Hand Isolation Research Articles

Hand pose estimation and tracking in real and virtual interaction:A review

Vision-based 3D hand tracking is a key and popular component for interaction studies in a broad range of domains such as virtual reality (VR), augmented reality (AR) and natural human-computer interaction (HCI). While this research field has been well studied in the last decades, most approaches have considered the human hand in isolation and not in action or in interaction with the surrounding environment. Even the common collaborative and strong interactions with the other hand have been ignored. However, many of today's computer applications require more and more hand-object interactions. Furthermore, employing contextual information about the object in the hand (e.g. the shape, the texture, and the pose) can remarkably constrain the tracking problem. The most studied contextual constraints involve interaction with real objects and not with virtual objects which is still a very big challenge. The goal of this survey is to develop an up-to-date taxonomy of the state-of-the-art vision-based hand pose estimation and tracking methods with a new classification scheme: hand-object interaction constraints. This taxonomy allows us to examine the strengths and weaknesses of the current state of the art and to highlight future trends in the domain.

OP0237-HPR Upper Limb Exercise, Education and Self Management in Early Rheumatoid Arthritis (The Extra Programme)- Results from a Randomised Controlled Trial

BackgroundUpper limb dysfunction occurs early in people with rheumatoid arthritis (RA) and deteriorates as disease progresses, impacting on independence. Exercise is a key component in the management of upper limb...

Strength Measurements of the Intrinsic Hand Muscles: A Review of the Development and Evaluation of the Rotterdam Intrinsic Hand Myometer

Numerous neurological diseases are accompanied by atrophy of the intrinsic muscles of the hand. Muscle strength testing of these muscles is frequently used for clinical decision making. Traditionally, these strength measurements have focused on manual muscle testing (MMT) or on grip and pinch strength dynamometry. We have developed a hand-held dynamometer, the Rotterdam Intrinsic Hand Myometer (RIHM), to measure this intrinsic muscle strength. The RIHM was designed such that it can measure a wide range of muscle groups, such as the abduction and adduction strength of the little finger and index finger, the opposition, palmar abduction (anteposition) and opposition strength of the thumb, and intrinsic muscles of the fingers combined in the intrinsic plus position. We found that the reliability of RIHM measurements in nerve injury patients was comparable to grip and pinch strength measurements and is appropriate to study the functional recovery of the intrinsic muscles of the hand in isolation. We have applied the RIHM in a recent study on the long-term outcome of muscle strength in patients with ulnar and median nerve injuries and found that while recovery of grip and pinch strength was relatively good, recovery of the ulnar nerve innervated muscles measured with the RIHM was poor. This poor recovery could not be detected with manual muscle strength testing or with grip and pinch dynamometry. We conclude that the RIHM provides an accurate clinical assessment of the muscle strength of the intrinsic hand muscles that adds valuable information to MMT and grip and pinch dynamometry.

Long-term outcome of muscle strength in ulnar and median nerve injury: comparing manual muscle strength testing, grip and pinch strength dynamometers and a new intrinsic muscle strength dynamometer

To compare the outcome of muscle strength with manual muscle strength testing grip and pinch strength measurements and a dynamometer which allows for measurements of the intrinsic muscles of the hand in isolation (the Rotterdam Intrinsic Hand Myometer, RIHM). Thirty-four patients more than 2 years after ulnar and/or median nerve injury. Muscle strength was evaluated using manual muscle strength testing (MMST), grip, pinch and intrinsic muscle strength measurements. Manual muscle strength testing showed that most muscles recover to grade 3 or 4. Average grip strength recovery, as percentage of the uninjured hand, was 83%. Pinch strength recovery was 75%, 58% and 39% in patients with ulnar, median and combined nerve injuries, respectively. The RIHM measurements revealed a poor recovery of the ulnar nerve innervated muscles in particular (26-37%). No significant correlation (Pearson) was found between the measurements of the RIHM and grip strength. Pinch strength was significantly correlated with strength of the abduction of thumb and opposition of the thumb strength (r 0.55 and 0.72, p = 0.026, 0.002) as measured with the RIHM. While manual muscle strength testing and grip strength measurements show a reasonable to good recovery, measurements of the intrinsic muscles by means of the RIHM showed poor recovery of intrinsic muscle strength after peripheral nerve injury. No correlation was found between the recovery of intrinsic muscle strength and grip strength measurements.

The coordination of reaching and grasping in spastic hemiparesis

The kinematics and intrinsic dynamics of reaching and grasping movements in six subjects with spastic hemiparesis were studied. Movements were performed with both hands together as well as with each hand in isolation, and two target widths were used. As expected, large manual asymmetries existed in unimanual task performance. These asymmetries were more pronounced for grasping than for reaching, which was a consequence of the fact that in grasping the impaired hand stayed longer at zero velocity before lifting the object. This implies difficulties coordinating the more distal movement component (hand and fingers). In addition, the impaired hand attained the movement goal with a (1) decreased angular range of motion of the joints and (2) an increased trunk involvement. With respect to the intrinsic dynamics, intra- and inter-limb coupling was studied by evaluating cross-correlations of position–time functions joint pairs. In effector space the displacement of the wrist and ipsilateral shoulder were correlated, and in joint-angle space the elbow extension–shoulder flexion angle pair and the elbow extension–shoulder elevation angle pair were analysed. It was found that despite tight couplings between the different pairs, the couping strengths for the impaired limb were consistently lower. This was caused by fragmentation of the movement, mainly due to a large shoulder involvement at the start of the movement concurrent with little or no elbow extension. It is concluded that fragmentation of the movement, operationalised by the value of the cross-correlation between joint pairs is an essential variable by which the level of recovery of function can be captured. It was further shown that the unimpaired hand `mimicked' the impaired hand on a number of movement characteristics under bimanual responding. The impaired hand did not change its style of movement organisation among uni- and bimanual movement responding. It is argued that the apparent stability of the impaired hand can only be sustained at the cost of a decreased flexibility. Finally, inter-limb coupling, assessed by means of cross-correlations of the tangential velocity profiles of both hands, was shown to be high during the course of movement.

Hand covering with vibration-reducing bladder

An air isolation hand covering has a bladder consisting of a plurality of interconnected or independent inflation cells that is positioned between the hand and a hand-held tool or other vibrating object. The cells are oriented to permit easy bending of the hand covering in directions appropriate for grasping an object. The effectiveness of the bladder in reducing the vibration energy transmitted to the hand is a function of the shape and configuration of the bladder, the pressure in the bladder, the compressible fluid used, the volume of the bladder, and the grip force and push force used when clasping a tool or other object. The bladder can be filled with air or other fluid during the fabrication of the bladder or it can be inflated or deflated with a small pump and integral air valve connected to one of the air cavities.

Song Learning in the Anna Hummingbird (Calypte anna)

AbstractSongs of wild male Anna hummingbirds (Calypte anna) consist of syllables grouped into phrases. Nearest neighbors tend to share similar syllable types, rhythms and syntax. Songs from different localities contain different syllable types, syntax and repetition indices. A male raised by hand in isolation produced a song consisting of highly variable syllable types of a wide frequency range. The song was simple in structure, and syllables were not grouped into phrases. Three males raised by hand as a group sang songs containing two stereotyped syllable types sung in alternating sequence and without phrase structure. These three males shared syllable types and syntax. The data from our study indicate that despite its relatively simple syrinx the Anna hummingbird learns syllable types, frequency, rhythm and syntax (as do oscines with their more complex syringes) during the song development process.