We examined planning and execution of precision grasp in eight right-handed patients with a right pure motor or sensorimotor lacunar syndrome after a subcortical stroke and eight age-matched controls as they grasped and lifted an instrumented object whose weight could be varied without altering its visual appearance. Grip (normal) and load (tangential) forces at the fingertip-object interface w...

DASC Time-delayed anti-swing controller FHL Force transferred from the load to the helicopter kd Gain of the delayed feedback controller L Load cable length mL Load mass MHL Moment transferred from the load to the helicopter N Number of particles in the PSO PSO Particle swarm optimization algorithm RH Hook position vector RL Load position vector p,q,r Helicopter angular velocities Vmax Maximum ...

Introduction: Meniscal debridement remains the most commonly performed orthopaedic surgery in the US, even though several clinical long term studies have shown that total or partial meniscectomy may lead to cartilage degeneration and early onset of osteoarthritic changes. Repair should be considered depending on the type and the location of the meniscal tear. Good and excellent results have bee...

An atmospheric boundary layer wind tunnel study was performed to determine the overall horizontal wind load on multi-span duo-pitch greenhouses. The results of this study are intended for the stability design of inflexible cladding system greenhouses (designated as Class A in EN 13031-1) with roof pitch angles of 23–24° and ridge heights of 7.5–8m. Both static force and fluctuating pressure mea...

MUSCLES ARE THE MOTORS that power our movements, and, like all motors, muscles consume energy to carry out these actions. Quantifying the efficiency of locomotion (i.e., the mechanical power output divided by the metabolic power input) is the standard approach for relating the mechanics and energetics of movement. However, this approach is problematic when applied to legged locomotion such as w...

We analysed the execution of multijoint pointing movements in humans while weight or spring loads were applied to the pointing hand. Visual feedback on arm and hand position was excluded. Movement paths, final positions, and normalized velocity profiles were found to be load-independent, except for the very first movement after a load change. With increasing size of a weight load movement veloc...

This paper describes an investigation of the ability of humans to distinguish different levels of gearlever load. A test rig with a forward-backward moving gearshift lever was constructed using the typical interior dimensions of European B segment automobiles. The rig used a system of weights and pulleys to provide a load which could be varied in steps of 1%. Four reference loads were chosen wh...

We present a hydro-elastic actuator that has a linear spring intentionally placed in series between the hydraulic piston and actuator output. The spring strain is measured to get an accurate estimate of force. This measurement alone is used in PI feedback to control the force in the actuator. The spring allows for high force fidelity, good force control, minimum impedance, and large dynamic ran...

In daily life, object manipulation is usually performed concurrently to the execution of cognitive tasks. The aim of the present study was to determine which aspects of precision grip require cognitive resources using a motor-cognitive dual-task paradigm. Eighteen healthy participants took part in the experiment, which comprised two conditions. In the first condition, participants performed a m...

The external knee adduction torque has been proposed as a surrogate measure for medial compartment load during gait. However, a direct link between these two quantities has not been demonstrated using in vivo measurement of medial compartment load. This study uses in vivo data collected from a single subject with an instrumented knee implant to evaluate this link. The subject performed five dif...