BACKGROUND It is generally asserted that reliable and intuitive control of upper-limb prostheses requires adequate feedback of prosthetic finger positions and pinch forces applied to objects. Body-powered prostheses (BPPs) provide the user with direct proprioceptive feedback. Currently available BPPs often require high cable operation forces, which complicates control of the forces at the termi...

In this paper, we study the evolution of submannifold moving by mean curvature minus a external force field. We prove that the flow has a longtime smooth solution for all time under almost optimal conditions. Those conditions are that the second fundamental form on the initial submanifolds is not too large, the external force field, with its any order derivatives, is bounded, and the field is c...

Monitoring the push force is an important asset during wheelchair (WC) sports training. However, current instrumented wheels cannot be used without significantly altering the WC-user dynamics. Moreover, the push force could not be estimated directly from the WC acceleration because of the strong influence of the upper body movement on the WC-user dynamics. In this paper, we present a new method...

This study utilizes a biomechanical model of the thumb to estimate the force produced at the thumb-tip by each of the four extrinsic muscles. We used the principle of virtual work to relate joint torques produced by a given muscle force to the resulting endpoint force and compared the results to two separate cadaveric studies. When we calculated thumb-tip forces using the muscle forces and thum...

BACKGROUND Proper alignment of the scapula during upper extremity motion is important in maintaining shoulder joint function and health. Push-up plus exercise is considered as one of the best exercise to strengthen the muscles that stabilize the scapula. The purpose of the study is to examine the effects of push-up plus variants and elbow position on vertical ground reaction force and electromy...

This paper presents the procedure and results of two experiments dealing with the force resolution of the human finger and with haptic demands on push-buttons. The outcome is used to specify design details of a novel approach to a flexible control panel. A haptic display controlled by a PC enables the simulation of push-buttons with programmable forcedisplacement curves. The “just noticeable fo...

Breakup of electrified jets is important in applications as diverse as electrospraying, electroseparations and electrospray mass spectrometry. Breakup of a perfectly conducting, incompressible Newtonian liquid jet surrounded by a passive insulating gas that is stressed by a radial electric field is studied by a temporal analysis. An initially quiescent jet is subjected to axially periodic shape...

Electromyographic (EMG) crosstalk was systematically analyzed to evaluate the magnitude of common signal present between electrode pairs around the forearm. Surface EMG was recorded and analyzed from seven electrode pairs placed circumferentially around the proximal forearm in six healthy individuals. The cross-correlation function was used to determine the amount of common signal, which was fo...

To find an effective way to handle wheelchairs, 3-dimensional floor reactions of the hand and angular deviation of the elbow and wrist joints during push-up motion were studied in 10 healthy men. The push-up was carried out using 3 hand positions (fist, finger and palm) and a push-up device. In all hand positions, anteroposterior force (Fx) and the mediolateral force (Fy) appeared after the ver...