Humans routinely make movements to targets that have different accuracy requirements in
different directions. Examples extend from everyday occurrences such as gras** the …

The motor system can use a number of mechanisms to increase movement accuracy and
compensate for perturbing external forces, interaction torques, and neuromuscular noise …

Sudden disturbances (perturbations) to the hand and wrist are commonplace in daily
activities and workplaces when interacting with tools and the environment. It is important to …

Although force-feedback devices are already being used, the human ability to perceive
forces has not been documented thoroughly. The haptic perception of force direction and …

We tested an innovative method to estimate joint stiffness and dam** during multijoint
unfettered arm movements. The technique employs impulsive perturbations and a time …

Spasticity and muscular hypertonus are frequently found in stroke survivors and may have a
significant effect on functional impairment. These abnormal neuro-muscular properties …

This study presents and validates a Time-Frequency technique for measuring 2-dimensional
multijoint arm stiffness throughout a single planar movement as well as during static posture …

The mechanical properties of our limbs and how those properties are regulated by the
nervous system endow us with the ability to interact with our environment in numerous …

Many common tasks compromise arm stability along specific directions. Such tasks can be
completed only if the impedance of the arm is sufficient to compensate for the destabilizing …

Although many daily tasks tend to destabilize arm posture, it is still possible to have stable
interactions with the environment by regulating the multijoint mechanics of the arm in a task …