A PRELIMINARY STUDY OF BREAST MOVEMENT IN DIFFERENT BRA SUPPORT

To free women involved in physical activities from suffering breast pain due to insufficient breast support, thorough understanding of the breast displacement mechanism is needed. The study is aimed to determine the true movement of the breast in three types of bras, and ultimately, to build a scientific base for bra design improvement. 28 female participants were recruited and the breast movements in four different types of breast support were recorded using the electromagnetic tracking system for further analysis. The results showed that the trajectories of left and right breast in a crop-top bra for the lateral raise showed significant difference (p =.039). The effect of sportsbra was obvious in all four movements and the breast displacement decreased as the breast support level increased (from non-sportsbra to sportsbra)

A global bifurcation theorem for a multiparameter positone problem and its application to the one-dimensional perturbed Gelfand problem

We study the global bifurcation and exact multiplicity of positive solutions for u 00(x) + λ fε(u) = 0, − 1 0 is a bifurcation parameter, ε ∈ Θ is an evolution parameter, and Θ ≡ (σ1, σ2) is an open interval with 0 ≤ σ1 < σ2 ≤ ∞. Under some suitable hypotheses on fε , we prove that there exists ε0 ∈ Θ such that, on the (λ, kuk∞)-plane, the bifurcation curve is S-shaped for σ1 < ε < ε0 and is monotone increasing for ε0 ≤ ε < σ2. We give an application to prove global bifurcation of bifurcation curves for the one-dimensional perturbed Gelfand problem

Comparison of breast motion at different levels of support during physical activity

Optical tracking systems have been used in previous studies to capture the motion of the nude breast and breasts in bras, under the assumption that no breast-bra relative movement occurred within the bra. This study compared breast and bra movement through electromagnetic tracking and optical tracking systems to determine the relative breast movement occurring with different breast support and exercise-induced breast discomfort. Total of 30 female participants (mean age: 21.5 ± 2.3 years; cup sizes: A-F) were recruited and their movement at four different levels of breast support was recorded in two motion capture systems for further analysis and comparison. Significant differences between bra and breast vertical displacement were found at all support levels during periods of intense movement (r = 0.556; p < 0.05). Because the greatest bra displacement was observed when participants wore an everyday bra and the greatest breast displacement was observed when participants wore a crop-top bra, there was evident inconsistency in bra and breast motion and a high-impact sports bra was the most effective to reduce breast movement and discomfort among the four types of bras. An electromagnetic tracking system provided direct observation of the actual movement of the breasts, and an optical tracking system enabled us to monitor bra displacement. Significant differences were observed in bra and breast displacement during the intense movements included in this study. The results bring into question the assumption made in previous studies that no relative movement occurs within a breast support garment.This study is supported by Ministry of Science and Technology grants 103-2815-C-006-037-H and 105-2410-H-006-052, TAIWAN, and OT Motion Lab, Department of Occupational Therapy, National Cheng Kung University

THE CENTER OF MASS TRAJECTORY DURING FIXED-STANCE PUSH HANDS MOVEMENTS OF TAI CHI CHUAN

The purpose of this study was to investigate how Tai Chi Chuan (TCC) skills affect the whole body center of mass (COM) during Tai Chi Chuan fixed-stance push hands movement. Four TCC experts with push hands movement experience for 10.3±1.7 years and four TCC beginners with 2.5±1.3-year experience were recruited in this study. Three-dimensional kinematics data of the TCC fixed-stance push hands movements were collected and COM displacement and velocity during the movements were analyzed. The patterns of the COM between two groups during the push hands movement cycle were similar, but the COM displacement and velocity were different. Our investigation reveals that the experience-related differences in whole body COM transfers are reflected in the push hands movement cycle

KINETIC ANALYSIS OF THE UPPER EXTREMITY BETWEEN DIFFERENT STANCES IN TENNIS TWO-HANDED BACKHAND

INTRODUCTION: Now the tennis players could explore more racket capabilities through the change of racket materials and design. The open stance comes out in modern tennis relative to the traditional square stance. This study was conducted to analyze the upper extremity joint forces and moments between the different stances in advanced and intermediate athletes, who separated from ITN rating system, during two-handed stroke

ARMWRESTLING EXERCISE AND SHOULDER INTERNAL ROTATION STRENGTH

The purpose of this study was to investigate the differences in shoulder internal rotation strength between winner and loser during armwrestling. Prior to the armwrestling experiment, subjects would be tested for strength of shoulder internal rotation with 45 °/sec and 60 °/sec by isokinetic dynamometer. The results showed that the strength of shoulder internal rotation at angular velocity of 45°/sec and 60°/sec had significant difference between winner and loser (

BIOMECHANICAL ANALYSIS OF TRUNK & LOWER EXTREMITY IN TENNIS SERVE

The purpose of this study was to explore the two different serving pattems---flat serve and spin serve, using a motion analysis system to discover the 3-D kinematic changes of the ankle, knee, hip, pelvis and trunk in the overall serving motion, in conjunction with force plates that helped to measure the ground reaction force (GRF) and worked out the center of pressure (COP). The moment formed by COP with the whole body center of mass would then be analyzed to explore the kinematic characteristics of the body. A further understanding of the role of joints in the lower extremity during a serve will provide a reference to motions and techniques on training and teaching, with a view to improve serving efficiency and avoid sports injury