Breast support garments are ineffective at reducing breast motion during an aqua aerobics jumping exercise

The buoyant forces of water during aquatic exercise may provide a form of ‘natural’ breast support and help to minimise breast motion and alleviate exercise induced breast pain. Six larger-breasted females performed standing vertical land and water-based jumps, whilst wearing three breast support conditions. Underwater video cameras recorded the motion of the trunk and right breast. Trunk and relative breast kinematics were calculated as well as exercised induced breast pain scores. Key results showed that the swimsuit and sports bra were able to significantly reduce the superioinferior breast range of motion by 0.04 and 0.05 m, respectively, and peak velocity by 0.23 and 0.33 m/s, respectively, during land-based jumping when compared to the bare-breasted condition, but were ineffective at reducing breast kinematics during water-based jumping. Furthermore, the magnitude of the swimsuit superioinferior breast range of motion during water-based jumping was significantly greater than land-based jumping (0.13 m and 0.06 m), yet there were no significant differences in exercise induced breast pain, thus contradicting previously published relationships between these parameters on land. Furthermore, the addition of an external breast support garment was able to reduce breast kinematics on land but not in water, suggesting the swimsuit and sports bras were ineffective and improvements in swimwear breast support garments may help to reduce excessive breast motion during aqua aerobic jumping exercises

Junior Recital: Chris Mills, Classical Guitar

This recital is presented in partial fulfillment of the requirements for the degree Bachelor of Music in Performance. Mr. Mills studies guitar with Mary Akerman.https://digitalcommons.kennesaw.edu/musicprograms/1643/thumbnail.jp

Acute changes in clinical breast measurements following bra removal:implications for surgical practice

AbstractBackgroundStable measurement of breast position is crucial for objective pre-operative planning and post-operative evaluation. In clinical practice, breast measures are often taken immediately following bra removal. However, research shows that restrictive clothing (such as a bra) can cause acute anatomical changes, leading to the hypothesis that clinical breast measures may change over time following bra removal. This cross-sectional observational study aimed to provide simple clinical guidelines for the measurement of breast position which account for any acute changes in breast position following bra removal.MethodsThirteen participants of varying breast sizes had markers attached to their thorax and nipples to determine clinical measures of sternal notch to nipple distance, internipple distance, breast projection, and vertical nipple position. The positions of these landmarks were recorded using a motion capture system during 10 min of controlled sitting following bra removal.ResultsInternipple distance and breast projection remained unchanged over 10 min, while the resultant sternal notch to nipple distance extended by 2.8 mm in 299 s (right) and 3.7 mm in 348 s (left). The greatest change occurred in the vertical nipple position, which migrated an average of 4.1 mm in 365 s (right) and 6.6 mm in 272 s (left), however, for one participant vertical migration was up to 20 mm.ConclusionsInternipple distance and breast projection can be measured first following bra removal, followed by sternal notch to nipple distance, any measures associated with the vertical nipple position should be made more than 6 min after bra removal. These guidelines have implications for breast surgery, particularly for unilateral reconstruction based on the residual breast position

Impacts of elevated atmospheric ozone on peatland below-ground DOC characteristics

Rising concentrations of tropospheric ozone are having detrimental impacts on the growth of crop and forest species and some studies have reported inhibition of the allocation of carbon below ground. The effects of ozone on peatland ecosystems have received relatively little attention, despite their importance within the global carbon cycle. During this study, cores from a Welsh minerotrophic fen and ombrotrophic bog were exposed to four ambient/ elevated ozone concentration regimes representing current and predicted 2050 profiles. A large and significant reduction in the concentration of porewater dissolved organic carbon (DOC) was recorded in the fen cores exposed to the elevated ozone concentrations (up to −55%), with a concurrent shift to a higher molecularweight of the remaining soil carbon. No effects of ozone on DOC concentrations or characteristics were recorded for the bog cores. The data suggest higher ozone sensitivity of plants growing in the fen-type peatland, that the impacts on the vegetation may affect soil carbon characteristics through a reduction in root exudates and that theremay have been a shift in the source of substrate DOC for microbial consumption from vegetation exudates to native soil carbon. Theremay also have been a direct effect of ozone molecules reacting with soil organic matter after being transported into the soil through the aerenchyma tissue of the overlying vegetation. These qualitative changes in the soil carbon in response to elevated ozone may have important implications for carbon cycling in peatland ecosystems, and therefore climate change

Computer simulation of gymnastics vault landings

A computer simulation model of an International Gymnastics Federation (F.I.G.) landing mat and a gymnast was developed to investigate the mechanics of landing from the gymnastics vault. The landing mat model incorporated the multilayer design of the landing mat and its deformation characteristics were based upon experimental data. The gymnast model was based upon an elite level gymnast and contained subject-specific parameters. The gymnast was modelled as a seven-segment link system with 'lumped' muscles producing joint rotation at the hip, knee and ankle. Wobbling masses were included within the trunk, thigh and shank segments to represent soft tissue movement. A two segment bone within the shank and thigh provided estimates of bone bending moments and bone deformations. Joint torques were based upon the torque / angle / angular velocity relationship established during isokinetic dynamometry testing of the subject. The muscle forces were calculated from the joint torques and from moment arm data taken from the literature and scaled to the subject. The gymnast–mat model was evaluated using the kinetic, kinematic and EMG data collected from actual vaults performed by the subject. Evaluation results showed good agreement between the simulations and the actual performances with difference scores between 10.1 % and 23.6 %. The landing strategy and landing mat were optimised to minimise the ground reaction forces and bone bending moments. Optimised landing strategy results suggest that modifications to the gymnast's landing strategy could reduce the peak ground reaction forces but this may not decrease the peak internal joint forces. Optimised landing mat parameter results suggest that a landing mat with 20 % more damping could reduce the peak ground reaction forces and internal joint forces but this may increase the initial impact force between the foot and the mat's surface

Longitudinal variable selection by cross-validation in the case of many covariates

Longitudinal models are commonly used for studying data collected on individuals repeatedly through time. While there are now a variety of such models available (Marginal Models, Mixed Effects Models, etc.), far fewer options appear to exist for the closely related issue of variable selection. In addition, longitudinal data typically derive from medical or other large-scale studies where often large numbers of potential explanatory variables and hence even larger numbers of candidate models must be considered. Cross-validation is a popular method for variable selection based on the predictive ability of the model. Here, we propose a cross-validation Markov Chain Monte Carlo procedure as a general variable selection tool which avoids the need to visit all candidate models. Inclusion of a “one-standard error” rule provides users with a collection of good models as is often desired. We demonstrate the effectiveness of our procedure both in a simulation setting and in a real application.

CHANGES IN LUMBAR JOINT MOMENTS USING A FEMALE SPECIFIC TORSO AND DYNAMIC BREAST MODEL DURING RUNNING

This study aimed to investigate the effect of breast mass and motion on lumbar flexor / extensor moments during running. Kinematic and kinetic data were collected for a female participant running at 2.6 m/s. An MRI scan was used to calculate breast mass and centre of mass location. An OpenSim model was customised with two point-mass segments added to the torso to represent the breasts. Three model variations were constructed (combined breast and torso mass; separate breast and torso mass without breast motion; separate breast and torso mass with breast motion). Findings show that neglecting breast motion causes peak lumbar extensor moments to be underestimated by ~3.4%, compared with a combined breast and torso mass model. These results highlight the importance of including breast motion in female specific MSK models, during activities such as running

CHANGES IN LUMBAR JOINT MOMENTS USING A FEMALE SPECIFIC TORSO MODEL DURING RUNNING

The purpose of this study was to quantify the peak lumbar joint flexor / extensor moments following changes in torso and breast mass during running using an innovative computer musculoskeletal model. Kinematic and kinetic data were collected for a female participant running at 2.6 m/s. An MRI scan of the breasts was used to calculate breast mass and centre of mass location relative to the torso. An OpenSim whole body model was customised with two point-mass segments added to the torso to represent the breasts. Key findings have shown that changes in breast mass can cause peak lumbar flexor / extensors moments to be over or underestimated by up to ~18%. These results suggest that including the mass of the breasts in female specific models, during dynamic activities such as running, is an important aspect that must be considered for future work