Effect of Pedal Slope and Inward Angle on the Lower Limb Biomechanics During Elliptical Exercises
Date Issued
2009
Date
2009
Author(s)
Tsai, Yi-Shan
Abstract
Introduction：The concepts of elliptical trainer design were to simulate the motion of the human gait and avoid the impact force. The pervious papers showed the biomechanical environments of the gait and the elliptical exercise were totally different. Many new designs of the elliptical trainer were invented to approach the ambulation or other daily motions. However, the influences of those new designs on human musculoskeletal system have not been discussed. The purpose of this research is to investigate the effect of the slope and inward angle of pedal by quantifying lower limb dynamics.ethod：Eight young-male subjects without any musculoskeletal impairments or disability were recruited to this study. The range of leg length between 85.5~92 cm. The passive optical markers and electrodes were placed on subjects. The load cell installed on the left pedal measured the pedal reaction force. The elliptical exercise was measured at four level of pedal slopes (slop1,2,3,4) and inward angles（α=0,5,10,12°）. Totally, sixteen conditions with the same cadence and resistance (60 rpm, 30 watt) were discussed.esult: The investigation shows that there are no significant influences on all parameters with slope. However, the inward angle significantly changes the lower limb biomechanics in three planes. Inward angle can reduce the knee flexion angle of phase IX, but it will increase vertical PRF at the same time and, therefore, will increase the knee extensor moment of phase IX. Medial PRF is decreased in phase I and IX but increased in II and III. Besides, hip adduction angle increases near T0 and hip abduction angle increases in phase II and III. Inward angle also increases knee internal rotator angle and reduces knee external rotator moment. In addition, when α= 10,12°, the medial PRF is not stable and induces disturbed moments on frontal plane and transverse plane.onclusion: Pedal slope does not significantly affect the lower limb biomechanics. Inward angle can not make elliptical exercise more similar to walking and can not decrease knee extensor moment. The results may be caused by the fact that foot swings and closed to the center line of the body but toe out while walking, yet it is toe in during T3~T1 in the elliptical exercisr. Reducing the toe-in angle may improve the performance of lower limb biomechanics.
Subjects
elliptical trainer
kinematics
kinetics
slope
inward angle
Type
thesis
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