自行騎乘姿勢對運動學、力學、生理負荷與主觀費力程度之影響

This study aims to understand the relationship between riding posture and cycling comforts by assessing the kinematics, kinetics, physiological loading and subjective perceived exertion rating. Twenty young adults with mean age 24.6 years (SD=0.1) were recruited to participate in this study. A commercial city bike with the adjustable handlebar and saddle had been set on the indoor cycling stands. All subjects were asked to ride randomly with 9 different postures (3 handle ×3 saddle heights) for continuous one hour. A 3-D motion analysis system (Zebris Medical GmbH, Germany) was used to collect the kinematic data. The body pressure measurement system (Body Pressure Measurement System, Tekscan, U.S.A) was applied to measure the pressure distribution, force and displacement of centre of mass (COM). A heart rate monitor (Polar RS-800, Kempele, Finland) was used to record the heart rate as the physiological loading. Moreover, a subjective perceived exertion rating scale (Borg CR-10) was used to assess subjective comfort around the body regions. The results of this study indicated that the lower handlebar with higher saddle cause greater ROM in wrist-ulnar deviation, wrist extension, trunk flexion and hip abduction. It also reveals more force on hand region, more discomfort around hand, ankle and back, and higher physiological loading. While cycling with higher handlebar and lower saddle, it has more ROM in wrist flexion, more body displacement on buttock region, little trunk forward, and more discomfort rating in buttock region. For handlebar and saddle adjustment, the considerations of body dimensions and characteristics, the relationship between handlebar and saddle heights might improve the cycling comfort and diminish musculoskeletal injury.