Elbow joint position and hand pressure force sense under conditions of quick reaction in table tennis players

Joint position sense and force reproduction are the most commonly used measures of proprioception. It is interesting to measure proprioception in integration of the factors most commonly viewed as the most important in table tennis—speed, in particular quick reaction. The aim of this study was to evaluate the accuracy of replication of a specific range of motion and force of hand pressing under conditions of limited time. Forty table tennis players and 30 non-athletes participated in the study. Electrogoniometric and dynamometric methods were used in the investigation. The accuracy of replication of pronation and supination movements of the forearm at the elbow joint and force of hand pressing under conditions of limited time (performing the activity as fast as possible in response to visual signals) were measured. The tests performed in the study revealed that both female and male table tennis players were characterized by a higher level of forearm position sense during performing the fastest possible pronation and supination movements in most of the tasks. Better results of table tennis players than of the control group suggest that joint position and hand pressure sense integrated with quick reaction are important performance factors in table tennis. The results also indicate opportunities for using this methodology to monitor training.

Numerical simulation of the area shrinkage mass for the waist of elastic pantyhose by using FEM

Purpose The area shrinkage of the body under pressure is very important to evaluate the comfort of pressure sense, and it is an important index that appraises compression garment. The purpose of this paper is to obtain the area shrinkage mass of the waist cross section by using the finite-element method (FEM), and the waist of women’s pantyhose could be designed with a different degree of elasticity during the course of design based on clothing pressure comfort. Design/methodology/approach This study aimed at the problems existing in the wearing of women’s elastic pantyhose, took the waist of pantyhose as the research object, and the contact between human body and pantyhose as elastic contact. The finite-element model of the waist cross section and elastic pantyhose fabric was acquired through CT scan and Mimics software. After simulating on the corresponding displacement distribution of the waist of sample elastic pantyhose during the process of dressing by using ANSYS, the authors divided the waist cross section into 24 equal regions according to angle (every 15 degrees as a region), and then the area shrinkage mass of each region was obtained by area calculation formula. According to the tendency of area shrinkage distribution, the waist of women’s elastic pantyhose could be designed for different regions of tension considering the pressure comfort, so as to guarantee that the wearing comfort can be maintained on the premise of ensuring the functionality of the elastic pantyhose. Findings In this paper, the authors obtained the area shrinkage mass of elastic pantyhose at waist cross section, and this area shrinkage distribution could be used as an objective evaluation index for pressure comfort. All these solutions are of great significance to the optimization design of pantyhose and can provide theoretical basis for the structural improvement of functional pantyhose and the prediction of clothing pressure. Originality/value This paper simulated the area shrinkage mass for the waist of elastic pantyhose by using FEM, and the waist of women’s elastic pantyhose could be designed for different regions of tension considering the pressure comfort according to the area shrinkage distribution tendency, so as to guarantee the wearing comfort during the wearing process.

A Study on Tele-Existence of the Tactile Sense

This report describes, first, a glove with joint angle sensors made of chip coils to detect the joint angles of human fingers in real time and also describes artificial fingers with multiple joints used for a tele-existence system on the tactile sense. Characteristics of the artificial skin to be attached to the artificial fingers are based on the experimental results of force-displacement characteristics of the human skin. Secondly, sensations produced by the pressure and the strain applied to the finger tip surface were measured as functions of pressure force level and the direction of the strain force using psychophysical techniques. A study of pressure sense and a force vector sensor is useful from the view point of the tele-existence system for the tactile sense.