DETERMINANT OF LEG SPRING STIFFNESS DURING MAXIMAL HOPPING

Understanding stiffness of the lower extremities during human movement may provide important information for developing more effective training methods during sports activities. It has been reported that leg stiffness (Kleg) during submaximal hopping depends primarily on ankle stiffness (Farley & Morgenroth, 1999), but the way stiffness is regulated in maximal hopping is unknown. The aim of the present study was to investigate a major determinant of the leg stiffness during maximal hopping

Techniques of EMG signal analysis: detection, processing, classification and applications

Electromyography (EMG) signals can be used for clinical/biomedical applications, Evolvable Hardware Chip (EHW) development, and modern human computer interaction. EMG signals acquired from muscles require advanced methods for detection, decomposition, processing, and classification. The purpose of this paper is to illustrate the various methodologies and algorithms for EMG signal analysis to provide efficient and effective ways of understanding the signal and its nature. We further point up some of the hardware implementations using EMG focusing on applications related to prosthetic hand control, grasp recognition, and human computer interaction. A comparison study is also given to show performance of various EMG signal analysis methods. This paper provides researchers a good understanding of EMG signal and its analysis procedures. This knowledge will help them develop more powerful, flexible, and efficient applications

Post-marathon wearing of Masai Barefoot Technology shoes facilitates recovery from race-induced fatigue: an evaluation utilizing a visual analog scale

Kento Nakagawa, Takashi Obu, Kazuyuki KanosueFaculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan Purpose: To investigate the potential benefit of post-race wearing of unstable shoes (Masai Barefoot Technology [MBT]) on recovery from marathon race–induced fatigue.Patients and methods: Forty-five runners who participated in a full marathon race were divided into three groups: 1) MBT shoes, 2) trail running shoes, and 3) control (CON). Participants ran a full marathon with their own running shoes, and then put on the assigned shoes immediately after the race. They continued to wear the assigned shoes for the ensuing 3 days. The CON group wore their usual shoes. Estimates of post-race fatigue were made by the participants on questionnaires that utilized a visual analog scale. Estimates were made just after the race, as well as for the next 3 days.Results: The subjective fatigue of the MBT group was lower than that of the CON (P<0.05) or trail running shoe groups (P<0.05) on day 3.Conclusion: MBT shoe intervention can promote recovery from the fatigue induced by running a full marathon.Keywords: footwear, VAS, full maratho

Role of the medullary raphé in thermoregulatory vasomotor control in rats

To investigate the involvement of the medullary raphé in thermoregulatory vasomotor control, we chemically manipulated raphé neuronal activity while monitoring the tail vasomotor response to preoptic warming. For comparison, neuronal activity in the rostral ventrolateral medulla (RVLM) was manipulated in similar experiments. Injections of d,l-homocysteic acid (DLH; 0.5 mm, 0.3 μl) into a restricted region of the ventral medullary raphé suppressed the tail vasodilatation normally elicited by warming the preoptic area to 42 °C. DLH injection into the RVLM also suppressed the vasodilatation elicited by preoptic warming. Injection of bicuculline (0.5 mm, 0.3 μl) into the same raphé region suppressed the vasodilatation elicited by preoptic warming. Bicuculline injection into the RVLM did not suppress tail vasodilatation. These results suggest that neurones in both the medullary raphé and the RVLM are vasoconstrictor to the tail, but only those in the raphé receive inhibitory input from the preoptic area. That input might be direct and/or indirect (e.g. via the periaqueductal grey matter)