Abstract When an object that is grasped with a finger pulled by external force, the traction force perceived cutaneous receptors and proprioception in finger. Several attempts have been made to simulate pulling sensation using wearable devices, including mechanical asymmetric vibration tightening belt. In this study, we developed new method uses electrical simulation generate illusory simulatin...

One purpose of the present study was to compare indices of finger coordination during force production by the fingers of the right hand and of the left hand. The other purpose was to study the relation between the phenomena of force deficit during multifinger one-hand tasks and of bilateral force deficit during two-hand tasks. Thirteen healthy right-handed subjects performed maximal voluntary f...

This study investigated the effects of modifying contact finger forces in one direction-normal or tangential-on the entire set of the contact forces, while statically holding an object. Subjects grasped a handle instrumented with finger force-moment sensors, maintained it at rest in the air, and then slowly: (1) increased the grasping force, (2) tried to spread fingers apart, and (3) tried to s...

The wearable force feedback glove provides a promising solution for enhancing immersion during teleoperation. In this study, lightweight five-finger exoskeleton (EFFG) was designed, enabling driving detection and flexible feedback. This wireless prototype weighs only 278 g. features bionic structure optimized linkage length to ensure operator safety while providing extensive coverage of the fin...

This study explores the force synergy of human digits in both static and dynamic cylindrical grasping conditions. The patterns of digit force distribution, error compensation, and the relationships among digit forces are examined to quantify the synergetic patterns and coordination of multi-finger movements. This study recruited 24 healthy participants to perform cylindrical grasps using a glas...

Previous studies have shown that the interactions of human hand digits are influenced by internal constraints, i.e., biomechanical and central constraints. However, little is currently known about the influence of externally imposed mechanical constraints on multi-finger behavior. This study investigates maximal digit force production during fixed object and free object prehension in statics. T...

BACKGROUND Vibration-induced finger flexion reflex (VFR) in the upper extremity is inhibited by needle insertion acupuncture to the large intestine 4 (LI4) at the hand. This claim has a limitation because the inhibitory effect is deduced only from reduction in the maximum finger flexion (FF) force during the tonic flexion reflex by vibratory stimulation after acupuncture. METHODS The study wa...

The very light contact forces (∼0.60 N) applied by the fingertips during tactile exploration reveal a clearly optimized sensorimotor strategy. To investigate the cortical mechanisms involved with this behavior, we recorded 230 neurons in the somatosensory cortex (S1), as two monkeys scanned different surfaces with the fingertips in search of a tactile target without visual feedback. During the ...

A three-dimensional force transducer was installed in the neck of a violin under the A string at the D5 position in order to study the force with which the violinist clamps the string against the fingerboard under normal playing conditions. Violinists performed repetitive sequences of open A- and fingered D-tones using the ring finger at tempi of 1, 2, 4, 8, and 16 notes/s at mezzo-forte. At se...

Most trigger digit (TD) patients complain that they have problems using their hand in daily or occupational tasks due to single or multiple digits being affected. Unfortunately, clinicians do not know much about how this disease affects the subtle force coordination among digits during manipulation. Thus, this study examined the differences in force patterns during cylindrical grasp between TD ...