A COMPUTER SIMULATION FOR LEG STIFFNESS IN MAXIMAL SPRINTING

When humans and other mammals run, the body's complex system of muscle, tendon and ligament behave like spring. A computer simulation for terrestrial running at maximal speed is presented in this study, based on a leg with the properties of non-linear spring. At maximal speed, the horizontal speed has 'been conSidered constant while the vertical component was considered zero at landing. Three non-linear springs have been considered for quadriceps, hamstring, and gastrocnemius muscles with different stiffness coefficients. The goal of present study was to determine the relative importance of changes to the leg spring stiffness and the angle swept by the leg spring when the sprinter alters the landing angles (from braking to take-off) at maximal speed. Results also showed that at maximal speed the stiffness coeffiCients presented non-linear behaviour

I understand your pain but I do not feel it: lower affective empathy in response to others’ social pain in narcissism

Introduction: While the relationship between narcissism and empathy has been well-researched, studies have paid less attention to empathic accuracy, i.e., appreciating the precise strength of another person’s emotions, and self-other distinction, in terms of the disparity between affective ratings for self and other in response to emotive stimuli. Furthermore, empathic responses may vary depending on whether the pain is physical or social.Methods: We investigated empathic accuracy, affective empathy, and the distinction between pain, emotion and intensity ratings for self and other, in high (n = 44) and low (n = 43) narcissism groups (HNG and LNG, respectively) selected from 611 students, in response to both types of pain. Participants watched six videos where targets expressed genuine experiences of physical and social pain, and rated the perceived affect and pain experienced by the person in the video and their own empathic emotional responses.Results and discussion: The HNG displayed lower affective empathy and empathic accuracy than the LNG for both pain types. Within the HNG there was higher empathic accuracy for social vs. physical pain, despite reduced affective empathy for social pain, in contrast to the LNG. In addition to this paradox, the HNG demonstrated greater differences between ratings for the self and for target others than the LNG, suggesting that narcissism is associated with higher self-other distinction in response to viewing other people describing social pain