Response surface of horizontal velocity change over one period is given in figure 7. An increase in stiffness and width in the design domain leads the runner to have better sprint performance. Height and toe length have less effect on the sprint performance in unilateral amputees. It is concluded that bending stiffness distribution along the blade, contacting area and joint position of the multi-link model of the RSP were adjusted through determining the RSP parameters to improve sprinting performance.
Horizontal velocity change over one period and average horizontal velocity shows similar responses; however, the behavior of GRF impulse-related functions was slightly different. Therefore, an evaluation parameter was proposed to investigate the effect of both vertical and horizontal impulses as single value. Bouncing ball analogy was used to derive an evaluation parameter by simplifying the motion of the runner as given in figure 8. It was assumed that longer distance after each contact will increase performance. The human body was considered as mass , initial velocities and , in the horizontal and vertical axis, respectively. In the vertical direction, velocities before and
Response surface of horizontal velocity change over one period is given in figure 7. An increase in stiffness and width in the design domain leads the runner to have better sprint performance. Height and toe length have less effect on the sprint performance in unilateral amputees. It is concluded that bending stiffness distribution along the blade, contacting area and joint position of the multi-link model of the RSP were adjusted through determining the RSP parameters to improve sprinting performance.
Horizontal velocity change over one period and average horizontal velocity shows similar responses; however, the behavior of GRF impulse-related functions was slightly different. Therefore, an evaluation parameter was proposed to investigate the effect of both vertical and horizontal impulses as single value. Bouncing ball analogy was used to derive an evaluation parameter by simplifying the motion of the runner as given in figure 8. It was assumed that longer distance after each contact will increase performance. The human body was considered as mass , initial velocities and , in the horizontal and vertical axis, respectively. In the vertical direction, velocities before and after contact were assumed as same magnitude, but in opposite direction. Aerial time was obtained by calculating velocity in the vertical direction. Then, the change of velocity in the horizontal direction was calculated by using the horizontal impulse. If initial velocities were assumed the same, the final velocity will be directly related to the change of velocity. Then, evaluation parameter was obtained by omitting initial horizontal velocity term from horizontal distance. It was revealed that not only vertical impulse, but also horizontal impulse should be considered together to understand performance.
It was concluded that the change of shape and stiffness of the RSP affects the performance of athletes. Therefore, the choice of prosthesis holds an important place for individuals to perform well.
On the other hand, knee-buckling can be a risk for the transfemoral amputees who use artificial knee joints. Therefore, the knee buckling risk should be considered in the RSP design and optimization process. Knee-buckling occurs when moment exists in the direction of knee flexion at stance phase. The relative position of the artificial knee with respect to the center of pressure and ground reaction force vectors decides the direction of the joint moment around knee joint. Toe length is the parameter that changes bottom half of the shape of the prosthesis, thus, the effect of RSP toe length on prosthetic knee moment was investigated. As it can be seen in figure 9, the reduction of toe length causes a smaller moment in the opposite direction of knee flexion. In other words, it is easier to observe knee buckling if RSP toe length is reduced. On the other hand, an increase in toe length may cause a different type of trouble, such as tripping during swing phase. Since it may be a risk for fall, therefore the closest position to the ground was obtained. According to figure 10, when toe length increases, trajectory of the RSP become closer to ground. Therefore, an increase in toe length also increases the risk of touch down to the ground while swinging.
after contact were assumed as same magnitude, but in opposite direction. Aerial time was obtained by calculating velocity in the vertical direction. Then, the change of velocity in the horizontal direction was calculated by using the horizontal impulse. If initial velocities were assumed the same, the final velocity will be directly related to the change of velocity. Then, evaluation parameter was obtained by omitting initial horizontal velocity term from horizontal distance. It was revealed that not only vertical impulse, but also horizontal impulse should be considered together to understand performance.
It was concluded that the change of shape and stiffness of the RSP affects the performance of athletes. Therefore, the choice of prosthesis holds an important place for individuals to perform well.
On the other hand, knee-buckling can be a risk for the transfemoral amputees who use artificial knee joints. Therefore, the knee buckling risk should be considered in the RSP design and optimization process. Knee-buckling occurs when moment exists in the direction of knee flexion at stance phase. The relative position of the artificial knee with respect to the center of pressure and ground reaction force vectors decides the direction of the joint moment around knee joint. Toe length is the parameter that changes bottom half of the shape of the prosthesis, thus, the effect of RSP toe length on prosthetic knee moment was investigated. As it can be seen in figure 9, the reduction of toe length causes a smaller moment in the opposite direction of knee flexion. In other words, it is easier to observe knee buckling if RSP toe length is reduced. On the other hand, an increase in toe length may cause a different type of trouble, such as tripping during swing phase. Since it may be a risk for fall, therefore the closest position to the ground was obtained. According to figure 10, when toe length increases, trajectory of the RSP become closer to ground. Therefore, an increase in toe length also increases the risk of touch down to the ground while swinging.