Several studies have investigated whether vestibular signals can be processed to determine the magnitude of passive body motions. Many of them required subjects to report their perceived displacements offline, i.e., after being submitted to passive displacements. Here, we used a protocol that allowed us to complement these results by asking subjects to report their introspective estimation of t...

AIM The aim of the present study was to evaluate reactive hops under systematically modified acceleration conditions. It was hypothesized that a high preactivity of the leg extensors and phase-specific adjustments of the leg muscle activation would compensate the alterations caused by the various acceleration levels in order to maintain a high leg stiffness, thus enabling the jumper to perform ...

BRIC (BRain Injury Criterion) and RIC (Rotational Injury Criterion) have been proposed as Mild Traumatic Brain Injury (MTBI) predictors. Both predictors had been verified with football players' head impact data. This study employed two human brain Finite Element (FE) models of THUMS ver.3 and SIMon ver.4 to find out correlations between the MTBI predictors and FE-based brain injury predictors s...

In this study, we analyzed the swing motions of more experienced practitioner and new practitioner of iaido players by using tri-axial acceleration sensor and gyro sensor. Iaido is a modern Japanese martial art/sport. In this way, the acceleration and gyro sensor measurement enabled detailed motion information at the installation points to be displayed in a short time, thus making it possible t...

The objective of the present paper is to provide new insight not only to an original head trauma database but also to the intra-cranial response of the human head computed with an existing head FE model under accidental circumstances. More precisely, the separate contribution of rotational acceleration and linear acceleration at the time of impact to the intra-cerebral shearing stresses and bra...

Patients with cerebellar deficits made elbow flexion movements as rapidly as possible for three different angular distances. Electromyographic activity of biceps and triceps and the kinematics of the movements were analysed. Results were compared with those of normal subjects making both rapid and slow movements. In the patients, the first agonist burst of the biceps was frequently prolonged re...

A self-action problem for a point-like charged particle arbitrarily moving in flat space-time of six dimensions is considered. A consistent regularization procedure is proposed which relies on energy-momentum and angular momentum balance equations. Structure of the angular momentum tensor carried by the retarded ”LiénardWiechert” field testifies that a point-like source in six dimensions posses...

The kinematics of a two rotational degrees-of-freedom (DOF) spherical parallel manipulator (SPM) is developed based on the coordinate transformation approach and the cosine rule of a trihedral angle. The angular displacement, angular velocity, and angular acceleration between the actuators and end-effector are thus determined. Moreover, the dynamic model of the 2-DOF SPM is established by using...