, work, or nonwork rest. "Any activity restriction" was defined as being placed on any type of rest. Factors associated with any activity restriction were determined and the association between preterm birth and activity restriction was estimated with multivariable logistic regression. RESULTS: Of the 657 women in the trial, 646 (98%) responded to questions regarding activity restriction. Two hundred fifty-two (39.0%) were placed on any activity restriction at a median of 23.9 weeks (interquartile range 22.6-27.9 weeks). Women on activity restriction were older, more likely to have private insurance, less likely to be Hispanic, had a shorter cervical length, and were more likely to have funneling and intra-amniotic debris. Preterm birth at less than 37 weeks of gestation was more common among women placed on activity restriction (37% compared with 17%, P,.001). After controlling for potential confounding factors, preterm birth remained more common among those placed on activity restriction (adjusted odds ratio 2.37, 95% confidence interval 1.60-3.53). Results were similar for preterm birth at less than 34 weeks of gestation. CONCLUSION: Activity restriction did not reduce the rate of preterm birth in asymptomatic nulliparous women with a short cervix