A rigorous description of the magnitude and direction of the 3D force vector each thumb muscle produces at the thumb-tip is necessary to understand the biomechanical consequences to pinch of a variety of paralyses and surgical procedures (such as tendon transfers). In this study, we characterized the 3D force vector each muscle produces at the thumb-tip, and investigated if these thumb-tip forc...

Series elastic actuators have been widely used in humanrobot interactive systems due to their high controllability and improved human experience. One such system is the powered ankle exoskeleton. In [1], the torque control of a tethered ankle exoskeleton with a coil spring (Fig. 1) was investigated, which showed that the combination of model-free, integration-free feedback control and iterative...

Integrating an exoskeleton as the external apparatus for a brain–machine interface (BMI) has the advantage of providing multiple contact points to determine body segment postures and allowing control to and feedback from each joint. When using macaques as subjects to study the neural control of movement, an upper limb exoskeleton design with unlikely singularity is required to guarantee safe an...

Exoskeletons have been used for human performance restoration and enhancement for many years. Due to the dynamic nature of human locomotion, torque control is widely used in lower-limb exoskeleton assistance during stance phases of walking. In these systems, series-elastic actuators (SEA) are commonly used to provide low error torque tracking in the presence of unknown and changing human dynami...

Locusts jump by using a catapult mechanism in which energy produced by slow contractions of the extensor tibiae muscles of the hind legs is stored in distortions of the exoskeleton, most notably (1) the two semi-lunar processes at each knee joint and (2) the tendons of the extensor muscles themselves. The energy is then suddenly released from these stores to power the rapid, propulsive movement...

QUESTION What is the lifetime and current prevalence of thumb problems in Australian physiotherapists and what are the factors associated with thumb problems? DESIGN Survey of a random cross-section of physiotherapists. PARTICIPANTS 1562(approximately 10% of the total) registered Australian physiotherapists. OUTCOME MEASURES General questions covered demographic information, area of pract...

38 Objective: The purpose of this study was to investigate altered finger-thumb coupling in 39 individuals with chronic hemiparesis post-stroke. 40 Methods: First, an external device stretched finger flexor muscles by passively rotating the 41 metacarpophalangeal (MCP) joints. Subjects then performed isometric finger or thumb force 42 generation. Forces/torques and electromyographic (EMG) signa...

The present study identifies the mechanics of planar reaching movements performed by monkeys (Macaca mulatta) wearing a robotic exoskeleton. This device maintained the limb in the horizontal plane such that hand motion was generated only by flexor and extensor motions at the shoulder and elbow. The study describes the kinematic and kinetic features of the shoulder, elbow, and hand during reachi...

When arm movements are perturbed by a load, how does the nervous system adjust control signals to reduce error? While it has been shown that the nervous system is capable of compensating for the effects of limb dynamics and external forces, the strategies used to adapt to novel loads are not well understood. We used a robotic exoskeleton [kinesiological instrument for normal and altered reachin...