The human foot is only part that directly contact between the body and the external environment, and is ideally positioned to provide sensory information to the Central Nervous System (CNS) during static and dynamic tasks. Through cutaneous mechanoreceptors located in the dermis, the foot is able to recognize touch pressure and vibration stimuli, which provide important feedback information used for the fine coordination of movements. The purpose of this study is to quantitatively examine the effect of changing the foot cutaneous sensory by temperature stimulus on maximal performance and muscle activation using wavelet technique. Sixteen healthy subjects volunteered to participate in this study (Male: Age 21.4±2.4years; Height 174.7±5.3츠; Weight 70.6±5.2kg; Female: Age 20.5±0.6years; Height 163.2±3.1cm; Weight 55.6±4.8kg). Sensory pressure thresholds were determined for the plantar surface of the foot using monofilament. Kinematic, kinetic and EMG data which relative to maximal performance were collected while squat jumping in each temperature condition(cool 12-15℃ normal 28-30℃ hot 45-48℃). Maximal jump height was significant higher in normal condition. Vertical GRF in normal condition showed higher peak value the other conditions. And then EMG signal were significant different between temperature conditions during maximal performance. By changed sensory feedback on temperature, one can alter maximal performance and muscle activation pattern. Cutaneous feedback is important in performance and neuromuscular control, and temperature changes significantly influence on lower extremity during maximal squat jump performance of healthy subjects.
Purpose The present study explored biological autonomy and control of function in circumstances that assessed a presumed relationship to an environmental cycle. An understanding of this behavior appeals to the organism-environment system rather than simply the organism—we seek to expose the laws that underlie end-directed capabilities by measuring biological characteristics (motor synchrony) in an environmental cycle (circadian temperature). Methods Participants (n = 24) at the University of Connecticut (Storrs, USA) and the Seoul National University (Seoul, Korea) served in the study. The production of in-phase bi-manual coordination was examined at different circadian points (allowing comparison of day-night temperature effects) in two experimental designs; (1) normal temperature embedded in a 24 hour cycle (5:00, 12:00, 17:00, and 24:00), and (2) normal versus abnormal temperature [artificially decreasing or increasing] while embedded at two points (5:00 am, 5:00 pm) during the circadian process. A typical bi-manual stability measure varied significantly as a function of the day-night temperature cycle. Results While (i) circadian effects under the artificially perturbed temperature manipulation were not straightforward along the day-night temperature cycle, (ii) the circadian effect divided by the ordinary circadian seems to be constant along the day-night temperature cycle. Conclusions The discovery of direct and robust relation between biological aspects (body temperature and motor synchrony) an environmental process (circadian temperature cycle) may echo adaptation of our biological system to the environment. This relation supports the claim that the organism and the environment should be considered as integrated system in which biological (or physical) dynamics takes place as a mutual factor.
Purpose This is to provide essential data for training necessary for sweeping through the analysis of muscle activity generated at this time and how much sweeping and what trajectory moves the stone when the movement of the stone is controlled through sweeping. Methods To check and record the distance between the stones by checking the stop position of the stone made by sweeping each section, the length (progress distance) and width (progress direction) were recorded using a reference table and a record preparation table. With the EMG attached, a total of 60 sweeps were made 20 times each from the beginning of the section to the end of the section. Sweeping subjects were asked to sweep as much as possible under the same conditions in all three sections. Results As a result of the study, the muscle mobilization patterns of the 1st and 2nd sections of the stone with the faster speed and the 3rd section with the stone's slower speed appeared differently. It was confirmed that the sweeping motion of curling is a motion that is used evenly among the muscles of the upper extremity, and it can be verified that it is a suitable item for the development of upper body muscles. Also, the right deltoid's muscle activity rate during push and the right triceps brachii during pull was high. Conclusion Each section of the stone's sweeping effect is an exercise that has many variables, such as changes in atmospheric temperature and humidity, changes in ice temperature, temperature-size-number of pebbles, and the edge state-resilience of stones, etc. It is judged that experience can cope with these variables and requires training.
