Typing on touchscreen keyboards is inherently inaccurate as users tend to touch locations offset from their intended target. Offsets are user-specific and can further differ for a given user between postures (left-hand, right-hand, indexfinger or two-thumb typing). On the other hand, back-ofdevice interaction has been used to predict screen touches on randomised abstract targets. We propose a n...

OBJECTIVE Stenosing tenosynovitis of the thumb flexor tendon sheath is also known as trigger thumb. It is an inflammatory process that involves the flexor tendon sheath at the A1 pulley. Successful percutaneous or open treatment of trigger thumb depends on the ability of the clinician to properly predict the location of the A1 pulley. Longitudinal anatomic landmarks can facilitate safe treatmen...

To produce a torque about a joint in the human body there must be sufficient drive to excite motor neurones in the spinal cord to discharge action potentials. The number of motor neurones that are recruited, and the rate at which those motor neurones discharge action potentials, is directly linked to the summation of twitch forces in the muscle. However, the potential to generate a torque also ...

Capuchin monkeys present a wide variety of manipulatory skills and make routine use of tools both in captivity and in the wild. Efficient handling of objects in this genus has led several investigators to assume near-human thumb movements despite the lack of anatomical studies. Here we perform an anatomical analysis of muscles and bones in the capuchin hand. Trapezo-metacarpal joint surfaces ob...

The unique musculoskeletal structure of the human hand brings in wider dexterous capabilities to grasp and manipulate a repertoire of objects than the non-human primates. It has been widely accepted that the orientation and the position of the thumb plays an important role in this characteristic behavior. There have been numerous attempts to develop anthropomorphic robotic hands with varying le...

BACKGROUND Tendon transfer is a surgical technique for restoring upper limb motor control in patients with cervical spinal cord injuries (SCI), and offers a rare window into cortical neuroplasticity following regained arm and hand function. OBJECTIVE Here, we aimed to examine neuroplasticity mechanisms related to re-established voluntary motor control of thumb flexion following tendon transfe...

OBJECTIVE To assess the separate effects of thumb and finger extension/flexion on median nerve position and cross-sectional area. METHODS Ultrasonography was used to assess median nerve transverse position and cross-sectional area within the carpal tunnel at rest and its movement during volitional flexion of the individual digits of the hand. Both wrists of 165 normal subjects (11 men, 4 wome...

Despite the importance of the thumb to hand function, little is known about the origins of thumb impairment poststroke. Accordingly, the primary purpose of this study was to assess whether thumb flexors have heightened stretch reflexes (SRs) following stroke-induced hand impairment. The secondary purpose was to compare SR characteristics of thumb flexors in relation to those of finger flexors s...

The effect of the position of splintage on displacement of fractures of the waist of the scaphoid was studied during operations and in cadavers. We found that these fractures were best splinted in neutral or slight palmar flexion with no ulnar deviation. Providing the wrist was not ulnar deviated, the position of the thumb had no effect on displacement.