Backpacks are commonly worn by many people for multiple purposes. This study investigated the effects of habitual wearing of backpacks on lower limb kinematics and kinetics. Fourteen participants were recruited for analysis. All participants performed four randomly assigned scenarios, including running and walking at speeds of 3.5 and 1.5m/s, respectively, with and without load carriage. The motion analysis system and force plate were used to investigate the lower limb kinematics and kinetics. A paired sample t-test was performed for statistical measurement with a significance level of α.05. The results indicated that active force, breaking force, impact peak, loading rate, active peak, maximum braking, hip flexion, and hip range of motion were substantially higher under load carriage conditions than under walking condition, however, time to peak was lower. Conversely, during load carriage running, active force, braking impulse, time to peak, ankle plantarflexion, and ankle range of motion were all higher than those during running. Carrying a backpack weighing 10 of the body weight induced different foot strike patterns at both speeds; during load carriage walking, the hip tended to flex more; whereas, during load carriage running, the ankle tended to flex more. In conclusion, human body seems to adopt different gait strategies during load carriage walking and running. That is, the hip strategy is used during walking, while the ankle strategy is used during running.

The Effect of Bicycle Saddle Widths on Saddle Pressure in Female Cyclists

The Effect of Bicycle Saddle Widths on Saddle Pressure in Female Cyclists

Background: The effects of handlebar width on female cyclists are understudied; therefore, it is necessary to find an optimal handlebar width for women based on anatomical features. Methods: Ten healthy women participants whose muscle activity and movements were measured using four kinds of handlebar widths were observed using EMG and 3D motion analysis systems. Participants cycled at a constant cadence and power output using different handlebar widths in a counterbalanced order. The kinematic results and muscle activation, as a consequence of using different handlebar widths, were compared using a one-way repeated measures ANOVA (α = 0.05). Results: It was discovered that using a medium-width handlebar not only resulted in significantly lower bicep activation compared to narrow and self-selected widths, but also resulted in less triceps and latissimus dorsi activation compared to the self-selected width. Regarding kinematics, using a medium-width handlebar significantly reduced hip ROM, while using a narrow handlebar led to greater hip adduction. Conclusions: Cyclists are advised to use a handlebar width that matches their shoulder width, since this may avoid muscle fatigue while also allowing for better hip posture. However, commercial models are usually wider than female shoulders. Thus, these results provide insights useful for future handlebar design.

Purpose COVID-19 has rampaged the world. Nowaday, a lot of people in Taiwan still experiencing working from home, as well as exercising from home (EFH) to maintain their physical health. This study aimed to investigate the difference in training efficacy by joining online workout courses and coach supervision. Methods Twenty participants were recruited in this study. The subjects were randomly divided into coach supervision and online training groups. A pre-test was first conducted, followed by a post-test after 8 weeks of training intervention. The tests were to measure the participant’s muscle hypertrophy and sports performance, with the former including InBody body composition analysis, and the latter including the assessment of jumping ability, 20-metre sprint, bench press, and squat performances. The two-way mixed design measures ANOVA was applied for statistical measurement. If the correlation between the two factors was significant, the Bonferroni post hoc test will be applied to determine the main effects. (α = 0.05). Results There was no significant difference between the two training groups. However, substantial differences were observed between the jumping ability, bench press performance, and squat performance of the pre- and post-tests in both groups, with the participants generally performing better in the latter case. In terms of body composition and muscle circumference, no significant changes were found between both tests. Conclusion Participating online training courses at home is recommended when exercising outdoor is forbidden. Moreover, online training not only reduces the transmission of coronavirus, but also helps improve the immunity in a safe environment.