This paper discusses the influence of transverse reinforcement spacing and support width of concrete wide beam on shear performance. In order to evaluate the shear performance, a total of thirteen specimens were constructed and tested. The transverse reinforcement spacing, the number of legs and support width were considered as variables. From the test results, the shear strength equation of concrete wide beam is proposed for prediction of shear strength of concrete wide beam to consider the transverse reinforcement spacing and support width. It is shown that the proposed equation is able to predict shear strength reasonably well for concrete wide beam.

The purpose of this study is to identify which width of the base of support(BOS) is safer and more effective in lifting by comparing muscle activations and body sways when lifting objects under the width variation of the BOS. A total of fifteen healthy adults participated in this study. For the width variation of the BOS, the participants changed the width between their feet into three different types(10cm, 32cm, 45cm) and lifted a 10kg four times in each type after going up on a force plate. In order to measure body sways according to the width variation of the BOS, a motion analysis system was used. In addition, in order to measure the muscle activations of lower extremities, including the erector spinae, gluteus maximus, rectus femoris, and tibialis anterior, an electromyogram(EMG) analysis was employed. In addition, the Borg's scale was drawn by quantifying the subjective discomfort levels felt from each width of the BOS. In conclusion, no statistically significant differences according to the width variation of the BOS were observed(p=.295, .308)(p>.05). However, a statistically significant difference was exhibited between the Borg's scale, which indicates the discomfort levels from lifting performances, and the width variation of the BOS (p=.000*).

This study was designed to determine the effects of different widths in the base of support (BOS) on trunk and lower extremity muscle activation during upper extremity exercise. Twenty-seven healthy male subjects volunteered for this study. Exercises were performed for a total of 10 trials with a load of 10 repetitions maximum (10 RM) for each of the various widths of BOS (10 cm, 32 cm, 45 cm). The width of a BOS is the distance between each medial malleoli when a subject was in a comfortable standing position. Electromyography was used to determine muscle activation. Surface bipolar electrodes were applied over the tibialis anterior, medial gastrocnemius, biceps femoris, rectus femoris, gluteus maximus, upper rectus abdominis, and elector spinae muscle. Electromyographic (EMG) root mean square (RMS) signal intensity was normalized to 5 seconds of EMG obtained with a maximal voluntary isometric contraction (MVIC). The data were analyzed by atwo-factor analysis of variance (ANOVA) with repeated-measures () and Bonferroni post hoc test. The results were as follows: (1) There were significant differences in the width of the BOS (p=.006). (2) The post hoc test showed significant differences with the BOS between 10 cm and 32 cm, between 10 cm and 45 cm and between 32 cm and 35 cm (p=.008, p=.003, p=.011). (3) There was no interaction with the BOS and muscle. (p=.438) There were no significant differences in the muscle activation (p=.215).