WorldWideScience

Sample records for human forearm hand

  1. Robot Forearm and Dexterous Hand

    Science.gov (United States)

    Lovchik, Christopher S.

    2005-01-01

    An electromechanical hand-and-forearm assembly has been developed for incorporation into an anthropomorphic robot that would be used in outer space. The assembly is designed to offer manual dexterity comparable to that of a hand inside an astronaut s suit; thus, the assembly may also be useful as a prosthesis or as an end effector on an industrial robot.

  2. Monosynaptic Ia projections from intrinsic hand muscles to forearm motoneurones in humans

    Science.gov (United States)

    Marchand-Pauvert, V; Nicolas, G; Pierrot-Deseilligny, E

    2000-01-01

    Heteronymous Ia excitatory projections from intrinsic hand muscles to human forearm motoneurones (MNs) were investigated. Changes in firing probability of single motor units (MUs) in the flexor carpi radialis (FCR), flexor carpi ulnaris (FCU), flexor digitorum superficialis (FDS), extensor carpi radialis (ECR), extensor carpi ulnaris (ECU) and extensor digitorum communis (EDC) were studied after electrical stimuli were applied to the median and ulnar nerve at wrist level and to the corresponding homonymous nerve at elbow level.Homonymous facilitation, occurring at the same latency as the H reflex, and therefore attributed to monosynaptic Ia EPSPs, was found in all the sampled units. In many MUs an early facilitation was also evoked by heteronymous low-threshold afferents from intrinsic hand muscles. The low threshold (between 0.5 and 0.6 times motor threshold (MT)) and the inability of a pure cutaneous stimulation to reproduce this effect indicate that it is due to stimulation of group I muscle afferents.Evidence for a similar central delay (monosynaptic) in heteronymous as in homonymous pathways was accepted when the difference in latencies of the homonymous and heteronymous peaks did not differ from the estimated supplementary afferent conduction time from wrist to elbow level by more than 0.5 ms (conduction velocity in the fastest Ia afferents between wrist and elbow levels being equal to 69 m s−1).A statistically significant heteronymous monosynaptic Ia excitation from intrinsic hand muscles supplied by both median and ulnar nerves was found in MUs belonging to all forearm motor nuclei tested (although not in ECU MUs after ulnar stimulation). It was, however, more often found in flexors than in extensors, in wrist than in finger muscles and in muscles operating in the radial than in the ulnar side.It is argued that the connections of Ia afferents from intrinsic hand muscles to forearm MNs, which are stronger and more widely distributed than in the cat, might

  3. Evolution and homologies of primate and modern human hand and forearm muscles, with notes on thumb movements and tool use.

    Science.gov (United States)

    Diogo, Rui; Richmond, Brian G; Wood, Bernard

    2012-07-01

    In this paper, we explore how the results of a primate-wide higher-level phylogenetic analysis of muscle characters can improve our understanding of the evolution and homologies of the forearm and hand muscles of modern humans. Contrary to what is often suggested in the literature, none of the forearm and hand muscle structures usually present in modern humans are autapomorphic. All are found in one or more extant non-human primate taxa. What is unique is the particular combination of muscles. However, more muscles go to the thumb in modern humans than in almost all other primates, reinforcing the hypothesis that focal thumb movements probably played an important role in human evolution. What makes the modern human thumb myology special within the primate clade is not so much its intrinsic musculature but two extrinsic muscles, extensor pollicis brevis and flexor pollicis longus, that are otherwise only found in hylobatids. It is likely that these two forearm muscles play different functional roles in hylobatids and modern humans. In the former, the thumb is separated from elongated digits by a deep cleft and there is no pulp-to-pulp opposition, whereas modern humans exhibit powerful thumb flexion and greater manipulative abilities, such as those involved in the manufacture and use of tools. The functional and evolutionary significance of a third peculiar structure, the intrinsic hand structure that is often called the 'interosseous volaris primus of Henle' (and which we suggest is referred to as the musculus adductor pollicis accessorius) is still obscure. The presence of distinct contrahentes digitorum and intermetacarpales in adult chimpanzees is likely the result of prolonged or delayed development of the hand musculature of these apes. In relation to these structures, extant chimpanzees are more neotenic than modern humans. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. 3D pose estimation and motion analysis of the articulated human hand-forearm limb in an industrial production environment

    Science.gov (United States)

    Hahn, Markus; Barrois, Björn; Krüger, Lars; Wöhler, Christian; Sagerer, Gerhard; Kummert, Franz

    2010-09-01

    This study introduces an approach to model-based 3D pose estimation and instantaneous motion analysis of the human hand-forearm limb in the application context of safe human-robot interaction. 3D pose estimation is performed using two approaches: The Multiocular Contracting Curve Density (MOCCD) algorithm is a top-down technique based on pixel statistics around a contour model projected into the images from several cameras. The Iterative Closest Point (ICP) algorithm is a bottom-up approach which uses a motion-attributed 3D point cloud to estimate the object pose. Due to their orthogonal properties, a fusion of these algorithms is shown to be favorable. The fusion is performed by a weighted combination of the extracted pose parameters in an iterative manner. The analysis of object motion is based on the pose estimation result and the motion-attributed 3D points belonging to the hand-forearm limb using an extended constraint-line approach which does not rely on any temporal filtering. A further refinement is obtained using the Shape Flow algorithm, a temporal extension of the MOCCD approach, which estimates the temporal pose derivative based on the current and the two preceding images, corresponding to temporal filtering with a short response time of two or at most three frames. Combining the results of the two motion estimation stages provides information about the instantaneous motion properties of the object. Experimental investigations are performed on real-world image sequences displaying several test persons performing different working actions typically occurring in an industrial production scenario. In all example scenes, the background is cluttered, and the test persons wear various kinds of clothes. For evaluation, independently obtained ground truth data are used. [Figure not available: see fulltext.

  5. Stability Analysis for Hand-arm-forearm Dynamic System

    Directory of Open Access Journals (Sweden)

    Florin Bausic

    2014-07-01

    Full Text Available In this paper we propose a model with four degrees of freedom for hand-arm-forearm dynamic system. Using experimental data from [9] by means of the Simulink program, is built block diagram to simulate the dynamic system motion and phase diagrams are drawn by using Matlab. From the interpretation of these diagrams result, for a set of parameters ( m, c, k, FO, ω , stable moves for the hand-arm-forearm dynamic system.

  6. Wrist posture affects hand and forearm muscle stress during tapping.

    Science.gov (United States)

    Qin, Jin; Chen, Hua; Dennerlein, Jack T

    2013-11-01

    Non-neutral wrist posture is a risk factor of the musculoskeletal disorders among computer users. This study aimed to assess internal loads on hand and forearm musculature while tapping in different wrist postures. Ten healthy subjects tapped on a key switch using their index finger in four wrist postures: straight, ulnar deviated, flexed and extended. Torque at the finger and wrist joints were calculated from measured joint postures and fingertip force. Muscle stresses of the six finger muscles and four wrist muscles that balanced the calculated joint torques were estimated using a musculoskeletal model and optimization algorithm minimizing the squared sum of muscle stress. Non-neutral wrist postures resulted in greater muscle stresses than the neutral (straight) wrist posture, and the stress in the extensor muscles were greater than the flexors in all conditions. Wrist extensors stress remained higher than 4.5 N/cm² and wrist flexor stress remained below 0.5 N/cm² during tapping. The sustained high motor unit recruitment of extensors suggests a greater risk than other muscles especially in flexed wrist posture. This study demonstrated from the perspective of internal tissue loading the importance of maintaining neutral wrist posture during keying activities.

  7. An Exoskeleton Robot for Human Forearm and Wrist Motion Assist

    Science.gov (United States)

    Ranathunga Arachchilage Ruwan Chandra Gopura; Kiguchi, Kazuo

    The exoskeleton robot is worn by the human operator as an orthotic device. Its joints and links correspond to those of the human body. The same system operated in different modes can be used for different fundamental applications; a human-amplifier, haptic interface, rehabilitation device and assistive device sharing a portion of the external load with the operator. We have been developing exoskeleton robots for assisting the motion of physically weak individuals such as elderly or slightly disabled in daily life. In this paper, we propose a three degree of freedom (3DOF) exoskeleton robot (W-EXOS) for the forearm pronation/ supination motion, wrist flexion/extension motion and ulnar/radial deviation. The paper describes the wrist anatomy toward the development of the exoskeleton robot, the hardware design of the exoskeleton robot and EMG-based control method. The skin surface electromyographic (EMG) signals of muscles in forearm of the exoskeletons' user and the hand force/forearm torque are used as input information for the controller. By applying the skin surface EMG signals as main input signals to the controller, automatic control of the robot can be realized without manipulating any other equipment. Fuzzy control method has been applied to realize the natural and flexible motion assist. Experiments have been performed to evaluate the proposed exoskeleton robot and its control method.

  8. Archery-related injuries of the hand, forearm, and elbow.

    Science.gov (United States)

    Rayan, G M

    1992-10-01

    The five patients reported herein had various archery-related injuries of the upper extremities. Acute injuries included arrow laceration of a digital nerve and artery, contusion of forearm skin and subcutaneous tissue, and compression neuropathy of digital nerves from the bowstring. Chronic injuries included bilateral medial epicondylitis and median nerve compression at the wrist, de Quervain's tenosynovitis, and median nerve compression at the elbow. Essential measures for archery safety include use of archery protective gear, use of a light-weight bow, conditioning of the forearm flexor muscles, and modifications in drawing the bowstring.

  9. Determination of antiseptic efficacy of rubs on the forearm and consequences for surgical hand disinfection.

    Science.gov (United States)

    Hübner, N-O; Kellner, N B; Partecke, L I; Koburger, T; Heidecke, C-D; Kohlmann, T; Kramer, A

    2011-05-01

    While hands are acknowledged to be the most important source of pathogens from the skin of the surgical team, the transmission of pathogens from the forearms may also be relevant. Preoperative hand disinfection is recommended, but evidence-based standards for the forearms are lacking. As neither the European standard EN 12791 nor the American guidelines ASTM 1115 are applicable to the forearms, a new test method based on the European standard EN 12791 and the German Society for Hygiene and Microbiology (DGHM) method for testing for the efficacy of skin antiseptics was developed to address the forearms. The antiseptic efficacy of a commercially available alcohol-based hand rub [76.7% (w/w) ethanol] was assessed on the upper arm after 15s, 2.5 min, and 30 min, and on the lower arm after 2.5 min, 30 min, and 3 h. On the upper arm, application of the product followed the DGHM standard procedure. On the forearm, the product was applied by the participants themselves with the right hand over the left forearm and vice versa as performed during preoperative hand disinfection. Sampling and culture were performed according to the DGHM method for skin antisepsis on the upper arm. Twenty-two volunteers were investigated. The efficacy of the antiseptic treatment on the forearm was not significantly lower than on the upper arm for any of the areas tested (P > 0.05). Reduction factors for all tested areas and times were quite similar, with confidence intervals ranging between 1.43 and 2.31 log₁₀. We suggest that an application time of 10s may be sufficient for the treatment of the forearm as part of preoperative hand disinfection, provided that an appropriate product is used.

  10. Ulnar dominant hand and forearm: an electrophysiologic approach.

    Science.gov (United States)

    Abayev, Boris; Ha, Edward; Cruise, Cathy

    2005-09-01

    An ulnar-to-median anastomosis in the forearm is a rare condition, but may be present in any electromyographic case. A thorough approach to this condition is required to avoid misinterpretation of the electrodiagnostic report and confusion during the test. Prior to concluding that an anomaly is present, technical reason should be taken into consideration. The presence of volume-conducted potentials from various nearby muscles may confuse the electromyographer. Therefore, instead of using surface electrodes with unintended supramaximal intensity of stimulation, the needle electrodes may be used (in some cases) to localize specific muscles and to minimize volume-conducted potentials by not utilizing supramaximal stimulation intensity. The authors will discuss ulnar-to-median anastomosis in the forearm. This is the first attempt to put together all the information available in the literature about such an anastomosis.

  11. Effect of microgravity on forearm subcutaneous vascular resistance in humans

    DEFF Research Database (Denmark)

    Gabrielsen, A; Norsk, P; Videbæk, R;

    1995-01-01

    To test the hypothesis that the subcutaneous vascular constrictor response to an orthostatic stress in humans is augmented after exposure to microgravity, the following experiment was performed. Four male astronauts underwent a standardized stepwise lower body negative pressure (LBNP) profile 5 mo...... before and between 24 and 40 h after completion of the 10-day Spacelab D2 mission (STS-55). Forearm subcutaneous blood flow was continuously measured during LBNP by the 133Xe washout technique, and forearm subcutaneous vascular resistance (FSVR) was estimated by dividing mean arterial pressure by forearm...

  12. Vibrotactile grasping force and hand aperture feedback for myoelectric forearm prosthesis users

    NARCIS (Netherlands)

    Witteveen, Heidi J.B.; Rietman, Hans S.; Veltink, Peter H.

    2015-01-01

    Background: User feedback about grasping force and hand aperture is very important in object handling with myoelectric forearm prostheses but is lacking in current prostheses. Vibrotactile feedback increases the performance of healthy subjects in virtual grasping tasks, but no extensive validation o

  13. Compartment syndrome of forearm and hand as complication of prone position during neurosurgery operation

    Directory of Open Access Journals (Sweden)

    Dusica Stamenkovic

    2012-06-01

    Full Text Available We present a case of compartment syndrome (CS after neurosurgical operation where patient was 6 hours in prone position with forearm and hand beneath his chest. Clinical signs were confirmed with measuring of intra-compartmal pressure (ICP, and fasciotomy of forearm and hand were performed. After 3 months of rehabilitation all movements and strength in hand and fingers were come back. CS is a rare complication, but if unrecognized and untreated it can seriously damage extremities. Measuring of ICP is a simple and reliable diagnostic procedure in unclear cases and prompt fasciotomy is a salvage procedure with good results. [J Exp Integr Med 2012; 2(3.000: 277-279

  14. In vivo Estimation of Human Forearm and Wrist Dynamic Properties.

    Science.gov (United States)

    Park, Kyungbin; Chang, Pyung-Hun; Kang, Sang

    2016-05-27

    It is important to estimate the 3 degree-of-freedom (DOF) impedance of human forearm and wrist (i.e., forearm prono-supination, and wrist flexion-extension and radial-ulnar deviation) in motor control and in the diagnosis of altered mechanical resistance following stroke. There is, however, a lack of methods to characterize 3 DOF impedance. Thus, we developed a reliable and accurate impedance estimation method, the distal internal model based impedance control (dIMBIC)-based method, to characterize the 3 DOF impedance, including cross-coupled terms between DOFs, for the first time. Its accuracy and reliability were experimentally validated using a robot with substantial nonlinear joint friction. The 3 DOF human forearm and wrist impedance of 8 healthy subjects was reliably characterized, and its linear behavior was verified. Thus, the dIMBIC-based method can provide us with 3 DOF forearm and wrist impedance regardless of nonlinear robot joint friction. It is expected that, with the proposed method, the 3 DOF impedance estimation can promote motor control studies and complement the diagnosis of altered wrist and forearm resistance post stroke by providing objective impedance estimates, including cross-coupled terms.

  15. Tracking blood vessels in human forearms using visual servoing

    DEFF Research Database (Denmark)

    Savarimuthu, Thiusius Rajeeth; Ellekilde, Lars-Peter; Hansen, Morten

    compensation. By using images taken with near-infrared light to locate the blood vessels in a human forearm and using the same images to detects movements of the arm, this paper shows that it is possible make a robot arm, potentially equipped with a needle for drawing the blood, compensate for the movements...

  16. Radial forearm free flap morbidity: A rare case of a normal preoperative arteriogram and acute intraoperative hand ischemia

    OpenAIRE

    Bruner, Terrence W.; Hanasono, Matthew M.; Skoracki, Roman J

    2011-01-01

    The radial forearm free flap is ideal for reconstructive microsurgery due to its thin, pliable fasciocutaneous tissue, reliable anatomy and ease and simplicity of flap elevation. However, one of the major complications is hand ischemia due to sacrifice of the radial artery, although it is a rare occurrence. A case involving a 73-year-old man who developed intraoperative hand ischemia after elevation of a radial forearm free flap is presented.

  17. Peripheral Intravenous Catheterisation in Obstetric Patients in the Hand or Forearm Vein: A Randomised Trial.

    Science.gov (United States)

    Tan, Peng Chiong; Mackeen, Anjana; Khong, Su Yen; Omar, Siti Zawiah; Noor Azmi, M A

    2016-03-18

    A peripheral intravenous catheter is often inserted as part of care during labour. The catheter is inserted into the back of the hand or lower forearm vein in usual practice. There is no trial data to guide the care provider on which is the better insertion site in any clinical setting. 307 women admitted to the labour ward who required insertion of intravenous catheter were randomised to back of hand or lower forearm vein catheter insertion. Catheter insertion is by junior to mid-grade providers. We evaluated insertion success at the first attempt, pain during insertion and catheter replacement due to malfunction as main outcomes. After catheter removal, we recorded patient satisfaction with site, future site preference and insertion site swelling, bruising, tenderness, vein thrombosis and pain. Insertion of a catheter into back of hand vein is more likely to be successful at the first attempt. Insertion pain score, catheter replacement rate, patient satisfaction, patient fidelity to site in a future insertion and insertion site complications rate are not different between trial arms. In conclusion, both insertion sites are suitable; the back of the hand vein maybe easier to cannulate and seems to be preferred by our frontline providers.

  18. Associations between Handgrip Strength and Ultrasound-Measured Muscle Thickness of the Hand and Forearm in Young Men and Women.

    Science.gov (United States)

    Abe, Takashi; Counts, Brittany R; Barnett, Brian E; Dankel, Scott J; Lee, Kofan; Loenneke, Jeremy P

    2015-08-01

    It is unknown whether muscle size of intrinsic hand muscles is associated with handgrip strength. To investigate the relationships between handgrip strength and flexor muscle size of the hand and forearm, muscle thickness (MT) of 86 young adults (43 men and 43 women) between the ages of 18 and 34 y was measured by ultrasound. Two MTs (forearm radius and forearm ulna MT) in the anterior forearm, two MTs (lumbrical and dorsal interosseous MT) in the anterior hand and handgrip strength were measured on the right side. Linear regression with part (also referred to as semipartial) correlation coefficients revealed that forearm ulna MT positively correlated with handgrip strength in both men (part = 0.379, p = 0.001) and women (part = 0.268, p = 0.002). Dorsal interosseous MT correlated with handgrip strength in women only (part = 0.289, p = 0.001). Our results suggest that the forearm ulna and dorsal interosseous MTs for women and forearm ulna MTs for men are factors contributing to prediction of handgrip strength in young adults. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  19. Modified Sauvé-Kapandji procedure for restoration of forearm rotation in devascularized hands.

    Science.gov (United States)

    Wang, W; Liu, S; Liu, J; Ruan, H; Cai, Z; Fan, C

    2014-12-01

    The purpose of this study is to evaluate the clinical outcomes in patients with forearm rotation limitation after successful wrist-level revascularization who underwent a modified Sauvé-Kapandji (S-K) procedure. This was a retrospective review of the clinical records of nine patients (three women, six men) after successful wrist-level revascularization who underwent late restoration of forearm rotation. All patients were evaluated using a Mayo Modified Wrist Score. The mean patient age was 35 (range 19-45) years. Mean time to reconstruction was 2.5 (range 0.5-4) years. Mean postoperative pronation was 74°; mean postoperative supination was 80°. Overall results were excellent/good in seven patients, fair in one, and poor in one. No bone bridge was formed between the pseudarthrosis in any patient. Two patients had neurapraxia. Moderate pain and snapping occurred in one patient during movement at the ulnar amputation site. This modification of the S-K procedure can restore rotation of the forearm after hand revascularization; as such, it provides an alternative salvage procedure.

  20. Risk factors for persistent elbow, forearm and hand pain among computer workers

    DEFF Research Database (Denmark)

    Lassen, C. F.; Mikkelsen, S.; Kryger, Ann Isabel

    2005-01-01

    to elbow, forearm, or wrist-hand pain during the 12 months preceding the baseline questionnaire. Pain status (recovery versus persistence) at follow-up was examined in relation to computer work aspects and ergonomic, psychosocial, and personal factors by questionnaire. In addition, data on objectively......, and type-A behavior, the prognosis seemed independent of psychosocial workplace factors and personal factors. A few cases with severe pain were affected at a level which could be compared to clinical pain conditions. CONCLUSIONS: Our results do not support the hypothesis that computer work activity...

  1. Real-Time Classification of Hand Motions Using Ultrasound Imaging of Forearm Muscles.

    Science.gov (United States)

    Akhlaghi, Nima; Baker, Clayton A; Lahlou, Mohamed; Zafar, Hozaifah; Murthy, Karthik G; Rangwala, Huzefa S; Kosecka, Jana; Joiner, Wilsaan M; Pancrazio, Joseph J; Sikdar, Siddhartha

    2016-08-01

    Surface electromyography (sEMG) has been the predominant method for sensing electrical activity for a number of applications involving muscle-computer interfaces, including myoelectric control of prostheses and rehabilitation robots. Ultrasound imaging for sensing mechanical deformation of functional muscle compartments can overcome several limitations of sEMG, including the inability to differentiate between deep contiguous muscle compartments, low signal-to-noise ratio, and lack of a robust graded signal. The objective of this study was to evaluate the feasibility of real-time graded control using a computationally efficient method to differentiate between complex hand motions based on ultrasound imaging of forearm muscles. Dynamic ultrasound images of the forearm muscles were obtained from six able-bodied volunteers and analyzed to map muscle activity based on the deformation of the contracting muscles during different hand motions. Each participant performed 15 different hand motions, including digit flexion, different grips (i.e., power grasp and pinch grip), and grips in combination with wrist pronation. During the training phase, we generated a database of activity patterns corresponding to different hand motions for each participant. During the testing phase, novel activity patterns were classified using a nearest neighbor classification algorithm based on that database. The average classification accuracy was 91%. Real-time image-based control of a virtual hand showed an average classification accuracy of 92%. Our results demonstrate the feasibility of using ultrasound imaging as a robust muscle-computer interface. Potential clinical applications include control of multiarticulated prosthetic hands, stroke rehabilitation, and fundamental investigations of motor control and biomechanics.

  2. Bone and muscular anatomy of the forearm and hand in Tapirus terrestris (Perissodactyla, Tapiridae

    Directory of Open Access Journals (Sweden)

    Saulo Gonçalves Pereira

    2017-05-01

    Full Text Available In Brazil, there are two species of tapirs, the largest land mammals in Brazil, which belong to the order Perissodactyla, as do horses. Our aim was to describe the bone and muscular anatomy of the forearm and hand in T. terrestris and to propose adaptive functions. We used five anatomical specimens donated from a breeder to the Laboratory for Teaching and Research on Wild Animals of the Federal University of Uberlandia after death with no trauma. The bones were analyzed, the muscles dissected, and both described. The bones of the forearm and hand of the tapir are the ulna, radius, Os. metacarpalia, Os. carpi, phalanx and Os. sesamoideum. The muscles are M. extensor carpi radialis, M. ulnaris lateralis; M. flexor carpi radialis; M. extensor radialis communis; M. extensor digitorum longus II, III, IV and V, M. extensor digitorum lateralis; M. extensor digitorum; M. abductor longus; M. flexor digiti superficialis; M. flexor digitalis; M. flexor carpi ulnaris; M. flexor carpi obliquus; and M. interossei and M. lumbricales. Characteristics of bone and muscle structure are adapted to the development of the animal’s niche.

  3. Toward the restoration of hand use to a paralyzed monkey: brain-controlled functional electrical stimulation of forearm muscles.

    Science.gov (United States)

    Pohlmeyer, Eric A; Oby, Emily R; Perreault, Eric J; Solla, Sara A; Kilgore, Kevin L; Kirsch, Robert F; Miller, Lee E

    2009-06-15

    Loss of hand use is considered by many spinal cord injury survivors to be the most devastating consequence of their injury. Functional electrical stimulation (FES) of forearm and hand muscles has been used to provide basic, voluntary hand grasp to hundreds of human patients. Current approaches typically grade pre-programmed patterns of muscle activation using simple control signals, such as those derived from residual movement or muscle activity. However, the use of such fixed stimulation patterns limits hand function to the few tasks programmed into the controller. In contrast, we are developing a system that uses neural signals recorded from a multi-electrode array implanted in the motor cortex; this system has the potential to provide independent control of multiple muscles over a broad range of functional tasks. Two monkeys were able to use this cortically controlled FES system to control the contraction of four forearm muscles despite temporary limb paralysis. The amount of wrist force the monkeys were able to produce in a one-dimensional force tracking task was significantly increased. Furthermore, the monkeys were able to control the magnitude and time course of the force with sufficient accuracy to track visually displayed force targets at speeds reduced by only one-third to one-half of normal. Although these results were achieved by controlling only four muscles, there is no fundamental reason why the same methods could not be scaled up to control a larger number of muscles. We believe these results provide an important proof of concept that brain-controlled FES prostheses could ultimately be of great benefit to paralyzed patients with injuries in the mid-cervical spinal cord.

  4. Toward the restoration of hand use to a paralyzed monkey: brain-controlled functional electrical stimulation of forearm muscles.

    Directory of Open Access Journals (Sweden)

    Eric A Pohlmeyer

    Full Text Available Loss of hand use is considered by many spinal cord injury survivors to be the most devastating consequence of their injury. Functional electrical stimulation (FES of forearm and hand muscles has been used to provide basic, voluntary hand grasp to hundreds of human patients. Current approaches typically grade pre-programmed patterns of muscle activation using simple control signals, such as those derived from residual movement or muscle activity. However, the use of such fixed stimulation patterns limits hand function to the few tasks programmed into the controller. In contrast, we are developing a system that uses neural signals recorded from a multi-electrode array implanted in the motor cortex; this system has the potential to provide independent control of multiple muscles over a broad range of functional tasks. Two monkeys were able to use this cortically controlled FES system to control the contraction of four forearm muscles despite temporary limb paralysis. The amount of wrist force the monkeys were able to produce in a one-dimensional force tracking task was significantly increased. Furthermore, the monkeys were able to control the magnitude and time course of the force with sufficient accuracy to track visually displayed force targets at speeds reduced by only one-third to one-half of normal. Although these results were achieved by controlling only four muscles, there is no fundamental reason why the same methods could not be scaled up to control a larger number of muscles. We believe these results provide an important proof of concept that brain-controlled FES prostheses could ultimately be of great benefit to paralyzed patients with injuries in the mid-cervical spinal cord.

  5. Indirect hand and forearm vasomotion: Regional variations in cutaneous thermosensitivity during normothermia and mild hyperthermia.

    Science.gov (United States)

    Burdon, Catriona A; Tagami, Kyoko; Park, Joonhee; Caldwell, Joanne N; Taylor, Nigel A S

    2017-04-01

    In this experiment, hand and forearm vasomotor activity was investigated during localised, but stable heating and cooling of the face, hand and thigh, under open-loop (clamped) conditions. It was hypothesised that facial stimulation would provoke the most potent vascular changes. Nine individuals participated in two normothermic trials (mean body temperature clamp: 36.6°C; water-perfused suit and climate chamber) and two mildly hyperthermic trials (37.9°C). Localised heating (+5°C) and cooling (-5°C) stimuli were applied to equal surface areas of the face, hand and thigh (perfusion patches: 15min), while contralateral forearm or hand blood flows (venous-occlusion plethysmography) were measured (separate trials). Thermal sensation and discomfort votes were recorded before and during each thermal stimulation. When hyperthermic, local heating induced more sensitive vascular responses, with the combined thermosensitivity of both limb segments averaging 0.011mL·100mL(-1)·min(-1)·mmHg(-1)·°C(-1), and 0.005mL·100mL(-1)·min(-1)·mmHg(-1)·°C(-1) during localised cooling (P0.05). Therefore, regional differences in vasomotor and sensory sensitivity appeared not to exist. When combined with previous observations of sudomotor sensitivity, it seems that, during mild heating and cooling, regional representations within the somatosensory cortex may not translate into meaningful differences in thermal sensation or the central integration of thermoafferent signals. It was concluded that inter-site variations in the cutaneous thermosensitivity of these thermolytic effectors have minimal physiological significance over the ranges investigated thus far. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Free peroneal perforator-based sural neurofasciocutaneous flaps for reconstruction of hand and forearm

    Institute of Scientific and Technical Information of China (English)

    CAI Pei-hua; LIU Sheng-he; CHAI Yi-min; WANG Hai-ming; RUAN Hong-jiang; FAN Cun-yi

    2009-01-01

    Background Sural neurofasciocutaneous flap has been popularly used as an excellent option for the coverage of soft tissue defects in the lower third of leg, ankle and foot, but its free transplantation has been rarely reported. The objective of our work was to investigate the operative technique and clinical results of repairing the soft tissue defects of hand and forearm with free peroneal perforator-based sural neurofasciocutaneous flap. Methods Between May 2006 and March 2007, 10 patients including 7 men and 3 women were treated. Their ages ranged from 22 to 51 years. They presented to emergency with large soft tissue defects of 16 cm × 7 cm to 24 cm × 10 cm in size in hand and forearm after injured by motor vehicle accidents (2 cases) or crushed by machine (8 cases). Thorough debridements and primary treatments to associated tendon ruptures or bone fractures were performed on emergency. And free peroneal perforator-based sural neurofasciocutaneous flaps were transplanted when the wound areas were stable at 5 to 7 days after emergency treatment. The flaps were designed along the axis of the sural nerve according to the shape and size of the soft tissue defects, with the peroneal perforator above the lateral malleolus as the pedicle and along with a part of the peroneal artery for vascular anastomosis. Then the flaps were harvested to repair the recipient sites with the pereneal artery anastomosed to the radial (or ulnar) artery and the peroneal veins to one of the radial (or ulnar) veins and the cephalic vein respectively. The flap sizes ranged from 18 cm × 8 cm to 25 cm × 12 cm. The donor areas were closed by skin grafts. Results All of the 10 flaps survived after surgeries. Marginal necrosis occurred in only 2 cases. The skin grafts survived entirely in the donor sites, and no obvious influence on the donor legs was observed. All of the transplanted flaps presented favourable contours and good functions at 9 to 12 months' follow-up. Conclusions Peroneal

  7. Wearable Sensors for eLearning of Manual Tasks: Using Forearm EMG in Hand Hygiene Training.

    Science.gov (United States)

    Kutafina, Ekaterina; Laukamp, David; Bettermann, Ralf; Schroeder, Ulrik; Jonas, Stephan M

    2016-08-03

    In this paper, we propose a novel approach to eLearning that makes use of smart wearable sensors. Traditional eLearning supports the remote and mobile learning of mostly theoretical knowledge. Here we discuss the possibilities of eLearning to support the training of manual skills. We employ forearm armbands with inertial measurement units and surface electromyography sensors to detect and analyse the user's hand motions and evaluate their performance. Hand hygiene is chosen as the example activity, as it is a highly standardized manual task that is often not properly executed. The World Health Organization guidelines on hand hygiene are taken as a model of the optimal hygiene procedure, due to their algorithmic structure. Gesture recognition procedures based on artificial neural networks and hidden Markov modeling were developed, achieving recognition rates of 98 . 30 % ( ± 1 . 26 % ) for individual gestures. Our approach is shown to be promising for further research and application in the mobile eLearning of manual skills.

  8. Wearable Sensors for eLearning of Manual Tasks: Using Forearm EMG in Hand Hygiene Training

    Directory of Open Access Journals (Sweden)

    Ekaterina Kutafina

    2016-08-01

    Full Text Available In this paper, we propose a novel approach to eLearning that makes use of smart wearable sensors. Traditional eLearning supports the remote and mobile learning of mostly theoretical knowledge. Here we discuss the possibilities of eLearning to support the training of manual skills. We employ forearm armbands with inertial measurement units and surface electromyography sensors to detect and analyse the user’s hand motions and evaluate their performance. Hand hygiene is chosen as the example activity, as it is a highly standardized manual task that is often not properly executed. The World Health Organization guidelines on hand hygiene are taken as a model of the optimal hygiene procedure, due to their algorithmic structure. Gesture recognition procedures based on artificial neural networks and hidden Markov modeling were developed, achieving recognition rates of 98 . 30 % ( ± 1 . 26 % for individual gestures. Our approach is shown to be promising for further research and application in the mobile eLearning of manual skills.

  9. Wearable Sensors for eLearning of Manual Tasks: Using Forearm EMG in Hand Hygiene Training

    Science.gov (United States)

    Kutafina, Ekaterina; Laukamp, David; Bettermann, Ralf; Schroeder, Ulrik; Jonas, Stephan M.

    2016-01-01

    In this paper, we propose a novel approach to eLearning that makes use of smart wearable sensors. Traditional eLearning supports the remote and mobile learning of mostly theoretical knowledge. Here we discuss the possibilities of eLearning to support the training of manual skills. We employ forearm armbands with inertial measurement units and surface electromyography sensors to detect and analyse the user’s hand motions and evaluate their performance. Hand hygiene is chosen as the example activity, as it is a highly standardized manual task that is often not properly executed. The World Health Organization guidelines on hand hygiene are taken as a model of the optimal hygiene procedure, due to their algorithmic structure. Gesture recognition procedures based on artificial neural networks and hidden Markov modeling were developed, achieving recognition rates of 98.30% (±1.26%) for individual gestures. Our approach is shown to be promising for further research and application in the mobile eLearning of manual skills. PMID:27527167

  10. The effect of a forearm/hand splint compared with an elbow band as a treatment for lateral epicondylitis

    NARCIS (Netherlands)

    van de Streek, M.D.; van der Schans, C.P.; de Greef, M.H.G.; Postema, K.

    2004-01-01

    The aim of the present study was to compare the effect of a new prefabricated Thamert forearm/hand splint with the effect of a simple elbow band as a treatment for lateral epicondylitis. Forty-three (43) patients that met the inclusion criteria were randomly assigned to the elbow band group and the

  11. Muscular forearm activation in hand-grip tasks with superimposition of mechanical vibrations.

    Science.gov (United States)

    Fattorini, L; Tirabasso, A; Lunghi, A; Di Giovanni, R; Sacco, F; Marchetti, E

    2016-02-01

    The purpose of this paper is to evaluate the muscular activation of the forearm, with or without vibration stimuli at different frequencies while performing a grip tasks of 45s at various level of exerted force. In 16 individuals, 9 females and 7 males, the surface electromyogram (EMG) of extensor carpi radialis longus and the flexor carpi ulnari muscles were assessed. At a short latency from onset EMG, RMS and the level of MU synchronization were assessed to evaluate the muscular adaptations. Whilst a trend of decay of EMG Median frequency (MDFd) was employed as an index of muscular fatigue. Muscular tasks consists of the grip of an instrumented handle at a force level of 20%, 30%, 40%, 60% of the maximum voluntary force. Vibration was supplied by a shaker to the hand in mono-frequential waves at 20, 30, 33 and 40Hz. In relation to EMG, RMS and MU synchronization, the muscular activation does not seem to change with the superimposition of the mechanical vibrations, on the contrary a lower MDFd was observed at 33Hz than in absence of vibration. This suggests an early muscular fatigue induced by vibration due to the fact that 33Hz is a resonance frequency for the hand-arm system.

  12. Maintained hand function and forearm bone health 14 months after an in-home virtual-reality videogame hand telerehabilitation intervention in an adolescent with hemiplegic cerebral palsy.

    Science.gov (United States)

    Golomb, Meredith R; Warden, Stuart J; Fess, Elaine; Rabin, Bryan; Yonkman, Janell; Shirley, Bridget; Burdea, Grigore C

    2011-03-01

    Virtual reality videogames can be used to motivate rehabilitation, and telerehabilitation can be used to improve access to rehabilitation. These uses of technology to improve health outcomes are a burgeoning area of rehabilitation research. So far, there is a lack of reports of long-term outcomes of these types of interventions. The authors report a 15-year-old boy with hemiplegic cerebral palsy and epilepsy because of presumed perinatal stroke who improved his plegic hand function and increased his plegic forearm bone health during a 14-month virtual reality videogame hand telerehabilitation intervention. A total of 14 months after the intervention ended, repeat evaluation demonstrated maintenance of both increased hand function and forearm bone health. The implications of this work for the future of rehabilitation in children with neurological disabilities are discussed in this article.

  13. Pediatric Hereditary Angioedema as a Cause of Acute Compartment Syndrome of the Hand and Forearm: A Case Report.

    Science.gov (United States)

    Venditto, Chelsea; Jager, Zachary; LoGiudice, John; Matloub, Hani

    2017-05-01

    Compartment syndrome of the upper extremity is a surgical emergency that, when left untreated, can have dire consequences. Its causes are numerous, one of which is the uncommon entity hereditary angioedema, an autosomal dominant disease resulting in edema in a variety of potential locations, including the extremities. This is only the second time hereditary angioedema has been mentioned in the literature as a cause of compartment syndrome. We present a case of hereditary angioedema leading to hand and forearm compartment syndrome in a 13-year-old pediatric patient. Diagnosis of hereditary angioedema was made by our Rheumatology colleagues with physical exam and a thorough history, and confirmed by laboratory studies. Our patient presented with compartment syndrome of the hand and forearm and underwent hand and volar forearm fasciotomies. She was subsequently worked up for hereditary angioedema with laboratory results confirming the diagnosis. She was discharged after a 5-day hospitalization with prophylactic C1-inhibitor therapy. Hereditary angioedema is a rare but known cause of compartment syndrome of the upper extremity, and must be considered when patients present with compartment syndrome of unknown etiology. This disease can be diagnosed by laboratory studies and symptoms can be controlled with medical therapy.

  14. Intra-session and inter-day reliability of forearm surface EMG during varying hand grip forces.

    Science.gov (United States)

    Hashemi Oskouei, Alireza; Paulin, Michael G; Carman, Allan B

    2013-02-01

    Surface electromyography (EMG) is widely used to evaluate forearm muscle function and predict hand grip forces; however, there is a lack of literature on its intra-session and inter-day reliability. The aim of this study was to determine reliability of surface EMG of finger and wrist flexor muscles across varying grip forces. Surface EMG was measured from six forearm flexor muscles of 23 healthy adults. Eleven of these subjects undertook inter-day test-retest. Six repetitions of five randomized isometric grip forces between 0% and 80% of maximum force (MVC) were recorded and normalized to MVC. Intra- and inter-day reliability were calculated through the intraclass correlation coefficient (ICC) and standard error of measurement (SEM). Normalized EMG produced excellent intra-session ICC of 0.90 when repeated measurements were averaged. Intra-session SEM was low at low grip forces, however, corresponding normalized SEM was high (23-45%) due to the small magnitude of EMG signals. This may limit the ability to evaluate finer forearm muscle function and hand grip forces in daily tasks. Combining EMG of functionally related muscles improved intra-session SEM, improving within-subject reliability without taking multiple measurements. Removing and replacing electrodes inter-day produced poor ICC (ICC < 0.50) but did not substantially affect SEM.

  15. [A rare cause of compartment syndrome of the forearm and hand following snake bite injury].

    Science.gov (United States)

    Schnecker, K

    1990-06-01

    With the intention to commit suicide a 25 year old patient was bitten by his own rattle snake. At the time of the admission the skin of the right forearm was dark, a hemorrhagic necrotizing colour, and the patient was in shock. He was immediately taken to the intensive care unit and the shock symptoms were treated there. Parasthesias in the area of the nervus medianus were also noticed. The treatment included an antiserum and the release of the tourniquet which caused a further increase of the swelling of the forearm. The lesion led to a hemorrhagic necrotizing inflammation. The surgical incision of the loge of Guyon, the carpal channel, the forearm and proximal of the lacertus fibrosus was persuaded. The circulation improved immediately and after three weeks the nerval function had recovered. The skin defect was covered 14 days after the first operation with meshgraft.

  16. Hand-opening feedback for myoelectric forearm prostheses: performance in virtual grasping tasks influenced by different levels of distraction.

    Science.gov (United States)

    Witteveen, Heidi J B; de Rond, Leonie; Rietman, Johan S; Veltink, Peter H

    2012-01-01

    Sensory feedback and the required attentional demands are important aspects in prosthesis acceptance. In this study, hand-opening feedback is provided and the performance in a virtual grasping task is investigated. Simultaneously, a secondary task was performed to investigate the attentional demands. Ten nondisabled subjects performed the tasks with and without feedback about the hand opening through an array of eight vibrotactile stimulators on the forearm. Activation of one stimulator corresponded to one hand-opening position. For the dual-task experiments, subjects simultaneously performed a secondary auditory counting task. The addition of vibrotactile feedback increased the performance (expressed in percentages of correct hand positions, mean absolute errors in position, and percentages of deviations up to one hand-opening position), but the duration of the tasks was also increased. Three levels of distraction (no distraction, counting task, count and subtract task) were applied, which did not influence the performance in the grasping tasks except for the highest level of distraction. We concluded that the proposed method to provide hand-opening feedback through an array of eight vibrotactile stimulators is successful because the performance in a grasping task increases but it is not significantly attention demanding.

  17. Effectiveness of Occupational Therapy Interventions for Adults With Musculoskeletal Conditions of the Forearm, Wrist, and Hand: A Systematic Review

    Science.gov (United States)

    Hardison, Mark E.

    2017-01-01

    Occupational therapy practitioners are key health care providers for people with musculoskeletal disorders of the distal upper extremity. It is imperative that practitioners understand the most effective and efficient means for remediating impairments and supporting clients in progressing to independence in purposeful occupations. This systematic review provides an update to a previous review by summarizing articles published between 2006 and July 2014 related to the focused question, What is the evidence for the effect of occupational therapy interventions on functional outcomes for adults with musculoskeletal disorders of the forearm, wrist, and hand? A total of 59 articles were reviewed. Evidence for interventions was synthesized by condition within bone, joint, and general hand disorders; peripheral nerve disorders; and tendon disorders. The strongest evidence supports postsurgical early active motion protocols and splinting for various conditions. Very few studies have examined occupation-based interventions. Implications for occupational therapy practice and research are provided. PMID:28027038

  18. Microwave Imaging of Human Forearms: Pilot Study and Image Enhancement

    Directory of Open Access Journals (Sweden)

    Colin Gilmore

    2013-01-01

    Full Text Available We present a pilot study using a microwave tomography system in which we image the forearms of 5 adult male and female volunteers between the ages of 30 and 48. Microwave scattering data were collected at 0.8 to 1.2 GHz with 24 transmitting and receiving antennas located in a matching fluid of deionized water and table salt. Inversion of the microwave data was performed with a balanced version of the multiplicative-regularized contrast source inversion algorithm formulated using the finite-element method (FEM-CSI. T1-weighted MRI images of each volunteer’s forearm were also collected in the same plane as the microwave scattering experiment. Initial “blind” imaging results from the utilized inversion algorithm show that the image quality is dependent on the thickness of the arm’s peripheral adipose tissue layer; thicker layers of adipose tissue lead to poorer overall image quality. Due to the exible nature of the FEM-CSI algorithm used, prior information can be readily incorporated into the microwave imaging inversion process. We show that by introducing prior information into the FEM-CSI algorithm the internal anatomical features of all the arms are resolved, significantly improving the images. The prior information was estimated manually from the blind inversions using an ad hoc procedure.

  19. Sensitivity of different areas of the flexor aspect of the human forearm to corticosteroid-induced skin blanching.

    Science.gov (United States)

    Meyer, E; Smith, E W; Haigh, J M

    1992-10-01

    The intensity of corticosteroid-induced blanching has been found to vary at different areas of the flexor aspect of the human forearm. A retrospective analysis of 38,880 observations of skin blanching in 56 volunteers was conducted to assess the sensitivity of forearm skin to betamethasone 17-valerate. The mid-forearm appears to be more sensitive to the blanching response than do the areas close to the wrist or elbow. These results indicate that each preparation under evaluation should be applied to several sites along the forearm when using the human skin blanching assay in order to obtain an accurate comparative assessment of corticosteroid release from topical delivery vehicles.

  20. Anatomical study of the forearm and hand nerves of the domestic cat ( Felis catus), puma ( Puma concolor) and jaguar ( Panthera onca).

    Science.gov (United States)

    Sánchez, H L; Silva, L B; Rafasquino, M E; Mateo, A G; Zuccolilli, G O; Portiansky, E L; Alonso, C R

    2013-04-01

    The innervation of the forearm and hand regions of cats has not been well described despite its importance for any surgery or any neurological disorder. It is probably the main area where disorders of peripheral nerves in this species are observed. In felines, the forelimbs facilitate the jump and represent the most important way for capturing prey. The main muscles and nerves involved in this activity are located in the region of the forearm and hand. The aim of the present study was to provide a detailed description of the innervation of the forearm and hand regions of the jaguar and puma, in comparison with that of the domestic cat, contributing thus with the anatomical knowledge of the area for applying it to surgery and pathology. The forearms of three pumas and two jaguars (all of them fixed in formalin) and of six domestic cats (fresh) were dissected. The nerves path and their forearm distribution patterns of all three species were described. The analysed results indicate that the observed variations between species are minimal; thus, the anatomy described for domestic cats can be widely applied to American wild felids.

  1. Influence of the renin-angiotensin system on human forearm blood flow

    DEFF Research Database (Denmark)

    Stadeager, C; Hesse, B; Henriksen, O;

    1990-01-01

    Although angiotensin II is a potent vasoconstrictor agent in all tissues, including the human forearm, equivocal effects on forearm blood flow (FBF) have been found after angiotensin blockade. In 13 healthy Na(+)-depleted subjects FBF was measured by the 133Xe washout technique; subcutaneous...... and muscle blood flows were determined separately. FBF was measured during supine rest, after the arm was lowered, and during lower body negative pressure (LBNP). The measurements were repeated during intra-arterial saralasin infusion in six subjects and after intravenous administration of enalapril in seven...

  2. Discrimination of Human Forearm Motions on the Basis of Myoelectric Signals by Using Adaptive Fuzzy Inference System

    Science.gov (United States)

    Kiso, Atsushi; Seki, Hirokazu

    This paper describes a method for discriminating of the human forearm motions based on the myoelectric signals using an adaptive fuzzy inference system. In conventional studies, the neural network is often used to estimate motion intention by the myoelectric signals and realizes the high discrimination precision. On the other hand, this study uses the fuzzy inference for a human forearm motion discrimination based on the myoelectric signals. This study designs the membership function and the fuzzy rules using the average value and the standard deviation of the root mean square of the myoelectric potential for every channel of each motion. In addition, the characteristics of the myoelectric potential gradually change as a result of the muscle fatigue. Therefore, the motion discrimination should be performed by taking muscle fatigue into consideration. This study proposes a method to redesign the fuzzy inference system such that dynamic change of the myoelectric potential because of the muscle fatigue will be taken into account. Some experiments carried out using a myoelectric hand simulator show the effectiveness of the proposed motion discrimination method.

  3. Modulatory Effects of the Ipsi and Contralateral Ventral Premotor Cortex (PMv) on the Primary Motor Cortex (M1) Outputs to Intrinsic Hand and Forearm Muscles in Cebus apella.

    Science.gov (United States)

    Quessy, Stephan; Côté, Sandrine L; Hamadjida, Adjia; Deffeyes, Joan; Dancause, Numa

    2016-10-01

    The ventral premotor cortex (PMv) is a key node in the neural network involved in grasping. One way PMv can carry out this function is by modulating the outputs of the primary motor cortex (M1) to intrinsic hand and forearm muscles. As many PMv neurons discharge when grasping with either arm, both PMv within the same hemisphere (ipsilateral; iPMv) and in the opposite hemisphere (contralateral; cPMv) could modulate M1 outputs. Our objective was to compare modulatory effects of iPMv and cPMv on M1 outputs to intrinsic hand and forearm muscles. We used paired-pulse protocols with intracortical microstimulations in capuchin monkeys. A conditioning stimulus was applied in either iPMv or cPMv simultaneously or prior to a test stimulus in M1 and the effects quantified in electromyographic signals. Modulatory effects from iPMv were predominantly facilitatory, and facilitation was much more common and powerful on intrinsic hand than forearm muscles. In contrast, while the conditioning of cPMv could elicit facilitatory effects, in particular to intrinsic hand muscles, it was much more likely to inhibit M1 outputs. These data show that iPMv and cPMv have very different modulatory effects on the outputs of M1 to intrinsic hand and forearm muscles. © The Author 2016. Published by Oxford University Press.

  4. Sweating responses to isometric hand-grip exercise and forearm muscle metaboreflex in prepubertal children and elderly.

    Science.gov (United States)

    Amano, Tatsuro; Kai, Seiko; Nakajima, Michi; Ichinose-Kuwahara, Tomoko; Gerrett, Nicola; Kondo, Narihiko; Inoue, Yoshimitsu

    2017-02-01

    What is the central question of this study? Non-thermal factors (e.g. muscle metaboreflex) contribute to the sweating response during exercise. Although it is well recognized that the sweating responses caused by core temperature elevation in prepubertal children and the elderly are attenuated compared with young adults, it is unknown whether non-thermal sweating is also attenuated in these populations. What is the main finding and its importance? The non-thermal sweating response during isometric hand-grip exercise and isolated muscle metaboreflex were attenuated in prepubertal children compared with young adults in a non-uniform manner over the body, but only during the muscle metaboreflex in the elderly. This may explain the maturation- and ageing-related decline of sweating during exercise. The purpose of the present study was to investigate sweating responses to isometric hand-grip (IH) exercise and muscle metaboreflex in prepubertal children and the elderly. In hot conditions (ambient temperature, 35°C; relative humidity, 45%), 13 healthy young adults, 10 prepubertal children and 10 elderly subjects (aged 20.4 ± 1.2, 11.4 ± 0.5 and 63.5 ± 3.1 years, respectively) repeated a three hand-grip exercise protocol that consisted of 1 min IH exercise at 15, 30 or 45% of maximal voluntary contraction (MVC) followed by 2 min postexercise forearm occlusion. Local sweat rates (SRs) on the forehead, chest, forearm, thigh and palm were continuously measured (ventilated capsule method). The forehead SR in prepubertal children during IH exercise at 45% MVC was significantly lower than that of young adults (0.26 ± 0.22 and 0.08 ± 0.15 mg cm(-2)  min(-1) for young adults and children, respectively; P elderly at any exercise intensities. The SR on the chest (0.22 ± 0.22 and -0.01 ± 0.05 mg cm(-2)  min(-1) for young adults and children, respectively), forearm (0.14 ± 0.12 and 0.03 ± 0.04 mg cm(-2)  min(-1) ) and thigh (0.13 ± 0.10 and 0

  5. Quantification of hand and forearm muscle forces during a maximal power grip task.

    Science.gov (United States)

    Goislard de Monsabert, Benjamin; Rossi, Jérémy; Berton, Eric; Vigouroux, Laurent

    2012-10-01

    The aim of this study was to estimate muscle and joint forces during a power grip task. Considering the actual lack of quantification of such internal variables, this information would be essential for sports sciences, medicine, and ergonomics. This study also contributed to the advancement of scientific knowledge concerning hand control during power grip. A specially designed apparatus combining both an instrumented handle and a pressure map was used to record the forces at the hand/handle interface during maximal exertions. Data were processed such that the forces exerted on 25 hand anatomical areas were determined. Joint angles of the five fingers and the wrist were also computed from synchronized kinematic measurements. These processed data were used as input of a hand/wrist biomechanical model, which includes 23 degrees of freedom and 42 muscles to estimate muscle and joint forces. Greater forces were applied on the distal phalanges of the long fingers compared with the middle and the proximal ones. Concomitantly, high solicitations were observed for FDP muscles. A large cocontraction level of extensor muscles was also estimated by the model and confirmed previously reported activities and injuries of extensor muscles related to the power grip. Quantifying hand internal loadings also resulted in new insights into the thumb and the wrist biomechanics. Output muscle tension ratios were all in smaller ranges than the ones reported in the literature. Including wrist and finger interactions in this hand model provided new quantification of muscle load sharing, cocontraction level, and biomechanics of the hand. Such information could complete future investigations concerning handle ergonomics or pathomechanisms of hand musculoskeletal disorders.

  6. Estimation of Optimal Measurement Position of Human Forearm EMG Signal by Discriminant Analysis Based on Wilks' lambda

    Science.gov (United States)

    Kiso, Atsushi; Taniguchi, Yu; Seki, Hirokazu

    This paper describes the estimation of the optimal measurement position by discriminant analysis based on Wilks' lambda for myoelectric hand control. In previous studies, for motion discrimination, the myoelectric signals were measured at the same positions. However, the optimal measurement positions of the myoelectric signals for motion discrimination differ depending on the remaining muscles of amputees. Therefore, the purpose of this study is to estimate the optimal and fewer measurement positions for precise motion discrimination of a human forearm. This study proposes a method for estimating the optimal measurement positions by discriminant analysis based on Wilks' lambda, using the myoelectric signals measured at multiple positions. The results of some experiments on the myoelectric hand simulator show the effectiveness of the proposed optimal measurement position estimation method.

  7. Selective use of hand and forearm muscles during bone screw insertion: a natural torque meter.

    Science.gov (United States)

    Barros, Sérgio Estelita; Janson, Guilherme; Chiqueto, Kelly; Ferreira, Eduardo Silveira; Janson, Marcos

    2012-11-01

    To compare the maximum torque produced by different muscle groups and its influence on mini-implant insertion torque and fracture prevention. Eighty-seven professionals were evaluated for the maximum torque produced on a screwdriver by a combined action between the thumb and index finger (maximum digital torque [MDT]) and by the forearm supination movement (maximum brachial torque [MBT]). Ninety mini-implants distributed among 9 different diameters were fractured to determine the fracture torque (FT). The fracture resistance index (FRI) was obtained from: FRI_MDT = FT/MDT and FRI_MBT = FT/MBT. Analysis of variance and t tests were used to compare the groups. The MDT was smaller than the MBT, and the 2 measurements were smaller in female subjects. The FT increased for each 0.1-mm increment in diameter. The FRI_MDT was greater than FRI_MBT for all diameters. An FRI_MDT greater than 1 was found when the diameter was greater than or equal to 1.5 mm. An FRI_MBT greater than 1 occurred with diameters equal to or greater than 1.7 mm for female subjects and 1.8 mm for male subjects. The digital torque was 42% smaller than the brachial torque, and it was mechanically safer and biologically more compatible, allowing the prevention of the fracture of mini-implants with a diameter 1.5 mm or thicker owing to an insertion torque limitation at 15 N-cm. Copyright © 2012 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  8. Selective use of hand and forearm muscles during mini-implant insertion: a natural torquimeter.

    Science.gov (United States)

    Estelita, Sérgio; Janson, Guilherme; Chiqueto, Kelly; Ferreira, Eduardo; Janson, Marcos

    2012-12-01

    To compare maximum torque produced by different muscular groups and its influence on mini-implant insertion torque and fracture prevention. A prospective study involving in vivo and in vitro laboratory experiments. Eighty-seven professionals were evaluated for maximum torque produced using a screwdriver with combined action between thumb and index fingers [maximum digital torque (MDT)] and by forearm supination movement [maximum brachial torque (MBT)]. Ninety mini-implants distributed over nine different diameters and twenty commercially available mini-implants of two different diameters and trademarks were fractured to determine the fracture torque (FT). The fracture resistance index (FRI) was obtained from: FRI_MDT = FT/MDT and FRI_MBT = FT/MBT. The analysis of variance (ANOVA) and t tests were used to compare the groups. MDT was smaller than MBT and both were smaller in females. FT increased for each 0·1 mm of diameter increment. FRI_MDT was greater than FRI_MBT for all diameters. FRI_MDT>1 was found when the diameter was greater than or equal to 1·5 mm. FRI_MBT>1 occurred with diameters equal or greater than 1·7 mm for females and 1·8 mm for males. The 1.5 mm and 1.6 mm diameter of commercially available and mini-implants presented FRI_MBT1. Digital torque was 42% smaller than brachial torque, and it was mechanically safer and biologically more compatible, allowing fracture prevention of 1·5 mm or thicker mini-implant diameter due to insertion torque limitation at 15 N/cm.

  9. Return to Play After Forearm and Hand Injuries in the National Basketball Association.

    Science.gov (United States)

    Morse, Kyle W; Hearns, Krystle A; Carlson, Michelle Gerwin

    2017-02-01

    Hand injuries can result in significant time away from competition for professional basketball players. Time to return to play after hand injuries in elite athletes has not been well described. To report the return to play from metacarpal fractures, phalangeal fractures, and thumb ligament tears in National Basketball Association (NBA) players over a 5-year period. Descriptive epidemiology study. The NBA transaction report was analyzed from January 2009 to May 2014. Players were identified if they were added to the inactive list (IL), missed games due to their injury, or underwent surgery as a result of hand injury. Number of games missed due to injury, days spent on the IL, and age at injury were calculated by injury type and location. One hundred thirty-seven injuries were identified: 39 injuries to the hand and 98 injuries to the finger. Three major injury patterns were identified and analyzed: metacarpal fractures (n = 26), phalangeal fractures (n = 33), and thumb ligament tears (n = 9). The type of injury sustained affected return to play (P basketball players can lead to prolonged periods of time away from competition, especially after surgery. This study provides guidelines on expected return to play in the NBA after these common hand injuries.

  10. Return to Play After Forearm and Hand Injuries in the National Basketball Association

    Science.gov (United States)

    Morse, Kyle W.; Hearns, Krystle A.; Carlson, Michelle Gerwin

    2017-01-01

    Background: Hand injuries can result in significant time away from competition for professional basketball players. Time to return to play after hand injuries in elite athletes has not been well described. Purpose: To report the return to play from metacarpal fractures, phalangeal fractures, and thumb ligament tears in National Basketball Association (NBA) players over a 5-year period. Study Design: Descriptive epidemiology study. Methods: The NBA transaction report was analyzed from January 2009 to May 2014. Players were identified if they were added to the inactive list (IL), missed games due to their injury, or underwent surgery as a result of hand injury. Number of games missed due to injury, days spent on the IL, and age at injury were calculated by injury type and location. Results: One hundred thirty-seven injuries were identified: 39 injuries to the hand and 98 injuries to the finger. Three major injury patterns were identified and analyzed: metacarpal fractures (n = 26), phalangeal fractures (n = 33), and thumb ligament tears (n = 9). The type of injury sustained affected return to play (P < .05). All thumb ligament tears required surgery and had the longest return to play of 67.5 ± 17.7 days (P < .05). The return to play for surgically treated metacarpal fractures (56.7 ± 26.3 days) was significantly greater than nonsurgically treated metacarpal fractures (26.3 ± 12.1 days; P < .01). Return to play for surgically repaired phalangeal fractures (46.2 ± 10.8 days) trended greater but was not significantly different than phalangeal fractures treated nonsurgically (33.3 ± 28.5 days; P = .21). Conclusion: Hand injuries in professional basketball players can lead to prolonged periods of time away from competition, especially after surgery. This study provides guidelines on expected return to play in the NBA after these common hand injuries. PMID:28251168

  11. Peripheral neuropathies of the forearm and hand in rheumatoid arthritis: diagnosis and options for treatment.

    Science.gov (United States)

    Muramatsu, Keiichi; Tanaka, Hiroshi; Taguchi, Toshihiko

    2008-08-01

    Although the clinical hallmark of rheumatoid arthritis (RA) involves inflammatory joint disease, extra-articular manifestations may be evident in 20% of patients. Among them neurologic features involving both the peripheral and central nervous system are one of the more common, but little has been noticed about it in clinic. The same mechanisms participating in joint destruction, synovial inflammation, and vasculitis contribute to the various RA neurological complications. In this article, we reviewed clinical outcomes of peripheral neuropathies of the upper extremity associated with RA and discussed the proper diagnosis and operative indication. Magnetic resonance imaging and electrophysiological examination are the best tools to lead the final diagnosis of nerve palsy secondary to RA synovial cyst. Such neuropathies require consideration in the differential diagnosis of wrist and hand disability. Surgical decompression is recommended at prompt timing if neurophysiologic studies demonstrate denervation or significant motor abnormalities, or sensory symptoms progress despite adequate medication.

  12. Vascular recruitment in forearm muscles during exercise

    DEFF Research Database (Denmark)

    Palm, T; Nielsen, S L; Lassen, N A

    1983-01-01

    Blood flow and filtration of water across the vascular bed in human forearm muscles were studied at rest and during graded exercise with a hand ergometer. Blood flow was measured by dye dilution and water filtration was determined after injection of hyperoncotic albumin solution (23%) in the brac......Blood flow and filtration of water across the vascular bed in human forearm muscles were studied at rest and during graded exercise with a hand ergometer. Blood flow was measured by dye dilution and water filtration was determined after injection of hyperoncotic albumin solution (23...

  13. An aggressive group a streptococcal cellulitis of the hand and forearm requiring surgical debridement.

    Science.gov (United States)

    Bharucha, Neil J; Alaia, Michael J; Paksima, Nader; Christoforou, Dimitrios; Gupta, Salil

    2011-01-03

    Group A streptococcus is responsible for a diverse range of soft tissue infections. Manifestations range from minor oropharyngeal and cellulitic skin infections to more severe conditions such as necrotizing fasciitis and septic shock. Troubling increases in the incidence and the severity of streptococcal infections have been reported over the past 25 years. Cases of streptococcal necrotizing fasciitis have received significant attention in the literature, with prompt surgical debridement being the mainstay of treatment. However, cases of rapidly progressing upper extremity streptococcal cellulitis leading to shock and a subsequent surgical intervention have not been well described. This article presents a case of an 85-year-old woman with a rapidly progressing, erythematous, painful, swollen hand associated with fever, hypotension, and mental status change. Due to a high clinical suspicion for necrotizing fasciitis, the patient was rapidly resuscitated and underwent immediate surgical irrigation and debridement. All intraoperative fascial pathology specimens were negative for necrotizing fasciitis, leading to a final diagnosis of Group A streptococcal cellulitis. Although surgical intervention is not commonly considered in patients with cellulitis, our patient benefited from irrigation and debridement with soft tissue decompression. In cases of necrotizing fasciitis as well as rapidly progressive cellulitis, prompt diagnosis and aggressive treatment may help patients avoid the catastrophic consequences of rapidly progressive group A streptococcal infections.

  14. Optimal Mapping of Torus Self-Organizing Map for Human Forearm Motions Discrimination on the Basis of Myoelectric Signals

    Science.gov (United States)

    Kiso, Atsushi; Seki, Hirokazu

    This paper describes an optimal mapping of the torus self-organizing map for a human forearm motion discrimination on the basis of the myoelectric signals. This study uses the torus self-organizing map (Torus-SOM) for the motion discrimination. The normal SOM identify input data into the same feature group by using the all units of map. Then there is a possibility of the misrecognition motion around the boundary lines of the motion groups. Therefore, this study proposes the mapping method of SOM that the learning units of the same motion concentrate on one local range and the learning unit groups of each motion separates enough. As a result, the variance in the same motion group becomes small and the variance between each motion groups becomes big. Some experiments on the myoelectric hand simulator show the effectiveness of the proposed motion discrimination method.

  15. A natural human hand model

    NARCIS (Netherlands)

    Van Nierop, O.A.; Van der Helm, A.; Overbeeke, K.J.; Djajadiningrat, T.J.P.

    2007-01-01

    We present a skeletal linked model of the human hand that has natural motion. We show how this can be achieved by introducing a new biology-based joint axis that simulates natural joint motion and a set of constraints that reduce an estimated 150 possible motions to twelve. The model is based on obs

  16. Effect of muscle relaxation on the oxygenation of human skeletal muscle: a prospective in-vivo experiment using an isolated forearm technique.

    Science.gov (United States)

    Rhee, Ka Young; Kim, Tae-Yop; Oh, In Su; Lee, Seoung Joon; Ledowski, Thomas

    2015-02-01

    Total oxygen consumption has been found to be reduced under deep neuromuscular blockade due to a lower rate of metabolism of skeletal muscles. However, the magnitude of this effect in individual muscles has not been investigated. Thus the aim of this study was to compare the oxygenation of paralyzed versus non-paralyzed forearm muscle under tourniquet-provoked ischemia. After ethics approval and written informed consent, 30 patients scheduled for elective hand and wrist surgery were included. Ischemia was provoked by inflation of bilateral upper arm tourniquets and muscle relaxation was achieved via intravenous administration of rocuronium 0.9 mg/kg. Bilateral tourniquets were applied to both upper arms before induction of anesthesia and near infrared spectrometry (NIRS) electrodes applied on both forearms. Muscular ischemia in an isolated (= non-paralyzed, NP) as well as a paralyzed forearm (P) was created by sequential inflation of both tourniquets before and after intravenous administration of rocuronium. Muscle oxygen saturations (SmO2) of NIRS in both forearms and their changes were determined and compared. Data of 30 patients (15 male, 15 female; 41.8 ± 14.7 years) were analyzed. The speed of SmO2 decrease (50% decrease of SmO2 from baseline (median [percentiles]: NP 210 s [180/480s] vs. P 180 [180/300]) as well as the maximum decrease in SmO2 (minimum SmO2 in % (median [percentiles]: NP 20 [19/24] vs. P 21 [19/28]) were not significantly affected by neuromuscular paralysis. No significant effect of muscle relaxation on NIRS-assessed muscle oxygenation under tourniquet-induced ischemia was found in human forearm muscles.

  17. [Stab wounds of the hand and forearm due to Kuluna in Kinshasa (Democratic Republic of Congo): types of injuries and treatment].

    Science.gov (United States)

    Kibadi, K; Portaels, F; Pichot, Y; Kapinga, M; Moutet, F

    2015-01-01

    Democratic Republic of Congo (DRC), a particular form of juvenile delinquency and insecurity intensifies in the city of Kinshasa. This is the phenomenon Kuluna. It is organized gangs equipped with machetes and other weapons. The main objective of this study is to know the phenomenon Kuluna and describe the upper limb injuries caused by machetes, while insisting on the specifics of the management of these lesions in our communities. This retrospective descriptive study examines 14 cases of wounds of the hand and forearm due to stab phenomenon Kuluna, in Kinshasa. It covers the period from 1 November 2010 to 1 November 2013. Among the 14 patients with lesions in the hand and forearm admitted and treated at the Unit of Plastic Reconstructive and Aesthetic Surgery, Hand Surgery and Burns, University Clinics of Kinshasa to attacks due to the phenomenon Kuluna. We have 11 men and 3 women. The average age was 33, 5 years (extremes of 21 and 56 years). The right upper limb is reached that the left upper limb, respectively 12 patients and 2 patients. The lesions are localized to the wrist in the majority of cases (10 patients) in the palm of hand and in 3 patients in the fingers in 1 patient. The palmar surface is reached (10 cases) and the dorsal (4 cases). Zone 5 of the International Classification of flexor and Zone 8 topographic classification extensors at hand are the predilection sites of lesions respectively the palmar surface (6 out of 10) and the dorsal (2 case 4). The median nerve at the wrist is cut in half the cases. On bone lesions localized to the forearm, we observed a high incidence of fracture of the ulna (62.5%). The treatment begins with the stabilization of bone pieces, gestures revascularization and nerve sutures and suture tendon and finally skin coverage. Rehabilitation was mandatory, she supervises the actions of repair and it continues until the recovery of function.

  18. The nature of suprasegmental influences on the late reflex activity in human forearm muscles.

    Science.gov (United States)

    Chequer, R S; Goodin, D S; Aminoff, M J

    1991-12-06

    The earliest component of the late EMG response (M2) to sudden stretch of an isometrically contracting muscle is influenced by suprasegmental mechanism, but whether these are tonic, phasic, or both, is uncertain. We have therefore investigated the nature of these mechanisms by varying the predictability of the direction of perturbation of forearm muscles held isometrically against a constant flexor or extensor force of 2.3 N. We found that the M2 response did not change appreciably regardless of whether the direction of perturbation was known in advance or which hand was used by the subject. These findings suggest that any tonic supraspinal influence of the M2 response is of little significance compared to the importance of phasic mechanisms and provide support for the existence of a cerebral arc subserving this reflex component.

  19. Human hand modelling: kinematics, dynamics, applications

    NARCIS (Netherlands)

    Gustus, A.; Stillfried, G.; Visser, J.; Jörntell, H.; Van der Smagt, P.

    2012-01-01

    An overview of mathematical modelling of the human hand is given. We consider hand models from a specific background: rather than studying hands for surgical or similar goals, we target at providing a set of tools with which human grasping and manipulation capabilities can be studied, and hand funct

  20. Limitations of surface EMG signals of extrinsic muscles in predicting postures of human hand.

    Science.gov (United States)

    Vinjamuri, Ramana; Mao, Zhi-Hong; Sclabassi, Robert; Sun, Mingui

    2006-01-01

    This paper explores the limitations of sEMG (surface Electromyography) signals collected from the extrinsic muscles in the forearm in predicting the postures of human hand. Four subjects were asked to try ten extreme postures of hand which need high effort. Two of these four subjects were asked to try ten more normal postures which did not need effort During the experiments, muscle activity and static postures of the hand were measured. The data obtained were analyzed by principal component analysis. The results obtained revealed the limitations of sEMG signals of extrinsic muscles in reproducing the postures of the hand.

  1. The human hand as an inspiration for robot hand development

    CERN Document Server

    Santos, Veronica

    2014-01-01

    “The Human Hand as an Inspiration for Robot Hand Development” presents an edited collection of authoritative contributions in the area of robot hands. The results described in the volume are expected to lead to more robust, dependable, and inexpensive distributed systems such as those endowed with complex and advanced sensing, actuation, computation, and communication capabilities. The twenty-four chapters discuss the field of robotic grasping and manipulation viewed in light of the human hand’s capabilities and push the state-of-the-art in robot hand design and control. Topics discussed include human hand biomechanics, neural control, sensory feedback and perception, and robotic grasp and manipulation. This book will be useful for researchers from diverse areas such as robotics, biomechanics, neuroscience, and anthropologists.

  2. The analgesic effect of nitroglycerin added to lidocaine on quality of intravenous regional anesthesia in patients undergoing elective forearm and hand surgery

    Directory of Open Access Journals (Sweden)

    Hosein Kimiaei Asadi

    2013-01-01

    Full Text Available PURPOSE: To evaluate the effect of nitroglycerine (NTG on sensory and motor block onset and recovery time as well as the quality of tourniquet pain relief, when added to lidocaine (LID for intravenous regional anesthesia in elective forearm and hand surgery. METHODS: A randomized double-blinded clinical trial was performed on 40 patients that were randomly allocated into two groups received lidocaine 3 mg/kg with NTG 200 µg or received only lidocaine 3 mg/kg as the control. RESULTS: There was no difference between the two study groups in hemodynamic parameters before tourniquet inflation, at any time after inflation and after its deflation. There was no difference in the mean of pain score over time between the two groups. The onset time of sensory and motor blockades was shorter in the group received both LID and NTG. The mean recovery time of sensory blockade was longer in the former group. The frequency of opioid injections was significantly lower in those who administered LID and NTG. CONCLUSION: The adjuvant drug of NTG when added to LID is effective in improving the overall quality of anesthesia, shortening onset time of both sensory and motor blockades, and stabling homodynamic parameters in hand and forearm surgery.

  3. Virtual Reality Anatomy: Is It Comparable with Traditional Methods in the Teaching of Human Forearm Musculoskeletal Anatomy?

    Science.gov (United States)

    Codd, Anthony M.; Choudhury, Bipasha

    2011-01-01

    The use of cadavers to teach anatomy is well established, but limitations with this approach have led to the introduction of alternative teaching methods. One such method is the use of three-dimensional virtual reality computer models. An interactive, three-dimensional computer model of human forearm anterior compartment musculoskeletal anatomy…

  4. Virtual Reality Anatomy: Is It Comparable with Traditional Methods in the Teaching of Human Forearm Musculoskeletal Anatomy?

    Science.gov (United States)

    Codd, Anthony M.; Choudhury, Bipasha

    2011-01-01

    The use of cadavers to teach anatomy is well established, but limitations with this approach have led to the introduction of alternative teaching methods. One such method is the use of three-dimensional virtual reality computer models. An interactive, three-dimensional computer model of human forearm anterior compartment musculoskeletal anatomy…

  5. Efficient human hand kinematics for manipulation tasks

    OpenAIRE

    Cobos Guzmán, Salvador; Ferre Perez, Manuel; Sanchez-Uran Gonzalez, Miguel Angel; Ortego la Moneda, Javier; Peña, César

    2008-01-01

    This work is focused on obtaining efficient human hand models that are suitable for manipulation tasks. A 24 DoF kinematic model of the human hand is defined to realistic movements. This model is based on the human skeleton. Dynamic and Static constraints have been included in order to improve the movement realism. Two simplified hand models with 9 and 6 DoF have been developed according to the constraints predefined. These simplified models involve some errors in reconstructing the hand post...

  6. HUMAN HAND STUDY FOR ROBOTIC EXOSKELETON DELVELOPMENT

    Directory of Open Access Journals (Sweden)

    BIROUAS Flaviu Ionut

    2016-11-01

    Full Text Available This paper will be presenting research with application in the rehabilitation of hand motor functions by the aid of robotics. The focus will be on the dimensional parameters of the biological human hand from which the robotic system will be developed. The term used for such measurements is known as anthropometrics. The anthropometric parameters studied and presented in this paper are mainly related to the angular limitations of the finger joints of the human hand.

  7. Study of clutter origin in in-vivo epi-optoacoustic imaging of human forearms

    Science.gov (United States)

    Preisser, Stefan; Held, Gerrit; Akarçay, Hidayet G.; Jaeger, Michael; Frenz, Martin

    2016-09-01

    Epi-optoacoustic (OA) imaging offers flexible clinical diagnostics of the human body when the irradiation optic is attached to or directly integrated into the acoustic probe. Epi-OA images, however, encounter clutter that deteriorates contrast and significantly limits imaging depth. This study elaborates clutter origin in clinical epi-optoacoustic imaging using a linear array probe for scanning the human forearm. We demonstrate that the clutter strength strongly varies with the imaging location but stays stable over time, indicating that clutter is caused by anatomical structures. OA transients which are generated by strong optical absorbers located at the irradiation spot were identified to be the main source of clutter. These transients obscure deep in-plane OA signals when detected by the transducer either directly or after being acoustically scattered in the imaging plane. In addition, OA transients generated in the skin below the probe result in acoustic reverberations, which cause problems in image interpretation and limit imaging depth. Understanding clutter origin allows a better interpretation of clinical OA imaging, helps to design clutter compensation techniques and raises the prospect of contrast optimization via the design of the irradiation geometry.

  8. Implementation of mathematical phantom of hand and forearm in GEANT4 Monte Carlo code; Implementacao de fantoma matematico de mao e antebraco em codigo Monte Carlo GEANT4

    Energy Technology Data Exchange (ETDEWEB)

    Pessanha, Paula Rocha; Queiroz Filho, Pedro Pacheco de; Santos, Denison de Souza, E-mail: pessanha.paular@gmail.com, E-mail: queiroz@ird.gov.br, E-mail: santosd@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ),Rio de Janeiro, RJ (Brazil)

    2014-07-01

    In this work, the implementation of a hand and forearm Geant4 phantom code, for further evaluation of occupational exposure of ends of the radionuclides decay manipulated during procedures involving the use of injection syringe. The simulation model offered by Geant4 includes a full set of features, with the reconstruction of trajectories, geometries and physical models. For this work, the values calculated in the simulation are compared with the measurements rates by thermoluminescent dosimeters (TLDs) in physical phantom REMAB®. From the analysis of the data obtained through simulation and experimentation, of the 14 points studied, there was a discrepancy of only 8.2% of kerma values found, and these figures are considered compatible. The geometric phantom implemented in Geant4 Monte Carlo code was validated and can be used later for the evaluation of doses at ends.

  9. Selection of suitable hand gestures for reliable myoelectric human computer interface

    OpenAIRE

    2015-01-01

    Background Myoelectric controlled prosthetic hand requires machine based identification of hand gestures using surface electromyogram (sEMG) recorded from the forearm muscles. This study has observed that a sub-set of the hand gestures have to be selected for an accurate automated hand gesture recognition, and reports a method to select these gestures to maximize the sensitivity and specificity. Methods Experiments were conducted where sEMG was recorded from the muscles of the forearm while s...

  10. Local forearm and whole-body respiratory quotient in humans after an oral glucose load

    DEFF Research Database (Denmark)

    Simonsen, L; Bülow, J; Madsen, J

    1993-01-01

    The effects of an oral glucose load of 75 g on the local forearm and whole-body energy thermogenesis were measured in normal subjects during the 4 h after the glucose intake. Simultaneous assessment of substrate metabolism in the forearm was performed. Energy expenditure (EE) increased after...... the glucose load and had not returned to baseline level at the end of the experiment. Whole-body respiratory quotient (RQ) was, on average, 0.80 (SD 0.05) in the baseline condition and increased to a maximum of 0.91 (0.03) and then decreased to baseline level at the end of the experiment. The local forearm.......17) to 0.63 (0.17) 30 min after the glucose load (P body RQ...

  11. Review of human hand microbiome research.

    Science.gov (United States)

    Edmonds-Wilson, Sarah L; Nurinova, Nilufar I; Zapka, Carrie A; Fierer, Noah; Wilson, Michael

    2015-10-01

    Recent advances have increased our understanding of the human microbiome, including the skin microbiome. Despite the importance of the hands as a vector for infection transmission, there have been no comprehensive reviews of recent advances in hand microbiome research or overviews of the factors that influence the composition of the hand microbiome. A comprehensive and systematic database search was conducted for skin microbiome-related articles published from January 1, 2008 to April 1, 2015. Only primary research articles that used culture-independent, whole community analysis methods to study the healthy hand skin microbiome were included. Eighteen articles were identified containing hand microbiome data. Most focused on bacteria, with relatively little reported on fungi, viruses, and protozoa. Bacteria from four phyla were found across all studies of the hand microbiome (most to least relative abundance): Firmicutes, Actinobacteria, Proteobacteria, Bacteroidetes. Key factors that impacted the hand microbiome composition included temporal and biogeographical dynamics, as well as intrinsic (age, gender) and extrinsic (product use, cohabitants, pet-ownership) variables. There was more temporal variability in the composition of the hand microbiome than in other body sites, making identification of the "normal" microbiome of the hands challenging. The microbiome of the hands is in constant flux as the hands are a critical vector for transmitting microorganisms between people, pets, inanimate objects and our environments. Future studies need to resolve methodological influences on results, and further investigate factors which alter the hand microbiome including the impact of products applied to hands. Increased understanding of the hand microbiome and the skin microbiome in general, will open the door to product development for disease prevention and treatment, and may lead to other applications, including novel diagnostic and forensic approaches.

  12. Neural mechanisms influencing interlimb coordination during locomotion in humans: presynaptic modulation of forearm H-reflexes during leg cycling.

    Science.gov (United States)

    Nakajima, Tsuyoshi; Mezzarane, Rinaldo A; Klarner, Taryn; Barss, Trevor S; Hundza, Sandra R; Komiyama, Tomoyoshi; Zehr, E Paul

    2013-01-01

    Presynaptic inhibition of transmission between Ia afferent terminals and alpha motoneurons (Ia PSI) is a major control mechanism associated with soleus H-reflex modulation during human locomotion. Rhythmic arm cycling suppresses soleus H-reflex amplitude by increasing segmental Ia PSI. There is a reciprocal organization in the human nervous system such that arm cycling modulates H-reflexes in leg muscles and leg cycling modulates H-reflexes in forearm muscles. However, comparatively little is known about mechanisms subserving the effects from leg to arm. Using a conditioning-test (C-T) stimulation paradigm, the purpose of this study was to test the hypothesis that changes in Ia PSI underlie the modulation of H-reflexes in forearm flexor muscles during leg cycling. Subjects performed leg cycling and static activation while H-reflexes were evoked in forearm flexor muscles. H-reflexes were conditioned with either electrical stimuli to the radial nerve (to increase Ia PSI; C-T interval  = 20 ms) or to the superficial radial (SR) nerve (to reduce Ia PSI; C-T interval  = 37-47 ms). While stationary, H-reflex amplitudes were significantly suppressed by radial nerve conditioning and facilitated by SR nerve conditioning. Leg cycling suppressed H-reflex amplitudes and the amount of this suppression was increased with radial nerve conditioning. SR conditioning stimulation removed the suppression of H-reflex amplitude resulting from leg cycling. Interestingly, these effects and interactions on H-reflex amplitudes were observed with subthreshold conditioning stimulus intensities (radial n., ∼0.6×MT; SR n., ∼ perceptual threshold) that did not have clear post synaptic effects. That is, did not evoke reflexes in the surface EMG of forearm flexor muscles. We conclude that the interaction between leg cycling and somatosensory conditioning of forearm H-reflex amplitudes is mediated by modulation of Ia PSI pathways. Overall our results support a conservation of neural

  13. Neural mechanisms influencing interlimb coordination during locomotion in humans: presynaptic modulation of forearm H-reflexes during leg cycling.

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Nakajima

    Full Text Available Presynaptic inhibition of transmission between Ia afferent terminals and alpha motoneurons (Ia PSI is a major control mechanism associated with soleus H-reflex modulation during human locomotion. Rhythmic arm cycling suppresses soleus H-reflex amplitude by increasing segmental Ia PSI. There is a reciprocal organization in the human nervous system such that arm cycling modulates H-reflexes in leg muscles and leg cycling modulates H-reflexes in forearm muscles. However, comparatively little is known about mechanisms subserving the effects from leg to arm. Using a conditioning-test (C-T stimulation paradigm, the purpose of this study was to test the hypothesis that changes in Ia PSI underlie the modulation of H-reflexes in forearm flexor muscles during leg cycling. Subjects performed leg cycling and static activation while H-reflexes were evoked in forearm flexor muscles. H-reflexes were conditioned with either electrical stimuli to the radial nerve (to increase Ia PSI; C-T interval  = 20 ms or to the superficial radial (SR nerve (to reduce Ia PSI; C-T interval  = 37-47 ms. While stationary, H-reflex amplitudes were significantly suppressed by radial nerve conditioning and facilitated by SR nerve conditioning. Leg cycling suppressed H-reflex amplitudes and the amount of this suppression was increased with radial nerve conditioning. SR conditioning stimulation removed the suppression of H-reflex amplitude resulting from leg cycling. Interestingly, these effects and interactions on H-reflex amplitudes were observed with subthreshold conditioning stimulus intensities (radial n., ∼0.6×MT; SR n., ∼ perceptual threshold that did not have clear post synaptic effects. That is, did not evoke reflexes in the surface EMG of forearm flexor muscles. We conclude that the interaction between leg cycling and somatosensory conditioning of forearm H-reflex amplitudes is mediated by modulation of Ia PSI pathways. Overall our results support a

  14. Pain, wheal and flare in human forearm skin induced by bradykinin and 5-hydroxytryptamine

    DEFF Research Database (Denmark)

    Jensen, Kai; Tuxen, C; Pedersen-Bjergaard, U

    1990-01-01

    Pain was induced in 19 healthy individuals by double-blind injections into the forearm skin of 0.05 ml of physiological saline with or without active substances added. Bradykinin (0.5 nmol), 5-hydroxytryptamine (0.5 nmol) and a mixture of the two substances in half dosage (0.25 nmol + 0.25 nmol) ...

  15. Human eccrine hamartoma of the forearm-antebrachial organ of the ringtailed lemur (Lemur catta). A possible phylogenetic relationship?

    Science.gov (United States)

    Kopera, D; Soyer, H P; Kerl, H

    1994-06-01

    A 31-year-old woman presented with a clinically otherwise unsuspicious area of profuse sweating on her right forearm. Without triggering agents, sweating attacks producing a clear, serous fluid were observed daily. Histopathologic examination of a biopsy specimen showed hyperplastic eccrine glands with pale, stippled cytoplasm characteristic of eccrine hamartoma. No explanation, however, has been given for the fact that several authors observed eccrine hamartomas in the same anatomical location. Adolescent lemurs of the species catta (ringtailed lemur) are equipped with a pair of antebrachial cutaneous glands located on the volar surface of the wrist. They exude a clear secretion enabling them to "brachial branch mark" their territories. Histopathologic findings in the ringtailed lemur's antebrachial organ show characteristics of both apocrine and eccrine glands. In contrast to normal apocrine glands, however, the antebrachial organs of ringtailed lemurs reach the epidermis directly and are not connected to hair follicles. According to the "biogenetic law" of Ernst Haeckel, stating that ontogeny has to be seen as a short and incomplete repetition of phylogeny, a human fetus passes all evolutional stages from a single cell via amphibians and mammals to a human being. Thus, the antebrachial organ of the ringtailed lemur may be the "phylogenetic explanation" for eccrine hamartomas of the forearm in humans. The histopathologic findings of the antebrachial organ and of eccrine hamartomas are in accordance with this hypothesis.

  16. Effect of repeated forearm muscle cooling on the adaptation of skeletal muscle metabolism in humans

    Science.gov (United States)

    Wakabayashi, Hitoshi; Nishimura, Takayuki; Wijayanto, Titis; Watanuki, Shigeki; Tochihara, Yutaka

    2017-01-01

    This study aimed to investigate the effect of repeated cooling of forearm muscle on adaptation in skeletal muscle metabolism. It is hypothesized that repeated decreases of muscle temperature would increase the oxygen consumption in hypothermic skeletal muscle. Sixteen healthy males participated in this study. Their right forearm muscles were locally cooled to 25 °C by cooling pads attached to the skin. This local cooling was repeated eight times on separate days for eight participants (experimental group), whereas eight controls received no cold exposure. To evaluate adaptation in skeletal muscle metabolism, a local cooling test was conducted before and after the repeated cooling period. Change in oxy-hemoglobin content in the flexor digitorum at rest and during a 25-s isometric handgrip (10% maximal voluntary construction) was measured using near-infrared spectroscopy at every 2 °C reduction in forearm muscle temperature. The arterial blood flow was occluded for 15 s by upper arm cuff inflation at rest and during the isometric handgrip. The oxygen consumption in the flexor digitorum muscle was evaluated by a slope of the oxy-hemoglobin change during the arterial occlusion. In the experimental group, resting oxygen consumption in skeletal muscle did not show any difference between pre- and post-intervention, whereas muscle oxygen consumption during the isometric handgrip was significantly higher in post-intervention than in pre-test from thermoneutral baseline to 31 °C muscle temperature (P < 0.05). This result indicated that repeated local muscle cooling might facilitate oxidative metabolism in the skeletal muscle. In summary, skeletal muscle metabolism during submaximal isometric handgrip was facilitated after repeated local muscle cooling.

  17. Effect of repeated forearm muscle cooling on the adaptation of skeletal muscle metabolism in humans

    Science.gov (United States)

    Wakabayashi, Hitoshi; Nishimura, Takayuki; Wijayanto, Titis; Watanuki, Shigeki; Tochihara, Yutaka

    2017-07-01

    This study aimed to investigate the effect of repeated cooling of forearm muscle on adaptation in skeletal muscle metabolism. It is hypothesized that repeated decreases of muscle temperature would increase the oxygen consumption in hypothermic skeletal muscle. Sixteen healthy males participated in this study. Their right forearm muscles were locally cooled to 25 °C by cooling pads attached to the skin. This local cooling was repeated eight times on separate days for eight participants (experimental group), whereas eight controls received no cold exposure. To evaluate adaptation in skeletal muscle metabolism, a local cooling test was conducted before and after the repeated cooling period. Change in oxy-hemoglobin content in the flexor digitorum at rest and during a 25-s isometric handgrip (10% maximal voluntary construction) was measured using near-infrared spectroscopy at every 2 °C reduction in forearm muscle temperature. The arterial blood flow was occluded for 15 s by upper arm cuff inflation at rest and during the isometric handgrip. The oxygen consumption in the flexor digitorum muscle was evaluated by a slope of the oxy-hemoglobin change during the arterial occlusion. In the experimental group, resting oxygen consumption in skeletal muscle did not show any difference between pre- and post-intervention, whereas muscle oxygen consumption during the isometric handgrip was significantly higher in post-intervention than in pre-test from thermoneutral baseline to 31 °C muscle temperature ( P muscle cooling might facilitate oxidative metabolism in the skeletal muscle. In summary, skeletal muscle metabolism during submaximal isometric handgrip was facilitated after repeated local muscle cooling.

  18. Human computer interaction using hand gestures

    CERN Document Server

    Premaratne, Prashan

    2014-01-01

    Human computer interaction (HCI) plays a vital role in bridging the 'Digital Divide', bringing people closer to consumer electronics control in the 'lounge'. Keyboards and mouse or remotes do alienate old and new generations alike from control interfaces. Hand Gesture Recognition systems bring hope of connecting people with machines in a natural way. This will lead to consumers being able to use their hands naturally to communicate with any electronic equipment in their 'lounge.' This monograph will include the state of the art hand gesture recognition approaches and how they evolved from their inception. The author would also detail his research in this area for the past 8 years and how the future might turn out to be using HCI. This monograph will serve as a valuable guide for researchers (who would endeavour into) in the world of HCI.

  19. Local forearm and whole-body respiratory quotient in humans after an oral glucose load: methodological problems

    DEFF Research Database (Denmark)

    Simonsen, L; Bülow, J; Madsen, Jan Lysgård;

    1993-01-01

    The effects of an oral glucose load of 75 g on the local forearm and whole-body energy thermogenesis were measured in normal subjects during the 4 h after the glucose intake. Simultaneous assessment of substrate metabolism in the forearm was performed. Energy expenditure (EE) increased after...... and local forearm RQ are not significantly different in the fasting state. The finding of a decrease in local forearm RQ below 0.70 30 min after the glucose load probably indicates a non-steady state in the carbon dioxide exchange. Thus, indirect calorimetry cannot be applied locally during short time...

  20. Comparative anatomical analyses of the forearm muscles of Cebus libidinosus (Rylands et al. 2000: manipulatory behavior and tool use.

    Directory of Open Access Journals (Sweden)

    Tales Alexandre Aversi-Ferreira

    Full Text Available The present study describes the flexor and extensor muscles in Cebus libidinosus' forearm and compares them with those from humans, chimpanzees and baboons. The data is presented in quantitative anatomical indices for similarity. The capuchin forearm muscles showed important similarities with chimpanzees and humans, particularly those that act on thumb motion and allow certain degree of independence from other hand structures, even though their configuration does not enable a true opposable thumb. The characteristics of Cebus' forearm muscles corroborate the evolutionary convergence towards an adaptive behavior (tool use between Cebus genus and apes.

  1. A New Approach for Human Forearm Motion Assist by Actuated Artificial Joint-An Inner Skeleton Robot

    Science.gov (United States)

    Kundu, Subrata Kumar; Kiguchi, Kazuo; Teramoto, Kenbu

    In order to help the physical activities of the elderly or physically disabled persons, we propose a new concept of a power-assist inner skeleton robot (i.e., actuated artificial joint) that is supposed to assist the human daily life motion from inside of the human body. This paper presents an implantable 2 degree of freedom (DOF) inner skeleton robot that is designed to assist human elbow flexion-extension motion and forearm supination-pronation motion for daily life activities. We have developed a prototype of the inner skeleton robot that is supposed to assist the motion from inside of the body and act as an actuated artificial joint. The proposed system is controlled based on the activation patterns of the electromyogram (EMG) signals of the user's muscles by applying fuzzy-neuro control method. A joint actuator with angular position sensor is designed for the inner skeleton robot and a T-Mechanism is proposed to keep the bone arrangement similar to the normal human articulation after the elbow arthroplasty. The effectiveness of the proposed system has been evaluated by experiment.

  2. Constraint Study for a Hand Exoskeleton: Human Hand Kinematics and Dynamics

    Directory of Open Access Journals (Sweden)

    Fai Chen Chen

    2013-01-01

    Full Text Available In the last few years, the number of projects studying the human hand from the robotic point of view has increased rapidly, due to the growing interest in academic and industrial applications. Nevertheless, the complexity of the human hand given its large number of degrees of freedom (DoF within a significantly reduced space requires an exhaustive analysis, before proposing any applications. The aim of this paper is to provide a complete summary of the kinematic and dynamic characteristics of the human hand as a preliminary step towards the development of hand devices such as prosthetic/robotic hands and exoskeletons imitating the human hand shape and functionality. A collection of data and constraints relevant to hand movements is presented, and the direct and inverse kinematics are solved for all the fingers as well as the dynamics; anthropometric data and dynamics equations allow performing simulations to understand the behavior of the finger.

  3. 前臂再植术后患者早期预防手内在肌挛缩的康复护理%Rehabilitation nursing of patients after forearm replantation to prevent contracture of intrinsic muscle of hand

    Institute of Scientific and Technical Information of China (English)

    傅育红; 徐敏; 朱丽萍

    2013-01-01

    This paper introduces the rehabilitation methods and outcomes of patients after forearm replantation to prevent contracture of intrinsic muscle of hand.Nine patients with forearm replantation were treated by different orthosis for fixation and received physical therapy and occupational therapy to prevent contracture of intrinsic muscle of hand.Based on the test of finger joints functional recovery of hands(TAM) system,seven cases achieved to excellent grade of functional recovery;the two point discrimination of the finger pulp was 5~10cm;the touch sensation recovered to normal,the hand grip strength reached to 30kg,equal to 90% function of healthy side.One case achieved to good grade of functional recovery and one case was bad.Only one case was treated by functional reconstruction of hand intrinsic muscles.%报告了前臂离断再植术后预防手内在肌挛缩的康复训练过程和效果.对9例前臂离断再植术后患者在术后不同阶级采用不同的支具固定方法,进行相应的物理、作业疗法,预防前臂再植术后手内在肌挛缩.根据手关节活动范围系统评价标准,7例手功能恢复优,两点辨别觉5~10cm,触摸觉正常,握力30kg,相当于健侧手90%功能,中1例,差1例.本组仅1例行内在肌功能重建.

  4. User Interface Aspects of a Human-Hand Simulation System

    Directory of Open Access Journals (Sweden)

    Beifang Yi

    2005-10-01

    Full Text Available This paper describes the user interface design for a human-hand simulation system, a virtual environment that produces ground truth data (life-like human hand gestures and animations and provides visualization support for experiments on computer vision-based hand pose estimation and tracking. The system allows users to save time in data generation and easily create any hand gestures. We have designed and implemented this user interface with the consideration of usability goals and software engineering issues.

  5. Sensing human hand motions for controlling dexterous robots

    Science.gov (United States)

    Marcus, Beth A.; Churchill, Philip J.; Little, Arthur D.

    1988-01-01

    The Dexterous Hand Master (DHM) system is designed to control dexterous robot hands such as the UTAH/MIT and Stanford/JPL hands. It is the first commercially available device which makes it possible to accurately and confortably track the complex motion of the human finger joints. The DHM is adaptable to a wide variety of human hand sizes and shapes, throughout their full range of motion.

  6. User Interface Aspects of a Human-Hand Simulation System

    Directory of Open Access Journals (Sweden)

    Beifang Yi

    2005-10-01

    Full Text Available This paper describes the user interface design for a human-hand simulation system, a virtual environment that produces ground truth data (life-like human hand gestures and animations and provides visualization support for experiments on computer vision-based hand pose estimation and tracking. The system allows users to save time in data generation and easily create any hand gestures. We have designed and implemented this user interface with the consideration of usability goals and software engineering issues.

  7. Communication channel modeling of human forearm with muscle fiber tissue characteristics.

    Science.gov (United States)

    Zhang, Shuang; Pun, Sio Hang; Mak, Peng Un; Qin, Yu-Ping; Liu, Yi-He; Vai, Mang I

    2016-09-14

    Human-Body Communication (HBC) is a wireless communication method using the human body tissue as a transmission medium for signals. This paper on the basis of human muscle fiber tissues' characteristics, it is first proposed to establish the analytical model of galvanic coupling human-body communication channel. In this model, the parallel and the transverse electrical characteristics of muscular tissue are fully considered, and the model accurately presents the transmission mechanism of galvanic coupling human-body communication signals in the channel. At last, through compare with the experimental results and calculation results, the maximum error of the model is 22.4% and the average error is 14.2% within the frequency range.

  8. Human hand descriptions and gesture recognition for object manipulation.

    Science.gov (United States)

    Cobos, Salvador; Ferre, Manuel; Sánchez-Urán, M Ángel; Ortego, Javier; Aracil, Rafael

    2010-06-01

    This work focuses on obtaining realistic human hand models that are suitable for manipulation tasks. A 24 degrees of freedom (DoF) kinematic model of the human hand is defined. The model reasonably satisfies realism requirements in simulation and movement. To achieve realism, intra- and inter-finger constraints are obtained. The design of the hand model with 24 DoF is based upon a morphological, physiological and anatomical study of the human hand. The model is used to develop a gesture recognition procedure that uses principal components analysis (PCA) and discriminant functions. Two simplified hand descriptions (nine and six DoF) have been developed in accordance with the constraints obtained previously. The accuracy of the simplified models is almost 5% for the nine DoF hand description and 10% for the six DoF hand description. Finally, some criteria are defined by which to select the hand description best suited to the features of the manipulation task.

  9. Combined Hand Gesture — Speech Model for Human Action Recognition

    Directory of Open Access Journals (Sweden)

    Sheng-Tzong Cheng

    2013-12-01

    Full Text Available This study proposes a dynamic hand gesture detection technology to effectively detect dynamic hand gesture areas, and a hand gesture recognition technology to improve the dynamic hand gesture recognition rate. Meanwhile, the corresponding relationship between state sequences in hand gesture and speech models is considered by integrating speech recognition technology with a multimodal model, thus improving the accuracy of human behavior recognition. The experimental results proved that the proposed method can effectively improve human behavior recognition accuracy and the feasibility of system applications. Experimental results verified that the multimodal gesture-speech model provided superior accuracy when compared to the single modal versions.

  10. Combined hand gesture--speech model for human action recognition.

    Science.gov (United States)

    Cheng, Sheng-Tzong; Hsu, Chih-Wei; Li, Jian-Pan

    2013-12-12

    This study proposes a dynamic hand gesture detection technology to effectively detect dynamic hand gesture areas, and a hand gesture recognition technology to improve the dynamic hand gesture recognition rate. Meanwhile, the corresponding relationship between state sequences in hand gesture and speech models is considered by integrating speech recognition technology with a multimodal model, thus improving the accuracy of human behavior recognition. The experimental results proved that the proposed method can effectively improve human behavior recognition accuracy and the feasibility of system applications. Experimental results verified that the multimodal gesture-speech model provided superior accuracy when compared to the single modal versions.

  11. Quantification of nanoparticle uptake into hair follicles in pig ear and human forearm.

    Science.gov (United States)

    Raber, A S; Mittal, A; Schäfer, J; Bakowsky, U; Reichrath, J; Vogt, T; Schaefer, U F; Hansen, S; Lehr, C-M

    2014-04-10

    Drug delivery via the hair follicle (HF) especially with nanoparticles (NP) recently gained attention due to a depot effect and facilitated absorption conditions within the lower HF. With the prospect of transdermal drug delivery, it is of interest to optimize the follicular uptake of NP. In this study, a method was developed to quantify NP uptake into HF and applied in vitro in a pig ear model and in vivo in human volunteers. The influence of NP material on HF uptake was investigated using fluorescence-labeled NP based on poly(D,L-lactide-co-glycolide) (PLGA). All NP had similar hydrodynamic sizes (163-170 nm) but different surface modifications: (i) plain PLGA, (ii) chitosan-coated PLGA (Chit.-PLGA), and (iii) Chit.-PLGA coated with different phospholipids (PL) (DPPC (100), DPPC:Chol (85:15), and DPPC:DOTAP (92:8). Differential stripping was performed, including complete mass balance. The samples were extracted for fluorescence quantification. An effect of the PL coating on follicular uptake was observed as DPPC (100) and DPPC:DOTAP (92:8) penetrated into HF to a higher extent than the other tested NP. The effect was observed both in the pig ear model as well as in human volunteers, although it was statistically significant only in the in vitro model. An excellent in vitro-in vivo correlation (IVIVC, r(2)=0.987) between both models was demonstrated, further supporting the suitability of the pig ear model as a surrogate for the in vivo situation in humans for quantifying NP uptake into HF. These findings may help to optimize NP for targeting the HF and to improve transdermal delivery.

  12. Forearm metabolism during infusion of adrenaline

    DEFF Research Database (Denmark)

    Simonsen, L; Stefl, B; Bülow, J

    2000-01-01

    Human skeletal muscle metabolism is often investigated by measurements of substrate fluxes across the forearm. To evaluate whether the two forearms give the same metabolic information, nine healthy subjects were studied in the fasted state and during infusion of adrenaline. Both arms were...... catheterized in a cubital vein in the retrograde direction. A femoral artery was catheterized for blood sampling, and a femoral vein for infusion of adrenaline. Forearm blood flow was measured by venous occlusion strain-gauge plethysmography. Forearm subcutaneous adipose tissue blood flow was measured...... by the local 133Xe washout method. Metabolic fluxes were calculated as the product of forearm blood flow and a-v differences of metabolite concentrations. After baseline measurements, adrenaline was infused at a rate of 0.3 nmol kg-1 min-1. No difference in the metabolic information obtained in the fasting...

  13. Evidence for a rapid vasodilatory contribution to immediate hyperemia in rest-to-mild and mild-to-moderate forearm exercise transitions in humans.

    Science.gov (United States)

    Saunders, Natasha R; Tschakovsky, Michael E

    2004-09-01

    Controversy exists regarding the contribution of a rapid vasodilatory mechanism(s) to immediate exercise hyperemia. Previous in vivo investigations have exclusively examined rest-to-exercise (R-E) transitions where both the muscle pump and early vasodilator mechanisms may be activated. To isolate vasodilatory onset, the present study investigated the onset of exercise hyperemia in an exercise-to-exercise (E-E) transition, where no further increase in muscle pump contribution would occur. Eleven subjects lay supine and performed a step increase from rest to 3 min of mild (10% maximal voluntary contraction), rhythmic, dynamic forearm handgrip exercise, followed by a further step to moderate exercise (20% maximal voluntary contraction) in each of arm above (condition A) or below (condition B) heart level. Beat-by-beat measures of brachial arterial blood flow (Doppler ultrasound) and blood pressure (arterial tonometry) were performed. We observed an immediate increase in forearm vascular conductance in E-E transitions, and the magnitude of this increase matched that of the R-E transitions within each of the arm positions (condition A: E-E, 52.8 +/- 10.7 vs. R-E, 60.3 +/- 11.7 ml.min(-1).100 mmHg(-1), P = 0.66; condition B: E-E, 43.2 +/- 12.8 vs. R-E, 33.9 +/- 8.2 ml.min(-1).100 mmHg(-1), P = 0.52). Furthermore, changes in forearm vascular conductance were identical between R-E and E-E transitions over the first nine contraction-relaxation cycles in condition A. The immediate and identical increase in forearm vascular conductance in R-E and E-E transitions within arm positions provides strong evidence that rapid vasodilation contributes to immediate exercise hyperemia in humans. Specific vasodilatory mechanisms responsible remain to be determined.

  14. Intrinsic hand muscles and digit independence on the preferred and non-preferred hands of humans.

    Science.gov (United States)

    Reilly, Karen T; Hammond, Geoffrey R

    2006-09-01

    Although the superior dexterity of one hand is an almost ubiquitous human experience, it is unclear which characteristics of the motor system controlling the preferred hand produce this superior dexterity. Between-species studies show that greater dexterity is associated with a motor system that permits more independent movements of the digits. If between-hand dexterity differences are mediated by the same mechanism as between-species dexterity differences, then there should be asymmetries within the corticospinal tracts of humans that would result in between-hand independence differences. The evidence for asymmetries in the corticospinal tracts is sparse, and if an asymmetry does exist, it appears to be limited to the control of intrinsic hand muscles. We wondered, therefore, whether there might be a difference in the degree of independent control on the two hands during performance of a task that primarily uses intrinsic hand muscles. We examined digit individuation when subjects produced abduction or adduction forces with a single digit in isolation. Consistent with previous studies in which forces or movements in single digits were generated primarily by extrinsic hand muscles, we found no difference between the individuation of the digits on the preferred and non-preferred hands. We suggest that whereas independence differences underlie large dexterity differences between species, they do not underlie the more subtle dexterity differences between the preferred and non-preferred hands. Instead, the neural substrate for handedness might be asymmetrical connectivity within M1, with more profuse connections within the dominant than non-dominant M1 imparting a greater potential for excitatory and inhibitory interactions between movement representations which might then result in the more efficient coordination of hand and arm movements of the preferred hand.

  15. Contralateral tactile masking between forearms.

    Science.gov (United States)

    D'Amour, Sarah; Harris, Laurence R

    2014-03-01

    Masking effects have been demonstrated in which tactile sensitivity is affected when one touch is close to another on the body surface. Such effects are likely a result of local lateral inhibitory circuits that sharpen the spatial tuning of a given tactile receptor. Mutually inhibitory pathways have also been demonstrated between cortical tactile maps of the two halves of the body. Occasional reports have indicated that touches on one hand or forearm can affect tactile sensitivity at contralateral locations. Here, we measure the spatial tuning and effect of posture on this contralateral masking effect. Tactile sensitivity was measured on one forearm, while vibrotactile masking stimulation was applied to the opposite arm. Results were compared to sensitivity while vibrotactile stimulation was applied to a control site on the right shoulder. Sensitivity on the forearm was reduced by over 3 dB when the arms were touching and by 0.52 dB when they were held parallel. The masking effect depended on the position of the masking stimulus. Its effectiveness fell off by 1 STD when the stimulus was 29 % of arm length from the corresponding contralateral point. This long-range inhibitory effect in the tactile system suggests a surprisingly intimate relationship between the two sides of the body.

  16. A novel design method of anthropomorphic prosthetic hands for reproducing human hand grasping.

    Science.gov (United States)

    Sun, Baiyang; Xiong, Caihua; Chen, Wenrui; Zhang, Qiaofei; Mao, Liu; Zhang, Qin

    2014-01-01

    Because hand is often used for grasping, developing a design of prosthetic hands, particularly light and compact underactuated anthropomorphic transradial prostheses for reproducing human hand complex grasping is crucial for upper-limb amputees. Obviously, the less the number of actuators is, the worse the anthropomorphic motion capability of the prosthetic hands will be. This paper aims to design a transmission mechanism with few motors actuating fingers which could serve the relatively accurate grasp movement of a human hand and has the potential to be embedded in a palm including the motors. We start with establishing an index for evaluating the anthropomorphic motion capability of a prosthetic hand. Based on the optimization of this index, we determine the number of actuators in fingers and the transmission relationship between the actuators and the metacarpophalangeal(MCP) joints. Then, a new design method to mechanically implement the transmission relationship based on a novel decomposition of transmission matrix is proposed in this paper. Utilizing this method, we obtained the final mechanical structure of a new prosthetic hand.

  17. Durable Tactile Glove for Human or Robot Hand

    Science.gov (United States)

    Butzer, Melissa; Diftler, Myron A.; Huber, Eric

    2010-01-01

    A glove containing force sensors has been built as a prototype of tactile sensor arrays to be worn on human hands and anthropomorphic robot hands. The force sensors of this glove are mounted inside, in protective pockets; as a result of this and other design features, the present glove is more durable than earlier models.

  18. Human bite of the hand: clinical and surgical approach

    OpenAIRE

    Simancas-Pereira Hernán; Fonseca-Caro John Fredy; Acevedo-Granados Camilo Andrés

    2012-01-01

    Introduction: human bites of the hand carries a risk of infection and functional and/oraesthetic complications, according to the mechanism of trauma, duration and specificfactors of the victim and the aggressor. The management of acute episodes isessential and must be an interdisciplinary care.Objective: to review human bites of the hand.Methodology: Thematic review which included the evaluation of clinical casereports published in the last fifteen years in English and Spanish, obtained by el...

  19. Human Hand Motion Analysis and Synthesis of Optimal Power Grasps for a Robotic Hand

    Directory of Open Access Journals (Sweden)

    Francesca Cordella

    2014-03-01

    Full Text Available Biologically inspired robotic systems can find important applications in biomedical robotics, since studying and replicating human behaviour can provide new insights into motor recovery, functional substitution and human-robot interaction. The analysis of human hand motion is essential for collecting information about human hand movements useful for generalizing reaching and grasping actions on a robotic system. This paper focuses on the definition and extraction of quantitative indicators for describing optimal hand grasping postures and replicating them on an anthropomorphic robotic hand. A motion analysis has been carried out on six healthy human subjects performing a transverse volar grasp. The extracted indicators point to invariant grasping behaviours between the involved subjects, thus providing some constraints for identifying the optimal grasping configuration. Hence, an optimization algorithm based on the Nelder-Mead simplex method has been developed for determining the optimal grasp configuration of a robotic hand, grounded on the aforementioned constraints. It is characterized by a reduced computational cost. The grasp stability has been tested by introducing a quality index that satisfies the form-closure property. The grasping strategy has been validated by means of simulation tests and experimental trials on an arm-hand robotic system. The obtained results have shown the effectiveness of the extracted indicators to reduce the non-linear optimization problem complexity and lead to the synthesis of a grasping posture able to replicate the human behaviour while ensuring grasp stability. The experimental results have also highlighted the limitations of the adopted robotic platform (mainly due to the mechanical structure to achieve the optimal grasp configuration.

  20. The evolution of human and ape hand proportions.

    Science.gov (United States)

    Almécija, Sergio; Smaers, Jeroen B; Jungers, William L

    2015-07-14

    Human hands are distinguished from apes by possessing longer thumbs relative to fingers. However, this simple ape-human dichotomy fails to provide an adequate framework for testing competing hypotheses of human evolution and for reconstructing the morphology of the last common ancestor (LCA) of humans and chimpanzees. We inspect human and ape hand-length proportions using phylogenetically informed morphometric analyses and test alternative models of evolution along the anthropoid tree of life, including fossils like the plesiomorphic ape Proconsul heseloni and the hominins Ardipithecus ramidus and Australopithecus sediba. Our results reveal high levels of hand disparity among modern hominoids, which are explained by different evolutionary processes: autapomorphic evolution in hylobatids (extreme digital and thumb elongation), convergent adaptation between chimpanzees and orangutans (digital elongation) and comparatively little change in gorillas and hominins. The human (and australopith) high thumb-to-digits ratio required little change since the LCA, and was acquired convergently with other highly dexterous anthropoids.

  1. 3D Visual Sensing of the Human Hand for the Remote Operation of a Robotic Hand

    Directory of Open Access Journals (Sweden)

    Pablo Gil

    2014-02-01

    Full Text Available New low cost sensors and open free libraries for 3D image processing are making important advances in robot vision applications possible, such as three- dimensional object recognition, semantic mapping, navigation and localization of robots, human detection and/or gesture recognition for human-machine interaction. In this paper, a novel method for recognizing and tracking the fingers of a human hand is presented. This method is based on point clouds from range images captured by a RGBD sensor. It works in real time and it does not require visual marks, camera calibration or previous knowledge of the environment. Moreover, it works successfully even when multiple objects appear in the scene or when the ambient light is changed. Furthermore, this method was designed to develop a human interface to control domestic or industrial devices, remotely. In this paper, the method was tested by operating a robotic hand. Firstly, the human hand was recognized and the fingers were detected. Secondly, the movement of the fingers was analysed and mapped to be imitated by a robotic hand.

  2. 3D Visual Sensing of the Human Hand for the Remote Operation of a Robotic Hand

    Directory of Open Access Journals (Sweden)

    Pablo Gil

    2014-02-01

    Full Text Available New low cost sensors and open free libraries for 3D image processing are making important advances in robot vision applications possible, such as three-dimensional object recognition, semantic mapping, navigation and localization of robots, human detection and/or gesture recognition for human-machine interaction. In this paper, a novel method for recognizing and tracking the fingers of a human hand is presented. This method is based on point clouds from range images captured by a RGBD sensor. It works in real time and it does not require visual marks, camera calibration or previous knowledge of the environment. Moreover, it works successfully even when multiple objects appear in the scene or when the ambient light is changed. Furthermore, this method was designed to develop a human interface to control domestic or industrial devices, remotely. In this paper, the method was tested by operating a robotic hand. Firstly, the human hand was recognized and the fingers were detected. Secondly, the movement of the fingers was analysed and mapped to be imitated by a robotic hand.

  3. Issues in human/computer control of dexterous remote hands

    Science.gov (United States)

    Salisbury, K.

    1987-01-01

    Much research on dexterous robot hands has been aimed at the design and control problems associated with their autonomous operation, while relatively little research has addressed the problem of direct human control. It is likely that these two modes can be combined in a complementary manner yielding more capability than either alone could provide. While many of the issues in mixed computer/human control of dexterous hands parallel those found in supervisory control of traditional remote manipulators, the unique geometry and capabilities of dexterous hands pose many new problems. Among these are the control of redundant degrees of freedom, grasp stabilization and specification of non-anthropomorphic behavior. An overview is given of progress made at the MIT AI Laboratory in control of the Salisbury 3 finger hand, including experiments in grasp planning and manipulation via controlled slip. It is also suggested how we might introduce human control into the process at a variety of functional levels.

  4. Tactile feedback for myoelectric forearm prostheses

    NARCIS (Netherlands)

    Witteveen, H.J.B

    2014-01-01

    Tactile feedback about, at least, hand aperture and grasping force, is required for (1) optimal control of a myoelectric forearm prosthesis, (2) to reduce the burden on the visual system and (3) to enable more subconscious use of the prosthesis. In this thesis, the possibilities of vibrotactile and

  5. Motor synergies for dampening hand vibration during human walking.

    Science.gov (United States)

    Togo, Shunta; Kagawa, Takahiro; Uno, Yoji

    2012-01-01

    This study investigated the motion required to carry a cup filled with water without spilling it, which is a common human dexterous task. This task requires the individual to dampen hand vibration while walking. We hypothesize that a reduction in hand jerk and a constant cup angle are required to achieve this task. We measured movements while human subjects carried a cup with water (WW task) and with stones (WS task) using a three-dimensional position measurement system and then analyzed joint coordination. We empirically confirmed that the value of hand jerk and the variance in cup angle in the WW task were smaller than those in the WS task. We used uncontrolled manifold (UCM) analysis to quantify joint coordination corresponding to the motor synergy required to reduce the hand jerk and variance of the cup angle. UCM components, which did not affect the hand jerk and cup angle, were larger than orthogonal components, which directly affected the hand jerk and cup angle in the WW task. These results suggest that there is a coordinated control mechanism that reduces hand jerk and maintains a constant cup angle when carrying a cup filled with water without spilling it. In addition, we suggest that humans adopt a flexible and coordinated control strategy of allowing variance independent of the variables that should be controlled to achieve this dexterous task.

  6. 3D active workspace of human hand anatomical model

    Directory of Open Access Journals (Sweden)

    Ungureanu Loredana

    2007-05-01

    Full Text Available Abstract Background If the model of the human hand is created with accuracy by respecting the type of motion provided by each articulation and the dimensions of articulated bones, it can function as the real organ providing the same motions. Unfortunately, the human hand is hard to model due to its kinematical chains submitted to motion constraints. On the other hand, if an application does not impose a fine manipulation it is not necessary to create a model as complex as the human hand is. But always the hand model has to perform a certain space of motions in imposed workspace architecture no matter what the practical application does. Methods Based on Denavit-Hartenberg convention, we conceived the kinematical model of the human hand, having in mind the structure and the behavior of the natural model. We obtained the kinematical equations describing the motion of every fingertip with respect to the general coordinate system, placed on the wrist. For every joint variable, a range of motion was established. Dividing these joint variables to an appropriate number of intervals and connecting them, the complex surface bordering the active hand model workspace was obtained. Results Using MATLAB 7.0, the complex surface described by fingertips, when hand articulations are all simultaneously moving, was obtained. It can be seen that any point on surface has its own coordinates smaller than the maximum length of the middle finger in static position. Therefore, a sphere having the centre in the origin of the general coordinate system and the radius which equals this length covers the represented complex surface. Conclusion We propose a human hand model that represents a new solution compared to the existing ones. This model is capable to make special movements like power grip and dexterous manipulations. During them, the fingertips do not exceed the active workspace encapsulated by determined surfaces. The proposed kinematical model can help to choose

  7. Forearm posture and grip effects during push and pull tasks.

    Science.gov (United States)

    Di Domizio, Jennifer; Keir, Peter J

    2010-03-01

    Direction of loading and performance of multiple tasks have been shown to elevate muscle activity in the upper extremity. The purpose of this study was to evaluate the effects of gripping on muscle activity and applied force during pushing and pulling tasks with three forearm postures. Twelve volunteers performed five hand-based tasks in supinated, neutral and pronated forearm postures with the elbow at 90 degrees and upper arm vertical. All tasks were performed with the right (dominant) hand and included hand grip alone, push and pull with and without hand grip. Surface EMG from eight upper extremity muscles, hand grip force, tri-axial push and pull forces and wrist angles were recorded during the 10 s trials. The addition of a pull force to hand grip elevated activity in all forearm muscles (all p push with grip tasks, forearm extensor muscle activity tended to increase when compared with grip only while flexor activity tended to decrease. Forearm extensor muscle activity was higher with the forearm pronated compared with neutral and supinated postures during most isolated grip tasks and push or pull with grip tasks (all p push and pull forces could act to assist in creating grip force, forearm muscle activity generally decreased. These results provide strategies for reducing forearm muscle loading in the workplace. STATEMENT OF RELEVANCE: Tools and tasks designed to take advantage of coupling grip with push or pull actions may be beneficial in reducing stress and injury in the muscles of the forearm. These factors should be considered in assessing the workplace in terms of acute and cumulative loading.

  8. On the other hand: Increased cortical activation to human versus mechanical hands in infants.

    Science.gov (United States)

    Biondi, Marisa; Boas, David A; Wilcox, Teresa

    2016-11-01

    There is a large body of work demonstrating that infants are sensitive to the distinction between human and mechanical entities from the early months of life, and have different expectations for the way these entities move and interact. The current work investigates the extent to which the functional organization of the immature brain reflects these early emerging sensitivities. Infants aged 8months watched two kinds of hands (human or mechanical) engage in two kinds of events (one with a functional outcome and one without). Using functional near-infrared spectroscopy (fNIRS), we assessed hemodynamic activation in the left and right temporal and temporal-occipital cortex in response to these events. The neuroimaging data revealed a significantly greater increase in activation in the right middle-posterior temporal cortex to events executed by the human than the mechanical hand; the event in which the hand engaged (function or non-function) did not significantly influence hemodynamic responses. In comparison, the left middle-temporal cortex showed significantly greater activation to events executed by the human than mechanical hand, but only when the events were functionally relevant. That is, the left middle-posterior temporal cortex responded selectively to human (as compared to mechanical) agents, but only in the context of functionally relevant actions on objects. These results reveal that the immature brain is functionally specialized to support infants' processing of human and non-human agents as distinct entities. These results also shed light on the cognitive and cortical mechanisms that guide infants' learning about agentive action and object function.

  9. Human motor development and hand laterality: a kinematic analysis of drawing movements.

    Science.gov (United States)

    Blank, R; Miller, V; von Voss, H

    2000-12-08

    This study examines the developmental profiles of basic 'open-loop' drawing movements on the non-dominant hand (ND) in comparison with the dominant hand (D). Fifty-three right-handed children aged 7-14 years and 15 adults aged 27-43 years were examined. Each subject drew lines and circles of different sizes at maximum velocity with a pressure-sensitive pen on a computer graphics tablet. Small lines were drawn at 90 degrees to the axis of the forearm (lines using wrist movements (LWM)) and along the axis of the forearm (lines using elbow movements (LEM)). Larger lines were drawn at 90 degrees to the axis of the forearm (LEM). At both extremities, the movement frequencies of the proximally generated drawing movements increased in a parallel fashion at different levels. In LWM, the right-left-differences (RLD) were high in 7- to 8-year-old children; until puberty, the ND hand reached almost the performance of the D hand. In contrast, the RLD of the LFM increased at the same time. As adulthood approaches, frequencies of all drawings increased further while the LWM on the ND side remained stable. In adults, there were similar RLD for all line drawings involving predominantly flexion and extension movements. When drawing circles, the RLD were highest, though stable in all age groups. Hand laterality of pen use changes over time; these changes are dependent on complexity (combined/sequential cf. flexion-extension muscle activation) and on topography (proximal cf. distal movements). Distinct developmental profiles of motoneuronal populations of the cortex may be responsible for the distinct hand laterality effects and the decreasing variability of motor patterns. The drawing abilities and developmental changes on the untrained ND hand indicate that effector-specific practice plays a minor role.

  10. The effect of finger spreading on drag of the hand in human swimming

    CERN Document Server

    van Houwelingen, Josje; Kunnen, Rudie P J; van Heijst, GertJan F; Grift, Ernst Jan; Breugem, Wim Paul; Delfos, Rene; Westerweel, Jerry; Clercx, Herman J H; van de Water, Willem

    2016-01-01

    The effect of finger spreading on hydrodynamic drag in swimming is studied both with a numerical simulation and with laboratory experiments. Both approaches are based on the exact same 3D model of the hand with attached forearm. The virtual version of the hand with forearm was implemented in a numerical code by means of an immersed boundary method and the physical version was studied in a wind tunnel experiment. An enhancement of the drag coefficient of 2 and 5% compared to the case with closed fingers was found for the numerical simulation and experiment, respectively. A 5 and 8% favourable effect on the (dimensionless) force moment at an optimal finger spreading of 10 degrees was found, which indicates that the difference is more outspoken in the force moment. Also an analytical model is proposed, using scaling arguments similar to the Betz actuator disk model, to explain the drag coefficient as a function of finger spacing.

  11. Approaching human performance the functionality-driven Awiwi robot hand

    CERN Document Server

    Grebenstein, Markus

    2014-01-01

    Humanoid robotics have made remarkable progress since the dawn of robotics. So why don't we have humanoid robot assistants in day-to-day life yet? This book analyzes the keys to building a successful humanoid robot for field robotics, where collisions become an unavoidable part of the game. The author argues that the design goal should be real anthropomorphism, as opposed to mere human-like appearance. He deduces three major characteristics to aim for when designing a humanoid robot, particularly robot hands: _ Robustness against impacts _ Fast dynamics _ Human-like grasping and manipulation performance   Instead of blindly copying human anatomy, this book opts for a holistic design me-tho-do-lo-gy. It analyzes human hands and existing robot hands to elucidate the important functionalities that are the building blocks toward these necessary characteristics.They are the keys to designing an anthropomorphic robot hand, as illustrated in the high performance anthropomorphic Awiwi Hand presented in this book.  ...

  12. Inverse Kinematic Analysis of Human Hand Thumb Model

    Science.gov (United States)

    Toth-Tascau, Mirela; Pater, Flavius; Stoia, Dan Ioan; Menyhardt, Karoly; Rosu, Serban; Rusu, Lucian; Vigaru, Cosmina

    2011-09-01

    This paper deals with a kinematic model of the thumb of the human hand. The proposed model has 3 degrees of freedom being able to model the movements of the thumb tip with respect to the wrist joint centre. The kinematic equations are derived based on Denavit-Hartenberg Convention and solved in both direct and inverse way. Inverse kinematic analysis of human hand thumb model reveals multiple and connected solutions which are characteristic to nonlinear systems when the number of equations is greater than number of unknowns and correspond to natural movements of the finger.

  13. Human Hand Motion Analysis and Synthesis of Optimal Power Grasps for a Robotic Hand

    Directory of Open Access Journals (Sweden)

    Francesca Cordella

    2014-03-01

    and experimental trials on an arm-hand robotic system. The obtained results have shown the effectiveness of the extracted indicators to reduce the non-linear optimization problem complexity and lead to the synthesis of a grasping posture able to replicate the human behaviour while ensuring grasp stability. The experimental results have also highlighted the limitations of the adopted robotic platform (mainly due to the mechanical structure to achieve the optimal grasp configuration.

  14. Osteomyelitis and septic arthritis of the hand following human bites

    Energy Technology Data Exchange (ETDEWEB)

    Resnick, D.; Kerr, R.; Pineda, C.J.; Weisman, M.H.

    1985-10-01

    The spectrum of radiographic abnormalities accompanying bone and joint infection that results from human bites of the hand is presented in an analysis of 13 patients. Features include mono-articular involvement, predilection for a metacarpophalangeal joint, soft tissue swelling, joint space narrowing, bone erosions and periostitis. Magnification techniques may be required for early and accurate diagnosis. (orig.).

  15. Anthropomorphic Robot Hand And Teaching Glove

    Science.gov (United States)

    Engler, Charles D., Jr.

    1991-01-01

    Robotic forearm-and-hand assembly manipulates objects by performing wrist and hand motions with nearly human grasping ability and dexterity. Imitates hand motions of human operator who controls robot in real time by programming via exoskeletal "teaching glove". Telemanipulator systems based on this robotic-hand concept useful where humanlike dexterity required. Underwater, high-radiation, vacuum, hot, cold, toxic, or inhospitable environments potential application sites. Particularly suited to assisting astronauts on space station in safely executing unexpected tasks requiring greater dexterity than standard gripper.

  16. Dissociable neural responses to hands and non-hand body parts in human left extrastriate visual cortex.

    Science.gov (United States)

    Bracci, Stefania; Ietswaart, Magdalena; Peelen, Marius V; Cavina-Pratesi, Cristiana

    2010-06-01

    Accumulating evidence points to a map of visual regions encoding specific categories of objects. For example, a region in the human extrastriate visual cortex, the extrastriate body area (EBA), has been implicated in the visual processing of bodies and body parts. Although in the monkey, neurons selective for hands have been reported, in humans it is unclear whether areas selective for individual body parts such as the hand exist. Here, we conducted two functional MRI experiments to test for hand-preferring responses in the human extrastriate visual cortex. We found evidence for a hand-preferring region in left lateral occipitotemporal cortex in all 14 participants. This region, located in the lateral occipital sulcus, partially overlapped with left EBA, but could be functionally and anatomically dissociated from it. In experiment 2, we further investigated the functional profile of hand- and body-preferring regions by measuring responses to hands, fingers, feet, assorted body parts (arms, legs, torsos), and non-biological handlike stimuli such as robotic hands. The hand-preferring region responded most strongly to hands, followed by robotic hands, fingers, and feet, whereas its response to assorted body parts did not significantly differ from baseline. By contrast, EBA responded most strongly to body parts, followed by hands and feet, and did not significantly respond to robotic hands or fingers. Together, these results provide evidence for a representation of the hand in extrastriate visual cortex that is distinct from the representation of other body parts.

  17. Forearm Fractures in Children

    Science.gov (United States)

    ... secure them in place. Your doctor may recommend surgery if: Casts support and protect broken bones while they heal. Reproduced from Pring M, Chambers H: Pediatric forearm fractures. Orthopaedic Knowledge Online Journal 2007; 5(5). Accessed October 2014. • The bone ...

  18. Empirical modelling of the dynamic response of fatigue during intermittent submaximal contractions of human forearm and calf muscles.

    Science.gov (United States)

    Green, Simon; Stefanovic, Brad; Warman, Joel; Askew, Christopher D

    2015-02-01

    Maximum force (Fmax) declines during intermittent submaximal contractions, but the linearity of this fatigue response and number of underlying phases is not clear. Healthy men were studied during two experiments (n=10 each). Experiment 1 involved single bouts of intermittent forearm contractions (50% Fmax) to failure using both limbs assigned as Armcontrol or Armtraining. Experiment 2 involved five bouts of intermittent calf contractions (60% Fmax) to failure using the same limb where data from the longest single trial (Calfsingle) or averaged across five bouts (Calfaveraged) were analysed. Fmax was assessed at 25-30s intervals during exercise and fitted to ten mono- and biphasic functions consisting of linear and/or nonlinear terms. For each fatigue response, the function which provided the best fit was determined on statistical grounds. Biphasic functions provided the majority of best fits during Armcontrol (9/10), Armtraining (10/10), Calfsingle (7/10) and Calfaveraged (9/10). For each condition, linear functions provided the best fit in 4-5 out of 10 responses. Two biphasic functions differentiated only by their first term (linear versus exponential) provided the best fit for 29/40 fatigue responses. These outcomes suggest that fatigue during intermittent contractions exhibits a biphasic response characterised by nonlinear and linear behaviour.

  19. Validation of measurement protocols to assess oxygen consumption and blood flow in the human forearm by near-infrared spectroscopy

    Science.gov (United States)

    Van Beekvelt, Mireille C. P.; Colier, Willy N.; van Engelen, Baziel G. M.; Hopman, Maria T. E.; Wevers, Ron A.; Oeseburg, Berend

    1998-01-01

    Near infrared spectroscopy (NIRS) has been used to monitor oxygenation changes in muscle. Quantitative values for O2 consumption, blood flow and venous saturation have been reported by several investigators. The amount of these measurements is, however, still limited and complete validation has not yet been established. The aim of this study was to investigate the different NIRS methods to calculate O2 consumption (VO2) and forearm blood flow (FBF) and to validate the data with the accepted method of strain-gauge plethysmography and blood sampling. Thirteen subjects were tested in rest and during static isometric handgrip exercise at 10% MVC. The NIRS optodes were positioned on the flexor region of the arm. A significant correlation was found between plethysmograph data and NIRS [tHb] during venous occlusion in rest (r EQ 0.925 - 0.994, P exercise (r equals 0.895 - 0.990, P exercise. It seems that although NIRS is a good qualitative monitoring technique, quantification is difficult due to the great variability that is found between the subjects.

  20. X-Ray Exam: Forearm

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Forearm KidsHealth > For Parents > X-Ray Exam: Forearm A A A What's in ... español Radiografía: brazo What It Is A forearm X-ray is a safe and painless test that ...

  1. Long-lasting modulation of human motor cortex following prolonged transcutaneous electrical nerve stimulation (TENS) of forearm muscles: evidence of reciprocal inhibition and facilitation.

    Science.gov (United States)

    Tinazzi, Michele; Zarattini, Stefano; Valeriani, Massimiliano; Romito, Silvia; Farina, Simona; Moretto, Giuseppe; Smania, Nicola; Fiaschi, Antonio; Abbruzzese, Giovanni

    2005-03-01

    Several lines of evidence indicate that motor cortex excitability can be modulated by manipulation of afferent inputs, like peripheral electrical stimulation. Most studies in humans mainly dealt with the effects of prolonged low-frequency peripheral nerve stimulation on motor cortical excitability, despite its being known from animal studies that high-frequency stimulation can also result in changes of the cortical excitability. To investigate the possible effects of high-frequency peripheral stimulation on motor cortical excitability we recorded motor-evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) of the left motor cortex from the right flexor carpi radialis (FCR), extensor carpi radialis (ECR), and first dorsal interosseous (FDI) in normal subjects, before and after transcutaneous electrical nerve stimulation (TENS) of 30 min duration applied over the FCR. The amplitude of MEPs from the FRC was significantly reduced from 10 to 35 min after TENS while the amplitude of MEPs from ECR was increased. No effects were observed in the FDI muscle. Indices of peripheral nerve (M-wave) and spinal cord excitability (H waves) did not change throughout the experiment. Electrical stimulation of the lateral antebrachial cutaneous nerve has no significant effect on motor cortex excitability. These findings suggest that TENS of forearm muscles can induce transient reciprocal inhibitory and facilitatory changes in corticomotoneuronal excitability of forearm flexor and extensor muscles lasting several minutes. These changes probably may occur at cortical site and seem to be mainly dependent on stimulation of muscle afferents. These findings might eventually lead to practical applications in rehabilitation, especially in those syndromes in which the excitatory and inhibitory balance between agonist and antagonist is severely impaired, such as spasticity and dystonia.

  2. Flexor digitorum profundus tendon anatomy in the forearm

    Directory of Open Access Journals (Sweden)

    Teoman Dogan

    2012-04-01

    Methods: We used 11 forearms belonging to cadavers and fixed with formaldehyde. The forearms numbered 1, 2, 8, 9, 10, 11 were the left and right arms of the same cadavers. Those numbered 3, 4, 5, 6, 7 belonged to different cadavers. Dissections were made by using the atraumatic surgical technique. The tendons were studied to identify the structure and number of the fibers forming them. Results: The presence of a large common tendon was found in 10 of the 11 forearms. In 4 of these, the common tendon included the tendons of all four fingers. While the common tendon included 3 fingers in four forearms, it only included tendons belonging to 2 fingers in two forearms. It was not possible in one forearm to separate the common tendon into its fibers. In another forearm, tendons belonging to each digit were separate and independent starting at the muscle-tendon junction to the attachment points. Conclusion: The majority of the cadaver forearms used in the study displayed a single large FDP tendon in the zone between the muscle-tendon joint to the carpal tunnel entry prior to being distributed into each index. This anatomical feature should be considered in choosing materials and surgical technique for Zone V FDP tendon injuries, as well as in planning the rehabilitation process. [Hand Microsurg 2012; 1(1.000: 25-29

  3. Acute compartment syndrome of forearm and hand

    Science.gov (United States)

    Chandraprakasam, T.; Kumar, R. Ashok

    2011-01-01

    The diagnosis and treatment of the acute compartment syndrome is of paramount importance. Unless the viscious cycle is intervened at an appropriately early time it will result in irreversible damage leading to disability. In this review article we are discussing the basic pathophysiological process through which the various aetiological factors causing increased compartmental pressure lead to the progressive death of muscles and nerves. We also discuss the various clinical features that aid in the diagnosis and the role of intracompartmental pressure measurements. Finally we hope to ascertain the basic principles and the surgical techniques for treating this condition effectively. PMID:22022031

  4. The concomitant presence of two anomalous muscles in the forearm.

    Science.gov (United States)

    Ogun, Tunç Cevat; Karalezli, Nazim; Ogun, Cemile Oztin

    2007-09-01

    This article describes the concomitant presence of two anomalous forearm muscles in a 20-year-old man, discovered accidentally during an operation for a forearm injury. The first one was similar to a reverse palmaris longus muscle except for its direction to the Guyon's canal. The second one originated from the radial antebrachial fascia, superficial to all other forearm muscles in the lower half of the forearm, then diverged medially and extended into the Guyon's canal and was innervated by the ulnar nerve. The patient had no symptoms related to overcrowding of the Guyon's canal before the injury. A hand surgeon should be well informed about the anatomic variations of the hand to be comfortable during surgical practice.

  5. Visual Interpretation Of Hand Gestures For Human Computer Interaction

    Directory of Open Access Journals (Sweden)

    M.S.Sahane

    2014-01-01

    Full Text Available The use of hand gestures provides an attractive alternative to cumbersome interface devices for human-computer interaction (HCI. In particular, visual interpretation of hand gestures can help in achieving the ease and naturalness desired for HCI. This discussion is organized on the basis of the method used for modeling, analyzing, and recognizing gestures. We propose pointing gesture-based large display interaction using a depth camera. A user interacts with applications for large display by using pointing gestures with the barehand. The calibration between large display and depth camera can be automatically performed by using RGB-D camera.. We also discuss implemented gestural systems as well as other potential applications of vision-based gesture recognition. We discuss directions of future research in gesture recognition, including its integration with other natural modes of human computer interaction.

  6. Eye-Hand-Mouth Coordination in the Human Newborn.

    Science.gov (United States)

    Futagi, Yasuyuki

    2017-10-01

    There have been several studies concerning rudimentary coordination of the eyes, hands, and mouth in the human newborn. The author attempted to clarify the ontogenetic significance of the coordination during the earliest period of human life through a systematic review. The neural mechanism underlying the coordination was also discussed based on the current knowledge of cognitive neuroscience. Searches were conducted on PubMed and Google Scholar from their inception through March 2017. Studies have demonstrated that the coordination is a visually guided goal-directed motor behavior with intension and emotion. Current cognitive research has proved that feeding requires a large-scale neural network extending over several cortices. The eye-hand-mouth coordination in the newborn can be regarded as a precursor of subsequent self-feeding, and the coordination is very likely mediated through the underdeveloped but essentially the same network interconnecting cortices as in the adult. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Rotationally Actuated Prosthetic Hand

    Science.gov (United States)

    Norton, William E.; Belcher, Jewell G., Jr.; Carden, James R.; Vest, Thomas W.

    1991-01-01

    Prosthetic hand attached to end of remaining part of forearm and to upper arm just above elbow. Pincerlike fingers pushed apart to degree depending on rotation of forearm. Simpler in design, simpler to operate, weighs less, and takes up less space.

  8. Hands-free human-machine interaction with voice

    Science.gov (United States)

    Juang, B. H.

    2001-05-01

    Voice is natural communication interface between a human and a machine. The machine, when placed in today's communication networks, may be configured to provide automation to save substantial operating cost, as demonstrated in AT&T's VRCP (Voice Recognition Call Processing), or to facilitate intelligent services, such as virtual personal assistants, to enhance individual productivity. These intelligent services often need to be accessible anytime, anywhere (e.g., in cars when the user is in a hands-busy-eyes-busy situation or during meetings where constantly talking to a microphone is either undersirable or impossible), and thus call for advanced signal processing and automatic speech recognition techniques which support what we call ``hands-free'' human-machine communication. These techniques entail a broad spectrum of technical ideas, ranging from use of directional microphones and acoustic echo cancellatiion to robust speech recognition. In this talk, we highlight a number of key techniques that were developed for hands-free human-machine communication in the mid-1990s after Bell Labs became a unit of Lucent Technologies. A video clip will be played to demonstrate the accomplishement.

  9. Human-like Compliance for Dexterous Robot Hands

    Science.gov (United States)

    Jau, Bruno M.

    1995-01-01

    This paper describes the Active Electromechanical Compliance (AEC) system that was developed for the Jau-JPL anthropomorphic robot. The AEC system imitates the functionality of the human muscle's secondary function, which is to control the joint's stiffness: AEC is implemented through servo controlling the joint drive train's stiffness. The control strategy, controlling compliant joints in teleoperation, is described. It enables automatic hybrid position and force control through utilizing sensory feedback from joint and compliance sensors. This compliant control strategy is adaptable for autonomous robot control as well. Active compliance enables dual arm manipulations, human-like soft grasping by the robot hand, and opens the way to many new robotics applications.

  10. Color-Removal by Microorganisms Isolated from Human Hands

    Directory of Open Access Journals (Sweden)

    Tsukasa Ito

    2013-08-01

    Full Text Available Microorganisms are essential for human life. Microorganisms decompose the carbon compounds in dead animals and plants and convert them into carbon dioxide. Intestinal bacteria assist in food digestion. Some vitamins are produced by bacteria that live in the intestines. Sewage and industrial wastewater are treated by activated sludge composed of microbial communities. All of these are due to the ability of microbes to produce many enzymes that can degrade chemicals. How do teachers make students understand that microorganisms are always associated with humans, and that microorganisms have the ability to degrade chemicals? The presence of microorganisms on humans can be shown by incubating agar plates after they are touched by the hands of students. The ability of microorganisms to degrade chemicals can be shown by an analytical measurement of the degradation of chemicals. When the chemicals are dyes (colorants in water, microbial activity on degradation of dyes can be demonstrated by observing a decreasing degree of color as a result of the enzymatic activity (e.g., azoreductase. Dyes are widely used in the textile, food, and cosmetic industries. They are generally resistant to conventional biological wastewater treatment systems such as the activated sludge process (4. The discharge of wastewater containing dye pollutes surface water. The ability of microorganisms to decolorize and degrade dyes has been widely investigated to use for bioremediation purposes (5. The goal of this tip is to understand the presence of bacteria on human skin and the ability of bacteria to degrade colorant chemicals (decolorization. In this tip, students first cultivate and isolate bacteria on their hands, and then examine potential decolorization activity of each bacterium by observing the degree of color of the liquid in tubes in which bacteria isolated from students’ hands were inoculated. Decolorization activity of bacterial isolates from human skin has been

  11. Developing a computational model of human hand kinetics using AVS

    Energy Technology Data Exchange (ETDEWEB)

    Abramowitz, Mark S. [State Univ. of New York, Binghamton, NY (United States)

    1996-05-01

    As part of an ongoing effort to develop a finite element model of the human hand at the Institute for Scientific Computing Research (ISCR), this project extended existing computational tools for analyzing and visualizing hand kinetics. These tools employ a commercial, scientific visualization package called AVS. FORTRAN and C code, originally written by David Giurintano of the Gillis W. Long Hansen`s Disease Center, was ported to a different computing platform, debugged, and documented. Usability features were added and the code was made more modular and readable. When the code is used to visualize bone movement and tendon paths for the thumb, graphical output is consistent with expected results. However, numerical values for forces and moments at the thumb joints do not yet appear to be accurate enough to be included in ISCR`s finite element model. Future work includes debugging the parts of the code that calculate forces and moments and verifying the correctness of these values.

  12. A computational model of the human hand 93-ERI-053

    Energy Technology Data Exchange (ETDEWEB)

    Hollerbach, K.; Axelrod, T.

    1996-03-01

    The objectives of the Computational Hand Modeling project were to prove the feasibility of the Laboratory`s NIKE3D finite element code to orthopaedic problems. Because of the great complexity of anatomical structures and the nonlinearity of their behavior, we have focused on a subset of joints of the hand and lower extremity and have developed algorithms to model their behavior. The algorithms developed here solve fundamental problems in computational biomechanics and can be expanded to describe any other joints of the human body. This kind of computational modeling has never successfully been attempted before, due in part to a lack of biomaterials data and a lack of computational resources. With the computational resources available at the National Laboratories and the collaborative relationships we have established with experimental and other modeling laboratories, we have been in a position to pursue our innovative approach to biomechanical and orthopedic modeling.

  13. Annexin A5 scintigraphy of forearm as a novel in vivo model of skeletal muscle preconditioning in humans.

    NARCIS (Netherlands)

    Rongen, G.A.; Oyen, W.J.G.; Ramakers, B.P.; Riksen, N.P.; Boerman, O.C.; Steinmetz, N.; Smits, P.

    2005-01-01

    BACKGROUND: Nonlethal ischemia and reperfusion reduce ischemia-reperfusion-induced cell death, a phenomenon called ischemic preconditioning. In animal models, this potent endogenous protection is mimicked in vivo by administration of adenosine. In humans, exploitation of ischemic preconditioning is

  14. [Expanded pedicled forearm flap for reconstruction of multiple finger amputations].

    Science.gov (United States)

    Alvarez Jorge, A; Martelo Villar, F

    2000-05-01

    Soft-tissue injuries of the hand frequently require flap coverage to preserve structures damaged at the time of injury or to facilitate later reconstruction. The radial forearm flap makes local tissue readily available and offers a simple method of reconstruction. Secondary augmentation of the skin flap by means of tissue expansion appears to be a useful alternative to improve the possibilities of reconstruction. This case report describes a primary reconstruction of a hand with multiple finger amputations using both techniques: Forearm flap and tissue expansion.

  15. Hand Gesture and Neural Network Based Human Computer Interface

    Directory of Open Access Journals (Sweden)

    Aekta Patel

    2014-06-01

    Full Text Available Computer is used by every people either at their work or at home. Our aim is to make computers that can understand human language and can develop a user friendly human computer interfaces (HCI. Human gestures are perceived by vision. The research is for determining human gestures to create an HCI. Coding of these gestures into machine language demands a complex programming algorithm. In this project, We have first detected, recognized and pre-processing the hand gestures by using General Method of recognition. Then We have found the recognized image’s properties and using this, mouse movement, click and VLC Media player controlling are done. After that we have done all these functions thing using neural network technique and compared with General recognition method. From this we can conclude that neural network technique is better than General Method of recognition. In this, I have shown the results based on neural network technique and comparison between neural network method & general method.

  16. Individual left-hand and right-hand intra-digit representations in human primary somatosensory cortex.

    Science.gov (United States)

    Schweisfurth, Meike A; Frahm, Jens; Schweizer, Renate

    2015-09-01

    Individual intra-digit somatotopy of all phalanges of the middle and little finger of the right and left hand was studied by functional magnetic resonance imaging in 12 healthy subjects. Phalanges were tactilely stimulated and activation in BA 3b of the human primary somatosensory cortex could be observed for each individual phalanx. Activation peaks were further analysed using the Direction/Order (DiOr) method, which identifies somatotopy, if a significantly high number of subjects exhibit ordered distal-to-proximal phalanx representions along a similar direction. Based on DiOr, ordered and similar-direction-aligned intra-digit maps across subjects were found at the left hand for the little and middle finger and at the right hand for the little finger. In these digits the proximal phalanges were represented more medially along the course of the central sulcus than the distal phalanges. This is contrasted by the intra-digit maps for the middle finger of the right hand, which showed larger inter-subject variations of phalanx alignments without a similar within-digit representation across subjects. As all subjects were right-handed and as the middle finger of the dominant hand probably plays a more individual role in everyday tactile performance than the little finger of the right hand and all left-hand digits, the observed variation might reflect a functional somatotopy based on individual use of that particular digit at the dominant hand.

  17. Adaptation or exaptation? The case of the human hand

    Indian Academy of Sciences (India)

    Marta Linde-Medina

    2011-09-01

    A controversy of relevance to the study of biological form involves the concept of adaptation. This controversy is illustrated by the structure and function of the human hand. A review of the principal definitions of adaptation points to two main problems: (1) they are qualitative and make reference to the whole structure (or substructural feature) and (2) they are based on the idea of natural selection as a moulding factor. The first problem would be solved by a definition that encompasses quantitative measures of the effects of selection, drawing on new advances in the comparative method. The second problem is deeper and presents greater conceptual difficulties. I will argue that the idea of natural selection as a moulding factor depends on the notion of a genetic program for development. But regarding the hand, experimental evidence on limb development challenges the idea of a genetic program for skeletal pattern formation, undermining a simple application of standard adaptationist concepts. These considerations lead to a revised definition of adaptation and interpretation of the evolutionary determinants of the hand’s form.

  18. A reconstructed digit by transplantation of a second toe for control of an electromechanical prosthetic hand.

    Science.gov (United States)

    Chen, Zhong Wei; Hu, Tian Pei

    2002-01-01

    The treatment options for the loss of an entire human hand and part of the forearm are currently limited to the transplantation of toe(s) to the amputation stump or a Krukenberg's bifurcation hand, and using a cosmetic or functional prosthesis. The functional prosthetic hand, such as the prevailing myoelectrically controlled prosthetic hand, has an action accuracy that is affected by many factors. The acceptance rate of the three planes freedom myoelectronic hand by the patients was 46-90% because of poor function caused by the weakness of signal and strong external interference. In this report, the left second toe was transplanted to the patient's forearm amputation stump. Mandates from the brain are relayed by the action of this reconstructed digit, to control a special designed multidimension freedom electronic prosthetic hand. After rehabilitation and adaptation training, the correct recognition rate of the electronic prosthetic hand controlled by this reconstructed digit is a remarkable 100%.

  19. An EMG Keyboard for Forearm Amputees

    Directory of Open Access Journals (Sweden)

    Wenwei Yu

    2003-01-01

    Full Text Available A high-efficiency, easy-to-use input device is not only important for data entry but also for human-computer interaction. To date, there has been little research on input devices with many degrees of freedom (DOF that can be used by the handicapped. This paper presents the development of an electromyography (EMG-based input device for forearm amputees. To overcome the difficulties in analysing EMG and realising high DOF from biosignals, the following were integrated: (1 an online learning method to cope with nonlinearity and the individual difference of EMG signals; (2 a smoothing algorithm to deal with noisy recognition results and transition states; and (3 a modified Huffman coding algorithm to generate the optimal code, taking expected error and input efficiency into consideration. Experiments showed the validity of the system and the possibility for development of a quiet, free-posture (no postural restriction input device with many DOF for users, including forearm amputees.

  20. A study of retrograde degeneration of median nerve forearm ...

    African Journals Online (AJOL)

    Mona Mokhtar El Bardawil

    2013-10-22

    Oct 22, 2013 ... forearm segment in patients with CTS and its relation to variable severity of CTS in Egyptian patients. Patients ... Retrograde degeneration is not related to grade of severity of CTS. .... dominant hand using NEUROPACK 2 Electroneuromyog- ... was evaluated using Fisher Exact and Monte Carlo test.18,19.

  1. Features of hand-foot crawling behavior in human adults.

    Science.gov (United States)

    Maclellan, M J; Ivanenko, Y P; Cappellini, G; Sylos Labini, F; Lacquaniti, F

    2012-01-01

    Interlimb coordination of crawling kinematics in humans shares features with other primates and nonprimate quadrupeds, and it has been suggested that this is due to a similar organization of the locomotor pattern generators (CPGs). To extend the previous findings and to further explore the neural control of bipedal vs. quadrupedal locomotion, we used a crawling paradigm in which healthy adults crawled on their hands and feet at different speeds and at different surface inclinations (13°, 27°, and 35°). Ground reaction forces, limb kinematics, and electromyographic (EMG) activity from 26 upper and lower limb muscles on the right side of the body were collected. The EMG activity was mapped onto the spinal cord in approximate rostrocaudal locations of the motoneuron pools to characterize the general features of cervical and lumbosacral spinal cord activation. The spatiotemporal pattern of spinal cord activity significantly differed between quadrupedal and bipedal gaits. In addition, participants exhibited a large range of kinematic coordination styles (diagonal vs. lateral patterns), which is in contrast to the stereotypical kinematics of upright bipedal walking, suggesting flexible coupling of cervical and lumbosacral pattern generators. Results showed strikingly dissimilar directional horizontal forces for the arms and legs, considerably retracted average leg orientation, and substantially smaller sacral vs. lumbar motoneuron activity compared with quadrupedal gait in animals. A gradual transition to a more vertical body orientation (increasing the inclination of the treadmill) led to the appearance of more prominent sacral activity (related to activation of ankle plantar flexors), typical of bipedal walking. The findings highlight the reorganization and adaptation of CPG networks involved in the control of quadrupedal human locomotion and a high specialization of the musculoskeletal apparatus to specific gaits.

  2. Teleoperator hand controllers: A contextual human factors assessment

    Energy Technology Data Exchange (ETDEWEB)

    Draper, J.V.

    1994-05-01

    This document provides a human factors assessment of controllers for use with remotely controlled manipulators deployed to remove hazardous waste from underground storage tanks. The analysis concentrates on controller technique (i.e., the broad class of hand controller) and not on details of controller ergonomics. Examples of controller techniques include, for example, direct rate control, resolved unilateral position control, and direct bilateral position control. Using an existing concept, the Tank Waste Retrieval Manipulator System, as a reference, two basic types of manipulators may be identified for this application. A long reach, gross-positioning manipulator (LRM) may be used to position a smaller manipulator or an end-effector within a work site. For a Long Reach Manipulator, which will have an enormous motion range and be capable of high end-effector velocity, it will be safest and most efficient to use a resolved rate control system. A smaller, dexterous manipulator may be used to perform handling work within a relatively small work site, (i.e., to complete tasks requiring near-human dexterity). For a Dexterous Manipulator, which will have a smaller motion range than the LRM and be required to perform more difficult tasks, a resolved bilateral position control system will be safest and most efficient. However, during some waste recovery tasks it may be important to support the users by restricting movements to a single plane or axis. This can be done with a resolved bilateral position control system by (1) using the master controller force output to restrict controller inputs or (2) switching the controller to a multiaxis rate control mode and using the force output to provide a spring return to center functionality.

  3. Cerebral reorganisation of human hand movement following dynamic immobilisation

    NARCIS (Netherlands)

    de Jong, BM; Coert, JH; Stenekes, MW; Leenders, KL; Paans, AMJ; Nicolai, JRA

    2003-01-01

    Surgical treatment of a flexor tendon lesion of the hand is followed by a 6-week period of dynamic immobilisation. This is achieved by the elastic strings of a Kleinert splint, enabling only passive and no active flexor movements. After such immobilisation, the appearance of a temporary clumsy hand

  4. The resonant component of human physiological hand tremor is altered by slow voluntary movements.

    Science.gov (United States)

    Lakie, Martin; Vernooij, Carlijn A; Osborne, Timothy M; Reynolds, Raymond F

    2012-05-15

    Limb resonance imparts a characteristic spectrum to hand tremor. Movement will alter the resonance. We have examined the consequences of this change. Rectified forearm extensor muscle EMG and physiological hand tremor were recorded. In postural conditions the EMG spectrum is relatively flat whereas the acceleration spectrum is sharply peaked. Consequently, the gain between EMG and acceleration is maximal at the frequency where the tremor is largest (∼8 Hz). The shape of the gain curve implies mechanical resonance. Substantial alterations in posture do not significantly change the characteristics of the tremor or the shape or size of the gain curve. By contrast, slow or moderately paced voluntary wrist flexion–extension movements dramatically increase the hand tremor size and lower its peak frequency. These changes in size and frequency of the tremor cannot be attributed to changes in the EMG. Instead they reflect a very large change in the size and shape of the gain curve relating EMG to acceleration. The gain becomes larger and the peak moves to a lower frequency (∼6 Hz). We suggest that a movement-related (thixotropic) alteration in resonant properties of the wrist provides a simple explanation for these changes. The mechanism is illustrated by a model. Our new findings confirm that resonance plays a major role in wrist tremor. We also demonstrate that muscles operate very differently under postural and dynamic conditions. The different coupling between EMG and movement in posture and when moving must pose a considerable challenge for neural predictive control of skeletal muscles.

  5. Centre-surround organization of fast sensorimotor integration in human motor hand area

    DEFF Research Database (Denmark)

    Dubbioso, Raffaele; Raffin, Estelle; Karabanov, Anke

    2017-01-01

    Using the short-latency afferent inhibition (SAI) paradigm, transcranial magnetic stimulation (TMS) of the primary motor hand area (M1HAND) can probe how sensory input from limbs modulates corticomotor output in humans. Here we applied a novel TMS mapping approach to chart the spatial representat...... in M1HAND. Like homotopic SAI, heterotopic SAF was somatotopically expressed in M1HAND. Together, the results provide first-time evidence that fast sensorimotor integration involves centre-inhibition and surround-facilitation in human M1HAND....

  6. Reorganization of human motor cortex after hand replantation.

    Science.gov (United States)

    Röricht, S; Machetanz, J; Irlbacher, K; Niehaus, L; Biemer, E; Meyer, B U

    2001-08-01

    In 10 patients, reorganizational changes of the motor cortex contralateral to a replanted hand (MCreplant) were studied one to 14 years after complete traumatic amputation and consecutive successful replantation of the hand. The organizational state of MCreplant was assessed for the deafferentated and peripherally deefferentated hand-associated motor cortex and the adjacent motor representation of the proximal arm. For this, response maps were established for the first dorsal interosseus and biceps brachii muscle using focal transcranial magnetic stimulation (TMS) on a skull surface grid. Characteristics of the maps were center of gravity (COG), number of effective stimulation sites, amplitude sum, and amplitudes and response threshold at the optimal stimulation point. The COG is defined by the spatial distribution of response amplitudes on the map and lies over the cortex region with the most excitable corticospinal neurones supplying the recorded muscle. The COG of the biceps map in MCreplant was shifted laterally by 9.8 +/- 3.6 mm (range 5.0-15.7 mm). The extension of the biceps map in MCreplant was increased and the responses were enlarged and had lowered thresholds. For the muscles of the replanted hand, the pattern of reorganization was different: Response amplitudes were enlarged but thresholds, COG, and area of the cortical response map were normal. The different reorganizational phenomena observed for the motor cortical areas supplying the replanted hand and the biceps brachii of the same arm may be influenced by a different extent of deafferentation and by their different role in hand motor control.

  7. Optical Myography: Detecting Finger Movements by Looking at the Forearm

    Directory of Open Access Journals (Sweden)

    Christian eNissler

    2016-04-01

    Full Text Available One of the crucial problems found in the scientific community of assistive / rehabilitation robotics nowadays is that of automatically detecting what a disabled subject (for instance, a hand amputee wants to do, exactly when she wants to do it and strictly for the time she wants to do it. This problem, commonly called intent detection, has traditionally been tackled using surface electromyography, a technique which suffers from a number of drawbacks, including the changes in the signal induced by sweat and muscle fatigue. With the advent of realistic, physically plausible augmented- and virtual-reality environments for rehabilitation, this approach does not suffice anymore. In this paper we explore a novel method to solve the problem, that we call Optical Myography (OMG. The idea is to visually inspect the human forearm (or stump to reconstruct what fingers are moving and to what extent. In a psychophysical experiment involving ten intact subjects, we used visual fiducial markers (AprilTags and a standard web-camera to visualize the deformations of the surface of the forearm, which then were mapped to the intended finger motions. As ground truth, a visual stimulus was used, avoiding the need for finger sensors (force/position sensors, datagloves, etc.. Two machine-learning approaches, a linear and a non-linear one, were comparatively tested in settings of increasing realism. The results indicate an average error in the range of 0.05 to 0.22 (root mean square error normalized over the signal range, in line with similar results obtained with more mature techniques such as electromyography. If further successfully tested in the large, this approach could lead to vision-based intent detection of amputees, with the main application of letting such disabled persons dexterously and reliably interact in an augmented- / virtual-reality setup.

  8. Quantity of ethanol absorption after excessive hand disinfection using three commercially available hand rubs is minimal and below toxic levels for humans

    OpenAIRE

    Toma Cyril D; Kampf Guenter; Bieber Nora; Below Harald; Kramer Axel; Huebner Nils-Olaf; Assadian Ojan

    2007-01-01

    Abstract Background Despite the increasing promotion of alcohol-based hand rubs and the worldwide use of ethanol-based hand rubs in hospitals only few studies have specifically addressed the issue of ethanol absorption when repeatedly applied to human skin. The aim of this study was to assess if ethanol absorption occurs during hygienic and surgical hand disinfection using three different alcohol-based hand-rubs, and to quantify absorption levels in humans. Methods Twelve volunteers applied t...

  9. Reorganization of the Human Somatosensory Cortex in Hand Dystonia

    Directory of Open Access Journals (Sweden)

    Maria Jose Catalan

    2012-05-01

    Full Text Available Background and Purpose: Abnormalities of finger representations in the somatosensory cortex have been identified in patients with focal hand dystonia. Measuring blood flow with positron emission tomography (PET can be use to demonstrate functional localization of receptive fields. Methods: A vibratory stimulus was applied to the right thumb and little finger of six healthy volunteers and six patients with focal hand dystonia to map their receptive fields using H215O PET. Results: The cortical finger representations in the primary somatosensory cortex were closer to each other in patients than in normal subjects. No abnormalities were found in secondary somatosensory cortex, but the somatotopy there is less well distinguished. Conclusions: These data confirm prior electrophysiological and functional neuroimaging observations showing abnormalities of finger representations in somatosensory cortex of patients with focal hand dystonia.

  10. Evidence-based Comprehensive Approach to Forearm Arterial Laceration

    Directory of Open Access Journals (Sweden)

    Janice N. Thai

    2015-12-01

    Full Text Available Introduction: Penetrating injury to the forearm may cause an isolated radial or ulnar artery injury, or a complex injury involving other structures including veins, tendons and nerves. The management of forearm laceration with arterial injury involves both operative and nonoperative strategies. An evolution in management has emerged especially at urban trauma centers, where the multidisciplinary resource of trauma and hand subspecialties may invoke controversy pertaining to the optimal management of such injuries. The objective of this review was to provide an evidence-based, systematic, operative and nonoperative approach to the management of isolated and complex forearm lacerations. A comprehensive search of MedLine, Cochrane Library, Embase and the National Guideline Clearinghouse did not yield evidence-based management guidelines for forearm arterial laceration injury. No professional or societal consensus guidelines or best practice guidelines exist to our knowledge. Discussion: The optimal methods for achieving hemostasis are by a combination approach utilizing direct digital pressure, temporary tourniquet pressure, compressive dressings followed by wound closure. While surgical hemostasis may provide an expedited route for control of hemorrhage, this aggressive approach is often not needed (with a few exceptions to achieve hemostasis for most forearm lacerations. Conservative methods mentioned above will attain the same result. Further, routine emergent or urgent operative exploration of forearm laceration injuries are not warranted and not cost-beneficial. It has been widely accepted with ample evidence in the literature that neither injury to forearm artery, nerve or tendon requires immediate surgical repair. Attention should be directed instead to control of bleeding, and perform a complete physical examination of the hand to document the presence or absence of other associated injuries. Critical ischemia will require expeditious

  11. High frequency of the median artery of the forearm in South African ...

    African Journals Online (AJOL)

    an additional route of blood supply to the forearm that should be kept in mind by ... and Human Biology, University of the Witwatersrand, Johannesburg. B. J. George, B.D.S.• PH.O. ... anery of the forearm in Southern Africa. J Anar 1992; 181: ...

  12. Incidence of Connected Consciousness after Tracheal Intubation A Prospective, International, Multicenter Cohort Study of the Isolated Forearm Technique

    NARCIS (Netherlands)

    Sanders, Robert D.; Gaskell, Amy; Raz, Aeyal; Winders, Joel; Stevanovic, Ana; Rossaint, Rolf; Boncyk, Christina; Defresne, Aline; Tran, Gabriel; Tasbihgou, Seth; Meier, Sascha; Vlisides, Phillip E.; Fardous, Hussein; Hess, Aaron; Bauer, Rebecca M.; Absalom, Anthony; Mashour, George A.; Bonhomme, Vincent; Coburn, Mark; Sleigh, Jamie

    Background: The isolated forearm technique allows assessment of consciousness of the external world (connected consciousness) through a verbal command to move the hand (of a tourniquet-isolated arm) during intended general anesthesia. Previous isolated forearm technique data suggest that the

  13. Incidence of Connected Consciousness after Tracheal Intubation : A Prospective, International, Multicenter Cohort Study of the Isolated Forearm Technique

    NARCIS (Netherlands)

    Sanders, Robert; Gaskell, Amy; Raz, Aeyal; Winders, Joel; Stevanovic, Ana; Rossaint, Rolf; Boncyk, Christina; Defresne, Aline; Tran, Gabriel; Tasbihgou, Seth; Meier, Sascha; Vlisides, Phillip E; Fardous, Hussein; Hess, Aaron; Bauer, Rebecca M; Absalom, Anthony; Mashour, George A; Bonhomme, Vincent; Coburn, Mark; Sleigh, Jamie

    2016-01-01

    BACKGROUND: The isolated forearm technique allows assessment of consciousness of the external world (connected consciousness) through a verbal command to move the hand (of a tourniquet-isolated arm) during intended general anesthesia. Previous isolated forearm technique data suggest that the inciden

  14. Hand to hand.

    Science.gov (United States)

    Bedell, Susanna E; Graboys, Thomas B

    2002-08-01

    Examination of the hands has the potential to transform the encounter between physician and patient. Taking the hands conveys a sense of warmth and connectedness and is a means to communicate the physician's mindfulness. The hands can focus the examination on the individual patient as a complete human being, and not merely a disease or a collection of symptoms. The hands provide readily accessible information that may not be available through other evaluations, and they offer clues to a patient's physical and mental health. Commonplace observations, such as those revealed in the hands, can unravel medical mysteries and provide profound clinical insights.

  15. A synergy-based hand control is encoded in human motor cortical areas.

    Science.gov (United States)

    Leo, Andrea; Handjaras, Giacomo; Bianchi, Matteo; Marino, Hamal; Gabiccini, Marco; Guidi, Andrea; Scilingo, Enzo Pasquale; Pietrini, Pietro; Bicchi, Antonio; Santello, Marco; Ricciardi, Emiliano

    2016-02-15

    How the human brain controls hand movements to carry out different tasks is still debated. The concept of synergy has been proposed to indicate functional modules that may simplify the control of hand postures by simultaneously recruiting sets of muscles and joints. However, whether and to what extent synergic hand postures are encoded as such at a cortical level remains unknown. Here, we combined kinematic, electromyography, and brain activity measures obtained by functional magnetic resonance imaging while subjects performed a variety of movements towards virtual objects. Hand postural information, encoded through kinematic synergies, were represented in cortical areas devoted to hand motor control and successfully discriminated individual grasping movements, significantly outperforming alternative somatotopic or muscle-based models. Importantly, hand postural synergies were predicted by neural activation patterns within primary motor cortex. These findings support a novel cortical organization for hand movement control and open potential applications for brain-computer interfaces and neuroprostheses.

  16. [Human traveling wave EEG during voluntary movement of the hand].

    Science.gov (United States)

    Belov, D R; Stepanova, P A; Kolodiazhnyĭ, S F

    2014-01-01

    The traveling wave trajectories connected with the movements of the right hand were revealed. Above sensomotor cortex 28 electrodes were set as a rectangle--4 rows with 7 electrodes in each one. 2D center-out reaching task was used. The target appeared on the screen edge through the random intervals 0.5-2.5 s equiprobably at the left, on the right, from above or from below. The task was to touch the target with the joystick-operated cursor displacing the cursor in one of the sides from the center to edge. EEG from the target occurrence till cursor contact with it was analyzed. Leading on phase of spontaneous EEG waves in the local area of the left sensomotor cortex and in the centre of back-parietal cortex during cursor movement downwards (the hand with joystick moves to oneself) comparing to rest state and movements in three other directions is revealed. The over time smoothing of data concerning phase alignment reveals hidden constant components in EEG resembling evoked potentials.

  17. Blood flow in the forearm in patients with Rheumatoid arthritis and healthy subjects under local thermotherapy

    Directory of Open Access Journals (Sweden)

    C. Mucha

    2002-02-01

    Full Text Available Objectives: Muscle blood flow in the forearm of patients with rheuma-toid arthritis and healthy volunteers following treatment with temperature increasingarm baths, mudpacks and short- or decimeter-wave diathermy was studied in thisinvestigation. The aim of the study was to find out the difference of reactive hyperemia between the different temperature methods as well as the influence on theconsensual reaction. Subjects: Eighty patients with rheumatoid arthritis, stage 3 according toSteinbrocker, as well as 80 healthy human subjects had been assigned numerically in the four therapy- and controlgroups. Patients with diseases influencing the peripheral blood flow were excluded. Design: Blood flow was measured by venous occlusion plethysmography in both forearms with the subjects lyingsupine. The application of the local heat therapies had been excluded on the left forearm. The forearm blood flow wasmonitored before heat therapy, directly after as well as in two further 10 minutes intervals. An analysis of variancewas used to determine the influence on blood flow of the response to the heat therapies in patients with rheumatoidarthritis and healthy subjects.Results: Under homogeneous starting conditions and a statistically uniformed high blood flow in rest the reactive values of blood flow on the left-hand side of application and the right consensual side showed high significant differencesbetween all methods of therapy. Differences between the patients and the healthy subjects only showed tendencies withpartially lower reactions, concerning the patients with rheumatoid arthritis. All methods of heat therapy caused a statistically provable consensual reaction that turned out smaller after diathermic methods. Here the post therapeuticreaction of the blood flow on the side of application was also lower or rather shorter. Conclusion: Greater differences of the blood flow in rest between the patients with rheumatoid arthritis and healthysubjects

  18. Biomechanics of pronation and supination of the forearm.

    Science.gov (United States)

    Kapandji, A

    2001-02-01

    Pronation-supination, the rotation of the forearm around its longitudinal axis, is an important motion because it allows the hand to be oriented, allowing one to take food and carry it to the mouth, perform personal hygiene, and live autonomously. The motion depends on the integrity of two bones, the radius and the ulna, as well as joints, ligaments, and muscles. In every pathological case, as described in this article, the anatomical features must be restored for normal function.

  19. Android Hands

    DEFF Research Database (Denmark)

    Vlachos, Evgenios; Schärfe, Henrik

    2014-01-01

    . On such occasions, android and humanoid hand models should have similar structure, functions, and performance as the human hand. In this paper we present the anatomy, and the key functionalities of the human hand followed by a literature review on android/humanoid hands for grasping and manipulating objects...

  20. HUMAN NATURE, DIRTY HANDS AND SOCIAL DISORDER: A ...

    African Journals Online (AJOL)

    Dr Ike

    problems and various forms of immorality. Every society desires ..... 2(c) Human Nature and Machiavellian Challenge. Politics, in the .... salary (enforcing the laws against tax evasion with threats of .... shares something of the others concerns.

  1. Plexiform schwannoma of the forearm

    Energy Technology Data Exchange (ETDEWEB)

    Katsumi, Keiichi; Ogose, Akira; Hotta, Tetsuo; Hatano, Hiroshi; Kawashima, Hiroyuki; Endo, Naoto [Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Graduate School of Medical and Dental Sciences, Niigata University, Asahimachi 1-751, 951-8510, Niigata (Japan); Umezu, Hajime [Division of Pathology, Niigata University Hospital, Niigata (Japan)

    2003-12-01

    We report a case of plexiform schwannoma located in the flexor muscles of the forearm in the absence of other signs of neurofibromatosis or schwannomatosis. Magnetic resonance examination revealed a multinodular irregular inhomogeneous mass. Some nodules displayed a peripheral, high intensity rim and a central low intensity (target sign) on T2-weighted images. Pre-operative diagnosis of the rare plexiform schwannoma may be possible with careful imaging examination for the target sign. (orig.)

  2. Recovery of nerve injury-induced alexia for Braille using forearm anaesthesia.

    Science.gov (United States)

    Björkman, Anders; Rosén, Birgitta; Lundborg, Göran

    2008-04-16

    Nerve injuries in the upper extremity may severely affect hand function. Cutaneous forearm anaesthesia has been shown to improve hand sensation in nerve-injured patients. A blind man who lost his Braille reading capability after an axillary plexus injury was treated with temporary cutaneous forearm anaesthesia. After treatment sensory functions of the hand improved and the patient regained his Braille reading capability. The mechanism behind the improvement is likely unmasking of inhibited or silent neurons, but after repeated treatment sessions at increasing intervals the improvement has remained at 1-year follow-up, implying a structural change in the somatosensory cortex.

  3. Texture-induced vibrations in the forearm during tactile exploration

    Directory of Open Access Journals (Sweden)

    Benoit eDelhaye

    2012-07-01

    Full Text Available Humans can detect and discriminate between fine variations of surface roughness using activetouch. It is hitherto believed that roughness perception is mediated mostly by cutaneous andsubcutaneous afferents located in the fingertips. However, recent findings have shown thatfollowing abolishment of cutaneous afferences resulting from trauma or pharmacologicalintervention, the ability of subjects to discriminate between textures roughness was notsignificantly altered. These findings suggest that the somatosensory system is able to collecttextural information from other sources than fingertip afference. It follows that signalsresulting of the interaction of a finger with a rough surface must be transmitted to stimulatereceptor populations in regions far away from the contact. This transmission was characterizedby measuring in the wrist vibrations originating at the fingertip and thus propagating throughthe finger, the hand and the wrist during active exploration of textured surfaces. The spectralanalysis of the vibrations taking place in the forearm tissues revealed regularities that werecorrelated with the scanned surface and the speed of exploration. In the case of periodictextures, the vibration signal contained a fundamental frequency component corresponding tothe finger velocity divided by the spatial period of the stimulus. This regularity was found for awide range of textural length scales and scanning velocities. For non-periodic textures, thespectrum of the vibration did not contain obvious features that would enable discriminationbetween the different stimuli. However, for both periodic and non-periodic stimuli, theintensity of the vibrations could be related to the microgeometry of the scanned surfaces.

  4. New hand at the helm of CERN Human Resources

    CERN Multimedia

    2004-01-01

    Human resources is more than just an administrative function, said CERN's new HR Department head, Carla Bryois, in an interview with the Bulletin. Human resources management is about getting the best out of an organization's staff. That's good for the organisation as a whole, and it's good for the individual. A suitable task for a psychologist, you might think? And that's exactly the kind of person who has just taken over as head of CERN's Human Resources Department. Carla Bryois, who has Dutch and Swiss nationality, took up her duties on 1 April, and brings with her a wealth of experience from the private sector. Her career began with a degree in psychology and social sciences from the Geneva school made famous by Jean Piaget. From there, she went on to specialise in clinical psychology before taking a career break to raise a family. Carla Bryois, CERN's new HR Department head Returning to work, she moved from academic to occupational psychology, taking up a position in human resources with Elsevier scien...

  5. Illusory Sense of Human Touch from a Warm and Soft Artificial Hand

    CERN Document Server

    Cabibihan, John-John; Srinivasa, Yeshwin Mysore; Chan, Mark Aaron; Muruganantham, Arrchana

    2015-01-01

    To touch and be touched are vital to human development, well being, and relationships. However, to those who have lost their arms and hands due to accident or war, touching becomes a serious concern that often leads to psychosocial issues and social stigma. In this paper, we demonstrate that the touch from a warm and soft rubber hand can be perceived by another person as if the touch were coming from a human hand. We describe a three step process toward this goal. First, we made participants select artificial skin samples according to their preferred warmth and softness characteristics. At room temperature, the preferred warmth was found to be 28.4 deg C at the skin surface of a soft silicone rubber material that has a Shore durometer value of 30 at the OO scale. Second, we developed a process to create a rubber hand replica of a human hand. To compare the skin softness of a human hand and artificial hands, a robotic indenter was employed to produce a softness map by recording the displacement data when const...

  6. Compact Dexterous Robotic Hand

    Science.gov (United States)

    Lovchik, Christopher Scott (Inventor); Diftler, Myron A. (Inventor)

    2001-01-01

    A compact robotic hand includes a palm housing, a wrist section, and a forearm section. The palm housing supports a plurality of fingers and one or more movable palm members that cooperate with the fingers to grasp and/or release an object. Each flexible finger comprises a plurality of hingedly connected segments, including a proximal segment pivotally connected to the palm housing. The proximal finger segment includes at least one groove defining first and second cam surfaces for engagement with a cable. A plurality of lead screw assemblies each carried by the palm housing are supplied with power from a flexible shaft rotated by an actuator and output linear motion to a cable move a finger. The cable is secured within a respective groove and enables each finger to move between an opened and closed position. A decoupling assembly pivotally connected to a proximal finger segment enables a cable connected thereto to control movement of an intermediate and distal finger segment independent of movement of the proximal finger segment. The dexterous robotic hand closely resembles the function of a human hand yet is light weight and capable of grasping both heavy and light objects with a high degree of precision.

  7. Tissue oximetry: a comparison of mean values of regional tissue saturation, reproducibility and dynamic range of four NIRS-instruments on the human forearm

    DEFF Research Database (Denmark)

    Hyttel-Sørensen, Simon; Sorensen, Line C; Riera, Joan

    2011-01-01

    We compared absolute values of regional tissue hemoglobin saturation (StO(2)), reproducibility, and dynamic range of four different instruments on the forearm of adults. The sensors were repositioned 10 times on each subject. Dynamic range was estimated by exercise with subsequent arterial...... occlusion. Mean StO(2) was 70.1% ± 6.7 with INVOS 5100, 69.4% ± 5.0 with NIRO 200 NX, 63.4% ± 4.5 with NIRO 300, and 60.8% ± 3.6 with OxyPrem. The corresponding reproducibility S(w) was 5.4% (CI 4.4-6.9), 4.4% (CI 3.5-5.2), 4.1% (CI 3.3-4.9), and 2.7% (CI 2.2-3.2), respectively. The dynamic ranges ¿StO(2......) were 45.0%, 46.8%, 44.8%, and 27.8%, respectively. In conclusion, the three commercial NIRS instruments showed different absolute values, whereas reproducibility and dynamic range were quite similar....

  8. Tissue oximetry: a comparison of mean values of regional tissue saturation, reproducibility and dynamic range of four NIRS-instruments on the human forearm

    DEFF Research Database (Denmark)

    Hyttel-Sørensen, Simon; Sorensen, Line C; Riera, Joan

    2011-01-01

    We compared absolute values of regional tissue hemoglobin saturation (StO(2)), reproducibility, and dynamic range of four different instruments on the forearm of adults. The sensors were repositioned 10 times on each subject. Dynamic range was estimated by exercise with subsequent arterial...... occlusion. Mean StO(2) was 70.1% ± 6.7 with INVOS 5100, 69.4% ± 5.0 with NIRO 200 NX, 63.4% ± 4.5 with NIRO 300, and 60.8% ± 3.6 with OxyPrem. The corresponding reproducibility S(w) was 5.4% (CI 4.4-6.9), 4.4% (CI 3.5-5.2), 4.1% (CI 3.3-4.9), and 2.7% (CI 2.2-3.2), respectively. The dynamic ranges ΔStO(2......) were 45.0%, 46.8%, 44.8%, and 27.8%, respectively. In conclusion, the three commercial NIRS instruments showed different absolute values, whereas reproducibility and dynamic range were quite similar....

  9. Single treatment with ethanol hand rub is ineffective against human rhinovirus--hand washing with soap and water removes the virus efficiently.

    Science.gov (United States)

    Savolainen-Kopra, Carita; Korpela, Terttu; Simonen-Tikka, Marja-Leena; Amiryousefi, Ali; Ziegler, Thedi; Roivainen, Merja; Hovi, Tapani

    2012-03-01

    Ethanol-containing hand rubs are used frequently as a substitute for hand washing with water and soap. However, not all viruses are inactivated by a short term rubbing with alcohol. The capacity of a single round of instructed and controlled hand cleaning with water and soap or ethanol-containing hand rub, respectively, was tested for removal of human rhinovirus administered onto the skin of healthy volunteers on the back of the hands. Hand washing with soap and water appeared to be much more efficient for removing rhinoviruses from skin than rubbing hands with an ethanol-containing disinfectant. After washing with soap and water the virus was detected in 3/9 (33.3%) test persons from the left hand and 1/9 (11.1%) cases from the right hand, whereas the virus was detected invariably by real-time RT-PCR from both hands after cleaning with alcohol hand rub (P-value soap can clean efficiently hands contaminated with the virus responsible for an extensive share of common cold episodes.

  10. Quantity of ethanol absorption after excessive hand disinfection using three commercially available hand rubs is minimal and below toxic levels for humans

    Directory of Open Access Journals (Sweden)

    Toma Cyril D

    2007-10-01

    Full Text Available Abstract Background Despite the increasing promotion of alcohol-based hand rubs and the worldwide use of ethanol-based hand rubs in hospitals only few studies have specifically addressed the issue of ethanol absorption when repeatedly applied to human skin. The aim of this study was to assess if ethanol absorption occurs during hygienic and surgical hand disinfection using three different alcohol-based hand-rubs, and to quantify absorption levels in humans. Methods Twelve volunteers applied three hand-rubs containing 95% (hand-rub A, 85% (hand-rub B and 55% ethanol (hand-rub C; all w/w. For hygienic hand disinfection, 4 mL were applied 20 times for 30 s, with 1 minute break between applications. For surgical hand disinfection, 20 mL of each hand rub was applied to hands and arms up to the level of the elbow 10 times for 3 minutes, with a break of 5 minutes between applications. Blood concentrations of ethanol and acetaldehyde were determined immediately prior and up to 90 minutes after application using head space gas chromatography. Results The median of absorbed ethanol after hygienic hand disinfection was 1365 mg (A, 630 mg (B, and 358 mg (C. The proportion of absorbed ethanol was 2.3% (A, 1.1% (B, and 0.9% (C. After surgical hand disinfection, the median of absorbed ethanol was 1067 mg (A, 1542 mg (B, and 477 mg (C. The proportion of absorbed ethanol was 0.7% (A, 1.1% (B, and 0.5% (C. The highest median acetaldehyde concentration after 20 hygienic hand disinfections was 0.57 mg/L (hand-rub C, after 30 min, after 10 surgical hand disinfections 3.99 mg/L (hand-rub A, after 20 minutes. Conclusion The overall dermal and pulmonary absorption of ethanol was below toxic levels in humans and allows the conclusion that the use of the evaluated ethanol-based hand-rubs is safe.

  11. Quantifying forearm muscle activity during wrist and finger movements by means of multi-channel electromyography.

    Directory of Open Access Journals (Sweden)

    Marco Gazzoni

    Full Text Available The study of hand and finger movement is an important topic with applications in prosthetics, rehabilitation, and ergonomics. Surface electromyography (sEMG is the gold standard for the analysis of muscle activation. Previous studies investigated the optimal electrode number and positioning on the forearm to obtain information representative of muscle activation and robust to movements. However, the sEMG spatial distribution on the forearm during hand and finger movements and its changes due to different hand positions has never been quantified. The aim of this work is to quantify 1 the spatial localization of surface EMG activity of distinct forearm muscles during dynamic free movements of wrist and single fingers and 2 the effect of hand position on sEMG activity distribution. The subjects performed cyclic dynamic tasks involving the wrist and the fingers. The wrist tasks and the hand opening/closing task were performed with the hand in prone and neutral positions. A sensorized glove was used for kinematics recording. sEMG signals were acquired from the forearm muscles using a grid of 112 electrodes integrated into a stretchable textile sleeve. The areas of sEMG activity have been identified by a segmentation technique after a data dimensionality reduction step based on Non Negative Matrix Factorization applied to the EMG envelopes. The results show that 1 it is possible to identify distinct areas of sEMG activity on the forearm for different fingers; 2 hand position influences sEMG activity level and spatial distribution. This work gives new quantitative information about sEMG activity distribution on the forearm in healthy subjects and provides a basis for future works on the identification of optimal electrode configuration for sEMG based control of prostheses, exoskeletons, or orthoses. An example of use of this information for the optimization of the detection system for the estimation of joint kinematics from sEMG is reported.

  12. Quantifying forearm muscle activity during wrist and finger movements by means of multi-channel electromyography.

    Science.gov (United States)

    Gazzoni, Marco; Celadon, Nicolò; Mastrapasqua, Davide; Paleari, Marco; Margaria, Valentina; Ariano, Paolo

    2014-01-01

    The study of hand and finger movement is an important topic with applications in prosthetics, rehabilitation, and ergonomics. Surface electromyography (sEMG) is the gold standard for the analysis of muscle activation. Previous studies investigated the optimal electrode number and positioning on the forearm to obtain information representative of muscle activation and robust to movements. However, the sEMG spatial distribution on the forearm during hand and finger movements and its changes due to different hand positions has never been quantified. The aim of this work is to quantify 1) the spatial localization of surface EMG activity of distinct forearm muscles during dynamic free movements of wrist and single fingers and 2) the effect of hand position on sEMG activity distribution. The subjects performed cyclic dynamic tasks involving the wrist and the fingers. The wrist tasks and the hand opening/closing task were performed with the hand in prone and neutral positions. A sensorized glove was used for kinematics recording. sEMG signals were acquired from the forearm muscles using a grid of 112 electrodes integrated into a stretchable textile sleeve. The areas of sEMG activity have been identified by a segmentation technique after a data dimensionality reduction step based on Non Negative Matrix Factorization applied to the EMG envelopes. The results show that 1) it is possible to identify distinct areas of sEMG activity on the forearm for different fingers; 2) hand position influences sEMG activity level and spatial distribution. This work gives new quantitative information about sEMG activity distribution on the forearm in healthy subjects and provides a basis for future works on the identification of optimal electrode configuration for sEMG based control of prostheses, exoskeletons, or orthoses. An example of use of this information for the optimization of the detection system for the estimation of joint kinematics from sEMG is reported.

  13. Human cortical control of hand movements: parietofrontal networks for reaching, grasping, and pointing.

    Science.gov (United States)

    Filimon, Flavia

    2010-08-01

    In primates, control of the limb depends on many cortical areas. Whereas specialized parietofrontal circuits have been proposed for different movements in macaques, functional neuroimaging in humans has revealed widespread, overlapping activations for hand and eye movements and for movements such as reaching and grasping. This review examines the involvement of frontal and parietal areas in hand and arm movements in humans as revealed with functional neuroimaging. The degree of functional specialization, possible homologies with macaque cortical regions, and differences between frontal and posterior parietal areas are discussed, as well as a possible organization of hand movements with respect to different spatial reference frames. The available evidence supports a cortical organization along gradients of sensory (visual to somatosensory) and effector (eye to hand) preferences.

  14. Hand hygiene compliance in Penang, Malaysia: Human audits versus product usage.

    Science.gov (United States)

    Lee, Yew Fong; Merican, Hassan; Nallusamy, Revathy; Ong, Loke Meng; Mohamed Nazir, Paa; Hamzah, Hafizah Binti; McLaws, Mary-Louise

    2016-06-01

    Hand hygiene auditing is mandatory for all Malaysian public hospitals; nonetheless, the burden of auditing is impacting the support and sustainability of the program. We report an alternative method to routinely measure hand hygiene compliance with the aim to test whether alcohol-based handrub purchase data could be used as a proxy for usage because human auditing has decreased validity and reliability inherent in the methodology.

  15. Chimpanzee hand preference for throwing and infant cradling:implications for the origin of human handedness

    OpenAIRE

    Hopkins, William D.; Kim A Bard; Jones, A; Bales, S. L.

    1993-01-01

    Calvin (i983) has hypothesized that the neurophysiological, perceptual, and cognitive demands of throwing may have served as important evolutionary precursors to a variety of traits( e.g., handedness, tool use, and language processing) in early hominids. Eighty-eight percent of humans throw with their right hands (Healey, Liederman, and Geschwind I986), and Calvin has argued that this right-handed throwing evolved as a result of a left-hemisphere specialization for planned sequential movement...

  16. Human mitochondrial mTERF wraps around DNA through a left-handed superhelical tandem repeat.

    Science.gov (United States)

    Jiménez-Menéndez, Nereida; Fernández-Millán, Pablo; Rubio-Cosials, Anna; Arnan, Carme; Montoya, Julio; Jacobs, Howard T; Bernadó, Pau; Coll, Miquel; Usón, Isabel; Solà, Maria

    2010-07-01

    The regulation of mitochondrial DNA (mtDNA) processes is slowly being characterized at a structural level. We present here crystal structures of human mitochondrial regulator mTERF, a transcription termination factor also implicated in replication pausing, in complex with double-stranded DNA oligonucleotides containing the tRNA(Leu)(UUR) gene sequence. mTERF comprises nine left-handed helical tandem repeats that form a left-handed superhelix, the Zurdo domain.

  17. Hand Shape Recognition in Human Machine Interaction through the Singularity Detection with Wavelet Transform

    Science.gov (United States)

    Wei, Jinwen; Chen, Yanling; Qin, Hequn; Guo, Junjie

    This paper represents a hand shapes recognition system for the Human Machine Interaction (HMI) with service robot of disable people. This system uses a touchpad to precept the touching of fingers, as well as to provide a background for hand shapes image. Each finger can stay in one of the 4 statuses: stretch- touching on the pad, retracting-touching on the pad, stretch-detaching over the pad and retracting-detaching over the pad. Hand shapes, posed to express HMI instructions, are defined by the status combinations of Index finger, Middle finger, Ring finger and Little finger. Hand shape features, the relative heights of the fingertips, are extracted through the singularity detection with wavelet transform on hand shape contour. The hand shape recognition of this system is based on an optimized Bayesian decision binary tree. The design of 2 types of classifier in the tree and the corresponding error rates of the classifiers are analyzed. Implemented by a DSP processor, a correctness ratio of over 98% is obtained in the identification of 12 hand shapes. Experiments show that this system can provide a flexible, humanized and expendable HMI for service robot, as well as for other applications.

  18. Real Time Multiple Hand Gesture Recognition System for Human Computer Interaction

    Directory of Open Access Journals (Sweden)

    Siddharth S. Rautaray

    2012-05-01

    Full Text Available With the increasing use of computing devices in day to day life, the need of user friendly interfaces has lead towards the evolution of different types of interfaces for human computer interaction. Real time vision based hand gesture recognition affords users the ability to interact with computers in more natural and intuitive ways. Direct use of hands as an input device is an attractive method which can communicate much more information by itself in comparison to mice, joysticks etc allowing a greater number of recognition system that can be used in a variety of human computer interaction applications. The gesture recognition system consist of three main modules like hand segmentation, hand tracking and gesture recognition from hand features. The designed system further integrated with different applications like image browser, virtual game etc. possibilities for human computer interaction. Computer Vision based systems has the potential to provide more natural, non-contact solutions. The present research work focuses on to design and develops a practical framework for real time hand gesture.

  19. 带蒂阔筋膜张肌皮瓣与髂腹股沟皮瓣联合移植修复手部及前臂复杂皮肤缺损%Double Pedicled Flap Transfer Combining Groin Flap and Tensor Fascia Lata Myocutaneous Flap to Repair Complex Skin Defects of Hand and Forearm

    Institute of Scientific and Technical Information of China (English)

    徐文辉; 刘富岗; 崔志; 刘威; 时永科; 冯东亮

    2014-01-01

    目的:介绍带蒂阔筋膜张肌皮瓣与髂腹股沟皮瓣联合移植治疗手部及前臂复杂创面的手术方法和临床效果。方法:对7例手、腕及前臂部广泛皮肤套脱伤的患者,4例手部洞穿伤患者,2例全手逆行撕脱伤患者,急诊一期采用带蒂阔筋膜张肌皮瓣与髂腹股沟皮瓣联合移植修复皮肤缺损。髂腹股沟部供区创面直接闭合,大腿部供区创面取全厚层皮片植皮覆盖。术后半个月拆线,并进行皮瓣夹蒂训练,术后3周根据皮瓣夹蒂训练情况酌情断蒂,断蒂时将皮瓣内的腹壁浅神经、股前外侧皮神经分别于受区皮神经吻合。断蒂术后1~2个月分期皮瓣修整。结果:13例皮瓣全部存活,受区、供区伤口I期愈合。术后随访2~6个月,皮瓣柔软,质地良好,皮瓣温痛感觉良好,外形无臃肿,无坏死及破溃;总优良率为84.6%。结论:带蒂阔筋膜张肌皮瓣与髂腹股沟皮瓣联合移植治疗手部及前臂复杂创面,相对其他带蒂联合皮瓣移植患者手部体位较舒适,手术操作简单,安全性高,易于推广。%Objective:To introduce the surgical techniques and clinical outcomes of double pedicled flap transfer combining groin flap and tensor fascia lata myocutaneous flap to treat complex skin defects of hand and forearm. Method:Seven cases of hand or wrist and forearm were due to degloving injuries,four cases of penetrating injuries of hand,two cases of entire hand due to degloving injuries,were treated by transferring groin flap along with pedicled tensor fascia lata myocutaneous flap. All cases were treated with emergent one stage operation. The donor site of the groin flap was closed directly,while the wound at the donor site of the covered by full-tiffckness skin graft. Stitches were removed two weeks after the surgery when pedicle clamping exercise was initiated. Pedicle separation was done about after three weeks flap transfer

  20. Human left ventral premotor cortex mediates matching of hand posture to object use.

    Directory of Open Access Journals (Sweden)

    Guy Vingerhoets

    Full Text Available Visuomotor transformations for grasping have been associated with a fronto-parietal network in the monkey brain. The human homologue of the parietal monkey region (AIP has been identified as the anterior part of the intraparietal sulcus (aIPS, whereas the putative human equivalent of the monkey frontal region (F5 is located in the ventral part of the premotor cortex (vPMC. Results from animal studies suggest that monkey F5 is involved in the selection of appropriate hand postures relative to the constraints of the task. In humans, the functional roles of aIPS and vPMC appear to be more complex and the relative contribution of each region to grasp selection remains uncertain. The present study aimed to identify modulation in brain areas sensitive to the difficulty level of tool object - hand posture matching. Seventeen healthy right handed participants underwent fMRI while observing pictures of familiar tool objects followed by pictures of hand postures. The task was to decide whether the hand posture matched the functional use of the previously shown object. Conditions were manipulated for level of difficulty. Compared to a picture matching control task, the tool object - hand posture matching conditions conjointly showed increased modulation in several left hemispheric regions of the superior and inferior parietal lobules (including aIPS, the middle occipital gyrus, and the inferior temporal gyrus. Comparison of hard versus easy conditions selectively modulated the left inferior frontal gyrus with peak activity located in its opercular part (Brodmann area (BA 44. We suggest that in the human brain, vPMC/BA44 is involved in the matching of hand posture configurations in accordance with visual and functional demands.

  1. Gaze and hand position effects on finger-movement-related human brain activation.

    Science.gov (United States)

    Bédard, Patrick; Sanes, Jerome N

    2009-02-01

    Humans commonly use their hands to move and to interact with their environment by processing visual and proprioceptive information to determine the location of a goal-object and the initial hand position. It remains elusive, however, how the human brain fully uses this sensory information to generate accurate movements. In monkeys, it appears that frontal and parietal areas use and combine gaze and hand signals to generate movements, whereas in humans, prior work has separately assessed how the brain uses these two signals. Here we investigated whether and how the human brain integrates gaze orientation and hand position during simple visually triggered finger tapping. We hypothesized that parietal, frontal, and subcortical regions involved in movement production would also exhibit modulation of movement-related activation as a function of gaze and hand positions. We used functional MRI to measure brain activation while healthy young adults performed a visually cued finger movement and fixed gaze at each of three locations and held the arm in two different configurations. We found several areas that exhibited activation related to a mixture of these hand and gaze positions; these included the sensory-motor cortex, supramarginal gyrus, superior parietal lobule, superior frontal gyrus, anterior cingulate, and left cerebellum. We also found regions within the left insula, left cuneus, left midcingulate gyrus, left putamen, and right tempo-occipital junction with activation driven only by gaze orientation. Finally, clusters with hand position effects were found in the cerebellum bilaterally. Our results indicate that these areas integrate at least two signals to perform visual-motor actions and that these could be used to subserve sensory-motor transformations.

  2. Development of a prototype over-actuated biomimetic prosthetic hand.

    Directory of Open Access Journals (Sweden)

    Matthew R Williams

    Full Text Available The loss of a hand can greatly affect quality of life. A prosthetic device that can mimic normal hand function is very important to physical and mental recuperation after hand amputation, but the currently available prosthetics do not fully meet the needs of the amputee community. Most prosthetic hands are not dexterous enough to grasp a variety of shaped objects, and those that are tend to be heavy, leading to discomfort while wearing the device. In order to attempt to better simulate human hand function, a dexterous hand was developed that uses an over-actuated mechanism to form grasp shape using intrinsic joint mounted motors in addition to a finger tendon to produce large flexion force for a tight grip. This novel actuation method allows the hand to use small actuators for grip shape formation, and the tendon to produce high grip strength. The hand was capable of producing fingertip flexion force suitable for most activities of daily living. In addition, it was able to produce a range of grasp shapes with natural, independent finger motion, and appearance similar to that of a human hand. The hand also had a mass distribution more similar to a natural forearm and hand compared to contemporary prosthetics due to the more proximal location of the heavier components of the system. This paper describes the design of the hand and controller, as well as the test results.

  3. Development of a prototype over-actuated biomimetic prosthetic hand.

    Science.gov (United States)

    Williams, Matthew R; Walter, Wayne

    2015-01-01

    The loss of a hand can greatly affect quality of life. A prosthetic device that can mimic normal hand function is very important to physical and mental recuperation after hand amputation, but the currently available prosthetics do not fully meet the needs of the amputee community. Most prosthetic hands are not dexterous enough to grasp a variety of shaped objects, and those that are tend to be heavy, leading to discomfort while wearing the device. In order to attempt to better simulate human hand function, a dexterous hand was developed that uses an over-actuated mechanism to form grasp shape using intrinsic joint mounted motors in addition to a finger tendon to produce large flexion force for a tight grip. This novel actuation method allows the hand to use small actuators for grip shape formation, and the tendon to produce high grip strength. The hand was capable of producing fingertip flexion force suitable for most activities of daily living. In addition, it was able to produce a range of grasp shapes with natural, independent finger motion, and appearance similar to that of a human hand. The hand also had a mass distribution more similar to a natural forearm and hand compared to contemporary prosthetics due to the more proximal location of the heavier components of the system. This paper describes the design of the hand and controller, as well as the test results.

  4. 人体前臂组织各向异性的人体通信信道模型%Intra-body communication channel model based on anisotropic tissue in human forearm

    Institute of Scientific and Technical Information of China (English)

    刘益和; 张双; 秦雨萍; 张绍祥; 谭立文

    2014-01-01

    人体前臂是一个近似的圆柱体结构,由组织包裹组成。这些组织有的各向同性,如皮肤,脂肪;有的各向异性,如肌肉等。它们对人体电流信号的传播与分布有着极大的影响,特别是肌肉组织。应用麦克斯韦方程,结合人体组织特性和准静态条件下的边界条件,在柱坐标系下建立了基于人体组织特性的信道模型。用该模型,结合人体组织各向特性的电参数(肌肉),在MATLAB2010a 上分别计算出具有组织特性的信道模型和不具有组织特性的信道模型的结果。然后与在人体右前臂测量得到的数据相比较,发现加入组织特性的信道模型的增益曲线与实验数据保持高度一致,模型的平均误差比各向同性的信道模型误差下降了2%,最大误差也下降了3%,进一步降低了模型的失真率。%Human forearm approximates to a cylindrical structure;it is formed through encapsulating layers of human tissues. Some of them are isotropic,such as skin and fat,while the others like muscle are anisotropic.They have great effects on trans-mission and distribution of the current signal in human body,especially muscular tissue.Combining human tissues’characteris-tics and boundary conditions under the quasi-static condition,the channel model based on human tissues’characteristics is built in the cylindrical coordinate system by means of Maxwell equation.In combination with electric parameters of human anisotropic tis-sues (muscle),the obtained channel model is used to derive the channel model with human tissues’characteristics and the one without human tissues’characteristics respectively in MATLAB2010a.Afterwards,these results are compared with the data ob-tained from measurement on human right forearm.The comparison shows that the gain curve of the channel model with human tissues’characteristics is highly consistent with experimental data.Compared with the isotropic channel

  5. The effects of surface-induced loads on forearm muscle activity during steering a bicycle.

    Science.gov (United States)

    Arpinar-Avsar, Pinar; Birlik, Gülin; Sezgin, Onder C; Soylu, Abdullah R

    2013-01-01

    On the bicycle, the human upper extremity has two essential functions in steering the bicycle and in supporting the body. Through the handlebar, surface- induced loads are transmitted to the hand and arm of the bicycle rider under vibration exposure conditions. Thus, the purpose of the study was to investigate the effect of vibration exposure on forearm muscle activity for different road surfaces (i.e. smooth road, concrete stone pavement, rough road) and for different bicycles. Ten subjects participated in experiments and two types of bicycles, i.e. Road Bike (RB) and Mountain Bike (MTB) are compared. The acceleration magnitudes were dominant along x and z-axes. The r.m.s acceleration values in the z direction at the stem of MTB were at most 2.56, 7.04 and 10.76 m·s(-2) when pedaling respectively on asphalt road, concrete pavement and rough road. In the case of RB the corresponding values were respectively 4.43, 11.75 and 27.31 m·s(-2). The cumulative normalized muscular activity levels during MTB trials on different surfaces had the same tendency as with acceleration amplitudes and have ranked in the same order from lowest to highest value. Although road bike measurements have resulted in a similar trend of increment, the values computed for rough road trials were higher than those in MTB trials. During rough road measurements on MTB, rmsEMG of extensor muscles reached a value corresponding to approximately 50% of MVC (Maximum Voluntary Contraction). During RB trials performed on rough road conditions, rmsEMG (%MVC) values for the forearm flexor muscles reached 45.8% of their maximal. The level of muscular activity of forearm muscles in controlling handlebar movements has been observed to be enhanced by the increase in the level of vibration exposed on the bicycle. Since repeated forceful gripping and pushing forces to a handle of a vibratory tool can create a risk of developing circulatory, neurological, or musculoskeletal disorder, a bicycle rider can be

  6. Testing Tactile Masking between the Forearms.

    Science.gov (United States)

    D'Amour, Sarah; Harris, Laurence R

    2016-02-10

    Masking, in which one stimulus affects the detection of another, is a classic technique that has been used in visual, auditory, and tactile research, usually using stimuli that are close together to reveal local interactions. Masking effects have also been demonstrated in which a tactile stimulus alters the perception of a touch at a distant location. Such effects can provide insight into how components of the body's representations in the brain may be linked. Occasional reports have indicated that touches on one hand or forearm can affect tactile sensitivity at corresponding contralateral locations. To explore the matching of corresponding points across the body, we can measure the spatial tuning and effect of posture on contralateral masking. Careful controls are required to rule out direct effects of the remote stimulus, for example by mechanical transmission, and also attention effects in which thresholds may be altered by the participant's attention being drawn away from the stimulus of interest. The use of this technique is beneficial as a behavioural measure for exploring which parts of the body are functionally connected and whether the two sides of the body interact in a somatotopic representation. This manuscript describes a behavioural protocol that can be used for studying contralateral tactile masking.

  7. A woman with forearm amyotrophy.

    Science.gov (United States)

    Sagui, Emmanuel; Correa, Eléonore; Ricobono, Diane; Bregigeon, Michel; Brosset, Christian

    2009-01-01

    We present the case of a 33-year-old woman with benign sporadic monomelic amyotrophy of the distal part of the arm, called Hirayama disease. Clinical features included forearm amyotrophy sparing the brachioradialis muscle, cold paresis and causalgia. Neck magnetic resonance imaging was normal in neutral and flexion position. Electromyography showed denervated patterns in the extensor digitorum communis, and conduction studies ruled out multifocal motor neuropathy. Motor evoked potentials were normal. Serum IgG anti-GM1 antibodies were moderately raised but were negative 8 months later. Outcome was favourable within 15 months, with partial motor recovery. Pathogenesis remains controversial: neck flexion induced myelopathy via chronic anterior horn ischaemia due to forward displacement of the posterior wall of the dura mater, or benign variant of lower motor neuron disease? Whatever the pathomechanism is, the clinical features and outcome are the same.

  8. Hand-rearing reduces fear of humans in European starlings, Sturnus vulgaris.

    Directory of Open Access Journals (Sweden)

    Gesa Feenders

    Full Text Available Pending changes in European legislation ban the use of wild-caught animals in research. This change is partly justified on the assumption that captive-breeding (or hand-rearing increases welfare of captive animals because these practices result in animals with reduced fear of humans. However, there are few actual data on the long-term behavioural effects of captive-breeding in non-domestic species, and these are urgently needed in order to understand the welfare and scientific consequences of adopting this practice. We compared the response of hand-reared and wild-caught starlings to the presence of a human in the laboratory. During human presence, all birds increased their general locomotor activity but the wild-caught birds moved away from the human and were less active than the hand-reared birds. After the human departed, the wild-caught birds were slower to decrease their activity back towards baseline levels, and showed a dramatic increase in time at the periphery of the cage compared with the hand-reared birds. We interpret these data as showing evidence of a greater fear response in wild-caught birds with initial withdrawal followed by a subsequent rebound of prolonged attempts to escape the cage. We found no effects of environmental enrichment. However, birds in cages on low shelves were less active than birds on upper shelves, and showed a greater increase in the time spent at the periphery of their cages after the human departed, perhaps indicating that the lower cages were more stressful. In demonstrating reduced fear of humans in hand-reared birds, our results support one of the proposed welfare benefits of this practice, but without further data on the possible welfare costs of hand-rearing, it is not yet possible to reach a general conclusion about its net welfare impact. However, our results confirm a clear scientific impact of both hand-rearing and cage position at the behavioural level.

  9. Teleoperation of a robot manipulator from 3D human hand-arm motion

    Science.gov (United States)

    Kofman, Jonathan; Verma, Siddharth; Wu, Xianghai; Luu, Timothy

    2003-10-01

    The control of a robot manipulator by a human operator is often necessary in unstructured dynamic environments with unfamiliar objects. Remote teleoperation is required when human presence at the robot site is undesirable or difficult, such as in handling hazardous materials and operating in dangerous or inaccessible environments. Previous approaches have employed mechanical or other contacting interfaces which require unnatural motions for object manipulation tasks or hinder dexterous human motion. This paper presents a non-contacting method of teleoperating a robot manipulator by having the human operator perform the 3D human hand-arm motion that would naturally be used to compete an object manipulation task and tracking the motion with a stereo-camera system at a local site. The 3D human hand-arm motion is reconstructed at the remote robot site and is used to control the position and orientation of the robot manipulator end-effector in real-time. Images captured of the robot interacting with objects at the remote site provide visual feedback to the human operator. Tests in teleoperation of the robot manipulator have demonstrated the ability of the human to carry out object manipulator tasks remotely and the teleoperated robot manipulator system to copy human-arm motions in real-time.

  10. Cytomegalovirus survival and transferability and the effectiveness of common hand-washing agents against cytomegalovirus on live human hands.

    Science.gov (United States)

    Stowell, Jennifer D; Forlin-Passoni, Daniela; Radford, Kay; Bate, Sheri L; Dollard, Sheila C; Bialek, Stephanie R; Cannon, Michael J; Schmid, D Scott

    2014-01-01

    Congenital cytomegalovirus (CMV) transmission can occur when women acquire CMV while pregnant. Infection control guidelines may reduce risk for transmission. We studied the duration of CMV survival after application of bacteria to the hands and after transfer from the hands to surfaces and the effectiveness of cleansing with water, regular and antibacterial soaps, sanitizer, and diaper wipes. Experiments used CMV AD169 in saliva at initial titers of 1 × 10(5) infectious particles/ml. Samples from hands or surfaces (points between 0 and 15 min) were placed in culture and observed for at least 2 weeks. Samples were also tested using CMV real-time PCR. After application of bacteria to the hands, viable CMV was recovered from 17/20 swabs at 0 min, 18/20 swabs at 1 min, 5/20 swabs at 5 min, and 4/20 swabs at 15 min. After transfer, duration of survival was at least 15 min on plastic (1/2 swabs), 5 min on crackers and glass (3/4 swabs), and 1 min or less on metal and cloth (3/4 swabs); no viable virus was collected from wood, rubber, or hands. After cleansing, no viable virus was recovered using water (0/22), plain soap (0/20), antibacterial soap (0/20), or sanitizer (0/22). Viable CMV was recovered from 4/20 hands 10 min after diaper wipe cleansing. CMV remains viable on hands for sufficient times to allow transmission. CMV may be transferred to surfaces with reduced viability. Hand-cleansing methods were effective at eliminating viable CMV from hands.

  11. Improved experimental model for measuring skin degerming activity on the human hand.

    Science.gov (United States)

    Michaud, R N; McGrath, M B; Goss, W A

    1972-07-01

    A gloved-hand method is presented for evaluating the interaction of antimicrobial agents with the normal resident bacterial flora of human skin. One of the key features of the experimental model is a simplified technique for sampling the skin, which involves the addition of eluting fluid to the gloved hand. As with other skin sampling techniques, the number of bacteria recovered from the hands showed considerable variation from subject to subject. However, no significant differences were observed between the numbers of bacteria recovered from the right and left hands of individual subjects. The mean number of bacteria recovered from the hand before and after washing with nonmedicated soap was consistent and reproducible over a period of at least 5 consecutive days. The number of recoverable bacteria from the hand was greatly reduced by a single treatment with a surgical scrub preparation containing hexachlorophene. The extent of skin degerming achieved was little affected by the use of a surgical brush, and was maximal at approximately 30 min after contact with the hexachlorophene-containing formulation. It was determined that the level of transient bacteria on the hands could be controlled by a simple wash with nonmedicated soap, resulting in a stabilized base-line level from which treatment interactions with the resident microflora could be measured more precisely. The basic elements of the method presented fulfill the requirements of a satisfactory experimental model for the in vivo evaluation of skin-degerming agents on the hand. The selection of appropriate experimental designs allows treatment comparisons to be made with a high degree of statistical confidence.

  12. Florid reactive periostitis of the forearm bones in a child.

    Science.gov (United States)

    Mathew, S E; Madhuri, V; Alexander, M; Walter, N M; Gibikote, S V

    2011-03-01

    Florid reactive periostitis is a pronounced periosteal reaction, usually affecting the hands and feet, for which there is no obvious cause. It is rare in children and in long bones. We report an unusual case of florid reactive periostitis in a ten-year-old girl that involved both bones of the forearm. The lesion resolved over a period of one year, leaving a residual exostosis. She developed a physeal bar in the distal ulna in the region of the lesion at one-year follow-up. This was thought to be a complication of the biopsy procedure and was treated by resection and proximal ulnar lengthening.

  13. Texture-induced vibrations in the forearm during tactile exploration

    Science.gov (United States)

    Delhaye, Benoit; Hayward, Vincent; Lefèvre, Philippe; Thonnard, Jean-Louis

    2012-01-01

    Humans can detect and discriminate between fine variations of surface roughness using active touch. It is hitherto believed that roughness perception is mediated mostly by cutaneous and subcutaneous afferents located in the fingertips. However, recent findings have shown that following abolishment of cutaneous afferences resulting from trauma or pharmacological intervention, the ability of subjects to discriminate between textures roughness was not significantly altered. These findings suggest that the somatosensory system is able to collect textural information from other sources than fingertip afference. It follows that signals resulting of the interaction of a finger with a rough surface must be transmitted to stimulate receptor populations in regions far away from the contact. This transmission was characterized by measuring in the wrist vibrations originating at the fingertip and thus propagating through the finger, the hand and the wrist during active exploration of textured surfaces. The spectral analysis of the vibrations taking place in the forearm tissues revealed regularities that were correlated with the scanned surface and the speed of exploration. In the case of periodic textures, the vibration signal contained a fundamental frequency component corresponding to the finger velocity divided by the spatial period of the stimulus. This regularity was found for a wide range of textural length scales and scanning velocities. For non-periodic textures, the spectrum of the vibration did not contain obvious features that would enable discrimination between the different stimuli. However, for both periodic and non-periodic stimuli, the intensity of the vibrations could be related to the microgeometry of the scanned surfaces. PMID:22783177

  14. Characterization of evoked tactile sensation in forearm amputees with transcutaneous electrical nerve stimulation

    Science.gov (United States)

    Chai, Guohong; Sui, Xiaohong; Li, Si; He, Longwen; Lan, Ning

    2015-12-01

    Objective. The goal of this study is to characterize the phenomenon of evoked tactile sensation (ETS) on the stump skin of forearm amputees using transcutaneous electrical nerve stimulation (TENS). Approach. We identified the projected finger map (PFM) of ETS on the stump skin in 11 forearm amputees, and compared perceptual attributes of the ETS in nine forearm amputees and eight able-bodied subjects using TENS. The profile of perceptual thresholds at the most sensitive points (MSPs) in each finger-projected area was obtained by modulating current amplitude, pulse width, and frequency of the biphasic, rectangular current stimulus. The long-term stability of the PFM and the perceptual threshold of the ETS were monitored in five forearm amputees for a period of 11 months. Main results. Five finger-specific projection areas can be independently identified on the stump skin of forearm amputees with a relatively long residual stump length. The shape of the PFM was progressively similar to that of the hand with more distal amputation. Similar sensory modalities of touch, pressure, buzz, vibration, and numb below pain sensation could be evoked both in the PFM of the stump skin of amputees and in the normal skin of able-bodied subjects. Sensory thresholds in the normal skin of able-bodied subjects were generally lower than those in the stump skin of forearm amputees, however, both were linearly modulated by current amplitude and pulse width. The variation of the MSPs in the PFM was confined to a small elliptical area with 95% confidence. The perceptual thresholds of thumb-projected areas were found to vary less than 0.99 × 10-2 mA cm-2. Significance. The stable PFM and sensory thresholds of ETS are desirable for a non-invasive neural interface that can feed back finger-specific tactile information from the prosthetic hand to forearm amputees.

  15. [The effect of the membrana interossea antebrachii on the turning movement of the hand].

    Science.gov (United States)

    Küsswetter, W

    1979-09-20

    In human cadaveric forearm specimens the membrana interossea antebrachii was examined morphologically and biomechanically. Macroscopical, submacroscopical and microscopical findings reveal new facts about the structure, texture and the microscopical details of the membrana interossea. By measuring the interosseous space and by straingage measurement of elongation of the interosseous membrane during pronation and supination the influence of the membrana interossea antebrachii on pronation and supination of the hand was analyzed biomechanically.

  16. Morphology of muscle attachment sites in the modern human hand does not reflect muscle architecture.

    Science.gov (United States)

    Williams-Hatala, E M; Hatala, K G; Hiles, S; Rabey, K N

    2016-06-23

    Muscle attachment sites (entheses) on dry bones are regularly used by paleontologists to infer soft tissue anatomy and to reconstruct behaviors of extinct organisms. This method is commonly applied to fossil hominin hand bones to assess their abilities to participate in Paleolithic stone tool behaviors. Little is known, however, about how or even whether muscle anatomy and activity regimes influence the morphologies of their entheses, especially in the hand. Using the opponens muscles from a sample of modern humans, we tested the hypothesis that aspects of hand muscle architecture that are known to be influenced by behavior correlate with the size and shape of their associated entheses. Results show no consistent relationships between these behaviorally-influenced aspects of muscle architecture and entheseal morphology. Consequently, it is likely premature to infer patterns of behavior, such as stone tool making in fossil hominins, from these same entheses.

  17. The plate fixation in the treatment of complex forearm open fractures

    Directory of Open Access Journals (Sweden)

    Meric Ugurlar

    2017-04-01

    Conclusion: In high nergy traumas of the upper extremity associated with complex injuries and Type-IIIC forearm fractures, severity of soft tissue injuries determined the functional results in patients, demonstrating it is possible to achieve a safe and efficient fixation with immediate plate-screw osteosynthesis. [Hand Microsurg 2017; 6(1.000: 1-8

  18. Differential Effects of the Rod-and-Frame Illusion on the Timing of Forearm Rotations

    NARCIS (Netherlands)

    Lommertzen, J.; Zuijlen, A.M.J. van; Meulenbroek, R.G.J.; Lier, R.J. van

    2009-01-01

    The present study focused on the time course of the effects of the Rod-and-Frame Illusion (RFI) on the kinematics of targeted forearm rotations. Participants were asked to reproduce perceived rod orientations by propelling a hand-held cylinder forward while rotating it to the target orientation. Rod

  19. Hand Gesture Modeling and Recognition for Human and Robot Interactive Assembly Using Hidden Markov Models

    Directory of Open Access Journals (Sweden)

    Fei Chen

    2015-04-01

    Full Text Available Gesture recognition is essential for human and robot collaboration. Within an industrial hybrid assembly cell, the performance of such a system significantly affects the safety of human workers. This work presents an approach to recognizing hand gestures accurately during an assembly task while in collaboration with a robot co-worker. We have designed and developed a sensor system for measuring natural human-robot interactions. The position and rotation information of a human worker's hands and fingertips are tracked in 3D space while completing a task. A modified chain-code method is proposed to describe the motion trajectory of the measured hands and fingertips. The Hidden Markov Model (HMM method is adopted to recognize patterns via data streams and identify workers' gesture patterns and assembly intentions. The effectiveness of the proposed system is verified by experimental results. The outcome demonstrates that the proposed system is able to automatically segment the data streams and recognize the gesture patterns thus represented with a reasonable accuracy ratio.

  20. Hand Gesture Modeling and Recognition for Human and Robot Interactive Assembly Using Hidden Markov Models

    Directory of Open Access Journals (Sweden)

    Fei Chen

    2015-04-01

    Full Text Available Gesture recognition is essential for human and robot collaboration. Within an industrial hybrid assembly cell, the performance of such a system significantly affects the safety of human workers. This work presents an approach to recognizing hand gestures accurately during an assembly task while in collaboration with a robot co-worker. We have designed and developed a sensor system for measuring natural human-robot interactions. The position and rotation information of a human worker’s hands and fingertips are tracked in 3D space while completing a task. A modified chain-code method is proposed to describe the motion trajectory of the measured hands and fingertips. The Hidden Markov Model (HMM method is adopted to recognize patterns via data streams and identify workers’ gesture patterns and assembly intentions. The effectiveness of the proposed system is verified by experimental results. The outcome demonstrates that the proposed system is able to automatically segment the data streams and recognize the gesture patterns thus represented with a reasonable accuracy ratio.

  1. RGBD Video Based Human Hand Trajectory Tracking and Gesture Recognition System

    Directory of Open Access Journals (Sweden)

    Weihua Liu

    2015-01-01

    Full Text Available The task of human hand trajectory tracking and gesture trajectory recognition based on synchronized color and depth video is considered. Toward this end, in the facet of hand tracking, a joint observation model with the hand cues of skin saliency, motion and depth is integrated into particle filter in order to move particles to local peak in the likelihood. The proposed hand tracking method, namely, salient skin, motion, and depth based particle filter (SSMD-PF, is capable of improving the tracking accuracy considerably, in the context of the signer performing the gesture toward the camera device and in front of moving, cluttered backgrounds. In the facet of gesture recognition, a shape-order context descriptor on the basis of shape context is introduced, which can describe the gesture in spatiotemporal domain. The efficient shape-order context descriptor can reveal the shape relationship and embed gesture sequence order information into descriptor. Moreover, the shape-order context leads to a robust score for gesture invariant. Our approach is complemented with experimental results on the settings of the challenging hand-signed digits datasets and American sign language dataset, which corroborate the performance of the novel techniques.

  2. Involuntary human hand movements due to FM radio waves in a moving van.

    Science.gov (United States)

    Huttunen, P; Savinainen, A; Hänninen, Osmo; Myllylä, R

    2011-06-01

    Finland TRACT Involuntary movements of hands in a moving van on a public road were studied to clarify the possible role of frequency modulated radio waves on driving. The signals were measured in a direct 2 km test segment of an international road during repeated drives to both directions. Test subjects (n=4) had an ability to sense radio frequency field intensity variations of the environment. They were sitting in a minivan with arm movement detectors in their hands. A potentiometer was used to register the hand movements to a computer which simultaneously collected data on the amplitude of the RF signal of the local FM tower 30 km distance at a frequency of about 100 MHz. Involuntary hand movements of the test subjects correlated with electromagnetic field, i.e. FM radio wave intensity measured. They reacted also on the place of a geomagnetic anomaly crossing the road, which was found on the basis of these recordings and confirmed by the public geological maps of the area.In conclusion, RF irradiation seems to affect the human hand reflexes of sensitive persons in a moving van along a normal public road which may have significance in traffic safety.

  3. The application of force-sensing resistor sensors for measuring forces developed by the human hand.

    Science.gov (United States)

    Nikonovas, A; Harrison, A J L; Hoult, S; Sammut, D

    2004-01-01

    Most attempts to measure forces developed by the human hand have been implemented by placing force sensors on the object of interaction. Other researchers have placed sensors just on the subject's fingertips. In this paper, a system is described that measures forces over the entire hand using thin-film sensors and associated electronics. This system was developed by the authors and is able to obtain force readings from up to 60 thin-film sensors at rates of up to 400 samples/s per sensor. The sensors can be placed anywhere on the palm and/or fingers of the hand. The sensor readings, together with a video stream containing information about hand posture, are logged into a portable computer using a multiplexer, analogue-to-digital converter and software developed for the purpose. The system has been successfully used to measure forces involved in a range of everyday tasks such as driving a vehicle, lifting saucepans and hitting a golf ball. In the latter case, results are compared with those from an instrumented golf club. Future applications include the assessment of hand strength following disease, trauma or surgery, and to enable quantitative ergonomic investigations.

  4. Understanding Human Hand Gestures for Learning Robot Pick-and-Place Tasks

    Directory of Open Access Journals (Sweden)

    Hsien-I Lin

    2015-05-01

    Full Text Available Programming robots by human demonstration is an intuitive approach, especially by gestures. Because robot pick-and-place tasks are widely used in industrial factories, this paper proposes a framework to learn robot pick-and-place tasks by understanding human hand gestures. The proposed framework is composed of the module of gesture recognition and the module of robot behaviour control. For the module of gesture recognition, transport empty (TE, transport loaded (TL, grasp (G, and release (RL from Gilbreth's therbligs are the hand gestures to be recognized. A convolution neural network (CNN is adopted to recognize these gestures from a camera image. To achieve the robust performance, the skin model by a Gaussian mixture model (GMM is used to filter out non-skin colours of an image, and the calibration of position and orientation is applied to obtain the neutral hand pose before the training and testing of the CNN. For the module of robot behaviour control, the corresponding robot motion primitives to TE, TL, G, and RL, respectively, are implemented in the robot. To manage the primitives in the robot system, a behaviour-based programming platform based on the Extensible Agent Behavior Specification Language (XABSL is adopted. Because the XABSL provides the flexibility and re-usability of the robot primitives, the hand motion sequence from the module of gesture recognition can be easily used in the XABSL programming platform to implement the robot pick-and-place tasks. The experimental evaluation of seven subjects performing seven hand gestures showed that the average recognition rate was 95.96%. Moreover, by the XABSL programming platform, the experiment showed the cube-stacking task was easily programmed by human demonstration.

  5. Hand gesture recognition based on motion history images for a simple human-computer interaction system

    Science.gov (United States)

    Timotius, Ivanna K.; Setyawan, Iwan

    2013-03-01

    A human-computer interaction can be developed using several kind of tools. One choice is using images captured using a camera. This paper proposed a simple human-computer interaction system based on hand movement captured by a web camera. The system aims to classify the captured movement into one of three classes. The first two classes contain hand movements to the left and right, respectively. The third class contains non-hand movements or hand movements to other directions. The method used in this paper is based on Motion History Images (MHIs) and nearest neighbor classifier. The resulting MHIs are processed in two manners, namely by summing the pixel values along the vertical axis and reshaping into vectors. We also use two distance criteria in this paper, respectively the Euclidian distance and cross correlation. This paper compared the performance of the combinations of different MHI data processing and distance criteria using 10 runs of 2-fold cross validation. Our experiments show that reshaping the MHI data into vectors combined with a Euclidean distance criterion gives the highest average accuracy, namely 55.67%.

  6. Properties of cutaneous mechanoreceptors in the human hand related to touch sensation.

    Science.gov (United States)

    Vallbo, A B; Johansson, R S

    1984-01-01

    Recordings from single peripheral nerve fibres made it possible to analyse the functional properties of tactile afferent units supplying the glabrous skin of the human hand and to assess directly the relation between impulse discharge and perceptive experiences. The 17,000 tactile units in this skin area of the human hand are of four different types: two fast adapting types, FA I and FA II (formerly RA and PC), and two slowly adapting types, SA I and SA II. The receptive field characteristics and the densities in the skin of the type I units (FA I and SA I) indicate that these account for the detailed spatial resolution that is of paramount importance for the motor skill and the explorative role of the hand. The relationship between the stimulus amplitude and perceived intensity during sustained skin indentations did not match the corresponding stimulus response functions of SA units suggesting non-linear transformations within the central nervous system. These transformations, in turn, appear to vary between subjects. A single impulse in a single FA I unit may be felt when originating from the most important tactile regions of the hand, indicating that the psychophysical detection may be set by the threshold of the sense organs. Moreover, no significant noise seems to be superimposed in the respective central sensory pathways.

  7. Efficacy of soap and water and alcohol-based hand-rub preparations against live H1N1 influenza virus on the hands of human volunteers.

    Science.gov (United States)

    Grayson, M Lindsay; Melvani, Sharmila; Druce, Julian; Barr, Ian G; Ballard, Susan A; Johnson, Paul D R; Mastorakos, Tasoula; Birch, Christopher

    2009-02-01

    Although pandemic and avian influenza are known to be transmitted via human hands, there are minimal data regarding the effectiveness of routine hand hygiene (HH) protocols against pandemic and avian influenza. Twenty vaccinated, antibody-positive health care workers had their hands contaminated with 1 mL of 10(7) tissue culture infectious dose (TCID)(50)/0.1 mL live human influenza A virus (H1N1; A/New Caledonia/20/99) before undertaking 1 of 5 HH protocols (no HH [control], soap and water hand washing [SW], or use of 1 of 3 alcohol-based hand rubs [61.5% ethanol gel, 70% ethanol plus 0.5% chlorhexidine solution, or 70% isopropanol plus 0.5% chlorhexidine solution]). H1N1 concentrations were assessed before and after each intervention by viral culture and real-time reverse-transcriptase polymerase chain reaction (PCR). The natural viability of H1N1 on hands for >60 min without HH was also assessed. There was an immediate reduction in culture-detectable and PCR-detectable H1N1 after brief cutaneous air drying--14 of 20 health care workers had H1N1 detected by means of culture (mean reduction, 10(3-4) TCID(50)/0.1 mL), whereas 6 of 20 had no viable H1N1 recovered; all 20 health care workers had similar changes in PCR test results. Marked antiviral efficacy was noted for all 4 HH protocols, on the basis of culture results (14 of 14 had no culturable H1N1; (Peffective in reducing influenza A virus on human hands, although SW is the most effective intervention. Appropriate HH may be an important public health initiative to reduce pandemic and avian influenza transmission.

  8. Contributions of skin and muscle afferent input to movement sense in the human hand.

    Science.gov (United States)

    Cordo, Paul J; Horn, Jean-Louis; Künster, Daniela; Cherry, Anne; Bratt, Alex; Gurfinkel, Victor

    2011-04-01

    In the stationary hand, static joint-position sense originates from multimodal somatosensory input (e.g., joint, skin, and muscle). In the moving hand, however, it is uncertain how movement sense arises from these different submodalities of proprioceptors. In contrast to static-position sense, movement sense includes multiple parameters such as motion detection, direction, joint angle, and velocity. Because movement sense is both multimodal and multiparametric, it is not known how different movement parameters are represented by different afferent submodalities. In theory, each submodality could redundantly represent all movement parameters, or, alternatively, different afferent submodalities could be tuned to distinctly different movement parameters. The study described in this paper investigated how skin input and muscle input each contributes to movement sense of the hand, in particular, to the movement parameters dynamic position and velocity. Healthy adult subjects were instructed to indicate with the left hand when they sensed the unseen fingers of the right hand being passively flexed at the metacarpophalangeal (MCP) joint through a previously learned target angle. The experimental approach was to suppress input from skin and/or muscle: skin input by anesthetizing the hand, and muscle input by unexpectedly extending the wrist to prevent MCP flexion from stretching the finger extensor muscle. Input from joint afferents was assumed not to play a significant role because the task was carried out with the MCP joints near their neutral positions. We found that, during passive finger movement near the neutral position in healthy adult humans, both skin and muscle receptors contribute to movement sense but qualitatively differently. Whereas skin input contributes to both dynamic position and velocity sense, muscle input may contribute only to velocity sense.

  9. Operative design and technique of human hand allotransplantation%异体手移植的手术设计与操作

    Institute of Scientific and Technical Information of China (English)

    顾立强; 裴国献; 林昂如; 王钢; 朱立军

    2001-01-01

    Objective To introduce the operative design and technique of human hand allotransplantation. Methods Hand allotransplantation was performed in two patients with right hand defect. In another patient with loss of both hands and distal 2/3 of the forearm, bilateral allotransplantation of hands and forearms was done. The operations were done according to the procedures of autogenons limb replantation: preparation of the recipient area, preparation of the donor limb, and reattachment of the corresponding structures. The level of bony reconnection was determined first. The radius and ulna of the recipient site and the donor limb were approximated after step - like osteotomy and fixed with screws. After suturing of the flexor digitorum profundus, the ulnar and radial arteries were anastomosed. Aftev blood had feowed out ofveins for severd minutes of veins, the cephalic and basilic veins were anastomosed. Suturing of the flexor digitorum superficialis and the wrist, and then the wrist and finger extensors, coaptation of the nerves, and skin closure were done consecutively. Postoperatively, immunosupressive drugs were used to prevent rejection. Results Transplantation of four hands in three cases lasted 7 hours and 52 minutes , 9 hours and 10 minutes, 9 hours and 28 minutes, and 10 hours and 5 minutes respectively. The ischaemic time of the transplanted hands was 6 hours, 6 hours and 19 minutes, 8 hours and 59 minutes, and 7 hours and 58 minutes respectively. Blood circulation of three hands in two cases were fluent while venous crisis occurred in another case 3 hours postoperatively, which was corrected by surgical exploration. All transplanted hands survived without rejection reaction over 2 to 14 months period of follow - up. Satisfactory restoration of the function was obtained. Conclusions It was of emphasis to determine the replantation level in accordance with the stumps of the patient's hands in the operative design of hand allotransplantation. The

  10. Circadian rhythms and fractal fluctuations in forearm motion

    Science.gov (United States)

    Hu, Kun; Hilton, Michael F.

    2005-03-01

    Recent studies have shown that the circadian pacemaker --- an internal body clock located in the brain which is normally synchronized with the sleep/wake behavioral cycles --- influences key physiologic functions such as the body temperature, hormone secretion and heart rate. Surprisingly, no previous studies have investigated whether the circadian pacemaker impacts human motor activity --- a fundamental physiologic function. We investigate high-frequency actigraph recordings of forearm motion from a group of young and healthy subjects during a forced desynchrony protocol which allows to decouple the sleep/wake cycles from the endogenous circadian cycle while controlling scheduled behaviors. We investigate both static properties (mean value, standard deviation), dynamical characteristics (long-range correlations), and nonlinear features (magnitude and Fourier-phase correlations) in the fluctuations of forearm acceleration across different circadian phases. We demonstrate that while the static properties exhibit significant circadian rhythms with a broad peak in the afternoon, the dynamical and nonlinear characteristics remain invariant with circadian phase. This finding suggests an intrinsic multi-scale dynamic regulation of forearm motion the mechanism of which is not influenced by the circadian pacemaker, thus suggesting that increased cardiac risk in the early morning hours is not related to circadian-mediated influences on motor activity.

  11. Prosthetic Hand Lifts Heavy Loads

    Science.gov (United States)

    Carden, James R.; Norton, William; Belcher, Jewell G.; Vest, Thomas W.

    1991-01-01

    Prosthetic hand designed to enable amputee to lift diverse heavy objects like rocks and logs. Has simple serrated end effector with no moving parts. Prosthesis held on forearm by system of flexible straps. Features include ruggedness, simplicity, and relatively low cost.

  12. Electronic artificial hand controlled by reconstructed digit

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objecive: To treat the loss of part of the forearm with a multi-dimension-freedom electronic artificial hand,which is controlled by a reconstructed finger transplanted from the second toe to the forearm stump.Methods: The female patient was 19 years old, whose right hand and wrist were crushed into pieces by machine at work and her forearm was amputated at the level of 8 cm proximal to the wrist. The second toe of her left foot was transplanted to reconstruct the digit onto the stump of her forearm. Two months after the transplantation, the patient was transferred to the rehabilitation center for further rehabilitation training, which consisted of: training for adaptation to weight bearing, testing and training of sensibility to weight. testing and training for stability of the hand, and testing and training for the controlling function of the reconstructed digit. Results: The transplanted toe survived well. After rehabilitation the reconstructed digit functioned well. In testing the performance under control mandate, the accuracy rate of the electronic artificial hand was 100%.Conclusions: A 100% accuracy rate of the electronic artificial hand can be achieved by transplantation of the toe onto the stump of the forearm. It provides a useful pathway and an example for improvement of control accuracy of a multiple-freedom electronic artificial hand and reduction of false action.

  13. Free myocutaneous flap transfer to treat congenital Volkmann's contracture of the forearm.

    Science.gov (United States)

    Rubin, G; Palti, R; Gurevitz, S; Yaffe, B

    2015-07-01

    The purpose of this study is to report our experience with free functional muscle transfer procedures for the late sequelae of the rare condition of congenital Volkmann's ischaemic contracture of the forearm. Four children, with an average age of 9.5 years (range 1.5-17), were treated and were followed for a mean of 6 years (range 1-14). Two patients had dorsal forearm contractures, and two had both flexor and extensor forearm contractures. We carried out free functional muscle transfers to replace the flexor or extensor muscles. The functional result was assessed according to the classification system of Hovius and Ultee. All patients had wrist contractures and skeletal involvement with limb length discrepancy that influenced the outcome. All five transferred muscles survived and improved the function of the hand in three of the four patients. LEVEL OF EVIDENCE 4. © The Author(s) 2014.

  14. Anticipatory and Reactive Response to Falls: Muscle Synergy Activation of Forearm Muscles.

    Science.gov (United States)

    Couzens, Greg; Kerr, Graham

    2015-10-01

    We investigated the surface electromyogram response of six forearm muscles to falls onto the outstretched hand. The extensor carpi radialis longus, extensor carpi radialis brevis, extensor carpi ulnaris, abductor pollicis longus, flexor carpi radialis and flexor carpi ulnaris muscles were sampled from eight volunteers who underwent ten self-initiated falls. All muscles initiated prior to impact. Co-contraction is the most obvious surface electromyogram feature. The predominant response is in the radial deviators. The surface electromyogram timing we recorded would appear to be a complex anticipatory response to falling modified by the effect on the forearm muscles following impact. The mitigation of the force of impact is probably more importantly through shoulder abduction and extension and elbow flexion rather than action of the forearm muscles.

  15. The sensory somatotopic map of the human hand demonstrated at 4 Tesla.

    Science.gov (United States)

    Maldjian, J A; Gottschalk, A; Patel, R S; Detre, J A; Alsop, D C

    1999-07-01

    Recent attempts at high-resolution sensory-stimulated fMRI performed at 1.5 T have had very limited success at demonstrating a somatotopic organization for individual digits. Our purpose was to determine if functional MRI at 4 T can demonstrate the sensory somatotopic map of the human hand. Sensory functional MRI was performed at 4 T in five normal volunteers using a low-frequency vibratory stimulus on the pad of each finger of the left hand. A simple motor control task was also performed. The data were normalized to a standard atlas, and individual and group statistical parametric maps (SPMs) were computed for each task. Volume of activation and distribution of cluster maxima were compared for each task. For three of the subjects, the SPMs demonstrated a somatotopic organization of the sensory cortex. The group SPMs demonstrated a clear somatotopic organization of the sensory cortex. The thumb to fifth finger were organized, in general, with a lateral to medial, inferior to superior, and anterior to posterior relationship. There was overlap in the individual SPMs between fingers. The sensory activation spanned a space of 12-18 mm (thumb to fifth finger) on the primary sensory cortex. The motor activation occurred consistently at the superior-most extent of the sensory activation within and across subjects. The sensory somatotopic map of the human hand can be identified at 4 T. High-resolution imaging at 4 T can be useful for detailed functional imaging studies. Copyright 1999 Academic Press.

  16. Learning robotic eye-arm-hand coordination from human demonstration: a coupled dynamical systems approach.

    Science.gov (United States)

    Lukic, Luka; Santos-Victor, José; Billard, Aude

    2014-04-01

    We investigate the role of obstacle avoidance in visually guided reaching and grasping movements. We report on a human study in which subjects performed prehensile motion with obstacle avoidance where the position of the obstacle was systematically varied across trials. These experiments suggest that reaching with obstacle avoidance is organized in a sequential manner, where the obstacle acts as an intermediary target. Furthermore, we demonstrate that the notion of workspace travelled by the hand is embedded explicitly in a forward planning scheme, which is actively involved in detecting obstacles on the way when performing reaching. We find that the gaze proactively coordinates the pattern of eye-arm motion during obstacle avoidance. This study provides also a quantitative assessment of the coupling between the eye-arm-hand motion. We show that the coupling follows regular phase dependencies and is unaltered during obstacle avoidance. These observations provide a basis for the design of a computational model. Our controller extends the coupled dynamical systems framework and provides fast and synchronous control of the eyes, the arm and the hand within a single and compact framework, mimicking similar control system found in humans. We validate our model for visuomotor control of a humanoid robot.

  17. Life in our hands? Some ethical perspectives on the human genome and human genome diversity projects

    Directory of Open Access Journals (Sweden)

    Cornelius W. du Toit

    2014-01-01

    Full Text Available The article dealt with implications of the human genome and the human genome diversity project. It examined some theological implications, such as: humans as the image of God, God as the creator of life, the changed role of miracles and healings in religion, the sacredness of nature, life and the genome. Ethical issues that were addressed include eugenics, germline intervention, determinism and the human genome diversity project. Economic and legal factors that play a role were also discussed. Whilst positive aspects of genome research were considered, a critical stance was adopted towards patenting the human genome and some concluding guidelines were proposed.

  18. Prosthetic Hand With Two Gripping Fingers

    Science.gov (United States)

    Norton, William E.; Belcher, Jewell B.; Vest, Thomas W.; Carden, James R.

    1993-01-01

    Prosthetic hand developed for amputee who retains significant portion of forearm. Outer end of device is end effector including two fingers, one moved by rotating remaining part of forearm about its longitudinal axis. Main body of end effector is end member supporting fingers, roller bearing assembly, and rack-and-pinion mechanism. Advantage of rack-and-pinion mechanism enables user to open or close gap between fingers with precision and force.

  19. Dosimetry of hands and human factor; Dosimetria de manos y factor humano

    Energy Technology Data Exchange (ETDEWEB)

    Harr, R. [Sociedad Mexicana de Seguridad Radiologica A. C., Mexico D. F. (Mexico)

    2008-12-15

    The human factor in facilities where open radioactive sources are managed it can be controlled through the use of the ring dosimetry, however, that these devices only provide qualitative information that is not extrapolated to legislative limits. lt is present the case analysis of hands dosimetry of female person with responsibility for professional standards and a very high profile with ratings that allow her to have a high level of knowledge of the basic standards, and because with an attitude and a culture rooted of radiation protection, among other qualities. Their records reveal a trend in which monthly doses are below the 7 mSv, and only occasionally are between 7 and 12 mSv per month and hand. The other case correspond to a technician, trained in radiological techniques, also with a high profile, with two courses for occupationally exposed personnel more than 10 annual retraining, and work experience of over 10 years as occupationally exposed personnel, in which knowledge of standards and because of the entrenched culture of radiation protection and their interest degree in the care of their exposure is still in a phase half, in this case also shows a trend in the monthly dose where found registers between 7 and 11 mSv per month and hand. The third case is of a second technician with less experience and most basic knowledge, his dose register not show a real trend, sometimes be found reads of irregular values as if the dosimeter is not used and some other times as if misused by exposing to purpose (was observed at least one reading above the monthly 30 mSv). By way of conclusion, it is noted that the hands dosimetry is a useful tool to monitor transactions through the data compilation susceptible to analysis with variations which can be placed in the context of the human factor. (Author)

  20. Hand-assisted laparoscopic sigmoid colectomy skills acquisition: augmented reality simulator versus human cadaver training models.

    Science.gov (United States)

    Leblanc, Fabien; Senagore, Anthony J; Ellis, Clyde N; Champagne, Bradley J; Augestad, Knut M; Neary, Paul C; Delaney, Conor P

    2010-01-01

    The aim of this study was to compare a simulator with the human cadaver model for hand-assisted laparoscopic colorectal skills acquisition training. An observational prospective comparative study was conducted to compare the laparoscopic surgery training models. The study took place during the laparoscopic colectomy training course performed at the annual scientific meeting of the American Society of Colon and Rectal Surgeons. Thirty four practicing surgeons performed hand-assisted laparoscopic sigmoid colectomy on human cadavers (n = 7) and on an augmented reality simulator (n = 27). Prior laparoscopic colorectal experience was assessed. Trainers and trainees completed independently objective structured assessment forms. Training models were compared by trainees' technical skills scores, events scores, and satisfaction. Prior laparoscopic experience was similar in both surgeon groups. Generic and specific skills scores were similar on both training models. Generic events scores were significantly better on the cadaver model. The 2 most frequent generic events occurring on the simulator were poor hand-eye coordination and inefficient use of retraction. Specific events were scored better on the simulator and reached the significance limit (p = 0.051) for trainers. The specific events occurring on the cadaver were intestinal perforation and left ureter identification difficulties. Overall satisfaction was better for the cadaver than for the simulator model (p = 0.009). With regard to skills scores, the augmented reality simulator had adequate qualities for the hand-assisted laparoscopic colectomy training. Nevertheless, events scores highlighted weaknesses of the anatomical replication on the simulator. Although improvements likely will be required to incorporate the simulator more routinely into the colorectal training, it may be useful in its current form for more junior trainees or those early on their learning curve. Copyright 2010 Association of Program

  1. Measurement of forearm oxygen consumption

    DEFF Research Database (Denmark)

    Astrup, A; Simonsen, L; Bülow, J

    1988-01-01

    glucose. Heating increased rectal temperature by 0.6 degrees C, and plasma norepinephrine levels were increased compared with the control experiments. The present study explains the conflicting reports on glucose-induced thermogenesis in skeletal muscle and warns against heating the contralateral hand...

  2. Role of ulnar forearm free flap in oromandibular reconstruction.

    Science.gov (United States)

    Gabr, E M; Kobayashi, M R; Salibian, A H; Armstrong, W B; Sundine, M; Calvert, J W; Evans, G R D

    2004-01-01

    The ulnar forearm flap is not frequently utilized for oromandibular reconstruction. This study evaluated the usefulness of the ulnar free flap for reconstruction. A retrospective study of 32 patients was conducted. The ulnar forearm flap was combined with an osseous flap in 24 patients. Nine females and 23 males with a mean age of 58.15 years comprised our study population. Squamous-cell carcinoma was the diagnosis in 93.75% of cases (56.25% T4), of which 20% were recurrent. Functional evaluation of swallowing was based on the University of Washington Questionnaire (UWQ). The mean hospital stay was 9.8 days. The external carotid (100%) was the recipient artery, and the internal jugular (74.07%) was the main recipient vein. Overall flap survival was 96.8%. One flap was lost due to unsalvageable venous thrombosis. Major local complications were seen in 9.4% of cases and included partial flap loss, hematoma, and an orocutaneous fistula. At the time of this study, 21 patients were available for functional evaluation. Speech was rated excellent and good in 33.3% of patients. Swallowing was found good in 28.6% of patients. Chewing was rated excellent and good in 47.6% of patients. Cosmetic acceptance was rated good in 71.4% of cases. The ulnar forearm is a useful free flap in oromandibular reconstruction. It is available when the radial artery is the dominant artery of the hand. Being more hidden, it may be more cosmetically accepted. It affords pliable soft tissue for lining and/or covering of oromandibular defects, and can be used as a second choice after other free-flap failures. Copyright 2004 Wiley-Liss, Inc.

  3. THE EFFECTS OF SURFACE-INDUCED LOADS ON FOREARM MUSCLE ACTIVITY DURING STEERING A BICYCLE

    Directory of Open Access Journals (Sweden)

    Pinar Arpinar-Avsar

    2013-09-01

    Full Text Available On the bicycle, the human upper extremity has two essential functions in steering the bicycle and in supporting the body. Through the handlebar, surface- induced loads are transmitted to the hand and arm of the bicycle rider under vibration exposure conditions. Thus, the purpose of the study was to investigate the effect of vibration exposure on forearm muscle activity for different road surfaces (i.e. smooth road, concrete stone pavement, rough road and for different bicycles. Ten subjects participated in experiments and two types of bicycles, i.e. Road Bike (RB and Mountain Bike (MTB are compared. The acceleration magnitudes were dominant along x and z-axes. The r.m.s acceleration values in the z direction at the stem of MTB were at most 2.56, 7.04 and 10.76 m·s-2 when pedaling respectively on asphalt road, concrete pavement and rough road. In the case of RB the corresponding values were respectively 4.43, 11.75 and 27.31 m·s-2. The cumulative normalized muscular activity levels during MTB trials on different surfaces had the same tendency as with acceleration amplitudes and have ranked in the same order from lowest to highest value. Although road bike measurements have resulted in a similar trend of increment, the values computed for rough road trials were higher than those in MTB trials. During rough road measurements on MTB, rmsEMG of extensor muscles reached a value corresponding to approximately 50% of MVC (Maximum Voluntary Contraction. During RB trials performed on rough road conditions, rmsEMG (%MVC values for the forearm flexor muscles reached 45.8% of their maximal. The level of muscular activity of forearm muscles in controlling handlebar movements has been observed to be enhanced by the increase in the level of vibration exposed on the bicycle. Since repeated forceful gripping and pushing forces to a handle of a vibratory tool can create a risk of developing circulatory, neurological, or musculoskeletal disorder, a bicycle rider

  4. Ulnar nerve paralysis after forearm bone fracture.

    Science.gov (United States)

    Schwartsmann, Carlos Roberto; Ruschel, Paulo Henrique; Huyer, Rodrigo Guimarães

    2016-01-01

    Paralysis or nerve injury associated with fractures of forearm bones fracture is rare and is more common in exposed fractures with large soft-tissue injuries. Ulnar nerve paralysis is a rare condition associated with closed fractures of the forearm. In most cases, the cause of paralysis is nerve contusion, which evolves with neuropraxia. However, nerve lacerations and entrapment at the fracture site always need to be borne in mind. This becomes more important when neuropraxia appears or worsens after reduction of a closed fracture of the forearm has been completed. The importance of diagnosing this injury and differentiating its features lies in the fact that, depending on the type of lesion, different types of management will be chosen.

  5. [Functional hemitongue reconstruction with free forearm flap].

    Science.gov (United States)

    Liao, Gui-Qing; Su, Yu-Xiong; Liu, Hai-Chao; Li, Jin; Fahmha, Numan; Ou, De-Ming; Wang, Qin

    2008-07-01

    To investigate the clinical application of free forearm flap in the functional hemitongue reconstruction. From July 2002 to November 2006, 40 patients with tongue cancer underwent hemiglossectomy and primary hemitongue reconstruction with free forearm flaps. In some cases, the lateral antebrachial cutaneous nerves of the flaps were anastomosed with the lingual nerve to restore the flap sensation. All patients recovered uneventfully after surgery with no morbidity in the donor site. All free flaps survived. The average follow-up period was 2 years and 6 months. The aesthetic and functional results were both satisfactory. The swallowing and speech function were almost normal. The flap sensation was partially restored. Good functional hemitongue reconstruction can be achieved with free forearm flaps.

  6. Ulnar nerve paralysis after forearm bone fracture

    Directory of Open Access Journals (Sweden)

    Carlos Roberto Schwartsmann

    2016-08-01

    Full Text Available ABSTRACT Paralysis or nerve injury associated with fractures of forearm bones fracture is rare and is more common in exposed fractures with large soft-tissue injuries. Ulnar nerve paralysis is a rare condition associated with closed fractures of the forearm. In most cases, the cause of paralysis is nerve contusion, which evolves with neuropraxia. However, nerve lacerations and entrapment at the fracture site always need to be borne in mind. This becomes more important when neuropraxia appears or worsens after reduction of a closed fracture of the forearm has been completed. The importance of diagnosing this injury and differentiating its features lies in the fact that, depending on the type of lesion, different types of management will be chosen.

  7. Real-Time Hand Posture Recognition for Human-Robot Interaction Tasks.

    Science.gov (United States)

    Hernandez-Belmonte, Uriel Haile; Ayala-Ramirez, Victor

    2016-01-04

    In this work, we present a multiclass hand posture classifier useful for human-robot interaction tasks. The proposed system is based exclusively on visual sensors, and it achieves a real-time performance, whilst detecting and recognizing an alphabet of four hand postures. The proposed approach is based on the real-time deformable detector, a boosting trained classifier. We describe a methodology to design the ensemble of real-time deformable detectors (one for each hand posture that can be classified). Given the lack of standard procedures for performance evaluation, we also propose the use of full image evaluation for this purpose. Such an evaluation methodology provides us with a more realistic estimation of the performance of the method. We have measured the performance of the proposed system and compared it to the one obtained by using only the sampled window approach. We present detailed results of such tests using a benchmark dataset. Our results show that the system can operate in real time at about a 10-fps frame rate.

  8. Human Hand Kinematic Modeling Based on Robotic Concepts for Digit Animation with Dynamic Constraints

    Science.gov (United States)

    Tondu, Bertrand

    The recent development of highly anthropomorphic avatars in computer graphics has emphasized the importance of accurate hand kinematic models. Although kinematic methods derived from robotics have recently been applied to the modeling of hands, we consider that original/new and relevant results can be brought into play with the use of more advanced applications of robotic techniques to human hand kinematic modeling. Our chapter analyses some of these questions both in the non-differential and differential fields. More specifically, we study how to integrate the peculiar natural digit movement constraints into robotics-based inverse kinematic modeling. As a result, we propose an original approach based on an interpretation of each joint dynamic constraint as a linear joint synergy. This leads to defining the considered digit as a serial chain kinematically redundant in position and reducing the dimension of its joint space by associated joint synergies. The method is applied to the Cartesian positioning simulation of a 4 d.o.f. index model; a comparison with a Jacobian pseudo-inverse-based approach emphasizes its relevance.

  9. Physiological and subjective evaluation of a human-robot object hand-over task.

    Science.gov (United States)

    Dehais, Frédéric; Sisbot, Emrah Akin; Alami, Rachid; Causse, Mickaël

    2011-11-01

    In the context of task sharing between a robot companion and its human partners, the notions of safe and compliant hardware are not enough. It is necessary to guarantee ergonomic robot motions. Therefore, we have developed Human Aware Manipulation Planner (Sisbot et al., 2010), a motion planner specifically designed for human-robot object transfer by explicitly taking into account the legibility, the safety and the physical comfort of robot motions. The main objective of this research was to define precise subjective metrics to assess our planner when a human interacts with a robot in an object hand-over task. A second objective was to obtain quantitative data to evaluate the effect of this interaction. Given the short duration, the "relative ease" of the object hand-over task and its qualitative component, classical behavioral measures based on accuracy or reaction time were unsuitable to compare our gestures. In this perspective, we selected three measurements based on the galvanic skin conductance response, the deltoid muscle activity and the ocular activity. To test our assumptions and validate our planner, an experimental set-up involving Jido, a mobile manipulator robot, and a seated human was proposed. For the purpose of the experiment, we have defined three motions that combine different levels of legibility, safety and physical comfort values. After each robot gesture the participants were asked to rate them on a three dimensional subjective scale. It has appeared that the subjective data were in favor of our reference motion. Eventually the three motions elicited different physiological and ocular responses that could be used to partially discriminate them. Copyright © 2011 Elsevier Ltd and the Ergonomics Society. All rights reserved.

  10. Age-related changes in the joint position sense of the human hand

    Directory of Open Access Journals (Sweden)

    Kalisch T

    2012-11-01

    Full Text Available Tobias Kalisch,1,2,* Jan-Christoph Kattenstroth,2,* Rebecca Kowalewski,2 Martin Tegenthoff,1 Hubert R Dinse21Department of Neurology, BG-Kliniken Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; 2Neural Plasticity Lab, Institute for Neuroinformatics, Ruhr-University Bochum, Bochum, Germany*These authors contributed equally to this workAbstract: Age-related changes in lower limb joint position sense and their contributions to postural stability are well documented. In contrast, only a few studies have investigated the effect of age on proprioceptive hand function. Here, we introduce a novel test for measuring joint position sense in the fingers of the human hand. In a concurrent matching task, subjects had to detect volume differences between polystyrene balls grasped with their dominant (seven test stimuli: 126–505 cm3 and their nondominant hand (three reference stimuli: 210, 294, and 505 cm3. A total of 21 comparisons were performed to assess the number of errors, the weight of errors (ie, the volume difference between test and reference stimuli, and the direction of errors (ie, over- or underestimation of test stimulus. The test was applied to 45 healthy subjects aged 21 to 79 years. Our results revealed that all variables changed significantly with age, with the number of errors showing the strongest increase. We also assessed tactile acuity (two-point discrimination thresholds and sensorimotor performance (pegboard performance in a subset of subjects, but these scores did not correlate with joint position sense performance, indicating that the test reveals specific information about joint position sense that is not captured with pure sensory or motor tests. The average test–retest reliability assessed on 3 consecutive days was 0.8 (Cronbach's alpha. Our results demonstrate that this novel test reveals age-related decline in joint position sense acuity that is independent from sensorimotor performance.Keywords: aging, hand

  11. Ulnar nerve palsy after closed forearm fracture: a case report

    Directory of Open Access Journals (Sweden)

    Levent Kucuk

    2012-04-01

    Full Text Available Closed double bone forearm fractures are among the most common fractures of childhood. These fractures often heal without problems with closed reduction and casting. The leading complications are known as malunion and compartment syndrome. The reports about nerve injuries related with these fractures are very limited. We present an eight years old boy who admitted to our hospital with ulnar nerve palsy symptomps three months after his initial trauma. His initial trauma was a simple fall which caused radius and ulna fractures. Radiological assessment showed proper union of the fractures. We performed surgical exploration to the ulnar nerve. We found a trapped and damaged nerve in the fracture region. Even though the rate of complications about nerve injuries are extremely rare in forearm fractures, neurologic examinations should be performed before and after the reduction maneuvers. Neurologic examination will be not only a guide for fracture management but also an important point for medicolegal problems. [Hand Microsurg 2012; 1(1.000: 30-32

  12. Eye-hand Hybrid Gesture Recognition System for Human Machine Interface

    Directory of Open Access Journals (Sweden)

    N. R. Raajan

    2013-04-01

    Full Text Available Gesture Recognition has become a way for computers to recognise and understand human body language. They bridge the gap between machines and human beings and make the primitive interfaces like keyboards and mice redundant. This paper suggests a hybrid gesture recognition system for computer interface and wireless robot control. The real-time eye-hand gesture recognition system can be used for computer drawing, navigating cursors and simulating mouse clicks, playing games, controlling a wireless robot with commands and more. The robot illustrated in this paper is controlled by RF module. Playing a PING-PONG game has also been demonstrated using the gestures. The Haar cascade classifiers and template matching are used to detect eye gestures and convex hull for finding the defects and counting the number of fingers in the given region.

  13. Robustness of muscle synergies underlying three-dimensional force generation at the hand in healthy humans

    Science.gov (United States)

    Rymer, William Z.; Beer, Randall F.

    2012-01-01

    Previous studies using advanced matrix factorization techniques have shown that the coordination of human voluntary limb movements may be accomplished using combinations of a small number of intermuscular coordination patterns, or muscle synergies. However, the potential use of muscle synergies for isometric force generation has been evaluated mostly using correlational methods. The results of such studies suggest that fixed relationships between the activations of pairs of muscles are relatively rare. There is also emerging evidence that the nervous system uses independent strategies to control movement and force generation, which suggests that one cannot conclude a priori that isometric force generation is accomplished by combining muscle synergies, as shown in movement control. In this study, we used non-negative matrix factorization to evaluate the ability of a few muscle synergies to reconstruct the activation patterns of human arm muscles underlying the generation of three-dimensional (3-D) isometric forces at the hand. Surface electromyographic (EMG) data were recorded from eight key elbow and shoulder muscles during 3-D force target-matching protocols performed across a range of load levels and hand positions. Four synergies were sufficient to explain, on average, 95% of the variance in EMG datasets. Furthermore, we found that muscle synergy composition was conserved across biomechanical task conditions, experimental protocols, and subjects. Our findings are consistent with the view that the nervous system can generate isometric forces by assembling a combination of a small number of muscle synergies, differentially weighted according to task constraints. PMID:22279190

  14. Active Learning and Flipped Classroom, Hand in Hand Approach to Improve Students Learning in Human Anatomy and Physiology

    Science.gov (United States)

    Entezari, Maria; Javdan, Mohammad

    2016-01-01

    Because Human Anatomy and Physiology (A&P), a gateway course for allied health majors, has high dropout rates nationally, it is challenging to find a successful pedagogical intervention. Reports on the effect of integration of flipped classrooms and whether it improves learning are contradictory for different disciplines. Thus many educators…

  15. Bringing transcranial mapping into shape: Sulcus-aligned mapping captures motor somatotopy in human primary motor hand area

    DEFF Research Database (Denmark)

    Raffin, Estelle; Pellegrino, Giovanni; Di Lazzaro, Vincenzo;

    2015-01-01

    of the central sulcus following the bending of the central sulcus (CURVED). CURVED mapping employed a fixed (CURVED-450 FIX) or flexible coil orientation producing always a current perpendicular to the sulcal wall (CURVED-900 FLEX). During relaxation, CURVED but not STRAIGHT mapping revealed distinct......Motor representations express some degree of somatotopy in human primary motor hand area (M1HAND), but within-M1HAND corticomotor somatotopy has been difficult to study with transcranial magnetic stimulation (TMS). Here we introduce a “linear” TMS mapping approach based on the individual shape...... was lowest for CURVED-900 FLEX. Together, the results show that within-M1HAND somatotopy can be readily probed with linear TMS mapping aligned to the sulcal shape. Sulcus-aligned linear mapping will benefit non-invasive studies of representational plasticity in human M1HAND....

  16. A novel cortical target to enhance hand motor output in humans with spinal cord injury.

    Science.gov (United States)

    Long, Jinyi; Federico, Paolo; Perez, Monica A

    2017-06-01

    A main goal of rehabilitation strategies in humans with spinal cord injury is to strengthen transmission in spared neural networks. Although neuromodulatory strategies have targeted different sites within the central nervous system to restore motor function following spinal cord injury, the role of cortical targets remain poorly understood. Here, we use 180 pairs of transcranial magnetic stimulation for ∼30 min over the hand representation of the motor cortex at an interstimulus interval mimicking the rhythmicity of descending late indirect (I) waves in corticospinal neurons (4.3 ms; I-wave protocol) or at an interstimulus interval in-between I-waves (3.5 ms; control protocol) on separate days in a randomized order. Late I-waves are thought to arise from trans-synaptic cortical inputs and have a crucial role in the recruitment of spinal motor neurons following spinal cord injury. Motor evoked potentials elicited by transcranial magnetic stimulation, paired-pulse intracortical inhibition, spinal motor neuron excitability (F-waves), index finger abduction force and electromyographic activity as well as a hand dexterity task were measured before and after both protocols in 15 individuals with chronic incomplete cervical spinal cord injury and 17 uninjured participants. We found that motor evoked potentials size increased in spinal cord injury and uninjured participants after the I-wave but not the control protocol for ∼30 to 60 min after the stimulation. Intracortical inhibition decreased and F-wave amplitude and persistence increased after the I-wave but not the control protocol, suggesting that cortical and subcortical networks contributed to changes in corticospinal excitability. Importantly, hand motor output and hand dexterity increased in individuals with spinal cord injury after the I-wave protocol. These results provide the first evidence that late synaptic input to corticospinal neurons may represent a novel therapeutic target for improving motor function

  17. Cast index in predicting outcome of proximal pediatric forearm fractures

    Directory of Open Access Journals (Sweden)

    Hassaan Qaiser Sheikh

    2015-01-01

    Conclusion: Cast index is useful in predicting redisplacement of manipulated distal forearm fractures. We found that in proximal half forearm fractures it is difficult to achieve a CI of <0.8, but increased CI does not predict loss of position in these fractures. We therefore discourage the use of CI in proximal half forearm fractures.

  18. Opportunities to improve the in vivo measurement of manganese in human hands

    Science.gov (United States)

    Aslam; Chettle, D. R.; Pejović-Milić, A.; Waker, A. J.

    2009-01-01

    Manganese (Mn) is an element which is both essential for regulating neurological and skeletal functions in the human body and also toxic when humans are exposed to excessive levels. Its excessive inhalation as a result of exposure through industrial and environmental emissions can cause neurological damage, which may manifest as memory deficit, loss of motor control and reduction in the refinement of certain body motions. A number of clinical studies demonstrate that biological monitoring of Mn exposure using body fluids, particularly blood, plasma/serum and urine is of very limited use and reflect only the most recent exposure and rapidly return to within normal ranges. In this context, a non-invasive neutron activation technique has been developed at the McMaster University accelerator laboratory that could provide an alternative to measure manganese stored in the bones of exposed subjects. In a first pilot study we conducted recently on non-exposed human subjects to measure the ratio of Mn to Ca in hand bones, it was determined that the technique needed further development to improve the precision of the measurements. It could be achieved by improving the minimum detection limit (MDL) of the system from 2.1 µg Mn/g Ca to the reference value of 0.6 µg g-1 Ca (range: 0.16-0.78 µg Mn/g Ca) for the non-exposed population. However, the developed procedure might still be a suitable means of screening patients and people exposed to excessive amounts of Mn, who could develop many-fold increased levels of Mn in bones as demonstrated through various animal studies. To improve the MDL of the technique to the expected levels of Mn in a reference population, the present study investigates further optimization of irradiation conditions, which includes the optimal selection of proton beam energy, beam current and irradiation time and the effect of upgrading the 4π detection system. The maximum local dose equivalent that could be given to the hand as a result of irradiation

  19. Reverse adipofascial flap after resection of a malignant perineurioma of the forearm.

    Science.gov (United States)

    Takahashi, Mitsuhiko; Kasai, Tokio; Nishisho, Toshihiko; Takai, Michihiro; Endo, Hideko; Hirose, Takanori; Sairyo, Koichi

    2014-07-01

    The authors describe a patient with recurrent perineurioma arising in the subcutaneous tissue of the dorsal forearm and extending along the forearm fascia. Soft tissue perineurioma is a rare, originally benign peripheral nerve sheath neoplasm arising from the perineurium, a protective cell barrier surrounding the individual fascicles in peripheral nerves. Perineurioma has only recently been recognized as an entity distinct from other nerve sheath tumors, such as schwannoma and neurofibroma, with unique morphologic, ultrastructural, and immunoreactive features. The recurrent tumor had converted into malignant perineurioma, defined as increased nuclear pleomorphism and cellularity. The ill-marginate feature extending along the fascia required wide resection, leaving a substantial defect on the distal forearm. Surgical repair of large forearm skin defects is challenging because of limited skin extensibility for flap creation, the prominence of the site in terms of aesthetic outcome, and the risk of damage to extrinsic muscles that control delicate hand movements. The reverse forearm adipofascial flap, which was based on distal perforators of the radial artery, was suitable for the current case to cover the exposed myotendinous junctions of the forearm extensor muscles. This flap did not sacrifice skin, a major vessel, or skeletal muscles, and preserved function at both the donor and the recipient sites. The texture of the graft was similar to that of the surrounding skin. The clinical and histopathologic features of this rare tumor are also described to aid in the differential diagnosis and as a reference for surgeons who treat soft tissue neoplasms and may encounter this type of soft tumor.

  20. Lymphoid neogenesis in skin of human hand, nonhuman primate, and rat vascularized composite allografts.

    Science.gov (United States)

    Hautz, Theresa; Zelger, Bettina G; Nasr, Isam W; Mundinger, Gerhard S; Barth, Rolf N; Rodriguez, Eduardo D; Brandacher, Gerald; Weissenbacher, Annemarie; Zelger, Bernhard; Cavadas, Pedro; Margreiter, Raimund; Lee, W P Andrew; Pratschke, Johann; Lakkis, Fadi G; Schneeberger, Stefan

    2014-09-01

    The mechanisms of skin rejection in vascularized composite allotransplantation (VCA) remain incompletely understood. The formation of tertiary lymphoid organs (TLO) in hand transplantation has been recently described. We assess this phenomenon in experimental and clinical VCA rejection. Skin biopsies of human (n = 187), nonhuman primate (n = 11), and rat (n = 15) VCAs were analyzed for presence of TLO. A comprehensive immunohistochemical assessment (characterization of the cell infiltrate, expression of adhesion molecules) including staining for peripheral node addressin (PNAd) was performed and correlated with rejection and time post-transplantation. TLO were identified in human, nonhuman primate, and rat skin samples. Expression of PNAd was increased in the endothelium of vessels upon rejection in human skin (P = 0.003) and correlated with B- and T-lymphocyte numbers and LFA-1 expression. PNAd expression was observed at all time-points after transplantation and increased significantly after year 5. In nonhuman primate skin, PNAd expression was found during inflammatory conditions early and late after transplantation. In rat skin, PNAd expression was strongly associated with acute rejection and time post-transplantation. Lymphoid neogenesis and TLO formation can be uniformly found in experimental and human VCA. PNAd expression in vascular endothelium correlates with skin rejection and T- and B-cell infiltration.

  1. The Robonaut 2 Hand - Designed to do Work with Tools

    Science.gov (United States)

    Bridgwater, L. B.; Ihrke, C. A.; Diftler, M. A.; Abdallah, M. E.; Radford, N. A.; Rogers, J. M.; Yayathi, S.; Askew, R. S.; Linn, D. M.

    2011-01-01

    The second generation Robonaut hand has many advantages over its predecessor. This mechatronic device is more dexterous and has improved force control and sensing giving it the capability to grasp and actuate a wider range of tools. It can achieve higher peak forces at higher speeds than the original. Developed as part of a partnership between General Motors and NASA, the hand is designed to more closely approximate a human hand. Having a more anthropomorphic design allows the hand to attain a larger set of useful grasps for working with human interfaces. Key to the hand s improved performance is the use of lower friction drive elements and a redistribution of components from the hand to the forearm, permitting more sensing in the fingers and palm where it is most important. The following describes the design, mechanical/electrical integration, and control features of the hand. Lessons learned during the development and initial operations along with planned refinements to make it more effective are presented.

  2. Perforator anatomy of the radial forearm free flap versus the ulnar forearm free flap for head and neck reconstruction

    NARCIS (Netherlands)

    Hekner, D.D.; Roeling, TAP; van Cann, EM

    2016-01-01

    The aim of this study was to investigate the vascular anatomy of the distal forearm in order to optimize the choice between the radial forearm free flap and the ulnar forearm free flap and to select the best site to harvest the flap. The radial and ulnar arteries of seven fresh cadavers were injecte

  3. Serum cytokine profiles of children with human enterovirus 71-associated hand, foot, and mouth disease.

    Science.gov (United States)

    Han, Jun; Wang, Ying; Gan, Xing; Song, Juan; Sun, Peng; Dong, Xiao-Ping

    2014-08-01

    Cytokine profiles may impact the pathogenicity and severity of hand, foot, and mouth disease caused by human enterovirus (HEV) 71. In 91 severe or mild HEV 71-associated hand, foot, and mouth disease children, serum was collected between days 2 and 10 or day >10. Serum cytokines including Type 1 T helper (Th1) cytokines: interleukin (IL)-2, interferon-gamma (IFN-γ), IL-12, and IL-18, Type 1 T helper (Th2) cytokines: IL-4, IL-10, IL-13, proinflammatory cytokines: IL-1α, IL-1β, IL-6, IL-8, IL-17, and tumor necrosis factor alpha (TNF-α), were assessed during the early stage and recovery. In the patients with mild illness, the peaks of IL-8 and IL-10 were observed on day 6 and that of IL-18 was on day 4. In the patients with severe illness, all cytokines spiked on day 3 and peaked on day 11. All cytokines except IL-6, IL-8, IL-18, and TNF-α were significantly correlated with immunoglobulin M levels by the end of the disease course. Cytokine profile variations between the patients with mild and severe illness may indicate prognosis and strain virulence, useful in clinical treatment of patients.

  4. Changes in sensory hand representation and pain thresholds induced by motor cortex stimulation in humans.

    Science.gov (United States)

    Houzé, Bérengère; Bradley, Claire; Magnin, Michel; Garcia-Larrea, Luis

    2013-11-01

    Shrinking of deafferented somatosensory regions after neural damage is thought to participate to the emergence of neuropathic pain, and pain-relieving procedures have been reported to induce the normalization of altered cortical maps. While repetitive magnetic stimulation (rTMS) of the motor cortex can lessen neuropathic pain, no evidence has been provided that this is concomitant to changes in sensory maps. Here, we assessed in healthy volunteers the ability of 2 modes of motor cortex rTMS commonly used in pain patients to induce changes in pain thresholds and plastic phenomena in the S1 cortex. Twenty minutes of high-frequency (20 Hz) rTMS significantly increased pain thresholds in the contralateral hand, and this was associated with the expansion of the cortical representation of the hand on high-density electroencephalogram source analysis. Neither of these effects were observed after sham rTMS, nor following intermittent theta-burst stimulation (iTBS). The superiority of 20-Hz rTMS over iTBS to induce sensory plasticity may reflect its better match with intrinsic cortical motor frequencies, which oscillate at around 20 Hz. rTMS-induced changes might partly counterbalance the plasticity induced by a nerve lesion, and thus substantiate the use of rTMS to treat human pain. However, a mechanistic relation between S1 plasticity and pain-relieving effects is far from being established.

  5. Non-primary motor areas in the human frontal lobe are connected directly to hand muscles.

    Science.gov (United States)

    Teitti, S; Määttä, S; Säisänen, L; Könönen, M; Vanninen, R; Hannula, H; Mervaala, E; Karhu, J

    2008-04-15

    Structural studies in primates have shown that, in addition to the primary motor cortex (M1), premotor areas are a source of corticospinal tracts. The function of these putative corticospinal neuronal tracts in humans is still unclear. We found frontal non-primary motor areas (NPMAs), which react to targeted non-invasive magnetic pulses and activate peripheral muscles as fast as or even faster than those in M1. Hand muscle movements were observed in all our subjects about 20 ms after transcranial stimulation of the superior frontal gyrus (Brodmann areas 6 and 8). Stimulation of NPMA could activate both proximal and distal upper limb muscles with the same delay as a stimulation of the M1, indicating converging motor representations with direct functional connections to the hand. We suggest that these non-primary cortical motor representations provide additional capacity for the fast execution of movements. Such a capacity may play a role in motor learning and in recovery from motor deficits.

  6. Acute forearm compartment syndrome following haemodialysis access fistula puncture in uraemia.

    Science.gov (United States)

    Lin, Chin-Ta; Dai, Niann-Tzyy; Chen, Shyi-Gen; Chang, Shun-Cheng

    2016-10-01

    Acute compartment syndrome is a well-described surgical emergency that requires immediate diagnosis and operative intervention. Vascular access-associated compartment syndrome is rarely reported in haemodialysis patients. The purpose of this article is to document evidence that catheter-related puncture, which results in arteriovenous fistula injury in uraemia, may cause acute forearm compartment syndrome. Between September 2007 and September 2012, five consecutive patients presented to our section with tense swollen forearms with skin blistering, decreased hand sensation and reduced capillary return in the fingers. Their ages ranged from 65 to 81 years (mean 72.8 years). All of the patients underwent emergent exploration after the diagnosis of acute forearm compartment syndrome. The patients' details were reviewed. The time interval between dialysis completion and return to the emergency department ranged from 6 to 9 h (mean 7.4 h). During operation, the bleeding was found to originate from the site of the fistula puncture and was repaired with 9-0 nylon suture under microscopy. After adequate wound care, a reconstructive procedure with a split-thickness skin graft was performed in all of the five patients. There was no vascular or neurological deficit of the forearm or hand within the mean follow-up period of 14.8 months (range 12-18 months). In this series, we report five cases of forearm compartment syndrome in uraemia, secondary to bleeding from a catheter-related puncture of a haemodialysis access fistula. However, there is no case series that focuses upon this specific topic in the present literature. This problem deserves more attention. © 2014 Royal Australasian College of Surgeons.

  7. [Optimizing surgical hand disinfection].

    Science.gov (United States)

    Kampf, G; Kramer, A; Rotter, M; Widmer, A

    2006-08-01

    For more than 110 years hands of surgeons have been treated before a surgical procedure in order to reduce the bacterial density. The kind and duration of treatment, however, has changed significantly over time. Recent scientific evidence suggests a few changes with the aim to optimize both the efficacy and the dermal tolerance. Aim of this article is the presentation and discussion of new insights in surgical hand disinfection. A hand wash should be performed before the first disinfection of a day, ideally at least 10 min before the beginning of the disinfection as it has been shown that a 1 min hand wash significantly increases skin hydration for up to 10 min. The application time may be as short as 1.5 min depending on the type of hand rub. Hands and forearms should be kept wet with the hand rub for the recommended application time in any case. A specific rub-in procedure according to EN 12791 has been found to be suitable in order to avoid untreated skin areas. The alcohol-based hand rub should have a proven excellent dermal tolerance in order to ensure appropriate compliance. Considering these elements in clinical practice can have a significant impact to optimize the high quality of surgical hand disinfection for prevention of surgical site infections.

  8. Hand dug wells in Namibia: An underestimated water source or a threat to human health?

    Science.gov (United States)

    Wanke, H.; Nakwafila, A.; Hamutoko, J. T.; Lohe, C.; Neumbo, F.; Petrus, I.; David, A.; Beukes, H.; Masule, N.; Quinger, M.

    The rural population of parts of northern and western Namibia uses hand dug wells for their domestic water supply, partly because no other source (e.g., deep tube wells) is available, but also as a substitute for pipeline water that is often perceived as being too expensive. The water quality of these wells is usually not monitored or controlled, thus a study has been carried out in four study areas in Namibia: southern Omusati/Oshana area, Okongo/Ohangwena area, Omatjete/Omaruru area, Okanguati/Kunene area. Hand dug wells have been tested for on-site parameters: electric conductivity, pH and temperature while samples were taken for major inorganic constituents and several minor and trace constituents including fluoride and nitrate. In addition a sampling campaign in 2010 included the determination of coliform bacteria and Escherichia coli. Results were classified according to the Namibian Water Guidelines. The constituents making the water unfit for human consumption are fluoride, nitrate, sulphate and total dissolved solids. Contamination by E. coli was indicated in nearly all wells that are used for livestock watering. For the Omatjete/Omaruru study area an isotope based study on the source of nitrate has indicated manure as a source. The range of recharge values obtained for the studied villages ranges from 1 mm/a to locally more than 100 mm/a. Overall the water resource in the shallow perched aquifers in the study areas is in many places inappropriate for human consumption. Treatment to improve the quality or introduction of protection measures is necessary to bring this resource to an acceptable quality according to national and/or international standards.

  9. Modulation of ongoing EMG by different classes of low-threshold mechanoreceptors in the human hand.

    Science.gov (United States)

    McNulty, P A; Macefield, V G

    2001-12-15

    1. We have previously demonstrated that the input from single FA I and SA II cutaneous mechanoreceptors in the glabrous skin of the human hand is sufficiently strong to modulate ongoing EMG of muscles acting on the digits. Some unresolved issues have now been addressed. 2. Single cutaneous (n = 60), joint (n = 2) and muscle spindle (n = 34) afferents were recorded via tungsten microelectrodes inserted into the median and ulnar nerves at the wrist. Spike-triggered averaging was used to investigate synaptic coupling between these afferents and muscles acting on the digits. The activity of 37 % of FA I (7/19), 20 % of FA II (1/5) and 52 % of SA II afferents (11/21) evoked a reflex response. The discharge from muscle spindles, 15 SA I and two joint afferents did not modulate EMG activity. 3. Two types of reflex responses were encountered: a single excitatory response produced by irregularly firing afferents, or a cyclic modulation evoked by regularly discharging afferents. Rhythmic stimulation of one FA I afferent generated regularly occurring bursts which corresponded to the associated cyclic EMG response. 4. Selectively triggering from the first or last spike of each burst of one FA I afferent altered the averaged EMG profile, suggesting that afferent input modulates the associated EMG and not vice versa. 5. The discharge from single FA I, FA II and SA II afferents can modify ongoing voluntary EMG in muscles of the human hand, presumably via a spinally mediated oligosynaptic pathway. Conversely, we saw no evidence of such modulation by SA I, muscle spindle or joint afferents.

  10. Design and validation of a morphing myoelectric hand posture controller based on principal component analysis of human grasping.

    Science.gov (United States)

    Segil, Jacob L; Weir, Richard F ff

    2014-03-01

    An ideal myoelectric prosthetic hand should have the ability to continuously morph between any posture like an anatomical hand. This paper describes the design and validation of a morphing myoelectric hand controller based on principal component analysis of human grasping. The controller commands continuously morphing hand postures including functional grasps using between two and four surface electromyography (EMG) electrodes pairs. Four unique maps were developed to transform the EMG control signals in the principal component domain. A preliminary validation experiment was performed by 10 nonamputee subjects to determine the map with highest performance. The subjects used the myoelectric controller to morph a virtual hand between functional grasps in a series of randomized trials. The number of joints controlled accurately was evaluated to characterize the performance of each map. Additional metrics were studied including completion rate, time to completion, and path efficiency. The highest performing map controlled over 13 out of 15 joints accurately.

  11. Magic Hands

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    THE two most amazing things on the planet may well be the human brain and human hands. When they work together, the results can be enchanting. At an international folk art fair held recently in Beijing, artisans and masters from Japan, India, Switzerland, Peru, South

  12. Human handedness: is there a difference in the independence of the digits on the preferred and non-preferred hands?

    Science.gov (United States)

    Reilly, Karen T; Hammond, Geoffrey R

    2004-05-01

    In non-human primates, comparative studies show that greater dexterity is associated with greater independent control over the digits. Studies of humans, however, show no difference in the degree of independent control of single digits on the more dexterous preferred hand and its less dexterous partner. We wondered whether there might be a difference in the degree of independent control on the two hands during performance of functionally relevant tasks. Many object manipulation tasks require the ability to produce and control forces with more than one finger at the same time. We hypothesized that asymmetrical independence, with greater independence on the preferred than the non-preferred hand, would be evident with a task that requires the simultaneous production of force in two digits. We examined digit individuation when subjects produced flexion forces with a single digit in isolation, and simultaneous flexion forces in all ten combinations of two digits. Consistent with previous studies, we found no difference between the individuation of the digits on the preferred and non-preferred hands during force production with single digits in isolation. Similarly, no asymmetry was present when forces were produced by two digits. However, separation of two-digit forces into thumb-to-digit opposition forces and non-opposition forces showed that although there was no difference in individuation between the two hands for non-opposition forces, the digits on the preferred hand were more independent than those on the non-preferred hand for opposition forces. We suggest that this independence asymmetry is not itself the underlying cause of the dexterity differences between the hands, but rather arises from a difference in the capacity for use-dependent reorganization of the motor cortical circuits controlling each hand, and that this difference might underlie the dexterity differences between the hands.

  13. Thermogenic response to adrenaline during restricted blood flow in the forearm

    DEFF Research Database (Denmark)

    Simonsen, L; Stefl, B; Christensen, N J

    1999-01-01

    To elucidate the underlying mechanism behind the thermogenic effect of adrenaline in human skeletal muscle, nine healthy subjects were studied during intravenous infusion of adrenaline. Restriction of blood flow to one forearm was obtained by external compression of the brachial artery, to separate...

  14. Thenar muscle blood flow and bone mineral in the forearms of lumberjacks.

    Science.gov (United States)

    Karjalainen, P; Alhava, E M; Valtola, J

    1975-02-01

    Forty lumberjacks who had used a chain saw for 0-20 years and who had no general disease affecting the bones were studied by measuring the thenar muscle blood flow of both hands by the 133-Xe local clearance method. Bone mineral in the left forearm in the region of cancellous and cortical bone was assessed by the 241-Am gamma ray attenuation method. Virbration was found to decrease the blood flow in the saw-bearing left hand compared with the right hand of the lumberjacks. The bone mineral density (g/vm-3) was lower in the forearm bones of the lumberjacks than in controls of the same age with healthy bones. Moreover the poorer the thenar muscle blood flow, the greater was the decrease in the mineral density of the distal radius. Measurement of the mineral density of the forearm bones by the gramma ray attenuation method can be used for early detection of bone lesions in traumatic vasospastic disease.

  15. Residual Upper Arm Motor Function Primes Innervation of Paretic Forearm Muscles in Chronic Stroke after Brain-Machine Interface (BMI Training.

    Directory of Open Access Journals (Sweden)

    Marco Rocha Curado

    Full Text Available Abnormal upper arm-forearm muscle synergies after stroke are poorly understood. We investigated whether upper arm function primes paralyzed forearm muscles in chronic stroke patients after Brain-Machine Interface (BMI-based rehabilitation. Shaping upper arm-forearm muscle synergies may support individualized motor rehabilitation strategies.Thirty-two chronic stroke patients with no active finger extensions were randomly assigned to experimental or sham groups and underwent daily BMI training followed by physiotherapy during four weeks. BMI sessions included desynchronization of ipsilesional brain activity and a robotic orthosis to move the paretic limb (experimental group, n = 16. In the sham group (n = 16 orthosis movements were random. Motor function was evaluated with electromyography (EMG of forearm extensors, and upper arm and hand Fugl-Meyer assessment (FMA scores. Patients performed distinct upper arm (e.g., shoulder flexion and hand movements (finger extensions. Forearm EMG activity significantly higher during upper arm movements as compared to finger extensions was considered facilitation of forearm EMG activity. Intraclass correlation coefficient (ICC was used to test inter-session reliability of facilitation of forearm EMG activity.Facilitation of forearm EMG activity ICC ranges from 0.52 to 0.83, indicating fair to high reliability before intervention in both limbs. Facilitation of forearm muscles is higher in the paretic as compared to the healthy limb (p<0.001. Upper arm FMA scores predict facilitation of forearm muscles after intervention in both groups (significant correlations ranged from R = 0.752, p = 0.002 to R = 0.779, p = 0.001, but only in the experimental group upper arm FMA scores predict changes in facilitation of forearm muscles after intervention (R = 0.709, p = 0.002; R = 0.827, p<0.001.Residual upper arm motor function primes recruitment of paralyzed forearm muscles in chronic stroke patients and predicts changes in

  16. Clonal CD8+ T Cell Persistence and Variable Gene Usage Bias in a Human Transplanted Hand.

    Directory of Open Access Journals (Sweden)

    Joseph Y Kim

    Full Text Available Immune prophylaxis and treatment of transplanted tissue rejection act indiscriminately, risking serious infections and malignancies. Although animal data suggest that cellular immune responses causing rejection may be rather narrow and predictable based on genetic background, there are only limited data regarding the clonal breadth of anti-donor responses in humans after allogeneic organ transplantation. We evaluated the graft-infiltrating CD8+ T lymphocytes in skin punch biopsies of a transplanted hand over 178 days. Profiling of T cell receptor (TCR variable gene usage and size distribution of the infiltrating cells revealed marked skewing of the TCR repertoire indicating oligoclonality, but relatively normal distributions in the blood. Although sampling limitation prevented complete assessment of the TCR repertoire, sequencing further identified 11 TCR clonal expansions that persisted through varying degrees of clinical rejection and immunosuppressive therapy. These 11 clones were limited to three TCR beta chain variable (BV gene families. Overall, these data indicate significant oligoclonality and likely restricted BV gene usage of alloreactive CD8+ T lymphocytes, and suggest that changes in rejection status are more due to varying regulation of their activity or number rather than shifts in the clonal populations in the transplanted organ. Given that controlled animal models produce predictable BV usage in T lymphocytes mediating rejection, understanding the determinants of TCR gene usage associated with rejection in humans may have application in specifically targeted immunotherapy.

  17. Radial forearm free flap pharyngoesophageal reconstruction.

    Science.gov (United States)

    Azizzadeh, B; Yafai, S; Rawnsley, J D; Abemayor, E; Sercarz, J A; Calcaterra, T C; Berke, G S; Blackwell, K E

    2001-05-01

    This study evaluates the outcome of pharyngoesophageal reconstruction using radial forearm free flaps with regard to primary wound healing, speech, and swallowing in patients requiring laryngopharyngectomy. Retrospective review in the setting of a tertiary, referral, and academic center. Twenty patients underwent reconstruction of the pharyngoesophageal segment using fasciocutaneous radial forearm free flaps. All free flap transfers were successful. An oral diet was resumed in 85% of the patients after surgery. Postoperative pharyngocutaneous fistulas occurred in 4 patients (20%) with 3 resolving spontaneously. Distal strictures also occurred in 20% of the patients. Five patients who underwent tracheoesophageal puncture achieved useful speech. Advantages of radial forearm free flaps for microvascular pharyngoesophageal function include high flap reliability, limited donor site morbidity, larger vascular pedicle caliber, and the ability to achieve good quality tracheoesophageal speech. The swallowing outcome is similar to that achieved after jejunal flap pharyngoesophageal reconstruction. The main disadvantage of this technique relates to a moderately high incidence of pharyngocutaneous fistulas, which contributes to delayed oral intake in affected patients.

  18. Metabolic forearm vasodilation is enhanced following Bier block with phentolamine.

    Science.gov (United States)

    Moradkhan, Raman; McQuillan, Patrick; Hogeman, Cynthia; Leuenberger, Andrea; Linton-Frazier, Latoya; Leuenberger, Urs A

    2007-10-01

    The extent to which sympathetic nerve activity restrains metabolic vasodilation in skeletal muscle remains unclear. We determined forearm blood flow (FBF; ultrasound/Doppler) and vascular conductance (FVC) responses to 10 min of ischemia [reactive hyperemic blood flow (RHBF)] and 10 min of systemic hypoxia (inspired O(2) fraction = 0.1) before and after regional sympathetic blockade with the alpha-receptor antagonist phentolamine via Bier block in healthy humans. In a control group, we performed sham Bier block with saline. Consistent with alpha- receptor inhibition, post-phentolamine, basal FVC (FBF/mean arterial pressure) increased (pre vs. post: 0.42 +/- 0.05 vs. 1.03 +/- 0.21 units; P phentolamine, total RHBF (over 3 min) increased substantially (pre vs. post: 628 +/- 75 vs. 826 +/- 92 ml/min; P phentolamine (pre vs. post: 0.43 +/- 0.06 vs. 1.16 +/- 0.17 units; P < 0.01; n = 8) but not post-saline (pre vs. post: 0.93 +/- 0.16 vs. 0.87 +/- 0.19 ml/min; P = not significant; n = 5), the FVC response to hypoxia (arterial O(2) saturation = 77 +/- 1%) was markedly enhanced. These data suggest that sympathetic vasoconstrictor nerve activity markedly restrains skeletal muscle vasodilation induced by local (forearm ischemia) and systemic (hypoxia) vasodilator stimuli.

  19. Vasoconstricting effect of angiotensin II in human hand veins: influence of aging, diabetes mellitus and hypertension.

    Science.gov (United States)

    Harada, Kazuhiro; Ohmori, Masami; Fujimura, Akio

    2002-09-01

    We examined human hand veins to determine whether venoconstricting response to angiotensin II (Ang II) and noradrenaline (NA) was influenced by aging or such diseases as diabetes mellitus (DM) and hypertension (HT). Twenty healthy male subjects (20-73 years), and 8 male patients with non-insulin-dependent DM and 8 male patients with essential HT were included in this study. A constant dose (50 ng/min) of Ang II or increasing dose (2-256 ng/min) of NA was infused into the dorsal hand vein and its diameter was measured using a linear variable differential transformer. The constant infusion of Ang II caused rapid desensitization or tachyphylaxis. The venoconstriction by Ang II in the 8 elderly subjects (58 to 73 years) was significantly (p<0.05) larger than that in the 8 young subjects (20 to 36 years) from 6 to 18 min after the start of the infusion (after 6 min: 63.6+/-11.6 (mean+/-SD)% vs. 39.9+/-20.8%, 12 min: 34.0+/-11.9% vs. 12.0+/-12.0%). However, the venoconstriction by Ang II in the patients with DM or HT was not significantly different from that in the 9 age-matched control subjects. No significant difference in venoconstrictor response to NA was observed between the young and elderly subjects, nor between the control subjects and the patients with DM or HT. These findings indicated that venoconstrictor response to Ang II might be greater in the elderly but might not be influenced by DM nor HT.

  20. Decoding individual finger movements from one hand using human EEG signals.

    Directory of Open Access Journals (Sweden)

    Ke Liao

    Full Text Available Brain computer interface (BCI is an assistive technology, which decodes neurophysiological signals generated by the human brain and translates them into control signals to control external devices, e.g., wheelchairs. One problem challenging noninvasive BCI technologies is the limited control dimensions from decoding movements of, mainly, large body parts, e.g., upper and lower limbs. It has been reported that complicated dexterous functions, i.e., finger movements, can be decoded in electrocorticography (ECoG signals, while it remains unclear whether noninvasive electroencephalography (EEG signals also have sufficient information to decode the same type of movements. Phenomena of broadband power increase and low-frequency-band power decrease were observed in EEG in the present study, when EEG power spectra were decomposed by a principal component analysis (PCA. These movement-related spectral structures and their changes caused by finger movements in EEG are consistent with observations in previous ECoG study, as well as the results from ECoG data in the present study. The average decoding accuracy of 77.11% over all subjects was obtained in classifying each pair of fingers from one hand using movement-related spectral changes as features to be decoded using a support vector machine (SVM classifier. The average decoding accuracy in three epilepsy patients using ECoG data was 91.28% with the similarly obtained features and same classifier. Both decoding accuracies of EEG and ECoG are significantly higher than the empirical guessing level (51.26% in all subjects (p<0.05. The present study suggests the similar movement-related spectral changes in EEG as in ECoG, and demonstrates the feasibility of discriminating finger movements from one hand using EEG. These findings are promising to facilitate the development of BCIs with rich control signals using noninvasive technologies.

  1. Decoding individual finger movements from one hand using human EEG signals.

    Science.gov (United States)

    Liao, Ke; Xiao, Ran; Gonzalez, Jania; Ding, Lei

    2014-01-01

    Brain computer interface (BCI) is an assistive technology, which decodes neurophysiological signals generated by the human brain and translates them into control signals to control external devices, e.g., wheelchairs. One problem challenging noninvasive BCI technologies is the limited control dimensions from decoding movements of, mainly, large body parts, e.g., upper and lower limbs. It has been reported that complicated dexterous functions, i.e., finger movements, can be decoded in electrocorticography (ECoG) signals, while it remains unclear whether noninvasive electroencephalography (EEG) signals also have sufficient information to decode the same type of movements. Phenomena of broadband power increase and low-frequency-band power decrease were observed in EEG in the present study, when EEG power spectra were decomposed by a principal component analysis (PCA). These movement-related spectral structures and their changes caused by finger movements in EEG are consistent with observations in previous ECoG study, as well as the results from ECoG data in the present study. The average decoding accuracy of 77.11% over all subjects was obtained in classifying each pair of fingers from one hand using movement-related spectral changes as features to be decoded using a support vector machine (SVM) classifier. The average decoding accuracy in three epilepsy patients using ECoG data was 91.28% with the similarly obtained features and same classifier. Both decoding accuracies of EEG and ECoG are significantly higher than the empirical guessing level (51.26%) in all subjects (pmovement-related spectral changes in EEG as in ECoG, and demonstrates the feasibility of discriminating finger movements from one hand using EEG. These findings are promising to facilitate the development of BCIs with rich control signals using noninvasive technologies.

  2. NOTE: A preliminary study for non-invasive quantification of manganese in human hand bones

    Science.gov (United States)

    Aslam; Pejović-Milić, A.; Chettle, D. R.; McNeill, F. E.; Pysklywec, M. W.; Oudyk, J.

    2008-10-01

    Manganese (Mn) is a nutrient essential for regulating neurological and skeletal functions in the human body, but it is also toxic when humans are excessively exposed to Mn. Blood (or serum/plasma) and other body fluids reflect only the most recent exposure and rapidly return to within normal ranges, even when there has been a temporary excursion in response to exposure. In this context, we have been developing a non-invasive measurement of Mn stored in bone, using in vivo neutron activation analysis. Following feasibility studies, a first pilot study, using neutron activation analysis to measure Mn in the bones of the hand of ten healthy male human subjects, was conducted with the approval of the concerned research ethics boards. The participants of this study had no known history of exposure to Mn. Two volunteers were excluded from this study due to technical problems with their measurements. The inverse variance weighted mean value of Mn/Ca for the participants of this study is 0.12 ± 0.68 µg Mn/g Ca which is comparable within uncertainties with the estimated range of 0.16 0.78 µg Mn/g Ca and mean value of 0.63 ± 0.30 µg Mn/g Ca derived from cadaver data. It is recommended to investigate the use of the diagnostic technique for in vivo measurements of workers exposed occupationally to excessive amounts of Mn who could develop many-fold increased levels of Mn in bones as demonstrated through various animal studies. The technique needs further development to improve the precision of in vivo measurements in the non-exposed population.

  3. A region finding method to remove the noise from the images of the human hand gesture recognition system

    Science.gov (United States)

    Khan, Muhammad Jibran; Mahmood, Waqas

    2015-12-01

    The performance of the human hand gesture recognition systems depends on the quality of the images presented to the system. Since these systems work in real time environment the images may be corrupted by some environmental noise. By removing the noise the performance of the system can be enhanced. So far different noise removal methods have been presented in many researches to eliminate the noise but all have its own limitations. We have presented a region finding method to deal with the environmental noise that gives better results and enhances the performance of the human hand gesture recognition systems so that the recognition rate of the system can be improved.

  4. Neural coupling of cooperative hand movements: a reflex and fMRI study.

    Science.gov (United States)

    Dietz, Volker; Macauda, Gianluca; Schrafl-Altermatt, Miriam; Wirz, Markus; Kloter, Evelyne; Michels, Lars

    2015-04-01

    The neural control of "cooperative" hand movements reflecting "opening a bottle" was explored in human subjects by electromyographic (EMG) and functional magnetic resonance imaging (fMRI) recordings. EMG responses to unilateral nonnoxious ulnar nerve stimulation were analyzed in the forearm muscles of both sides during dynamic movements against a torque applied by the right hand to a device which was compensated for by the left hand. For control, stimuli were applied while task was performed in a static/isometric mode and during bilateral synchronous pro-/supination movements. During the dynamic cooperative task, EMG responses to stimulations appeared in the right extensor and left flexor muscles, regardless of which side was stimulated. Under the control conditions, responses appeared only on the stimulated side. fMRI recordings showed a bilateral extra-activation and functional coupling of the secondary somatosensory cortex (S2) during the dynamic cooperative, but not during the control, tasks. This activation might reflect processing of shared cutaneous input during the cooperative task. Correspondingly, it is assumed that stimulation-induced unilateral volleys are processed in S2, leading to a release of EMG responses to both forearms. This indicates a task-specific neural coupling during cooperative hand movements, which has consequences for the rehabilitation of hand function in poststroke patients.

  5. Three-Fingered Robot Hand

    Science.gov (United States)

    Ruoff, C. F.; Salisbury, J. K.

    1984-01-01

    Mechanical joints and tendons resemble human hand. Robot hand has three "human-like" fingers. "Thumb" at top. Rounded tips of fingers covered with resilient material provides high friction for griping. Hand potential as prosthesis for humans.

  6. Morphological features, nerve supply and characteristics of intramuscular tendinous laminae of multitendoned muscles in human forearm*%人前臂多肌腱肌肉的形态特点、神经分布及肌内腱板特征

    Institute of Scientific and Technical Information of China (English)

    王灵战; 王立群; 孟壮志; 刘海英; 李建国; 呼和

    2011-01-01

    Objective: To discuss the role of multitendoned muscles in human forearm in the movement of 2-5 fingers by observing their morphological features, nerve supply and the arrangement of the intramuscular tendinous laminae or fibrous septa. Methods: Dissecting and observing the nervous origin, the arrangement and intramuscular septa in the transverse sections in multitendoned muscles in the human forearm with aid of SXP-1C operating microscope. Results:, The muscle bellies of multitendoned muscles were fused with those of the adjacent muscles at the origin and distally separated into 4 relatively independent muscle bundles. The muscle bundles tapered distally and were continuous with the tendons which were inserted on 2-5 fingers. No obvious demarcation lay among these muscle bundles, while the muscle bundle to the index finger was more independent Usually more than 4 main nerve trunks innervated each multitendoned muscle and entered into the muscle at the different sites. The sections of multitendoned muscles showed that the incomplete intramuscular tendinous laminae or fibrous septa existed in them. Conclusion: The morphological features, nerve supply and the existence of the incomplete intramuscular tendinous laminae or fibrous septa in multitendoned muscles in the human forearm are correlated with the limitation of independent movement of 2-5 fingers. Surgeons should pay attention to the branches of median nerve to forearm when performing the operation on the anterior cubital region and proximal part of the forearm.%目的:观察人前臂多肌腱肌肉的形态特点、神经分布及其横断面内肌内腱板或纤维隔的特征,探讨其在手指运动中的作用.方法:在SXP-1C型手术显微镜下,解剖、观察前臂多肌腱肌肉的神经分支来源、分布及其横断面内的肌内间隔.结果:前臂多肌腱肌肉在起始处与毗邻肌肉的肌腹相结合,远侧分为4个相对独立的肌束,并逐渐移行至第2~5指肌腱.4个肌束之

  7. Early Pleistocene human hand phalanx from the Sima del Elefante (TE) cave site in Sierra de Atapuerca (Spain).

    Science.gov (United States)

    Lorenzo, Carlos; Pablos, Adrián; Carretero, José Miguel; Huguet, Rosa; Valverdú, Josep; Martinón-Torres, María; Arsuaga, Juan Luis; Carbonell, Eudald; Bermúdez de Castro, José María

    2015-01-01

    In this study, a new Early Pleistocene proximal hand phalanx (ATE9-2) from the Sima del Elefante cave site (TE - Sierra de Atapuerca, Spain), ascribed to Homo sp., is presented and comparatively described in the context of the evolution of the genus Homo. The ATE9-2 specimen is especially important because of the paucity of hand bones in the human fossil record during the Early Pleistocene. The morphological and metrical analyses of the phalanx ATE9-2 indicate that there are no essential differences between it and comparator fossil specimens for the genus Homo after 1.3 Ma (millions of years ago). Similar to Sima de los Huesos and Neandertal specimens, ATE9-2 is a robust proximal hand phalanx, probably reflecting greater overall body robusticity in these populations or a higher gracility in modern humans. The age of level TE9 from Sima del Elefante and morphological and metrical studies of ATE9-2 suggest that the morphology of the proximal hand phalanges and, thus, the morphology of the hand could have remained stable over the last 1.2-1.3 Ma. Taking into account the evidence recently provided by a metacarpal from Kaitio (Kenya) from around 1.42 Ma, we argue that modern hand morphology is present in the genus Homo subsequent to Homo habilis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Forearm Range of Motion in Australovenator wintonensis (Theropoda, Megaraptoridae.

    Directory of Open Access Journals (Sweden)

    Matt A White

    Full Text Available The hypertrophied manual claws and modified manus of megaraptoran theropods represent an unusual morphological adaptation among carnivorous dinosaurs. The skeleton of Australovenator wintonensis from the Cenomanian of Australia is among the most complete of any megaraptorid. It presents the opportunity to examine the range of motion of its forearm and the function of its highly modified manus. This provides the basis for behavioural inferences, and comparison with other Gondwanan theropod groups. Digital models created from computed tomography scans of the holotype reveal a humerus range of motion that is much greater than Allosaurus, Acrocanthosaurus, Tyrannosaurus but similar to that of the dromaeosaurid Bambiraptor. During flexion, the radius was forced distally by the radial condyle of the humerus. This movement is here suggested as a mechanism that forced a medial movement of the wrist. The antebrachium possessed a range of motion that was close to dromaeosaurids; however, the unguals were capable of hyper-extension, in particular manual phalanx I-2, which is a primitive range of motion characteristic seen in allosaurids and Dilophosaurus. During flexion, digits I and II slightly converge and diverge when extended which is accentuated by hyperextension of the digits in particular the unguals. We envision that prey was dispatched by its hands and feet with manual phalanx I-2 playing a dominant role. The range of motion analysis neither confirms nor refutes current phylogenetic hypotheses with regards to the placement of Megaraptoridae; however, we note Australovenator possessed, not only a similar forearm range of motion to some maniraptorans and basal coelurosaurs, but also similarities with Tetanurans (Allosauroids and Dilophosaurus.

  9. Electromyographic assessment of forearm muscle function in tennis players with and without Lateral Epicondylitis.

    Science.gov (United States)

    Alizadehkhaiyat, Omid; Frostick, Simon P

    2015-12-01

    There is no consensus about the main aetiology of Lateral Epicondylitis (LE) or Tennis Elbow. While electromyographic assessment of alterations in neuromuscular control and activation patterns of forearm muscles has received increasing interest as potential intrinsic factors in non-tennis players, there has been insufficient attention in tennis players. The purpose of present review was to search the literature for the electromyographic studies of forearm muscles in tennis players in order to (1) identify related implications for LE, (2) highlight key technical and methodological shortcomings, and (3) suggest potential pathways for future research. An electronic search of PubMed, Scopus, Web of Science, and Google Scholars (1980 to October 2014) was conducted. Titles, abstracts, and full-text articles were screened to identify "peer-reviewed" studies specifically looking into "electromyographic assessment of forearm muscles" in "tennis players". After screening 104 articles, 13 original articles were considered in the main review involving a total of 216 participants (78% male, 22% female). There were indications of increased wrist extensor activity in all tennis strokes and less experienced single-handed players, however with insufficient evidence to support their relationship with the development of LE. Studies varied widely in study population, sample size, gender, level of tennis skills, electrode type, forearm muscles studied, EMG recording protocol, EMG normalisation method, and reported parameters. As a result, it was not possible to present combined results of existing studies and draw concrete conclusions in terms of clinical implications of findings. There is a need for establishment of specific guidelines and recommendations for EMG assessment of forearm musculature particularly in terms of electrode and muscle selection. Further studies of both healthy controls and tennis players suffering from LE with adequate sample sizes and well-defined demographics

  10. Learning Dexterous Manipulation for a Soft Robotic Hand from Human Demonstration

    OpenAIRE

    2016-01-01

    Dexterous multi-fingered hands can accomplish fine manipulation behaviors that are infeasible with simple robotic grippers. However, sophisticated multi-fingered hands are often expensive and fragile. Low-cost soft hands offer an appealing alternative to more conventional devices, but present considerable challenges in sensing and actuation, making them difficult to apply to more complex manipulation tasks. In this paper, we describe an approach to learning from demonstration that can be used...

  11. [Diagnostics of the skeletal massiveness and human somatotype using hand bones].

    Science.gov (United States)

    Zviagin, V N; Zamiatina, A O; Galitskaia, O I

    2003-01-01

    The skeleton massiveness (SM) and the somatotype of human constitution were determined on the basis of osteometry of bones of carpal and metacarpal bones (MB) and of phalanxes. Seventy male and 13 female skeletons from the collection of the chair for anthropology, Moscow State University, were investigated. Described are the results of examinations of 8 carpal bones made according to 3 signs (length, width, and height), and of 5 metacarpal bones made according to 4 signs (length, base and head width, and base height); investigation findings of finger phalanxes (in full) are also presented. Methods of current multidimensional statistics were used within the case study, i.e. related with the key components--for SM specification and the discriminative analysis--for constitution specification. The SM determination accuracy according to type A was 40%, according to type B--80%, according to type C--37.5% and according to type D--52.9%. The classification accuracy of constitutions by carpal bones was 50.0%, by MB--46.4%, and by MB plus finger phalanxes--48.1%. It is pointed out that it was for the first time that the elaborated quantitative criteria of osteometry of hand bones could be used in the expertise practice for the purpose of personality identification by osseous remains.

  12. A Study on Decoding Models for the Reconstruction of Hand Trajectories from the Human Magnetoencephalography

    Directory of Open Access Journals (Sweden)

    Hong Gi Yeom

    2014-01-01

    Full Text Available Decoding neural signals into control outputs has been a key to the development of brain-computer interfaces (BCIs. While many studies have identified neural correlates of kinematics or applied advanced machine learning algorithms to improve decoding performance, relatively less attention has been paid to optimal design of decoding models. For generating continuous movements from neural activity, design of decoding models should address how to incorporate movement dynamics into models and how to select a model given specific BCI objectives. Considering nonlinear and independent speed characteristics, we propose a hybrid Kalman filter to decode the hand direction and speed independently. We also investigate changes in performance of different decoding models (the linear and Kalman filters when they predict reaching movements only or predict both reach and rest. Our offline study on human magnetoencephalography (MEG during point-to-point arm movements shows that the performance of the linear filter or the Kalman filter is affected by including resting states for training and predicting movements. However, the hybrid Kalman filter consistently outperforms others regardless of movement states. The results demonstrate that better design of decoding models is achieved by incorporating movement dynamics into modeling or selecting a model according to decoding objectives.

  13. Enhanced propriospinal excitation from hand muscles to wrist flexors during reach-to-grasp in humans.

    Science.gov (United States)

    Giboin, Louis-Solal; Lackmy-Vallée, Alexandra; Burke, David; Marchand-Pauvert, Véronique

    2012-01-01

    In humans, propriospinal neurons located at midcervical levels receive peripheral and corticospinal inputs and probably participate in the control of grip tasks, but their role in reaching movements, as observed in cats and primates, is still an open question. The effect of ulnar nerve stimulation on flexor carpi radialis (FCR) motor evoked potential (MEP) was tested during reaching tasks and tonic wrist flexion. Significant MEP facilitation was observed at the end of reach during reach-to-grasp but not during grasp, reach-to-point, or tonic contractions. MEP facilitation occurred at a longer interstimulus interval than expected for convergence of corticospinal and afferent volleys at motoneuron level and was not paralleled by a change in the H-reflex. These findings suggest convergence of the two volleys at propriospinal level. Ulnar-induced MEP facilitation was observed when conditioning stimuli were at 0.75 motor response threshold (MT), but not 1 MT. This favors an increased excitability of propriospinal neurons rather than depression of their feedback inhibition, as has been observed during tonic power grip tasks. It is suggested that the ulnar-induced facilitation of FCR MEP during reach may be due to descending activation of propriospinal neurons, assisting the early recruitment of large motoneurons for rapid movement. Because the feedback inhibitory control is still open, this excitation can be truncated by cutaneous inputs from the palmar side of the hand during grasp, thus assisting movement termination. It is concluded that the feedforward activation of propriospinal neurons and their feedback control may be involved in the internal model, motor planning, and online adjustments for reach-to-grasp movements in humans.

  14. The human touch: skin temperature during the rubber hand illusion in manual and automated stroking procedures.

    Directory of Open Access Journals (Sweden)

    Marieke Rohde

    Full Text Available A difference in skin temperature between the hands has been identified as a physiological correlate of the rubber hand illusion (RHI. The RHI is an illusion of body ownership, where participants perceive body ownership over a rubber hand if they see it being stroked in synchrony with their own occluded hand. The current study set out to replicate this result, i.e., psychologically induced cooling of the stimulated hand using an automated stroking paradigm, where stimulation was delivered by a robot arm (PHANToM(TM force-feedback device. After we found no evidence for hand cooling in two experiments using this automated procedure, we reverted to a manual stroking paradigm, which is closer to the one employed in the study that first produced this effect. With this procedure, we observed a relative cooling of the stimulated hand in both the experimental and the control condition. The subjective experience of ownership, as rated by the participants, by contrast, was strictly linked to synchronous stroking in all three experiments. This implies that hand-cooling is not a strict correlate of the subjective feeling of hand ownership in the RHI. Factors associated with the differences between the two designs (differences in pressure of tactile stimulation, presence of another person that were thus far considered irrelevant to the RHI appear to play a role in bringing about this temperature effect.

  15. The Human Touch: Skin Temperature during the Rubber Hand Illusion in Manual and Automated Stroking Procedures

    Science.gov (United States)

    Rohde, Marieke; Wold, Andrew; Karnath, Hans-Otto; Ernst, Marc O.

    2013-01-01

    A difference in skin temperature between the hands has been identified as a physiological correlate of the rubber hand illusion (RHI). The RHI is an illusion of body ownership, where participants perceive body ownership over a rubber hand if they see it being stroked in synchrony with their own occluded hand. The current study set out to replicate this result, i.e., psychologically induced cooling of the stimulated hand using an automated stroking paradigm, where stimulation was delivered by a robot arm (PHANToMTM force-feedback device). After we found no evidence for hand cooling in two experiments using this automated procedure, we reverted to a manual stroking paradigm, which is closer to the one employed in the study that first produced this effect. With this procedure, we observed a relative cooling of the stimulated hand in both the experimental and the control condition. The subjective experience of ownership, as rated by the participants, by contrast, was strictly linked to synchronous stroking in all three experiments. This implies that hand-cooling is not a strict correlate of the subjective feeling of hand ownership in the RHI. Factors associated with the differences between the two designs (differences in pressure of tactile stimulation, presence of another person) that were thus far considered irrelevant to the RHI appear to play a role in bringing about this temperature effect. PMID:24260454

  16. Sensory Evaluation of Post Traumatic Thumb after Reconstruction with Reverse Radial Forearm Flap

    Directory of Open Access Journals (Sweden)

    Tayeb Ghadimi

    2013-09-01

    Full Text Available Background: Thumb is with a special role in hand function. Therefore, in addition to the significance of using thin, pliable, color-matched, and hairless cover in resurfacing the lesion in this area, recovery of sensation should also be taken into consideration. Materials and Methods: Thirteen patients with thumb degloving injuries were candidates for sensate reverse island radial forearm surgery. After transferring the flap, forearm lateral sensory nerve was sewn to the thumb digital nerve. At least for two years, these patients received regular diagnosis, and monofilament, static two point discrimination (S-2PD, and moving two point discrimination (M-2PD tests were taken from them.Results: Monofilament test did not show normal sensation recovery, at protective sensation threshold, in the parents. The difference between monofilament test and normal thumb was statistically significant (p<0.0001. In spite of this, the protective sensation was restored in all flaps after two years. According to the results from S-2PD and M-2PD tests, the restored sensation was at protective threshold or reduced, and the difference was statistically significant (p<0.0001.Conclusion: Given difficulties of performing free flaps, and also deficiencies of pedicle flaps, the forearm radial island flap is known as one of the primary choices in most of the thumb soft tissue and hand defects reconstruction, due to its advantages, especially restoring the sensation of the injured site.

  17. The fighting hypothesis in combat : How well does the fighting hypothesis explain human left-handed minorities?

    NARCIS (Netherlands)

    Groothuis, Ton G.G.; McManus, I.C.; Schaafsma, Sara M.; Geuze, Reint H.; McGrew, WC; Schiefenhovel, W; Marchant, LF

    2013-01-01

    The strong population bias in hand preference in favor of right-handedness seems to be a typical human trait. An elegant evolutionary hypothesis explaining this trait is the so-called fighting hypothesis that postulates that left-handedness is under frequency-dependent selection. The fighting hypoth

  18. (Not) Made by the human hand: media consciousness and immediacy in the cultural production of the real

    NARCIS (Netherlands)

    van de Port, M.

    2011-01-01

    Taking its examples from the realm of popular religion and popular culture, this essay shows how sensations of im-mediacy are sought and produced in a great number of fantasy scripts. Some of these scripts seek to undo media-awareness: concealing or denying the involvement of the human hand they pro

  19. Preliminary study on proportional and simultaneous estimation of hand posture using surface EMG based on synergy concept.

    Science.gov (United States)

    Li, Shunchong; Chen, Xingyu; Sheng, Xinjun; Zhu, Xiangyang

    2013-01-01

    Most of current myoelectric prostheses are using sequential and on-off control strategy within pattern classification framework, which is of robustness. But it is not a natural neuromuscular control scheme. On the other hand, there are two difficulties to control the prosthesis proportionally and simultaneously. First, human hand is high dimensional with more than 20 degrees-of-freedom (DOFs); Second, extracting such control information from EMG is hard due to signal crosstalk and noises. This paper is aimed at proposing a new method for proportional and simultaneous myoelectric control, taking advantage of synergy concept. The hand motion and corresponding forearm EMG signals were collected simultaneously. Principal component analysis (PCA) is used to reduce hand motion dimension. And support vector regression (SVR) is adopted to build the connection between hand posture and EMG. Offline analysis validated the effectiveness of this method, and preliminary and positive results have been obtained.

  20. The Concomitant Presence of Two Anomalous Muscles in the Forearm

    OpenAIRE

    Ogun, Tunç Cevat; Karalezli, Nazım; Ogun, Cemile Oztin

    2007-01-01

    This article describes the concomitant presence of two anomalous forearm muscles in a 20-year-old man, discovered accidentally during an operation for a forearm injury. The first one was similar to a reverse palmaris longus muscle except for its direction to the Guyon’s canal. The second one originated from the radial antebrachial fascia, superficial to all other forearm muscles in the lower half of the forearm, then diverged medially and extended into the Guyon’s canal and was innervated by ...

  1. The study of intramuscular nerve distribution patterns and relative spindle abundance of the thenar and hypothenar muscles in human hand.

    Science.gov (United States)

    Xie, Peng; Jiang, Yanjun; Zhang, Xiaoming; Yang, Shengbo

    2012-01-01

    The intramuscular nerve distribution and relative spindle abundance of the human hand have not been well defined, although this is important in guiding hand surgery. Forty human hands were dissected and subjected to modified Sihler's stain and haematoxylin and eosin stain to investigate intramuscular nerve distribution and relative spindle abundance, respectively. The flexor pollicis brevis (FPB), adductor pollicis (AP), and abductor digiti minimi (ADM) contain separate nerve compartments. Neural anastomoses were observed in the thenar and hypothenar muscles, including the Y-like, O-like, H-like, and U-like appearance. We found that U-like neural anastomoses may be the characteristic of the opponens muscles. The relative spindle abundance was the greatest in the opponens muscles which may coordinate fine movements. Except for the two opponens muscles, the rest of the thenar and hypothenar muscles could be used as whole muscle or half-muscle donors for muscle transplant. Our nerve map of the hand offers valuable guidance for hand reconstruction.

  2. Bringing transcranial mapping into shape: Sulcus-aligned mapping captures motor somatotopy in human primary motor hand area.

    Science.gov (United States)

    Raffin, Estelle; Pellegrino, Giovanni; Di Lazzaro, Vincenzo; Thielscher, Axel; Siebner, Hartwig Roman

    2015-10-15

    Motor representations express some degree of somatotopy in human primary motor hand area (M1HAND), but within-M1HAND corticomotor somatotopy has been difficult to study with transcranial magnetic stimulation (TMS). Here we introduce a "linear" TMS mapping approach based on the individual shape of the central sulcus to obtain mediolateral corticomotor excitability profiles of the abductor digiti minimi (ADM) and first dorsal interosseus (FDI) muscles. In thirteen young volunteers, we used stereotactic neuronavigation to stimulate the right M1HAND with a small eight-shaped coil at 120% of FDI resting motor threshold. We pseudorandomly stimulated six targets located on a straight mediolateral line corresponding to the overall orientation of the central sulcus with a fixed coil orientation of 45° to the mid-sagittal line (STRAIGHT-450FIX) or seven targets in the posterior part of the crown of the central sulcus following the bending of the central sulcus (CURVED). CURVED mapping employed a fixed (CURVED-450FIX) or flexible coil orientation producing always a current perpendicular to the sulcal wall (CURVED-900FLEX). During relaxation, CURVED but not STRAIGHT mapping revealed distinct corticomotor excitability peaks in M1HAND with the excitability maximum of ADM located medially to the FDI maximum. This mediolateral somatotopy was still present during tonic contraction of the ADM or FDI. During ADM contraction, cross-correlation between the spatial excitability profiles of ADM and FDI was lowest for CURVED-900FLEX. Together, the results show that within-M1HAND somatotopy can be readily probed with linear TMS mapping aligned to the sulcal shape. Sulcus-aligned linear mapping will benefit non-invasive studies of representational plasticity in human M1HAND.

  3. Skin contact transfer of three fragrance residues from candles to human hands.

    Science.gov (United States)

    Api, Anne Marie; Bredbenner, Amy; McGowen, Margaret; Niemiera, David; Parker, Lori; Renskers, Kevin; Selim, Sami; Sgaramella, Richard; Signorelli, Richard; Tedrow, Sebastian; Troy, William

    2007-08-01

    The dermal hand transfer of three fragrance materials (cinnamic aldehyde, d-limonene and eugenol) from scented candles was determined in 10 subjects (i.e., 20 hands) after grasping scented candles for 5 consecutive 20s exposures/grasps. The fragrance materials from each subject's hands were recovered by isopropyl alcohol wipes and subsequent extractions. Removal efficiencies for both cinnamic aldehyde and eugenol placed directly on the hands were not concentration dependent and ranged from 103% to 106%. The removal efficiency of d-limonene showed an inverse relation with 74.3% removed at the low concentration of 50 microg and 63.8% removed at the high concentration of 500 microg. The residue/transfer of d-limonene from the candles to the hands was below the limit of detection of 50 microg. The residue/transfer of cinnamic aldehyde and eugenol to each subject's hands was consistent between subjects as well as between each exposure/grasp. The total mean residues of cinnamic aldehyde and eugenol transferred per grasp from the candles to the hands were 0.255 microg/cm(2) and 0.279 microg/cm(2), respectively.

  4. Treatment of diaphyseal forearm fractures in children

    Directory of Open Access Journals (Sweden)

    Matthew L. Vopat

    2014-06-01

    Full Text Available Both bone forearm fractures are common orthopedic injuries. Optimal treatment is dictated not only by fracture characteristics but also patient age. In the pediatric population, acceptable alignment can tolerate greater fracture displacement due to the bone’s ability to remodel with remaining growth. Generally, these fractures can be successfully managed with closed reduction and casting, however operative fixation may also be required. The optimal method of fixation has not been clearly established. Currently, the most common operative interventions are open reduction with plate fixation versus closed or open reduction with intramedullary fixation. Plating has advantages of being more familiar to many surgeons, being theoretically superior in the ability to restore radial bow, and providing the possibility of hardware retention. Recently, intramedullary nailing has been gaining popularity due to decreased soft tissue dissection; however, a second operation is needed for hardware removal generally 6 months after the index procedure. Current literature has not established the superiority of one surgical method over the other. The goal of this manuscript is to review the current literature on the treatment of pediatric forearm fractures and provide clinical recommendations for optimal treatment, focusing specifically on children ages 3-10 years old.

  5. Hand posture classification using electrocorticography signals in the gamma band over human sensorimotor brain areas

    Science.gov (United States)

    Chestek, Cynthia A.; Gilja, Vikash; Blabe, Christine H.; Foster, Brett L.; Shenoy, Krishna V.; Parvizi, Josef; Henderson, Jaimie M.

    2013-04-01

    Objective. Brain-machine interface systems translate recorded neural signals into command signals for assistive technology. In individuals with upper limb amputation or cervical spinal cord injury, the restoration of a useful hand grasp could significantly improve daily function. We sought to determine if electrocorticographic (ECoG) signals contain sufficient information to select among multiple hand postures for a prosthetic hand, orthotic, or functional electrical stimulation system.Approach. We recorded ECoG signals from subdural macro- and microelectrodes implanted in motor areas of three participants who were undergoing inpatient monitoring for diagnosis and treatment of intractable epilepsy. Participants performed five distinct isometric hand postures, as well as four distinct finger movements. Several control experiments were attempted in order to remove sensory information from the classification results. Online experiments were performed with two participants. Main results. Classification rates were 68%, 84% and 81% for correct identification of 5 isometric hand postures offline. Using 3 potential controls for removing sensory signals, error rates were approximately doubled on average (2.1×). A similar increase in errors (2.6×) was noted when the participant was asked to make simultaneous wrist movements along with the hand postures. In online experiments, fist versus rest was successfully classified on 97% of trials; the classification output drove a prosthetic hand. Online classification performance for a larger number of hand postures remained above chance, but substantially below offline performance. In addition, the long integration windows used would preclude the use of decoded signals for control of a BCI system. Significance. These results suggest that ECoG is a plausible source of command signals for prosthetic grasp selection. Overall, avenues remain for improvement through better electrode designs and placement, better participant training

  6. METHOD OF PHYSIOTHERAPY MEDICAL PROCEDURES FOR THERMAL IMPACT ON SELECTED AREAS WITH HUMAN HANDS THERMOELECTRIC DEVICES

    Directory of Open Access Journals (Sweden)

    A. B. Sulin

    2015-01-01

    Full Text Available The device for thermal impact on separate zones of a hand of the person executed on the basis of thermoelectric converters of energy is considered. The advantages consisting in high environmental friendliness, noiselessness, reliability, functionality, universality are noted it. The technique of carrying out medical (preventive physiotherapeutic procedures, the hands of the person consisting in contrast thermal impact on a site with various level of heating and cooling, and also lasting expositions is described.

  7. Manual activity shapes structure and function in contralateral human motor hand area

    DEFF Research Database (Denmark)

    Granert, Oliver; Peller, Martin; Gaser, Christian

    2011-01-01

    From longitudinal voxel-based morphometry (VBM) studies we know that relatively short periods of training can increase regional grey matter volume in trained cortical areas. In 14 right-handed patients with writer's cramp, we employed VBM to test whether suppression (i.e., immobilization) or enha......1(HAND) is dynamically shaped by the level of manual activity. This bi-directional structural plasticity is functionally relevant as local grey matter changes are mirrored by changes in regional excitability....

  8. Human-Computer Interaction Based on Hand Gestures Using RGB-D Sensors

    Directory of Open Access Journals (Sweden)

    Sergio Llorente

    2013-09-01

    Full Text Available In this paper we present a new method for hand gesture recognition based on an RGB-D sensor. The proposed approach takes advantage of depth information to cope with the most common problems of traditional video-based hand segmentation methods: cluttered backgrounds and occlusions. The algorithm also uses colour and semantic information to accurately identify any number of hands present in the image. Ten different static hand gestures are recognised, including all different combinations of spread fingers. Additionally, movements of an open hand are followed and 6 dynamic gestures are identified. The main advantage of our approach is the freedom of the user’s hands to be at any position of the image without the need of wearing any specific clothing or additional devices. Besides, the whole method can be executed without any initial training or calibration. Experiments carried out with different users and in different environments prove the accuracy and robustness of the method which, additionally, can be run in real-time.

  9. Human dorsomedial parieto-motor circuit specifies grasp during the planning of goal-directed hand actions.

    Science.gov (United States)

    Vesia, Michael; Barnett-Cowan, Michael; Elahi, Behzad; Jegatheeswaran, Gaayathiri; Isayama, Reina; Neva, Jason L; Davare, Marco; Staines, W Richard; Culham, Jody C; Chen, Robert

    2017-07-01

    According to one influential view, two specialized parieto-frontal circuits control prehension: a dorsomedial stream for hand transport during reaching and a dorsolateral stream for preshaping the fingers during grasping. However, recent evidence argues that an area within the dorsomedial stream-macaque area V6A and, its putative human homolog, superior parietal occipital cortex (SPOC) - encodes both hand transport and grip formation. We tested whether planning varied hand actions modulates functional connectivity between left SPOC and ipsilateral primary motor cortex (M1) using a dual-site, paired-pulse transcranial magnetic stimulation paradigm with two coils (dsTMS). Participants performed three different hand actions to a target object comprising a small cylinder atop a larger cylinder. These actions were: reaching-to-grasp the top (GT) using a precision grip, reaching-to-grasp the bottom (GB) using a whole-hand grip, or reaching-to-touch (Touch) the side of the target object without forming a grip. Motor-evoked potentials (MEPs) from TMS to M1, with or without preceding TMS to SPOC, were recorded from first dorsal interosseous (FDI) and abductor digiti minimi (ADM) hand muscles in two experiments that varied timing parameters (the stimulus onset asynchrony, SOA, between the 'GO' cue and stimulation and interpulse interval, IPI, between SPOC and M1 stimulation). We found that preparatory response amplitudes in the SPOC-M1 circuit of different hand muscles were selectively modulated early in the motor plan for different types of grasps. First, based on SPOC-M1 interactions, across two experiments, the role of the ADM was facilitated during a whole-hand grasp of a large object (GB) relative to other conditions under certain timing parameters (SOA = 150 msec; IPI = 6 msec). Second, the role of the FDI was facilitated during hand action planning compared to rest. These findings suggest that the human dorsomedial parieto-motor stream plays a causal role in

  10. [An accessory muscle and additional variants of the forearm].

    Science.gov (United States)

    Arnold, G; Zech, M

    1977-01-01

    A report is given on an accessory muscle of the forearm. The muscle originates from the medial epicondyle and the fascia of the forearm and inserts into the pisiform bone and retinaculum. The accessory muscle has a great similarity with the flexor carpi ulnaris muscle.

  11. Teaching Strategies for the Forearm Pass in Volleyball

    Science.gov (United States)

    Casebolt, Kevin; Zhang, Peng; Brett, Christine

    2014-01-01

    This article shares teaching strategies for the forearm pass in the game of volleyball and identifies how they will help students improve their performance and development of forearm passing skills. The article also provides an assessment rubric to facilitate student understanding of the skill.

  12. Teaching Strategies for the Forearm Pass in Volleyball

    Science.gov (United States)

    Casebolt, Kevin; Zhang, Peng; Brett, Christine

    2014-01-01

    This article shares teaching strategies for the forearm pass in the game of volleyball and identifies how they will help students improve their performance and development of forearm passing skills. The article also provides an assessment rubric to facilitate student understanding of the skill.

  13. Biomechanics of forearm rotation: force and efficiency of pronator teres.

    Directory of Open Access Journals (Sweden)

    Pere Ibáñez-Gimeno

    Full Text Available Biomechanical models are useful to assess the effect of muscular forces on bone structure. Using skeletal remains, we analyze pronator teres rotational efficiency and its force components throughout the entire flexion-extension and pronation-supination ranges by means of a new biomechanical model and 3D imaging techniques, and we explore the relationship between these parameters and skeletal structure. The results show that maximal efficiency is the highest in full elbow flexion and is close to forearm neutral position for each elbow angle. The vertical component of pronator teres force is the highest among all components and is greater in pronation and elbow extension. The radial component becomes negative in pronation and reaches lower values as the elbow flexes. Both components could enhance radial curvature, especially in pronation. The model also enables to calculate efficiency and force components simulating changes in osteometric parameters. An increase of radial curvature improves efficiency and displaces the position where the radial component becomes negative towards the end of pronation. A more proximal location of pronator teres radial enthesis and a larger humeral medial epicondyle increase efficiency and displace the position where this component becomes negative towards forearm neutral position, which enhances radial curvature. Efficiency is also affected by medial epicondylar orientation and carrying angle. Moreover, reaching an object and bringing it close to the face in a close-to-neutral position improve efficiency and entail an equilibrium between the forces affecting the elbow joint stability. When the upper-limb skeleton is used in positions of low efficiency, implying unbalanced force components, it undergoes plastic changes, which improve these parameters. These findings are useful for studies on ergonomics and orthopaedics, and the model could also be applied to fossil primates in order to infer their locomotor form

  14. Biomechanics of forearm rotation: force and efficiency of pronator teres.

    Science.gov (United States)

    Ibáñez-Gimeno, Pere; Galtés, Ignasi; Jordana, Xavier; Malgosa, Assumpció; Manyosa, Joan

    2014-01-01

    Biomechanical models are useful to assess the effect of muscular forces on bone structure. Using skeletal remains, we analyze pronator teres rotational efficiency and its force components throughout the entire flexion-extension and pronation-supination ranges by means of a new biomechanical model and 3D imaging techniques, and we explore the relationship between these parameters and skeletal structure. The results show that maximal efficiency is the highest in full elbow flexion and is close to forearm neutral position for each elbow angle. The vertical component of pronator teres force is the highest among all components and is greater in pronation and elbow extension. The radial component becomes negative in pronation and reaches lower values as the elbow flexes. Both components could enhance radial curvature, especially in pronation. The model also enables to calculate efficiency and force components simulating changes in osteometric parameters. An increase of radial curvature improves efficiency and displaces the position where the radial component becomes negative towards the end of pronation. A more proximal location of pronator teres radial enthesis and a larger humeral medial epicondyle increase efficiency and displace the position where this component becomes negative towards forearm neutral position, which enhances radial curvature. Efficiency is also affected by medial epicondylar orientation and carrying angle. Moreover, reaching an object and bringing it close to the face in a close-to-neutral position improve efficiency and entail an equilibrium between the forces affecting the elbow joint stability. When the upper-limb skeleton is used in positions of low efficiency, implying unbalanced force components, it undergoes plastic changes, which improve these parameters. These findings are useful for studies on ergonomics and orthopaedics, and the model could also be applied to fossil primates in order to infer their locomotor form. Moreover, activity

  15. Biomechanics of Forearm Rotation: Force and Efficiency of Pronator Teres

    Science.gov (United States)

    Ibáñez-Gimeno, Pere; Galtés, Ignasi; Jordana, Xavier; Malgosa, Assumpció; Manyosa, Joan

    2014-01-01

    Biomechanical models are useful to assess the effect of muscular forces on bone structure. Using skeletal remains, we analyze pronator teres rotational efficiency and its force components throughout the entire flexion-extension and pronation-supination ranges by means of a new biomechanical model and 3D imaging techniques, and we explore the relationship between these parameters and skeletal structure. The results show that maximal efficiency is the highest in full elbow flexion and is close to forearm neutral position for each elbow angle. The vertical component of pronator teres force is the highest among all components and is greater in pronation and elbow extension. The radial component becomes negative in pronation and reaches lower values as the elbow flexes. Both components could enhance radial curvature, especially in pronation. The model also enables to calculate efficiency and force components simulating changes in osteometric parameters. An increase of radial curvature improves efficiency and displaces the position where the radial component becomes negative towards the end of pronation. A more proximal location of pronator teres radial enthesis and a larger humeral medial epicondyle increase efficiency and displace the position where this component becomes negative towards forearm neutral position, which enhances radial curvature. Efficiency is also affected by medial epicondylar orientation and carrying angle. Moreover, reaching an object and bringing it close to the face in a close-to-neutral position improve efficiency and entail an equilibrium between the forces affecting the elbow joint stability. When the upper-limb skeleton is used in positions of low efficiency, implying unbalanced force components, it undergoes plastic changes, which improve these parameters. These findings are useful for studies on ergonomics and orthopaedics, and the model could also be applied to fossil primates in order to infer their locomotor form. Moreover, activity

  16. Shape-estimation of human hand using polymer flex sensor and study of its application to control robot arm

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Hyuck; Kim, Dae Hyun [Seoul National University of Technology, Seoul (Korea, Republic of)

    2015-02-15

    Ultrasonic inspection robot systems have been widely researched and developed for the real-time monitoring of structures such as power plants. However, an inspection robot that is operated in a simple pattern has limitations in its application to various structures in a plant facility because of the diverse and complicated shapes of the inspection objects. Therefore, accurate control of the robot is required to inspect complicated objects with high-precision results. This paper presents the idea that the shape and movement information of an ultrasonic inspector's hand could be profitably utilized for the accurate control of robot. In this study, a polymer flex sensor was applied to monitor the shape of a human hand. This application was designed to intuitively control an ultrasonic inspection robot. The movement and shape of the hand were estimated by applying multiple sensors. Moreover, it was successfully shown that a test robot could be intuitively controlled based on the shape of a human hand estimated using polymer flex sensors.

  17. Decoding of human hand actions to handle missing limbs in Neuroprosthetics

    Directory of Open Access Journals (Sweden)

    Jovana eBelic

    2015-02-01

    Full Text Available The only way we can interact with the world is through movements, and our primary interactions are via the hands, thus any loss of hand function has immediate impact on our quality of life. However, to date it has not been systematically assessed how coordination in the hand's joints affects every day actions. This is important for two fundamental reasons. Firstly, to understand the representations and computations underlying motor control in-the-wild situations, and secondly to develop smarter controllers for prosthetic hands that have the same functionality as natural limbs. In this work we exploit the correlation structure of our hand and finger movements in daily-life. The novelty of our idea is that instead of averaging variability out, we take the view that the structure of variability may contain valuable information about the task being performed. We asked seven subjects to interact in 17 daily-life situations, and quantified behaviour in a principled manner using CyberGlove body sensor networks that, after accurate calibration, track all major joints of the hand. Our key findings are: 1. We confirmed that hand control in daily-life tasks is very low-dimensional, with four to five dimensions being sufficient to explain 80-90% of the variability in the natural movement data. 2. We established a universally applicable measure of manipulative complexity that allowed us to measure and compare limb movements across tasks. We used Bayesian latent variable models to model the low-dimensional structure of finger joint angles in natural actions. 3. This allowed us to build a naïve classifier that within the first 1000ms of action initiation (from a flat hand start configuration predicted which of the 17 actions was going to be executed - enabling us to reliably predict the action intention from very short-time-scale initial data, further revealing the foreseeable nature of hand movements for control of neuroprosthetics and tele operation

  18. Thermovision Analysis Changes of Human Hand Surface Temperature in Cold Pressor Test

    Directory of Open Access Journals (Sweden)

    Agnieszka Chwałczyńska

    2015-01-01

    Full Text Available The cold pressor test (CTP as a diagnostic method of the circulatory system reactivity may be a basis for the qualification for thermal stimulation therapy. The aim of the work was a thermovisual assessment of the reaction to the Hines and Brown cold pressor test. A group of 30 healthy men in the age of 23.5 ± 0.8 years were examined. The average weight of the examinees was 78.4 ± 9.2 kg, their height 180.7 ± 5.9 cms, and BMI 23.9 ± 2.2 kg/m2. A thermovisual picture of a tested and not tested hand of all the subjects was taken before and after the cold pressor test. Under the influence of cold water the surface temperature of a tested hand has decreased in a statistically significant way by 8.3°C on average, which is 29% of the temperature before the test, whilst the temperature of an untested hand dropped by 0.67°C. The decreases of temperature were not even and there was a statistically significant difference between the dorsal and palmar side of the hand. The correlation between the changes of systolic blood pressure and the hand surface temperature before and after CTP was observed.

  19. Obtaining and preservation of the donor hands in human hand allotransplantation%异体手移植供手的获取和保存

    Institute of Scientific and Technical Information of China (English)

    王钢; 朱立军; 杨运平; 裴国献; 顾立强

    2001-01-01

    Objective To discuss the methods of obtaining and preservation of the donor hands in human allotransplantation. Methods After brain death of the donor was confirmed, the whole donor arm was sterilized with 3 % iodine tincture and 75 % ethyl alcohol and strapped with sterile towels. A circular incision 5 cm above the elbow was made, and the brachial artery was dissected and catheterized for perfusion of UW solution at 4℃. The arm was amputated with the brachial artery still in continuity and catheterized. When the fluid refluxed from the veins was clear, the artery was divided. The marked donor arm was wrapped in aseptic dressing and sealed in a plastic bag. The bag was immersed in ice water and transported rapidly. Carotid artery blood of the donor was taken for examination. Results The time from brain death to amputation of the donor arm was 5 minutes and 6 minutes respectively. The time from amputation to reperfusion of the hand allotransplant was 6 hours and 6 hours and 19 minutes respectively. Postoperatively, the vital signs were normal and blood circulation of the transplants was excellent. Immunological and histological examination indicated no occurrence of rejection. Ten months after the operation, motor function of the fingers in both cases was graded good by total active motion evaluation. In case 1, the function of the median and ulnar nerve recovered to excellent and good respectively, while in case 2 both recovered to fair. Conclusions The obtaining and preservation of the donor arm was successful in the present 2 cases of human hand allotransplantation according to the satisfactory postoperative outcome.%目的通过2例异体手移植探讨获取和保存供手的方法。方法在供者被宣布脑死亡后,将拟取肢体用3 %碘酒、75 %酒精常规消毒,从肘关节以上5 cm平面作环形皮肤切口,游离肱动脉后插管,用4℃ UW液灌注(保留插管)后行前臂离断(肱动脉相连),再灌洗至回流

  20. Compartment Syndrome of the Hand: A Little Thought about Diagnosis

    Science.gov (United States)

    Reichman, Eric F.

    2016-01-01

    Compartment syndrome of the forearm is a well described entity but there have been relatively few case reports in the emergency medicine literature of hand compartment syndromes (HCS). Prompt recognition and treatment of this potential limb threat are essential to minimize morbidity and mortality. Presented is a case of a documented hand compartment syndrome following a motor vehicle collision. PMID:27293917

  1. Synergistic control of forearm based on accelerometer data and artificial neural networks

    Directory of Open Access Journals (Sweden)

    B. Mijovic

    2008-05-01

    Full Text Available In the present study, we modeled a reaching task as a two-link mechanism. The upper arm and forearm motion trajectories during vertical arm movements were estimated from the measured angular accelerations with dual-axis accelerometers. A data set of reaching synergies from able-bodied individuals was used to train a radial basis function artificial neural network with upper arm/forearm tangential angular accelerations. The trained radial basis function artificial neural network for the specific movements predicted forearm motion from new upper arm trajectories with high correlation (mean, 0.9149-0.941. For all other movements, prediction was low (range, 0.0316-0.8302. Results suggest that the proposed algorithm is successful in generalization over similar motions and subjects. Such networks may be used as a high-level controller that could predict forearm kinematics from voluntary movements of the upper arm. This methodology is suitable for restoring the upper limb functions of individuals with motor disabilities of the forearm, but not of the upper arm. The developed control paradigm is applicable to upper-limb orthotic systems employing functional electrical stimulation. The proposed approach is of great significance particularly for humans with spinal cord injuries in a free-living environment. The implication of a measurement system with dual-axis accelerometers, developed for this study, is further seen in the evaluation of movement during the course of rehabilitation. For this purpose, training-related changes in synergies apparent from movement kinematics during rehabilitation would characterize the extent and the course of recovery. As such, a simple system using this methodology is of particular importance for stroke patients. The results underlie the important issue of upper-limb coordination.

  2. A key region in the human parietal cortex for processing proprioceptive hand feedback during reaching movements

    DEFF Research Database (Denmark)

    Reichenbach, Alexandra; Thielscher, Axel; Peer, Angelika

    2014-01-01

    neuroimaging studies have focused mainly on identifying the parts of the posterior parietal cortex (PPC) that contribute to visually guided movements. We used event-related TMS and force perturbations of the reaching hand to test whether the same sub-regions of the left PPC contribute to the processing...... of proprioceptive-only and of multi-sensory information about hand position when reaching for a visual target. TMS over two distinct stimulation sites elicited differential effects: TMS applied over the posterior part of the medial intraparietal sulcus (mIPS) compromised reaching accuracy when proprioception...... was the only sensory information available for correcting the reaching error. When visual feedback of the hand was available, TMS over the anterior intraparietal sulcus (aIPS) prolonged reaching time. Our results show for the first time the causal involvement of the posterior mIPS in processing proprioceptive...

  3. Human Hand as a Meta-tool%手的元工具特征——基于历史唯物主义的视野

    Institute of Scientific and Technical Information of China (English)

    高剑平; 张正华; 罗芹

    2012-01-01

    手的形成与手的工具化是相伴相生的自然选择过程。人手的形成必然具备工具化的特点,工具化了的手是人手形成的标志。手的形成意味着人类的诞生,人类最早的制造工具活动就是从“手”中开始的。手具有自然属性和工具属性:自然属性与一般动物无异,工具属性则从人类诞生之日起就存在着。手的形成过程就是其元工具特征演化并凝固于手的过程。而器械作为手的工具属性的延伸,成为了人类改造自然的强大力量。%Human hand is a recta-tool. The forming of human hand and its function as a tool, which transacted each other, share a very long and same history. A human hand has to be a tool at first, and becoming a tool is the final stage of forming human hand. Human being must have human hand first and the first human behavior of making tools is from 'hand'. Human hand has natural property and instrumental property. The natural property of human hands is the same to animals', while the instrumental property exists only in human being as early as the existence of us. Machines which are powerful tool for practice, are the hands of human being' instrumental hand.

  4. Epithelioid Sarcoma of the Forearm Arising from Perineural Sheath of Median Nerve Mimicking Carpal Tunnel Syndrome

    Directory of Open Access Journals (Sweden)

    Hiromasa Fujii

    2009-01-01

    Full Text Available We report here a case of epithelioid sarcoma in the forearm of a 33-year-old male presenting with symptoms and signs of carpal tunnel syndrome originating from the direct involvement of the median nerve. Due to the slow growing of the tumor, the patient noticed the presence of tumor mass in his forearm after several months from the initial onset of the symptoms. Magnetic resonance imaging showed an 8×4 cm mass involving the median nerve in the middle part of the forearm, and histological analysis of the biopsy specimen revealed the diagnosis of epithelioid sarcoma. Radical surgical resection was performed in conjunction with adjuvant chemotherapy. The function of the flexors were restored by the multiple tendon transfers (EIP→FDS; ECRL→FDP; BrR→FPL; EDM→opponens with superficial cutaneous branch of radial nerve transfer to the resected median nerve. The function of the affected hand showed excellent with the DASH disability/symptom score of 22.5, and both the grasp power and sensory of the median nerve area has recovered up to 50% of the normal side. The patient returned to his original vocation and alive with continuous disease free at 3.5-year follow-up since initial treatment.

  5. Supinator Extender (SUE): a pneumatically actuated robot for forearm/wrist rehabilitation after stroke.

    Science.gov (United States)

    Allington, James; Spencer, Steven J; Klein, Julius; Buell, Meghan; Reinkensmeyer, David J; Bobrow, James

    2011-01-01

    The robot described in this paper, SUE (Supinator Extender), adds forearm/wrist rehabilitation functionality to the UCI BONES exoskeleton robot and to the ArmeoSpring rehabilitation device. SUE is a 2-DOF serial chain that can measure and assist forearm supination-pronation and wrist flexion-extension. The large power to weight ratio of pneumatic actuators allows SUE to achieve the forces needed for rehabilitation therapy while remaining lightweight enough to be carried by BONES and ArmeoSpring. Each degree of freedom has a range of 90 degrees, and a nominal torque of 2 ft-lbs. The cylinders are mounted away from the patient's body on the lateral aspect of the arm. This is to prevent the danger of a collision and maximize the workspace of the arm robot. The rotation axis used for supination-pronation is a small bearing just below the subject's wrist. The flexion-extension motion is actuated by a cantilevered pneumatic cylinder, which allows the palm of the hand to remain open. Data are presented that demonstrate the ability of SUE to measure and cancel forearm/wrist passive tone, thereby extending the active range of motion for people with stroke.

  6. The effects of smoke hand grenades on human lung cells and bacteria for toxicity screening purposes

    NARCIS (Netherlands)

    Hulst, M. van; Klerk, W.P.C. de; Langenberg, J.P.; Tuinman, I.L.; Alblas, M.J.

    2013-01-01

    Exposure to signaling smoke is almost impossible to avoid, and may have adverse health effects. Hand grenades with signaling smoke are used during training and/or military operations. To obtain the most realistic results when estimating the toxicity of the smoke, not only the smoke–forming compositi

  7. The effects of smoke hand grenades on human lung cells and bacteria for toxicity screening purposes

    NARCIS (Netherlands)

    Hulst, M. van; Klerk, W.P.C. de; Langenberg, J.P.; Tuinman, I.L.; Alblas, M.J.

    2013-01-01

    Exposure to signaling smoke is almost impossible to avoid, and may have adverse health effects. Hand grenades with signaling smoke are used during training and/or military operations. To obtain the most realistic results when estimating the toxicity of the smoke, not only the smoke–forming

  8. Prospective biomechanical evaluation of donor site morbidity after radial forearm free flap.

    Science.gov (United States)

    Riecke, Björn; Kohlmeier, Carsten; Assaf, Alexandre T; Wikner, Johannes; Drabik, Anna; Catalá-Lehnen, Philip; Heiland, Max; Rendenbach, Carsten

    2016-02-01

    Although the radial forearm free flap (RFF) is a commonly-used microvascular flap for orofacial reconstruction, we are aware of few prospective biomechanical studies of the donor site. We have therefore evaluated the donor site morbidity biomechanically of 30 consecutive RFF for orofacial reconstruction preoperatively and three months postoperatively. This included the Mayo wrist score, the Disabilities of the Arm, Shoulder and Hand (DASH) score, grip strength, followed by tip pinch, key pinch, palmar pinch, and range of movement of the wrist. Primary defects were all closed with local full-thickness skin grafts from the donor site forearm, thereby circumventing the need for a second defect. Postoperative functional results showed that there was a reduction in hand strength measured by (grip strength: -24.1%, in tip pinch: -23.3%, in key pinch: -16.5, and in palmar pinch: -19.3%); and wrist movement measured by extension (active=14.3% / passive= -11.5%) and flexion = -14.8% / -8.9%), and radial (-9.8% / -9.8%) and ulnar (-11.0% / -9.3%) abduction. The Mayo wrist score was reduced by 9.4 points (-12.9%) and the DASH score increased by 16.1 points (+35.5%) compared with the same forearm preoperatively. The local skin graft resulted in a robust wound cover with a good functional result. Our results show that the reduction in hand strength and wrist movement after harvest of a RFF is objectively evaluable, and did not reflect the subjectively noticed extent and restrictions in activities of daily living. Use of a local skin graft avoids a second donor site and the disadvantages of a split-thickness skin graft.

  9. Interosseous membrane reconstruction with a suture-button construct for treatment of chronic forearm instability.

    Science.gov (United States)

    Gaspar, Michael P; Kane, Patrick M; Pflug, Emily M; Jacoby, Sidney M; Osterman, A Lee; Culp, Randall W

    2016-09-01

    The purpose of this study was to report outcomes of interosseous membrane (IOM) reconstruction with a suture-button construct for treatment of chronic longitudinal forearm instability. We performed a retrospective review with prospective follow-up of patients who underwent ulnar shortening osteotomy and IOM reconstruction with the Mini TightRope device from 2011 through 2014. Bivariate statistical analysis was used for comparison of preoperative and postoperative Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) scores, range of motion, grip strength, and ulnar variance. Complications and patient satisfaction were also recorded. Ten patients (mean age, 45.3 years) satisfied inclusion criteria: 8 treated for post-traumatic sequelae of Essex-Lopresti-type injuries, 1 for forearm instability secondary to previous elbow surgery, and 1 for instability secondary to trauma and multiple elbow surgeries. Surgeries were performed an average of 28.6 months from initial injury. At mean follow-up of 34.6 months after surgery, significant improvement was observed in elbow flexion-extension arc (+23° vs. preoperatively; P = .007), wrist flexion-extension arc (+22°; P = .016), QuickDASH score (-48; P = .000), and ulnar variance (-3.3 mm; P = .006). Three patients required additional surgery: 1 revision ulnar shortening osteotomy for persistent impingement, 1 revision ulnar osteotomy and Mini TightRope removal for lost forearm supination, and 1 fixation of a radial shaft fracture after a fall. IOM reconstruction using a suture-button construct is an effective treatment option for chronic forearm instability. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  10. Nerve fibre and sensory end organ density in the epidermis and papillary dermis of the human hand.

    Science.gov (United States)

    Kelly, E J; Terenghi, G; Hazari, A; Wiberg, M

    2005-09-01

    Quantification of sensory recovery after peripheral nerve surgery is difficult and no accurate techniques are available at present. Quantification of reinnervated skin has been used experimentally, and in some clinical studies, but the lack of knowledge about the normal sensory distribution has been a problem. The purpose of this study was, therefore, to map the density of sensory end organs, nerve fibres and free nerve endings in the glabrous skin of the human hand. Skin biopsies were taken from patients undergoing acute and elective hand surgery. Nerve fibres were stained in the epidermis and papillary dermis and quantified in five sites on the palm of the hand, using protein gene product 9.5 immunoreactivity-a panneuronal marker. The finger tip skin was found to have more than twice the nerve fibre density in the papillary dermis than the skin of the palm, and the number of Meissner corpuscles in the finger tip was also higher than in the palm. We found a reduction in innervation density with increasing age in the dermis, however, that was not the case for the epidermis. The innervation of the epidermis showed high interindividual variability and unlike the papillary dermis did not display any pattern of distribution in the hand.

  11. Reconstruction of the replanted hand with latissimus dorsi muscle and serratus anterior fascia combined flap.

    Science.gov (United States)

    Ozçelik, Derya; Uğurlu, Kemal; Turan, Tuğrul

    2003-04-01

    Reconstruction with the latissimus dorsi muscle flap, combined with the serratus anterior fascia flap, was performed to cover two large and separate palmar and dorsal forearm skin defects in a patient, whose hand had been replanted 20 days earlier after traumatic amputation at the distal forearm level. As a result, a total forearm amputation was salvaged by microsurgical replantation and a free combined flap of the subscapular system. This new application of the combined flap allowed the reconstruction of large and separate wounds of the replanted hand, and provided gliding surfaces for tendons.

  12. Design and experiment of human hand motion driven electromagnetic energy harvester using dual Halbach magnet array

    Science.gov (United States)

    Salauddin, M.; Park, Jae Y.

    2017-03-01

    We present a dual Halbach array electromagnetic energy harvester that generates significant power from hand shaking vibration. The magnetic-spring configuration is employed for generating sufficient power from the hand motion of irregular and low-frequency vibrations. However, significant power generation at low-frequency vibrations is challenging because the power flow decreases as the frequency decreases; moreover, designing a spring-mass system that is suitable for low-frequency-vibration energy harvesting is difficult. In this work, our proposed device overcomes both of these challenges by using a dual Halbach array and magnetic springs. During the experiment, vibration was applied in a horizontal direction to reduce the gravity effect on the Halbach-array structure. To achieve an increased power generation at low-amplitude and low-frequency vibrations, the magnetic structure of the dual Halbach array and the magnetic springs were optimized in terms of the operating frequency and the power density. A prototype was fabricated and tested both using a vibration exciter and by manual hand-shaking. The fabricated device showed resonant behavior during the vibration exciter test. For the vibration exciter test, the prototype device offers a maximum average power of 2.92 mW to a 62 Ω optimum load, at a 6 Hz resonance frequency and under a 0.5 g acceleration. The prototype device is capable of delivering a maximum average power of 2.27 mW from hand shaking. The fabricated device exhibited a normalized power density 0.46 mW cm‑2g‑2 which is very high compared to the current state-of-the-art devices, representing its ability in powering portable and wearable smart devices from extremely low frequency vibration.

  13. A key region in the human parietal cortex for processing proprioceptive hand feedback during reaching movements.

    Science.gov (United States)

    Reichenbach, Alexandra; Thielscher, Axel; Peer, Angelika; Bülthoff, Heinrich H; Bresciani, Jean-Pierre

    2014-01-01

    Seemingly effortless, we adjust our movements to continuously changing environments. After initiation of a goal-directed movement, the motor command is under constant control of sensory feedback loops. The main sensory signals contributing to movement control are vision and proprioception. Recent neuroimaging studies have focused mainly on identifying the parts of the posterior parietal cortex (PPC) that contribute to visually guided movements. We used event-related TMS and force perturbations of the reaching hand to test whether the same sub-regions of the left PPC contribute to the processing of proprioceptive-only and of multi-sensory information about hand position when reaching for a visual target. TMS over two distinct stimulation sites elicited differential effects: TMS applied over the posterior part of the medial intraparietal sulcus (mIPS) compromised reaching accuracy when proprioception was the only sensory information available for correcting the reaching error. When visual feedback of the hand was available, TMS over the anterior intraparietal sulcus (aIPS) prolonged reaching time. Our results show for the first time the causal involvement of the posterior mIPS in processing proprioceptive feedback for online reaching control, and demonstrate that distinct cortical areas process proprioceptive-only and multi-sensory information for fast feedback corrections.

  14. Potential role of hands in the spread of respiratory viral infections: studies with human parainfluenza virus 3 and rhinovirus 14.

    Science.gov (United States)

    Ansari, S A; Springthorpe, V S; Sattar, S A; Rivard, S; Rahman, M

    1991-10-01

    Hands often become contaminated with respiratory viruses, either directly or through contact with contaminated surfaces. Spread of such viruses could then occur by touching the nasal mucosa or the conjunctivae. In this quantitative study, we compared the survival of mucin-suspended human parainfluenza virus 3 (HPIV-3) and rhinovirus 14 (RV-14) and the transfer of the viruses to and from the fingers of adult volunteers. When each finger pad was contaminated with 10 microliters of either HPIV-3 (1.3 x 10(5) to 5.5 x 10(5) PFU) or RV-14 (2.1 x 10(4) to 1.1 x 10(5) PFU), less than 1.0% of HPIV-3 and 37.8% of RV-14 remained viable after 1 h; after 3 h, nearly 16% of RV-14 could still be detected, whereas HPIV-3 became undetectable. Tests on the potential spread of viruses from contaminated hands or surfaces were conducted 20 min after contamination of the donor surface by pressing together donor and recipient surfaces for 5 s. Transfer of HPIV-3 from finger to finger or finger to metal disk could not be detected, but 1.5% of infectious HPIV-3 was transferred from disk to finger. Irrespective of the type of donor or recipient surface, 0.7 to 0.9% of RV-14 was transferred. The relatively rapid loss of HPIV-3 infectivity on hands suggests that their role in the direct spread of parainfluenza viruses is limited. However, the findings of this study further reinforce the view that hands can be vehicles for rhinovirus colds. These results also suggest a role for nonporous environmental surfaces in the contamination of hands with respiratory viruses.

  15. Convergence of human brain mapping tools: neuronavigated TMS parameters and fMRI activity in the hand motor area.

    Science.gov (United States)

    Sarfeld, Anna-Sophia; Diekhoff, Svenja; Wang, Ling E; Liuzzi, Gianpiero; Uludağ, Kamil; Eickhoff, Simon B; Fink, Gereon R; Grefkes, Christian

    2012-05-01

    Functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) are well-established tools for investigating the human motor system in-vivo. We here studied the relationship between movement-related fMRI signal changes in the primary motor cortex (M1) and electrophysiological properties of the hand motor area assessed with neuronavigated TMS in 17 healthy subjects. The voxel showing the highest task-related BOLD response in the left hand motor area during right hand movements was identified for each individual subject. This fMRI peak voxel in M1 served as spatial target for coil positioning during neuronavigated TMS. We performed correlation analyses between TMS parameters, BOLD signal estimates and effective connectivity parameters of M1 assessed with dynamic causal modeling (DCM). The results showed a negative correlation between the movement-related BOLD signal in left M1 and resting as well as active motor threshold (MT) obtained for left M1. The DCM analysis revealed that higher excitability of left M1 was associated with a stronger coupling between left supplementary motor area (SMA) and M1. Furthermore, BOLD activity in left M1 correlated with ipsilateral silent period (ISP), i.e. the stronger the task-related BOLD response in left M1, the higher interhemispheric inhibition effects targeting right M1. DCM analyses revealed a positive correlation between the coupling of left SMA with left M1 and the duration of ISP. The data show that TMS parameters assessed for the hand area of M1 do not only reflect the intrinsic properties at the stimulation site but also interactions with remote areas in the human motor system.

  16. Comparative analysis of muscle architecture in primate arm and forearm.

    Science.gov (United States)

    Kikuchi, Yasuhiro

    2010-04-01

    A comparative study of myological morphology, i.e. muscle mass (MM), muscle fascicle length and muscle physiological cross-sectional area (an indicator of the force capacity of muscles), was conducted in nine primate species: human (Homo sapiens), chimpanzee (Pan troglodytes), gibbon (Hylobates spp.), papio (Papio hamadryas), lutong (Trachypithecus francoisi), green monkey (Chlorocebus aethiops), macaque monkey (Macaca spp.), capuchin monkey (Cebus albifrons) and squirrel monkey (Saimiri sciureus). The MM distributions and the percentages in terms of functional categories were calculated as the ratios of the muscle masses. Moreover, individual normalized data were compared directly amongst species, independent of size differences. The results show that the different ratios of forearm-rotation muscles between chimpanzee and gibbons may be related to the differences in their main positional behaviour, i.e. knuckle-walking in chimpanzees and brachiation in gibbons, and the different frequencies of arm-raising locomotion between these two species. Moreover, monkeys have larger normalized MM values for the elbow extensor muscles than apes, which may be attributed to the fact that almost all monkeys engage in quadrupedal locomotion. The characteristics of the muscle internal parameters of ape and human are discussed in comparison with those of monkey.

  17. Estimation of height of an individual from forearm length on the population of Eastern India

    Directory of Open Access Journals (Sweden)

    Biswa Bhusan Mohanty1, Divya Agrawal1, Kunal Mishra2, Pusparaj Samantsinghar2, Prafulla Kumar Chinara1

    2013-08-01

    Full Text Available Height is a fundamental unit to assess growth and nutrition, for calculating body surface area and predicting pulmonary function in a person. But measurement of height may be hindered by muscle weakness, joint & spinal deformity. So, some alternative method should be there to measure height of a person in these cases. Also, when dismembered human fragments are encountered in scenes of mass disaster, the height of a person is to be calculated for identification. Estimation of stature from skeletal fragments is of great interest in forensic science. The aim of the current study is to find out a regression equation that could calculate the height of a person precisely and reproducibly from forearm length. 300 stu-dents (M = 206, F = 94 aged 18-25 years, who had no disability, were studied at SCB Medical College, Cuttack. Height & forearm lengths were measured. Prediction equation for height was de-rived using linear equation method.

  18. Warm hands, cold heart: progressive whole-body cooling increases warm thermosensitivity of human hands and feet in a dose-dependent fashion.

    Science.gov (United States)

    Filingeri, Davide; Morris, Nathan B; Jay, Ollie

    2017-01-01

    What is the central question of this study? Investigations on inhibitory/facilitatory modulation of vision, touch and pain show that conditioning stimuli outside the receptive field of testing stimuli modulate the central processing of visual, touch and painful stimuli. We asked whether contextual modulation also exists in human temperature integration. What is the main finding and its importance? Progressive decreases in whole-body mean skin temperature (the conditioning stimulus) significantly increased local thermosensitivity to skin warming but not cooling (the testing stimuli) in a dose-dependent fashion. In resembling the central mechanisms underlying endogenous analgesia, our findings point to the existence of an endogenous thermosensory system in humans that could modulate local skin thermal sensitivity to facilitate thermal behaviour. Although inhibitory/facilitatory central modulation of vision and pain has been investigated, contextual modulation of skin temperature integration has not been explored. Hence, we tested whether progressive decreases in whole-body mean skin temperature (Tsk ; a large conditioning stimulus) alter the magnitude estimation of local warming and cooling stimuli applied to hairy and glabrous skin. On four separate occasions, eight men (27 ± 5 years old) underwent a 30 min whole-body cooling protocol (water-perfused suit; temperature, 5°C), during which a quantitative thermosensory test, consisting of reporting the perceived magnitude of warming and cooling stimuli (±8°C from 30°C baseline) applied to the hand (palm/dorsum) and foot (sole/dorsum), was performed before cooling and every 10 min thereafter. The cooling protocol resulted in large progressive reductions in Tsk [10 min, -3.36°C (95% confidence interval -2.62 to -4.10); 20 min, -5.21°C (-4.47 to -5.95); and 30 min, -6.32°C (-5.58 to -7.05); P temperature. While thermosensitivity to local skin cooling remained unchanged (P = 0.831), sensitivity to skin

  19. Optical coherence tomography, In vivo human hand explorer, optical coherence microscope

    CSIR Research Space (South Africa)

    Jonathan, E

    2008-07-01

    Full Text Available giving the palm skin its wavy shape which also is the normal DEJ shape (Figs. 1 and 2). Sweat secreting ducts appear whiter due to enhanced reflectivity as a result of the relatively high refractive index of sweat. Blood vessels (BV) appear as low... if the device affords non- invasive, non-destructive, and non-contact operation to avoid disturbing normal functioning of the palm during assessment. The hand palm hosts micron-size organs, for example, a dense network of blood vessels, sweat glands, ducts...

  20. Function of the sensate free forearm flap after partial glossectomy.

    Science.gov (United States)

    Biglioli, Federico; Liviero, Fabio; Frigerio, Alice; Rezzonico, Angela; Brusati, Roberto

    2006-09-01

    To compare functional recovery of sensitive free forearm flaps with non-sensitive free forearm flaps, following reconstruction for partial glossectomy. Sixteen patients underwent partial glossectomy for oncological reasons, of whom: nine patients underwent repair with non-sensitive free forearm flaps (group A) and seven with sensitive free flaps (group B). All patients underwent the following tests: (1) tactile sensitivity evaluation, localization of stimulus, sharp/blunt definition, discrimination between two points (static and dynamic), thermal sensitivity to heat/cold; (2) speech evaluation by means of the modified Fanzago test; (3) subjective evaluation concerning the degree of satisfaction of the following functions: swallowing, feeding and talking. The sensitivity and logopaedic evaluation tests and the subjective evaluation charts highlight an overall better functional recovery of the sensitive repair than the non-sensitive ones. In patients who have undergone partial glossectomy repair with free forearm neurofasciocutaneous flaps allow good recovery of oral functions and, therefore, a good quality of life.

  1. Epidemiology of forearm fractures in adults in Denmark

    DEFF Research Database (Denmark)

    Abrahamsen, Bo; Jørgensen, N R; Schwarz, P

    2015-01-01

    National epidemiological studies of forearm fractures are scarce. We examined in- and outpatient rates in Denmark, including anatomical location, surgery, hospitalization ratio, recurrent fractures, and ratio of forearm to hip fractures. This may be useful for triangulation in countries with less...... detailed information. Rates were higher than previously estimated. INTRODUCTION: Despite a significant contribution to the overall burden of osteoporotic, nonvertebral fractures, relatively little information is available about age- and gender-specific incidence rates for many countries including Denmark....... METHODS: We used national individual patient data on inpatient and outpatient treatment to calculate rates of forearm fractures, taking readmissions into account, with subtables for distal and proximal fractures. We also calculated ratios of forearm to hip fractures that may be useful when imputing...

  2. Forearm posture and mobility in quadrupedal dinosaurs.

    Directory of Open Access Journals (Sweden)

    Collin S VanBuren

    Full Text Available Quadrupedality evolved four independent times in dinosaurs; however, the constraints associated with these transitions in limb anatomy and function remain poorly understood, in particular the evolution of forearm posture and rotational ability (i.e., active pronation and supination. Results of previous qualitative studies are inconsistent, likely due to an inability to quantitatively assess the likelihood of their conclusions. We attempt to quantify antebrachial posture and mobility using the radius bone because its morphology is distinct between extant sprawled taxa with a limited active pronation ability and parasagittal taxa that have an enhanced ability to actively pronate the manus. We used a sliding semi-landmark, outline-based geometric morphometric approach of the proximal radial head and a measurement of the angle of curvature of the radius in a sample of 189 mammals, 49 dinosaurs, 35 squamates, 16 birds, and 5 crocodilians. Our results of radial head morphology showed that quadrupedal ceratopsians, bipedal non-hadrosaurid ornithopods, and theropods had limited pronation/supination ability, and sauropodomorphs have unique radial head morphology that likely allowed limited rotational ability. However, the curvature of the radius showed that no dinosaurian clade had the ability to cross the radius about the ulna, suggesting parallel antebrachial elements for all quadrupedal dinosaurs. We conclude that the bipedal origins of all quadrupedal dinosaur clades could have allowed for greater disparity in forelimb posture than previously appreciated, and future studies on dinosaur posture should not limit their classifications to the overly simplistic extant dichotomy.

  3. Forearm posture and mobility in quadrupedal dinosaurs.

    Science.gov (United States)

    VanBuren, Collin S; Bonnan, Matthew

    2013-01-01

    Quadrupedality evolved four independent times in dinosaurs; however, the constraints associated with these transitions in limb anatomy and function remain poorly understood, in particular the evolution of forearm posture and rotational ability (i.e., active pronation and supination). Results of previous qualitative studies are inconsistent, likely due to an inability to quantitatively assess the likelihood of their conclusions. We attempt to quantify antebrachial posture and mobility using the radius bone because its morphology is distinct between extant sprawled taxa with a limited active pronation ability and parasagittal taxa that have an enhanced ability to actively pronate the manus. We used a sliding semi-landmark, outline-based geometric morphometric approach of the proximal radial head and a measurement of the angle of curvature of the radius in a sample of 189 mammals, 49 dinosaurs, 35 squamates, 16 birds, and 5 crocodilians. Our results of radial head morphology showed that quadrupedal ceratopsians, bipedal non-hadrosaurid ornithopods, and theropods had limited pronation/supination ability, and sauropodomorphs have unique radial head morphology that likely allowed limited rotational ability. However, the curvature of the radius showed that no dinosaurian clade had the ability to cross the radius about the ulna, suggesting parallel antebrachial elements for all quadrupedal dinosaurs. We conclude that the bipedal origins of all quadrupedal dinosaur clades could have allowed for greater disparity in forelimb posture than previously appreciated, and future studies on dinosaur posture should not limit their classifications to the overly simplistic extant dichotomy.

  4. Technique for and an anatomic guide to forearm tendon repair.

    Science.gov (United States)

    Burnham, Jeremy M; Hollister, Anne M; Rush, David A; Avallone, Thomas J; Shi, Runhua; Jordan, Jenee' C

    2011-06-01

    Forearm lacerations involving muscle bellies are usually treated by repairing muscle fascia. Repair of tendons themselves is stronger and restores normal muscle anatomy better. Tendon repair requires good knowledge of forearm muscle and tendon anatomy. We have made cadaver measurements to produce graphical maps of locations of individual muscles tendons of origin and insertion, some practical guides for finding tendon ends and a simple grasping stitch for intramuscular tendons.

  5. Human synaptic plasticity gene expression profile and dendritic spine density changes in HIV-infected human CNS cells: role in HIV-associated neurocognitive disorders (HAND.

    Directory of Open Access Journals (Sweden)

    Venkata Subba Rao Atluri

    Full Text Available HIV-associated neurocognitive disorders (HAND is characterized by development of cognitive, behavioral and motor abnormalities, and occur in approximately 50% of HIV infected individuals. Our current understanding of HAND emanates mainly from HIV-1 subtype B (clade B, which is prevalent in USA and Western countries. However very little information is available on neuropathogenesis of HIV-1 subtype C (clade C that exists in Sub-Saharan Africa and Asia. Therefore, studies to identify specific neuropathogenic mechanisms associated with HAND are worth pursuing to dissect the mechanisms underlying this modulation and to prevent HAND particularly in clade B infection. In this study, we have investigated 84 key human synaptic plasticity genes differential expression profile in clade B and clade C infected primary human astrocytes by using RT(2 Profile PCR Array human Synaptic Plasticity kit. Among these, 31 and 21 synaptic genes were significantly (≥3 fold down-regulated and 5 genes were significantly (≥3 fold up-regulated in clade B and clade C infected cells, respectively compared to the uninfected control astrocytes. In flow-cytometry analysis, down-regulation of postsynaptic density and dendrite spine morphology regulatory proteins (ARC, NMDAR1 and GRM1 was confirmed in both clade B and C infected primary human astrocytes and SK-N-MC neuroblastoma cells. Further, spine density and dendrite morphology changes by confocal microscopic analysis indicates significantly decreased spine density, loss of spines and decreased dendrite diameter, total dendrite and spine area in clade B infected SK-N-MC neuroblastoma cells compared to uninfected and clade C infected cells. We have also observed that, in clade B infected astrocytes, induction of apoptosis was significantly higher than in the clade C infected astrocytes. In conclusion, this study suggests that down-regulation of synaptic plasticity genes, decreased dendritic spine density and induction of

  6. [Bacteriological study of oral cavity of people of Mexican origin to determine etiology agents of human infections in hand bite].

    Science.gov (United States)

    Cañedo-Guzmán, Cristhyan Baruch; Espinosa-Gutiérrez, Alejandro; Guzmán-Murillo, María Antonia

    2013-01-01

    Hand infections secondary to human bites often leave serious consequences on the functioning of the hand. Such infections are caused by different bacteria. Most bacteriological studies have been made to people of Anglo-Saxon origin or descent, and based on these findings; provide treatment to patients of different origins which may not always be as effective. Descriptive, internal stratified 17 patients were isolated samples of oral cavity and dental plaque bacterial species to identify and define the possible treatment according to the species identified. Microorganisms were isolated Gram (+) and Gram (-) belonging to the normal flora of the oral cavity and dental plaque in all the cases studied, presenting a variable number of microorganisms according to age but not by sex. The group of Gram-positive bacteria isolated showed sensitivity to: erythromycin, chloramphenicol and ciprofloxacin. In the group of Gram negative: kanamycin, amoxicillin + clavulanic acid, ciprofloxacin and norfloxacin, E. Corrodens sensitive to the group of quinolones as ciprofloxacin, norfloxacin as well as ceftriaxone and cefoperazone sulbactam. The bacterial species that are commonly found in normal flora of the oral cavity and dental plaque may be potential pathogens in a hand injury where to find the appropriate conditions for their development.

  7. [Superposition of the motor commands during creation of static efforts by human hand muscles].

    Science.gov (United States)

    Vereshchaka, I V; Horkovenko, A V

    2012-01-01

    The features of superposition of central motor commands (CMCs) have been studied during generation of the "two-joint" isometric efforts by hand. The electromyogram (EMG) amplitudes which were recorded from the humeral belt and shoulder muscles have been used for estimation of the CMCs intensity. The forces were generated in the horizontal plane of the work space; the position of arm was fixed. Two vectors of equal amplitudes and close direction and their geometrical sum were compared. The hypothesis of the CMCs' superposition in the task of the force vector summation has been examined. The directions of the constituent and resulting forces with satisfactory superposition of the CMCs were defined. Differences in the co-activation patterns for flexor and extensor muscles of both joints were shown. The high level of the flexor muscles activity has been observed during extension efforts, while the flexion directions demonstrated much weaker activation of the extensor muscles.

  8. Dexterous control of a prosthetic hand using fine-wire intramuscular electrodes in targeted extrinsic muscles.

    Science.gov (United States)

    Cipriani, Christian; Segil, Jacob L; Birdwell, J Alex; ff Weir, Richard F

    2014-07-01

    Restoring dexterous motor function equivalent to that of the human hand after amputation is one of the major goals in rehabilitation engineering. To achieve this requires the implementation of a effortless human-machine interface that bridges the artificial hand to the sources of volition. Attempts to tap into the neural signals and to use them as control inputs for neuroprostheses range in invasiveness and hierarchical location in the neuromuscular system. Nevertheless today, the primary clinically viable control technique is the electromyogram measured peripherally by surface electrodes. This approach is neither physiologically appropriate nor dexterous because arbitrary finger movements or hand postures cannot be obtained. Here we demonstrate the feasibility of achieving real-time, continuous and simultaneous control of a multi-digit prosthesis directly from forearm muscles signals using intramuscular electrodes on healthy subjects. Subjects contracted physiologically appropriate muscles to control four degrees of freedom of the fingers of a physical robotic hand independently. Subjects described the control as intuitive and showed the ability to drive the hand into 12 postures without explicit training. This is the first study in which peripheral neural correlates were processed in real-time and used to control multiple digits of a physical hand simultaneously in an intuitive and direct way.

  9. Forearm hair density and risk of keratinocyte cancers in Australian adults.

    Science.gov (United States)

    von Schuckmann, L A; Hughes, M C; Green, A C; van der Pols, J C

    2016-11-01

    Evidence suggests that progenitor cells of keratinocyte cancers (basal cell carcinoma (BCC) and squamous cell carcinoma (SCC)) may originate from epidermal stem cells including hair follicle stem cells. We hypothesised that, therefore, a relatively higher density of hair follicles on human skin may increase keratinocyte cancer risk. To evaluate this, we assessed density of mid-forearm hair in Australian adults who were randomly selected participants in a community-based cohort study of skin cancer. Hair density was assessed clinically against a set of four standard photographs showing grades of hair density, and incidence data on histologically confirmed BCC and SCC across a 20-year period were collected. Incidence rate ratios were calculated for categories of forearm hair density using multivariable regression analysis with adjustment for age, sex, phenotypic characteristics and markers of chronic sun exposure. Among the 715 participants (43 % male, average age 61 years), 237 developed at least one BCC and 115 persons developed at least one SCC. Participants with dense forearm hair (n = 169, all male) had a higher incidence of BCC (IRR = 2.24, 95 % CI 1.20, 4.18, P = 0.01) and SCC (IRR = 2.80, 95 % CI 1.20, 6.57, P = 0.02) compared to individuals with sparse forearm hair after multivariable adjustment. Stratified analyses showed that among men, those with dense versus sparse hair developed SCC more commonly (IRR = 3.01, 95 % CI 1.03, 8.78, P = 0.04). Women with moderate versus sparse hair density were more likely affected by BCC (IRR = 2.29, 95 % CI 1.05, 5.00, P = 0.038). Thus, our study suggests that in both men and women, a higher density of body hair may be associated with increased BCC and SCC risk.

  10. Diagnostic imaging of the hand. 3. rev. and enl. ed.; Bildgebende Diagnostik der Hand

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Rainer [Herz und Gefaessklinik GmbH, Bad Neustadt (Germany). Klinik fuer Diagnostische und Interventionelle Radiologie; Lanz, Ulrich

    2015-07-01

    The book on diagnostic imaging of the hand covers the following issues: projection radiography, cinematography, MRT and CR arthrography, arthroscopy, arteriography, skeleton scintiscanning, sonography, computerized tomography, magnetic resonance tomography, anatomy of forearm and carpus, anatomy of metacarpus and fingers, carpal function and morphometry, postoperative X-ray diagnostic, growing hand skeleton, normative variants, malformations and deformities, trauma of the distal forearm, lesions of the ulnocarpal complex (TFCC), scaphoid fractures, scaphoid arthrosis, fractures of other carpus bones, carpal luxations and luxation fractures, carpal instabilities, fractures of the metacarpalla, finger fractures, arthrosis deformans, enthesiopathies, sport induced soft tissue lesions, osteonecrosis, impingement syndromes, osteopenic skeletal diseases, metabolis diseases, crystal-induced osteoarthropaties, rheumatoid arthritis, spondyloarthritis, rheumatic fever, collagenoses, infective arthritis, osteomyelitis, soft tissue infections, cystoids bone lesions, skeletal tumors, soft tissue tumors, carpal tunnel syndrome, nerve compression syndrome, arterial perfusion disturbances, differential diagnostic tables on hand lesions.

  11. Human Body Explorations: Hands-On Investigations of What Makes Us Tick.

    Science.gov (United States)

    Kalumuck, Karen E.

    This book presents science activities on the human body with materials that can be purchased in a grocery store or pharmacy. Each activity includes an explorer and facilitator guide. Activities include: (1) "Naked Egg"; (2) "Cellular Soap Opera"; (3) "Acid in Your Stomach"; (4) "How Much Do You C?"; (5)…

  12. Automated volumetric grid generation for finite element modeling of human hand joints

    Energy Technology Data Exchange (ETDEWEB)

    Hollerbach, K.; Underhill, K. [Lawrence Livermore National Lab., CA (United States); Rainsberger, R. [XYZ Scientific Applications, Inc., Livermore, CA (United States)

    1995-02-01

    We are developing techniques for finite element analysis of human joints. These techniques need to provide high quality results rapidly in order to be useful to a physician. The research presented here increases model quality and decreases user input time by automating the volumetric mesh generation step.

  13. Muscular Pedicled Lateral Chest Composite Flap—A New Nonmicrosurgical Option for Forearm Salvage

    Directory of Open Access Journals (Sweden)

    Ichiro Shiokawa, MD

    2014-12-01

    Full Text Available Summary: Posttraumatic upper or lower limb salvage is still challenging. Under difficult situations in which only one vessel supplies the hand or foot, free microvascular reconstruction might damage not only the transferred tissue but also the terminal hand or foot. Two cases of incomplete amputation of the unilateral forearm with large radius bone and soft tissue loss were reconstructed using a newly-refined pedicled osteomyocutaneous flap including vascularized rib, lateral part of the latissimus dorsi muscle, and skin as a lateral chest flap. After insetting of the flap, the transferred limb is fixed with a soft bandage, and the flap is divided no less than 4 weeks after the first operation. The flap completely survived, and bone union between the rib and radius was observed. Although our treatment needed a two-stage procedure, safe and secure reconstruction with an appropriate amount of tissue for salvage was accomplished.

  14. One-bone forearm procedure for acquired pseudoarthrosis of the ulna combined with radial head dislocation in a child: a case with 20 years follow-up.

    Science.gov (United States)

    Hahn, Soo Bong; Kang, Ho Jung; Hyung, Ji Ho; Choi, Yun Rak

    2011-01-01

    This report describes a 6 year-old boy who was treated with one-bone forearm procedure for acquired pseudoarthrosis of the ulna combined with radial head dislocation after radical ulna debridement for osteomyelitis. At more than 20 years of follow-up, the patient had a nearly full range of elbow movements with a few additional surgical procedures. Pronation and supination was restricted by 45°, but the patient had near-normal elbow and hand functions without the restriction of any daily living activity. This case shows that one-bone forearm formation is a reasonable option for forearm stability in longstanding pseudoarthrosis of the ulna with radial head dislocation in a child.

  15. Optimal measurement position estimation by discriminant analysis based on Wilks' lambda for myoelectric hand control.

    Science.gov (United States)

    Kiso, Atsushi; Taniguchi, Yu; Seki, Hirokazu

    2011-01-01

    This paper describes an optimal measurement position estimation by the discriminant analysis based on Wilks' lambda for the myoelectric hand control. In the past studies, the myoelectric signals were measured from the same positions for the motions discrimination. However, the optimal measurement positions of the myoelectric signals for the motion discrimination are different according to the remaining muscle situation of amputees. Therefore the purpose of this study is to estimate the optimal and fewer measurement positions for the precise motion discrimination of the human forearm. This study proposes the estimation method of the optimal measurement positions by the discriminant analysis based on Wilks' lambda among the myoelectric signal measured from multiple positions. Some experiments on the myoelectric hand simulator show the effectiveness of the proposed optimal measurement position estimation method.

  16. Key Insights into Hand Biomechanics: Human Grip Stiffness Can Be Decoupled from Force by Cocontraction and Predicted from Electromyography

    Directory of Open Access Journals (Sweden)

    Hannes Höppner

    2017-05-01

    Full Text Available We investigate the relation between grip force and grip stiffness for the human hand with and without voluntary cocontraction. Apart from gaining biomechanical insight, this issue is particularly relevant for variable-stiffness robotic systems, which can independently control the two parameters, but for which no clear methods exist to design or efficiently exploit them. Subjects were asked in one task to produce different levels of force, and stiffness was measured. As expected, this task reveals a linear coupling between force and stiffness. In a second task, subjects were then asked to additionally decouple stiffness from force at these force levels by using cocontraction. We measured the electromyogram from relevant groups of muscles and analyzed the possibility to predict stiffness and force. Optical tracking was used for avoiding wrist movements. We found that subjects were able to decouple grip stiffness from force when using cocontraction on average by about 20% of the maximum measured stiffness over all force levels, while this ability increased with the applied force. This result contradicts the force–stiffness behavior of most variable-stiffness actuators. Moreover, we found the thumb to be on average twice as stiff as the index finger and discovered that intrinsic hand muscles predominate our prediction of stiffness, but not of force. EMG activity and grip force allowed to explain 72 ± 12% of the measured variance in stiffness by simple linear regression, while only 33 ± 18% variance in force. Conclusively the high signal-to-noise ratio and the high correlation to stiffness of these muscles allow for a robust and reliable regression of stiffness, which can be used to continuously teleoperate compliance of modern robotic hands.

  17. Key Insights into Hand Biomechanics: Human Grip Stiffness Can Be Decoupled from Force by Cocontraction and Predicted from Electromyography

    Science.gov (United States)

    Höppner, Hannes; Große-Dunker, Maximilian; Stillfried, Georg; Bayer, Justin; van der Smagt, Patrick

    2017-01-01

    We investigate the relation between grip force and grip stiffness for the human hand with and without voluntary cocontraction. Apart from gaining biomechanical insight, this issue is particularly relevant for variable-stiffness robotic systems, which can independently control the two parameters, but for which no clear methods exist to design or efficiently exploit them. Subjects were asked in one task to produce different levels of force, and stiffness was measured. As expected, this task reveals a linear coupling between force and stiffness. In a second task, subjects were then asked to additionally decouple stiffness from force at these force levels by using cocontraction. We measured the electromyogram from relevant groups of muscles and analyzed the possibility to predict stiffness and force. Optical tracking was used for avoiding wrist movements. We found that subjects were able to decouple grip stiffness from force when using cocontraction on average by about 20% of the maximum measured stiffness over all force levels, while this ability increased with the applied force. This result contradicts the force–stiffness behavior of most variable-stiffness actuators. Moreover, we found the thumb to be on average twice as stiff as the index finger and discovered that intrinsic hand muscles predominate our prediction of stiffness, but not of force. EMG activity and grip force allowed to explain 72 ± 12% of the measured variance in stiffness by simple linear regression, while only 33 ± 18% variance in force. Conclusively the high signal-to-noise ratio and the high correlation to stiffness of these muscles allow for a robust and reliable regression of stiffness, which can be used to continuously teleoperate compliance of modern robotic hands. PMID:28588472

  18. Hand Anatomy

    Science.gov (United States)

    ... Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Bones Joints Muscles Nerves Vessels Tendons Anatomy The upper extremity is ...

  19. Decoding subtle forearm flexions using fractal features of surface electromyogram from single and multiple sensors

    Directory of Open Access Journals (Sweden)

    Kumar Dinesh

    2010-10-01

    of other features ranged between 58% and 73%. Conclusions The results show that the MFL and FD of a single channel sEMG recorded from the forearm can be used to accurately identify a set of finger and wrist flexions even when the muscle activity is very weak. A comparison with other features demonstrates that this feature set offers a dramatic improvement in the accuracy of identification of the wrist and finger movements. It is proposed that such a system could be used to control a prosthetic hand or for a human computer interface.

  20. Effect of sport training on forearm bone sites in female handball and soccer players.

    Science.gov (United States)

    Boshnjaku, Arben; Dimauro, Ivan; Krasniqi, Ermira; Grazioli, Elisa; Tschan, Harald; Migliaccio, Silvia; DI Luigi, Luigi; Caporossi, Daniela

    2016-12-01

    The objective of this study was to evaluate the bone mineral density (BMD) and Z-score of a skeletal region, considered as weight-bearing site in trained handball players (HP), but as non-weight-bearing site in trained soccer players (SP). The bone health status of the same site was also analyzed in an untrained group (CG). BMD and Z-score at distal forearm regions (dominant, D; non-dominant, ND) were evaluated in 30 female HP and in 30 female SP, who have been training for 7.7±3.8 years, 17 hours per week, as well as in 30 females CG. Playing handball was associated with higher BMD of the skeleton at both measured sites than in CG. Also in comparison with SP, HPs' arms showed a significant increase in BMD. On the other hand, female SP have been reported to exhibit an enhanced ND arm BMD compared with controls. The benefits of exercise appeared to be significantly improved only in SP sub-group who started sport activity before or at menarche. These athletes showed at ND forearm a BMD 4% greater than those SP who started later, reaching a BMD of 11.6% higher than CG, a value similar to the corresponding in HP sub-group. Moreover, their D arm BMD was 7.1% higher compared with CG. This study indicates that, compared with non-trained subjects, long-term high-impact sport participation is associated with an higher bone health state, especially if the playing careers were started before or at menarche. This effect was observed at level of both forearms in HP, which are considered as weight-bearing sites for this discipline but also on the same skeletal regions of SP, which are not directly loaded by sport-related regular training.

  1. Development of rotational movements, hand shaping, and accuracy in advance and withdrawal for the reach-to-eat movement in human infants aged 6-12 months.

    Science.gov (United States)

    Sacrey, Lori-Ann R; Karl, Jenni M; Whishaw, Ian Q

    2012-06-01

    The reach-to-eat movement, transport of a hand to grasp an object that is withdrawn and placed in the mouth, is amongst the earliest developing functional movements of human infants. The present longitudinal study is the first description of the maturation of hand-rotation, hand shaping, and accuracy associated with the advance and withdrawal phases of the movement. Eight infants, aged 6-12 months, and eight adults, were video recorded as they reached for familiar objects or food items. Hand, arm, and trunk movements were assessed frame-by-frame with the Skilled Reaching Rating Scale, previously developed for the assessment of adult reaching, and supplementary kinematic analysis. Reach-to-eat maturation was characterized by three changes. First, for advance, a simple open hand transport gradually matured to a movement associated with pronation and hand shaping of the digits for precision grasping. Second, for withdrawal to the mouth, a direct withdrawal movement gradually became associated with hand supination that oriented the target object to the mouth. Third, associated with the maturation of rotational movements, inaccurate and fragmented hand transport and withdrawal movements developed into precise targeting of the hand-to-object and object-to-mouth. Across the age range, there was a decrease in bimanual reaching and an increase in right handed reaching. The results are discussed in relation to the idea that the maturation of the reach-to-eat movement involves the development of rotational and shaping movements of the hand and visual and somatosensory guidance of a preferred hand.

  2. A New Profile Shape Matching Stereovision Algorithm for Real-time Human Pose and Hand Gesture Recognition

    Directory of Open Access Journals (Sweden)

    Dong Zhang

    2014-02-01

    Full Text Available This paper presents a new profile shape matching stereovision algorithm that is designed to extract 3D information in real time. This algorithm obtains 3D information by matching profile intensity shapes of each corresponding row of the stereo image pair. It detects the corresponding matching patterns of the intensity profile rather than the intensity values of individual pixels or pixels in a small neighbourhood. This approach reduces the effect of the intensity and colour variations caused by lighting differences. As with all real-time vision algorithms, there is always a trade-off between accuracy and processing speed. This algorithm achieves a balance between the two to produce accurate results for real-time applications. To demonstrate its performance, the proposed algorithm is tested for human pose and hand gesture recognition to control a smart phone and an entertainment system.

  3. [Nerve entrapment syndrome of the elbow and forearm].

    Science.gov (United States)

    Allieu, Y; Amara, B

    2002-02-01

    In this study we will discuss entrapment of the median, ulnair, radial and lateral antebrachial nerves of the elbow and the forearm. Compression of the nerves may occur when they traverse a tunnel and an incompatibility exists between the diameter of the tunnel and its contents (e.g. nerves, tendons,...). However, at the elbow and the forearm the nerves are also exposed to particularly dynamic compressions. This is due to anatomical relationships changing between the nerve and its surrounding muscles, tendons and aponevroses during the motion of flexion-extension of the elbow and the prono-supination of the forearm. The possibility of this dynamic factor should be thoroughly explored during the examination through appropriate dynamic tests as described in this study.

  4. Human-Machine Interaction Control Based on Force Myograph and Electrical Stimulation Sensory Feedback for Multi-DOF Robotic Hand%基于肌力信号与电刺激感觉反馈的多自由度机械手人机交互控制

    Institute of Scientific and Technical Information of China (English)

    李楠; 刘波; 霍宏; 叶玉璇; 姜力

    2015-01-01

    为使操作者能够灵活控制多自由度机械手并能感受到机械手的抓取力,提出了一种具有双向信息传输能力的可穿戴式人机交互系统及控制方法.该系统利用压力传感器(FSR)阵列采集与操作者手部动作对应的前臂肌力信号,基于SVM(支持向量机)多类分类器算法实现对手部动作的识别,通过发送动作模式码控制机械手动作.另外,基于经皮神经电刺激(TENS)原理,将机械手抓取力信号转变为电刺激信号刺激体表皮肤,实现机械手抓握力向人体的感觉反馈.实验表明,基于肌力信号和SVM分类器的动作模式识别方法可实现对10种手部动作的识别,成功率不低于95%;电刺激感觉反馈可向人体准确反馈抓取力感并实现盲抓取.%A wearable bi-directional human-machine interaction (HMI) system and its control methods are proposed to enable the user to control multi-DOF robotic hand freely and feel the gripping force from the robotic hand. A force sensory resistor (FSR) array is built to measure the forearm force myographic (FMG) signals corresponding to different hand motions of the user. A multiclass classifier is designed based on the support vector machine (SVM) algorithm to recognize the hand motions and generate motion codes to control the robotic hand movements. Moreover, sensory feedback is achieved by transforming the gripping force signals of the robotic hand into electrical stimulation signals of skin based on the principle of transcutaneous electrical nerve stimulation (TENS). Experimental results show that the motion mode recognition method based on FMG and SVM can identify 10 typical hand motions with the accuracy of above 95%. The electrical stimulation method can feed back the perception of gripping force to the body accurately and help the user to grip objects without vision.

  5. Effectiveness of hand washing on the removal of iron oxide nanoparticles from human skin ex vivo.

    Science.gov (United States)

    Lewinski, Nastassja A; Berthet, Aurélie; Maurizi, Lionel; Eisenbeis, Antoine; Hopf, Nancy B

    2017-08-01

    In this study, the effectiveness of washing with soap and water in removing nanoparticles from exposed skin was investigated. Dry, nanoscale hematite (α-Fe2O3) or maghemite (γ-Fe2O3) powder, with primary particle diameters between 20-30 nm, were applied to two samples each of fresh and frozen ex vivo human skin in two independent experiments. The permeation of nanoparticles through skin, and the removal of nanoparticles after washing with soap and water were investigated. Bare iron oxide nanoparticles remained primarily on the surface of the skin, without penetrating beyond the stratum corneum. Skin exposed to iron oxide nanoparticles for 1 and 20 hr resulted in removal of 85% and 90%, respectively, of the original dose after washing. In the event of dermal exposure to chemicals, removal is essential to avoid potential local irritation or permeation across skin. Although manufactured at an industrial scale and used extensively in laboratory experiments, limited data are available on the removal of engineered nanoparticles after skin contact. Our finding raises questions about the potential consequences of nanoparticles remaining on the skin and whether alternative washing methods should be proposed. Further studies on skin decontamination beyond use of soap and water are needed to improve the understanding of the potential health consequences of dermal exposure to nanoparticles.

  6. Design of a compact low-power human-computer interaction equipment for hand motion

    Science.gov (United States)

    Wu, Xianwei; Jin, Wenguang

    2017-01-01

    Human-Computer Interaction (HCI) raises demand of convenience, endurance, responsiveness and naturalness. This paper describes a design of a compact wearable low-power HCI equipment applied to gesture recognition. System combines multi-mode sense signals: the vision sense signal and the motion sense signal, and the equipment is equipped with the depth camera and the motion sensor. The dimension (40 mm × 30 mm) and structure is compact and portable after tight integration. System is built on a module layered framework, which contributes to real-time collection (60 fps), process and transmission via synchronous confusion with asynchronous concurrent collection and wireless Blue 4.0 transmission. To minimize equipment's energy consumption, system makes use of low-power components, managing peripheral state dynamically, switching into idle mode intelligently, pulse-width modulation (PWM) of the NIR LEDs of the depth camera and algorithm optimization by the motion sensor. To test this equipment's function and performance, a gesture recognition algorithm is applied to system. As the result presents, general energy consumption could be as low as 0.5 W.

  7. Ergonomics applications of a mechanical model of the human operator in power hand tool operation.

    Science.gov (United States)

    Lin, Jia-Hua; Radwin, Robert; Nembhard, David

    2005-02-01

    Applications of a new model for predicting power threaded-fastener-driving tool operator response and capacity to react against impulsive torque reaction forces are explored for use in tool selection and ergonomic workplace design. The model is based on a mechanical analog of the human operator, with parameters dependent on work location (horizontal and vertical distances); work orientation (horizontal and vertical); and tool shape (in-line, pistol grip, and right angle); and is stratified by gender. This model enables prediction of group means and variances of handle displacement and force for a given tool configuration. Response percentiles can be ascertained for specific tool operations. For example, a sample pistol grip nutrunner used on a horizontal surface at 30 cm in front of the ankles and 140 cm above the floor results in a predicted mean handle reaction displacement of 39.0 (SD=28.1) mm for males. Consequently 63%of the male users exceed a 30 mm handle displacement limit. When a right angle tool of similar torque output is used instead, the model predicted that only 4.6%of the male tool users exceed a 30 mm handle displacement. A method is described for interpolating individual subject model parameters at any given work location using linear combinations in relation to the range of modeled factors. Additional examples pertinent to ergonomic workstation design and tool selection are provided to demonstrate how the model can be used to aid tool selection and workstation design.

  8. [Cutaneo-muscular reflexes of the human hand. II. Neurophysiologic aspects of reflex organization and coordination].

    Science.gov (United States)

    Meinck, H M; Berkefeld, J; Conrad, B

    1987-09-01

    The organization and coordination of cutaneo-muscular reflexes of human finger and arm muscles to electrical stimulation of the digital nerves were investigated in 14 healthy volunteers. Thumb and finger muscles, although antagonists, showed homonymous reflex effects whereas the wrist and elbow muscles exhibited an reciprocally alternating reflex pattern in pairs of antagonists (Fig. 1). The mechanographical correlate of the homonymous reflex activity in distal muscles was a short release (Fig. 6). The receptive field for evoking such reflex effects covered both the palmar and dorsal surfaces of the fingers (Fig. 2). However, with stimulation of the thumb, the muscles of the fingers and of the wrist showed reflex reversal (Figs 3, 5). If the stimulus was moved from the second to the fifth fingers, a successive attenuation of the transcortical reflex component was seen (Fig. 4). It is concluded that the reflexes investigated are complex flexor reflexes comprising both a distal release and a proximal flexion synergy. According to opposition of the thumb in grasping, the receptive field terminates between thumb and index finger. These reflexes are supposed to have no assisting function during corticalized manipulatory movements--in contrast to the long-loop reflexes evoked by epicritic sensibility. The transcortical servo is blocked if the eliciting stimulus is contaminated by nociceptive signals; its receptive field is confined to those fingers used in the precision grip.

  9. Similar hand shaping in reaching-for-food (skilled reaching) in rats and humans provides evidence of homology in release, collection, and manipulation movements.

    Science.gov (United States)

    Sacrey, Lori-Ann R; Alaverdashvili, Mariam; Whishaw, Ian Q

    2009-12-01

    Many animal species use their forelimbs to assist in eating, such as occurs in a reach-to-eat task (skilled reaching) in which a forelimb is extended to grasp food that is placed in the mouth for eating. It is unclear the extent to which the skilled reaching movements of different species share common ancestry and so are homologous or evolved independently and so are analogous (homoplasy). Here hand shaping (the movements of the hand and digits) that occur as the hand is transported to the target, were examined using high-speed (1000 frames/s) video recording and kinematic measurement (Peak Motus) in the rat (Rattus norvegicus) and human (Homo sapiens). Ten movement similarities were identified from the point that the limb initiated transport towards the food item to the point that the food was grasped. The digits were closed and semi-flexed as the hand was lifted (released from a substrate) and supinated. They closed further as the hand was collected for aiming. They then extended as the hand was transported to the target and then opened in conjunction with pronation to orient the hand for grasping (manipulation). Finally the digits were flexed and closed for grasping. These movements occurred at approximately the same point of limb transport in both species even though the rat used a whole paw grasp and the humans used a pincer grasp. Bushbabies (Galago garnettii), titi monkeys (Callicebus brunneus), rhesus monkeys (Macaca mulatta) and the bonobo (Pan paniscus) displayed similar hand shaping in skilled reaching despite species differences in grasping movements. Homologous hand shaping in the rodent clade and the primate clade and within the primate lineage is discussed in relation to its possible derivation from hand shaping movements associated with stepping.

  10. Ultrasound in the diagnosis of a median neuropathy in the forearm: case report

    Directory of Open Access Journals (Sweden)

    Yoon Joon-Shik

    2007-12-01

    Full Text Available Abstract Background Electrodiagnostic studies are traditionally used in the diagnosis of focal neuropathies, however they lack anatomical information regarding the nerve and its surrounding structures. The purpose of this case is to show that high-resolution ultrasound used as an adjunct to electrodiagnostic studies may complement this lack of information and give insight to the cause. Case presentation A 60-year-old male patient sustained a forearm traction injury resulting in progressive weakness and functional loss in the first three digits of the right hand. High-resolution ultrasound showed the presence of an enlarged nerve and a homogenous soft-tissue structure appearing to engulf the nerve. The contralateral side was normal. Surgery revealed fibrotic bands emanating from the flexor digitorum profundus muscle compressing the median nerve thus confirming the ultrasound findings. Conclusion A diagnostically challenging case of median neuropathy in the forearm is presented in which high-resolution ultrasound was valuable in establishing an anatomic etiology and directing appropriate management.

  11. Median nerve neuropathy in the forearm due to recurrence of anterior wrist ganglion that originates from the scaphotrapezial joint: Case Report

    Directory of Open Access Journals (Sweden)

    Okada Kiyoshi

    2012-01-01

    Full Text Available Abstract Background Median nerve neuropathy caused by compression from a tumor in the forearm is rare. Cases with anterior wrist ganglion have high recurrence rates despite surgical treatment. Here, we report the recurrence of an anterior wrist ganglion that originated from the Scaphotrapezial joint due to incomplete resection and that caused median nerve neuropathy in the distal forearm. Case presentation A 47-year-old right-handed housewife noted the appearance of soft swelling on the volar aspect of her left distal forearm, and local resection surgery was performed twice at another hospital. One year after the last surgery, the swelling reappeared and was associated with numbness and pain in the radial volar aspect of the hand. Magnetic resonance imaging revealed that the multicystic lesion originated from the Scaphotrapezial joint and had expanded beyond the wrist. Exploration of the left median nerve showed that it was compressed by a large ovoid cystic lesion at the distal forearm near the proximal end of the carpal tunnel. We resected the cystic lesion to the Scaphotrapezial joint. Her symptoms disappeared 1 week after surgery, and complications or recurrent symptoms were absent 13 months after surgery. Conclusions A typical median nerve compression was caused by incomplete resection of an anterior wrist ganglion, which may have induced widening of the cyst. Cases with anterior wrist ganglion have high recurrence rates and require extra attention in their treatment.

  12. The visual development of hand-centered receptive fields in a neural network model of the primate visual system trained with experimentally recorded human gaze changes.

    Science.gov (United States)

    Galeazzi, Juan M; Navajas, Joaquín; Mender, Bedeho M W; Quian Quiroga, Rodrigo; Minini, Loredana; Stringer, Simon M

    2016-01-01

    Neurons have been found in the primate brain that respond to objects in specific locations in hand-centered coordinates. A key theoretical challenge is to explain how such hand-centered neuronal responses may develop through visual experience. In this paper we show how hand-centered visual receptive fields can develop using an artificial neural network model, VisNet, of the primate visual system when driven by gaze changes recorded from human test subjects as they completed a jigsaw. A camera mounted on the head captured images of the hand and jigsaw, while eye movements were recorded using an eye-tracking device. This combination of data allowed us to reconstruct the retinal images seen as humans undertook the jigsaw task. These retinal images were then fed into the neural network model during self-organization of its synaptic connectivity using a biologically plausible trace learning rule. A trace learning mechanism encourages neurons in the model to learn to respond to input images that tend to occur in close temporal proximity. In the data recorded from human subjects, we found that the participant's gaze often shifted through a sequence of locations around a fixed spatial configuration of the hand and one of the jigsaw pieces. In this case, trace learning should bind these retinal images together onto the same subset of output neurons. The simulation results consequently confirmed that some cells learned to respond selectively to the hand and a jigsaw piece in a fixed spatial configuration across different retinal views.

  13. Differences in greeting behaviour towards humans with varying levels of familiarity in hand-reared wolves (Canis lupus)

    Science.gov (United States)

    Kurys, Anita; Kubinyi, Enikő; Gácsi, Márta; Virányi, Zsófia

    2017-01-01

    Socialized wolves' relationship with humans is a much debated, but important question in light of dog domestication. Earlier findings reported no attachment to the caretaker at four months of age in a Strange Situation Test, while recently attachment to the caretaker was reported at a few weeks of age in a similar paradigm. To explore wolf–human relationship, we analysed behaviours of hand reared, extensively socialized wolves towards four visitor types: foster-parents, close acquaintances, persons met once before, and complete strangers during a greeting episode. As hypothesized, in the greeting context subjects showed more intense and friendly behaviour towards foster-parents, than other visitor types, which may reflect familiarity and affinity. However, differences were more pronounced in the group situation (at six months of age) than in the individual situation (at 12 and 24 months), suggesting that unique status of foster parents may become less distinct as wolves get older, while exploration of novel social agents is expressed more with older age. Fear related behaviour patterns were only found in the individual situation, mainly displayed towards strangers. We showed that, in case of extensively socialized wolves, distinctive affiliation and affinity towards the foster parent prevails into adulthood. PMID:28680658

  14. Laterality and grip strength influence hand bone micro-architecture in modern humans, an HRpQCT study.

    Science.gov (United States)

    Reina, Nicolas; Cavaignac, Etienne; Trousdale, William H; Laffosse, Jean-Michel; Braga, José

    2017-06-01

    It is widely hypothesized that mechanical loading, specifically repetitive low-intensity tasks, influences the inner structure of cancellous bone. As such, there is likely a relationship between handedness and bone morphology. The aim of this study is to determine patterns in trabecular bone between dominant and non-dominant hands in modern humans. Seventeen healthy patients between 22 and 32 years old were included in the study. Radial carpal bones (lunate, capitate, scaphoid, trapezium, trapezoid, 1st, 2nd and 3rd metacarpals) were analyzed with high-resolution micro-computed tomography. Additionally, crush and pinch grip were recorded. Factorial analysis indicated that bone volume ratio, trabeculae number (Tb.N), bone surface to volume ratio (BS.BV), body weight, stature and crush grip were all positively correlated with principal components 1 and 2 explaining 78.7% of the variance. Volumetric and trabecular endostructural parameters (BV/TV, BS/BV or Tb.Th, Tb.N) explain the observed inter-individual variability better than anthropometric or clinical parameters. Factors analysis regressions showed correlations between these parameters and the dominant side for crush strength for the lunate (r(2) = 0.640, P modern human wrist. © 2017 Anatomical Society.

  15. Hand Fractures

    Science.gov (United States)

    ... Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is ... serve as a framework. This framework supports the muscles that make the wrist ... When one of these hand bones is broken (fractured), it can prevent you ...

  16. Dissociation of the pathways mediating ipsilateral and contralateral motor-evoked potentials in human hand and arm muscles

    Science.gov (United States)

    Ziemann, Ulf; Ishii, Kenji; Borgheresi, Alessandra; Yaseen, Zaneb; Battaglia, Fortunato; Hallett, Mark; Cincotta, Massimo; Wassermann, Eric M

    1999-01-01

    Growing evidence points toward involvement of the human motor cortex in the control of the ipsilateral hand. We used focal transcranial magnetic stimulation (TMS) to examine the pathways of these ipsilateral motor effects.Ipsilateral motor-evoked potentials (MEPs) were obtained in hand and arm muscles of all 10 healthy adult subjects tested. They occurred in the finger and wrist extensors and the biceps, but no response or inhibitory responses were observed in the opponens pollicis, finger and wrist flexors and the triceps.The production of ipsilateral MEPs required contraction of the target muscle. The threshold TMS intensity for ipsilateral MEPs was on average 1.8 times higher, and the onset was 5.7 ms later (in the wrist extensor muscles) compared with size-matched contralateral MEPs.The corticofugal pathways of ipsilateral and contralateral MEPs could be dissociated through differences in cortical map location and preferred stimulating current direction.Both ipsi- and contralateral MEPs in the wrist extensors increased with lateral head rotation toward, and decreased with head rotation away from, the side of the TMS, suggesting a privileged input of the asymmetrical tonic neck reflex to the pathway of the ipsilateral MEP.Large ipsilateral MEPs were obtained in a patient with complete agenesis of the corpus callosum.The dissociation of the pathways for ipsilateral and contralateral MEPs indicates that corticofugal motor fibres other than the fast-conducting crossed corticomotoneuronal system can be activated by TMS. Our data suggest an ipsilateral oligosynaptic pathway, such as a corticoreticulospinal or a corticopropriospinal projection as the route for the ipsilateral MEP. Other pathways, such as branching of corticomotoneuronal axons, a transcallosal projection or a slow-conducting monosynaptic ipsilateral pathway are very unlikely or can be excluded. PMID:10420023

  17. Early postmenopausal diminution of forearm and spinal bone mineral density

    DEFF Research Database (Denmark)

    Bjarnason, K; Hassager, C; Ravn, Pernille

    1995-01-01

    sites (12%-13%, corresponding to about 1.0-1.5 SD), and extrapolation suggested reverse order of the rates of diminution thereafter (forearm > AP > LAT). When bone mineral content of the entire L3 vertebra (tBMC) was measured in vivo, AP tBMC could account for only 67% of the variation in LAT t...

  18. Mannitol extravasation during partial nephrectomy leading to forearm compartment syndrome

    OpenAIRE

    Erickson, Bradley A.; Yap,Ronald L.; Pazona,Joseph F.; Hartigan,Brian J.; Smith, Norm D.

    2007-01-01

    We present the first known complication of forearm compartment syndrome after mannitol infusion during partial nephrectomy. We stress the importance of excellent intravenous catheter access and constant visual monitoring of the intravenous catheter site during and after mannitol infusion as ways to prevent this complication. Prompt recognition of compartment syndrome with appropriate intervention can prevent long-term sequelae.

  19. Mannitol extravasation during partial nephrectomy leading to forearm compartment syndrome

    Directory of Open Access Journals (Sweden)

    Bradley A. Erickson

    2007-02-01

    Full Text Available We present the first known complication of forearm compartment syndrome after mannitol infusion during partial nephrectomy. We stress the importance of excellent intravenous catheter access and constant visual monitoring of the intravenous catheter site during and after mannitol infusion as ways to prevent this complication. Prompt recognition of compartment syndrome with appropriate intervention can prevent long-term sequelae.

  20. Plate osteosynthesis of simple forearm fractures : LCP versus DC plates

    NARCIS (Netherlands)

    Stevens, Charles Tjerk; Ten Duis, Henk Jan

    2008-01-01

    The aim of this study was to compare the time to radiological bony union of simple A-type fractures of the forearm, treated with either a locking compression plate (LCP) or a dynamic compression plate (DCP). For each fracture, the relation between the use of compression and radiological healing time

  1. Chronic exertional compartment syndrome of the forearm in adolescents.

    Science.gov (United States)

    García-Mata, Serafín

    2013-12-01

    Chronic exertional compartment syndrome (CECS) is a well-known process, although rare in the forearm. The diagnosis is based on history, clinical examination, and compartment pressure readings. My objective is to present the largest series of CECS of the forearm in adolescents and describe my experience in its management and evolution. I reviewed 5 patients, 4 male (competing in motorcycling or motocross) and 1 female (CECS in both the legs and forearms), aged between 15 and 18 years. Volar and dorsal compartments were affected in 3 patients and isolated volar in 2 cases. The clinical diagnosis was objectively confirmed by measuring ICP with a low-pressure digital transducer (Stryker). Open fasciotomy was carried out in 4 patients. They resumed their athletic activities 6 weeks after surgery without complications, increasing their athletic performance level in line with their preoperative status. All these patients remained asymptomatic, recovering their previous competitive levels. The results were objectively classified as excellent in all 4 cases. After a mean follow-up of 6 years, the condition has not relapsed in any of the patients. Two of the patients agreed to a new ICP measurement 1 year after the surgery, showing normal values. CECS in the forearm in adolescents is a rare condition that occurs after puberty. A high index of suspicion is necessary to diagnose it. It is based on symptoms and ICP measurements. Most patients are competing motorcyclists. Surgical treatment, involving isolated decompression of the superficial volar compartment, is safe and effective (restoring normal ICP).

  2. [A former bodybuilder with a swelling on the forearm].

    Science.gov (United States)

    Strijbos, Ruben M; Zwaard, Ton M

    2015-01-01

    A 56-year-old man came to the general practitioner with a solitary compressible swelling on his left forearm, which enlarged during exercise. The patient reported a history of bodybuilding and he worked as a plasterer. Physical examination revealed primary varicose of the upper extremity, a rare localisation of a common vascular disease.

  3. Palatomaxillary reconstruction with titanium mesh and radial forearm flap.

    Science.gov (United States)

    Sun, Guowen; Yang, Xudong; Tang, Enyi; Wen, Jianmin; Lu, Mingxing; Hu, Qingang

    2009-10-01

    The purpose of this study was to assess the treatment and prognosis of the palatomaxillary reconstruction with titanium mesh and the free radial forearm flap. This is a retrospective study of 19 patients with palatomaxillary defects who underwent immediate reconstruction using titanium mesh and a radial forearm flap during the 4-year period from 2004 to 2008. Intraoperatively, the titanium mesh was fixed to the residual bones for the reconstruction of hard-tissue defect after the tumor resection; then the free radial forearm flap was harvested to repair the soft-tissue defect, serving as the intraoral lining and titanium mesh covering. Postoperative esthetic appearance and function were followed-up. All of the patients achieved a satisfactory facial appearance. The speech assessment was good, and the oronasal reflux did not occur in all patients. Only 3 patients had titanium mesh exposure during the follow-up period. The free radial forearm flap with folded titanium mesh is a reliable option for reconstruction of palatomaxillary defects. It is highly effective for swallowing and speech rehabilitation as well as esthetic reconstruction.

  4. Plate osteosynthesis of simple forearm fractures : LCP versus DC plates

    NARCIS (Netherlands)

    Stevens, Charles Tjerk; Ten Duis, Henk Jan

    The aim of this study was to compare the time to radiological bony union of simple A-type fractures of the forearm, treated with either a locking compression plate (LCP) or a dynamic compression plate (DCP). For each fracture, the relation between the use of compression and radiological healing time

  5. Hand function after nerve repair.

    Science.gov (United States)

    Lundborg, G; Rosén, B

    2007-02-01

    Treatment of injuries to major nerve trunks in the hand and upper extremity remains a major and challenging reconstructive problem. Such injuries may cause long-lasting disabilities in terms of lost fine sensory and motor functions. Nowadays there is no surgical repair technique that can ensure recovery of tactile discrimination in the hand of an adult patient following nerve repair while very young individuals usually regain a complete recovery of functional sensibility. Post-traumatic nerve regeneration is a complex biological process where the outcome depends on multiple biological and environmental factors such as survival of nerve cells, axonal regeneration rate, extent of axonal misdirection, type of injury, type of nerve, level of the lesion, age of the patient and compliance to training. A major problem is the cortical functional reorganization of hand representation which occurs as a result of axonal misdirection. Although protective sensibility usually occurs following nerve repair, tactile discriminative functions seldom recover--a direct result of cortical remapping. Sensory re-education programmes are routinely applied to facilitate understanding of the new sensory patterns provided by the hand. New trends in hand rehabilitation focus on modulation of central nervous processes rather than peripheral factors. Principles are being evolved to maintain the cortical hand representation by using the brain capacity for visuo-tactile and audio-tactile interaction for the initial phase following nerve injury and repair (phase 1). After the start of the re-innervation of the hand (phase 2), selective de-afferentation, such as cutaneous anaesthesia of the forearm of the injured hand, allows expansion of the nerve-injured cortical hand representation, thereby enhancing the effects of sensory relearning. Recent data support the view that training protocols specifically addressing the relearning process substantially increase the possibilities for improved

  6. 78 FR 36308 - Proposed Information Collection (Elbow and Forearm Conditions Disability Benefits Questionnaire...

    Science.gov (United States)

    2013-06-17

    ... AFFAIRS Proposed Information Collection (Elbow and Forearm Conditions Disability Benefits Questionnaire... claim for VA disability benefits related to a claimant's diagnosis of an elbow and forearm. DATES... nancy.kessinger@va.gov . Please refer to ``OMB Control No. 2900--NEW (Elbow and Forearm...

  7. File list: Oth.Epd.50.AllAg.Forearm_skin [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  11. File list: His.Epd.10.AllAg.Forearm_skin [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  13. File list: His.Epd.50.AllAg.Forearm_skin [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  19. Acute compartment syndrome of the forearm caused by calcific tendinitis of the distal biceps.

    Science.gov (United States)

    Garayoa, Santiago Amillo; Romero-Muñoz, Luis M; Pons-Villanueva, Juan

    2010-12-01

    Acute compartment syndrome of the forearm requires immediate treatment to avoid damage of the soft tissues and a poor functional outcome for the forearm. Muscular and bone lesions are the main causes of acute compartment syndromes. We report a case of acute compartment syndrome of the forearm caused by a calcific tendinitis of the distal biceps.

  20. Versatility of radial forearm free flap for intraoral reconstruction

    Directory of Open Access Journals (Sweden)

    Jeremić Jelena V.

    2015-01-01

    Full Text Available Introduction. The radial forearm free flap has an important role in reconstruction of the oncologic defects in the region of head and neck. Objective. The aim was to present and evaluate clinical experience and results in the radial forearm free transfer for intraoral reconstructions after resections due to malignancies. Methods. This article illustrates the versatility and reliability of forearm single donor site in 21 patients with a variety of intraoral oncologic defects who underwent immediate (19 patients, 90.5% or delayed (2 patients, 9.5% reconstruction using free flaps from the radial forearm. Fascio-cutaneous flaps were used in patients with floor of the mouth (6 cases, buccal mucosa (5 cases, lip (1 case and a retromolar triangle (2 cases defects, or after hemiglossectomy (7 cases. In addition, the palmaris longus tendon was included with the flap in 2 patients that required oral sphincter reconstruction. Results. An overall success rate was 90.5%. Flap failures were detected in two (9.5% patients, in one patient due to late ischemic necrosis, which appeared one week after the surgery, and in another patient due to venous congestion, which could not be salvaged after immediate re-exploration. Two patients required re-exploration due to vein thrombosis. The donor site healed uneventfully in all patients, except one, who had partial loss of skin graft. Conclusion. The radial forearm free flap is, due to multiple advantages, an acceptable method for reconstructions after resection of intraoral malignancies. [Projekat Ministarstva nauke Republike Srbije, br. 41006

  1. Open Fracture of the Forearm Bones due to Horse Bite

    Directory of Open Access Journals (Sweden)

    John Ashutosh Santoshi

    2014-01-01

    Full Text Available Introduction: Fractures have been described mainly following falling accidents in horse-related injuries. Horse bites are uncommon accidents. We present a case of open fracture of the forearm due to horse bite. Case Report: A 35-year-old male farm-worker presented to the emergency room with alleged history of horse bite to the right forearm about 2 hours prior to presentation while feeding the horse. There was deformity of the forearm with multiple puncture wounds, deep abrasions and small lacerations on the distal-third of the forearm. Copious irrigation with normal saline was done and he was administered anti-tetanus and post-exposure rabies prophylaxis. Prophylactic antibiotic therapy was commenced. Radiographs revealed fracture of radius and ulna in the mid-shaft region. He underwent emergency wound debridement, and the ulna was stabilised with an intra-medullary square nail. Seventy-two hours later, he underwent re-debridement and conversion osteosynthesis. He had an uneventful recovery and at three-month follow-up, the fractures had healed radiographically in anatomic alignment. At two-year follow-up, he is doing well, is pain free and has a normal range of motion compared to the contralateral side. Conclusion: Horse bites behave as compound fractures however rabies prophylaxis will be needed and careful observation is needed. Early radical debridement, preliminary skeletal stabilisation, re-debridement and conversion osteosynthesis to plate, and antibiotic prophylaxis were the key to the successful management of our patient. Keywords: Horse; animal bite; forearm; open fracture

  2. Ulno-volar bayonet hand: Its differential diagnosis from Madelung's deformity

    Energy Technology Data Exchange (ETDEWEB)

    Christ, F.

    1981-04-01

    The ulno-volar bayonet hand related to the mostly hereditary multiple exostoses is compared to Madelung's forearm deformity under clinical and roentgenological view in differential diagnosis. The ulno-volar bayonet hand is considerably more seldom, basing upon dysplasia of the lower part of the ulna, less inconvenient in function, and hardly tending to the development of early arthrosis.

  3. Perseveration Found in a Human Drawing Task: Six-Fingered Hands Drawn by Patients with Right Anterior Insula and Operculum Damage

    Directory of Open Access Journals (Sweden)

    Chiharu Niki

    2014-01-01

    Full Text Available Background. Perseveration has been observed in a number of behavioural contexts, including speaking, writing, and drawing. However, no previous report describes patients who show perseveration only for drawing a human figure. Objective. The present report describes a group of patients who show body awareness-related cognitive impairment during a human figure drawing task, a different presentation from previously described neuropsychological cases. Methods. Participants were 15 patients who had a frontal lobe brain tumour around the insula cortex of the right hemisphere and had subsequently undergone a neurosurgical resective operation. Participants were asked to draw a human figure in both “hands-down” and “hands-up” configurations. Results. Eight of the 15 patients drew a human figure with six fingers during the “hands-up” and the “hands-down” human figure drawing tasks (one patient drew eight fingers. A statistical analysis of potential lesion areas revealed damage to the right anterior frontal insula and operculum in this group of patients relative to the five-finger drawing group. Conclusions. Our findings reveal a newly described neuropsychological phenomenon that could reflect impairment in attention directed towards body representations.

  4. Architectural properties of the neuromuscular compartments in selected forearm skeletal muscles.

    Science.gov (United States)

    Liu, An-Tang; Liu, Ben-Li; Lu, Li-Xuan; Chen, Gang; Yu, Da-Zhi; Zhu, Lie; Guo, Rong; Dang, Rui-Shan; Jiang, Hua

    2014-07-01

    The purposes f this study were to (i) explore the possibility of splitting the selected forearm muscles into separate compartments in human subjects; (ii) quantify the architectural properties of each neuromuscular compartment; and (iii) discuss the implication of these properties in split tendon transfer procedures. Twenty upper limbs from 10 fresh human cadavers were used in this study. Ten limbs of five cadavers were used for intramuscular nerve study by modified Sihler's staining technique, which confirmed the neuromuscular compartments. The other 10 limbs were included for architectural analysis of neuromuscular compartments. The architectural features of the compartments including muscle weight, muscle length, fiber length, pennation angle, and sarcomere length were determined. Physiological cross-sectional area and fiber length/muscle length ratio were calculated. Five of the selected forearm muscles were ideal candidates for splitting, including flexor carpi ulnaris, flexor carpi radials, extensor carpi radialis brevis, extensor carpi ulnaris and pronator teres. The humeral head of pronator teres contained the longest fiber length (6.23 ± 0.31 cm), and the radial compartment of extensor carpi ulnaris contained the shortest (2.90 ± 0.28 cm). The ulnar compartment of flexor carpi ulnaris had the largest physiological cross-sectional area (5.17 ± 0.59 cm(2)), and the ulnar head of pronator teres had the smallest (0.67 ± 0.06 cm(2)). Fiber length/muscle length ratios of the neuromuscular compartments were relatively low (average 0.27 ± 0.09, range 0.18-0.39) except for the ulnar head of pronator teres, which had the highest one (0.72 ± 0.05). Using modified Sihler's technique, this research demonstrated that each compartment of these selected forearm muscles has its own neurovascular supply after being split along its central tendon. Data of the architectural properties of each neuromuscular compartment provide insight into the 'design' of their

  5. The role of human parietal area 7A as a link between sequencing in hand actions and in overt speech production

    Directory of Open Access Journals (Sweden)

    Stefan eHeim

    2012-12-01

    Full Text Available Research on the evolutionary basis of the human language faculty has proposed the mirror neuron system as a link between motor processing and speech development. Consequently, most work has focussed on the left inferior frontal cortex, in particular Broca's region, and the left inferior parietal cortex. However, the direct link between planning of hand motor and speech actions remains to be elucidated. Thus, the present study investigated whether sequencing of hand motor actions vs. speech motor actions has a common neural denominator. For the hand motor task, 25 subjects performed single, repeated, or sequenced button presses with either the left or right hand. The speech task was in analogy; the same subjects produced the syllable "po" once or repeatedly, or a sequence of different syllables (po-pi-po. Speech motor vs. hand motor effectors resulted in increased perisylvian activation including Broca's region (left area 44 and areas medially adjacent to left area 45. In contrast, common activation for sequenced vs. repeated production of button presses and syllables revealed the effector-independent involvement of left area 7A in the superior parietal lobule (SPL in sequencing. These data demonstrate that sequencing of vocal gestures, an important precondition for ordered utterances and ultimately human speech, shares area 7A, rather than inferior parietal regions, as a common cortical module with hand motor sequencing. Interestingly, area 7A has previously also been shown to be involved in the observation of hand and non-hand actions. In combination with the literature, the present data thus suggest a distinction between area 44, which is specifically recruited for (cognitive aspects of speech, and SPL area 7A for general aspects of motor sequencing. In sum, the study demonstrates a yet little considered role of the superior parietal lobule in the origins of speech, and may be discussed in the light of embodiment of speech and language in the

  6. Split hand/foot malformation genetics supports the chromosome 7 copy segregation mechanism for human limb development

    Science.gov (United States)

    Klar, Amar J. S.

    2016-01-01

    Genetic aberrations of several unlinked loci cause human congenital split hand/foot malformation (SHFM) development. Mutations of the DLX5 (distal-less) transcription factor-encoding gene in chromosome 7 cause SHFM through haploinsufficiency, but the vast majority of cases result from heterozygous chromosomal aberrations of the region without mutating the DLX5 gene. To resolve this paradox, we invoke a chromosomal epigenetic mechanism for limb development. It is composed of a monochromatid gene expression phenomenon that we discovered in two fission yeasts with the selective chromosome copy segregation phenomenon that we discovered in mouse cells. Accordingly, one daughter cell inherits both expressed DLX5 copies while the other daughter inherits both epigenetically silenced ones from a single deterministic cell of the developing limb. Thus, differentiated daughter cells after further proliferation will correspondingly produce proximal/distal-limb tissues. Published results of a Chr. 7 translocation with a centromere-proximal breakpoint situated over 41 million bases away from the DLX locus, centromeric and DLX5-region inversions have satisfied key genetic and developmental biology predictions of the mechanism. Further genetic tests of the mechanism are proposed. We propose that the DNA double helical structure itself causes the development of sister cells' gene regulation asymmetry. We also argue against the conventionally invoked morphogen model of development. This article is part of the themed issue ‘Provocative questions in left–right asymmetry’. PMID:27821526

  7. The real role of forearm mixed nerve conduction velocity in the assessment of proximal forearm conduction slowing in carpal tunnel syndrome.

    Science.gov (United States)

    Chang, Ming-Hong; Lee, Yee-Chung; Hsieh, Peiyuan F

    2008-12-01

    The decrease of forearm median motor conduction velocity (CV) in carpal tunnel syndrome (CTS) is a common electrodiagnostic finding in clinical practice and is possibly secondary to either conduction block at wrist or retrograde conduction slowing (RCS). This study is attempted to confirm the existence of RCS and to explore why this controversy occurs for a long time. Eighty CTS patients and controls were recruited. In addition to conventional electrodiagnosis, subjects received further electrodiagnostic protocol. First, a recording electrode was placed over the wrist and then at elbow with palm stimulation to calculate indirect forearm mixed nerve CV (forearm-mix CV) that represented real measurement of nerve fibers through the carpal tunnel. Then, direct measurement of forearm-mix CV was performed with recording at the elbow and stimulation at the wrist. CTS patients had markedly prolonged distal motor and sensory latencies and significantly prolonged wrist-palm sensory and motor conduction. There was a significant decrease in forearm median motor CV; however, there was no difference in ulnar distal motor latency and forearm motor CV. The mild decrease of forearm median motor CV was not proportional to the marked reduction of W-P MCV and there was no demonstrated conduction block at wrist, implying the reduction of forearm median motor CV is unlikely due to conduction blockage or slowing of the large myelinating fibers at the wrist and RCS really occurs over the forearm median nerve. In addition, the direct Forearm-mix CV was similar in CTS and controls; however, there was a significant decrease in indirect forearm-mix CV only in the CTS. Moreover, the difference between direct and indirect forearm-mix CV was significantly greater and poor consistency of direct and indirect forearm-mix CV in CTS, suggesting that direct and indirect forearm-mix CV represent CV from quite different nerve fibers. Therefore, we conclude that RCS really does occur in CTS and the

  8. Clinical features the diaphyseal refractures of the forearm in children

    Directory of Open Access Journals (Sweden)

    A. Kosimov

    2014-03-01

    Full Text Available Background: The forearm refractures are the most common and serious injuries in the childhood. In our practice the refractures in children occur from 1.3% up to 5.2% among all fractures in children. Clinical characteristics of the refractures were highlighted insufficiently. Purpose: To study clinical signs of forearm refractures and effect of osteoreparative process. Material and methods: In the department of children's trauma of Scientific Research Institute of Traumatology and Orthopedics during the period from 2002 to 2012 from the general number of the patients 136 children with refracture of the tubular bones were revealed. With regard to the number of fractures twice refractures were in 132 patients, three times refractures found in 4 patients. From these patients 102 were boys and 34 were girls. According to structure of refracture localization the forearm refractures were on the leading place, which were observed in 109 (80.1% of patients. The refractures of the middle third forearm were noted in 82 patients, the refracture of middle upper third forearm - in 2 patients, the refracture of the lower third forearm was in 25 patients. Results: In the refractures at the second stage of regeneration (time of occurrence more than 3 months, especially at the moment of active process of the callus ossification the close of medullar canal occur and hematoma volume became significantly less than in primary fracture. At refractures hematoma at the place of fracture was more localized. At the refracture the weak pain is defined, and sometimes pain can be absent (about the reasons is said above, and the main active and passive movements in the full volume. The cases of absence of crepitation are possible in refractures. It is important that in refractures the longitudinal and impacted displacement we did not observe. In cases with painless clinical course of the refracture in the patients the active and passive movements were saved in complete volume

  9. Hand Eczema

    NARCIS (Netherlands)

    Coenraads, Pieter-Jan

    2012-01-01

    A 33-year-old woman presents with redness of the hands and reports the intermittent occurrence of tiny vesicles, scaling, and fissuring, accompanied by itching on the palms, fingers, and dorsal sides of the hands. She has two young children and works as a nurse in a nearby hospital. She has a histor

  10. Deep burn of hand and forearm treated by abdominal wall flap. A case report.

    Science.gov (United States)

    Chiummariello, Stefano; Del Torto, Giuseppe; Maffia, Romano; Pataia, Elisabetta; Alfano, Carmine

    2015-06-24

    Le ustioni della mano sono sempre state uno dei maggiori problemi per i chirurghi ricostruttori a causa della sua particolare anatomia e delle sue complesse funzioni. Una guarigione spontanea di lesioni profonde in queste aree può portare a risultati catastrofici: una copertura cutanea adeguata è fondamentale per tutte le funzioni. La copertura precoce dei tessuti molli residuanti è fondamentale al fine di evitare la formazione di contratture disabilitanti che con il tempo potrebbero determinare anchilosi articolare e retrazione tendinea. Escissione precoce e innesti cutanei rappresentano la terapia standard per le ustioni della mano; in alcuni casi quest’approccio è inapplicabile e, pertanto, il ricorso ai lembi diventa inevitabile. In questo articolo riportiamo un caso di ustione complessa del dorso della mano trattata in prima istanza con innesti cutanei e, quindi, con un lembo addominale, riuscendo ad ottenere un’ottima copertura ed un buon recupero delle funzioni.

  11. Increased sympathetic tone in forearm subcutaneous tissue in primary hypothyroidism

    DEFF Research Database (Denmark)

    Vagn Nielsen, H; Hasselström, K; Feldt-Rasmussen, U

    1987-01-01

    Sympathetic reflex regulation of subcutaneous blood flow (SBF) in the forearm was studied in eight patients with primary hypothyroidism. Diastolic arterial pressure was greater than or equal to 95 mmHg in five patients. SBF was determined by local clearance of Na99mTcO4. Sympathetic vasoconstrict......Sympathetic reflex regulation of subcutaneous blood flow (SBF) in the forearm was studied in eight patients with primary hypothyroidism. Diastolic arterial pressure was greater than or equal to 95 mmHg in five patients. SBF was determined by local clearance of Na99mTcO4. Sympathetic.......02)). In conclusion sympathetic vasoconstrictor activity in adipose tissue is markedly increased in primary hypothyroidism. Sympathetic tone and arterial pressure are reduced during treatment....

  12. Motion discrimination of throwing a baseball using forearm electrical impedance

    Science.gov (United States)

    Nakamura, Takao; Kusuhara, Toshimasa; Yamamoto, Yoshitake

    2013-04-01

    The extroversion or hyperextension of elbow joint cause disorders of elbow joint in throwing a baseball. A method, which is easy handling and to measure motion objectively, can be useful for evaluation of throwing motion. We investigated a possibility of motion discrimination of throwing a baseball using electrical impedance method. The parameters of frequency characteristics (Cole-Cole arc) of forearm electrical impedance were measured during four types of throwing a baseball. Multiple discriminant analysis was used and the independent variables were change ratios of 11 parameters of forearm electrical impedance. As results of 120 data with four types of throwing motion in three subjects, hitting ratio was very high and 95.8%. We can expect to discriminate throwing a baseball using multiple discriminant analysis of impedance parameters.

  13. Nonunion of forearm fracture: a rare instance in a toddler

    Directory of Open Access Journals (Sweden)

    Saini Pramod

    2012-12-01

    Full Text Available 【Abstract】 When compared to adults, pediatric frac-tures unite readily and nonunion is quite rare. Nonunion is often associated with open fractures, operative interventions, infection, pediatric osteogenesis imperfecta and neurofibromatosis. There are only a few studies and reports mentioning nonunion following conservative ma-nagement of closed pediatric fractures. We report here a case of an eighteen-month-old child who developed non-union following treatment of fracture of both forearm bones with cast and was successfully treated with plating. To the best of our knowledge, this is the youngest reported case of nonunion following conservative management of closed diaphyseal pediatric fracture. Key words: Forearm; Fractures, bone; Child

  14. Forearm muscle oxygenation decreases with low levels of voluntary contraction

    Science.gov (United States)

    Murthy, G.; Kahan, N. J.; Hargens, A. R.; Rempel, D. M.

    1997-01-01

    The purpose of our investigation was to determine if the near infrared spectroscopy technique was sensitive to changes in tissue oxygenation at low levels of isometric contraction in the extensor carpi radialis brevis muscle. Nine subjects were seated with the right arm abducted to 45 degrees, elbow flexed to 85 degrees, forearm pronated 45 degrees, and wrist and forearm supported on an armrest throughout the protocol. Altered tissue oxygenation was measured noninvasively with near infrared spectroscopy. The near infrared spectroscopy probe was placed over the extensor carpi radialis brevis of the subject's right forearm and secured with an elastic wrap. After 1 minute of baseline measurements taken with the muscle relaxed, four different loads were applied just proximal to the metacarpophalangeal joint such that the subjects isometrically contracted the extensor carpi radialis brevis at 5, 10, 15, and 50% of the maximum voluntary contraction for 1 minute each. A 3-minute recovery period followed each level of contraction. At the end of the protocol, with the probe still in place, a value for ischemic tissue oxygenation was obtained for each subject. This value was considered the physiological zero and hence 0% tissue oxygenation. Mean tissue oxygenation (+/-SE) decreased from resting baseline (100% tissue oxygenation) to 89 +/- 4, 81 +/- 8, 78 +/- 8, and 47 +/- 8% at 5, 10, 15, and 50% of the maximum voluntary contraction, respectively. Tissue oxygenation levels at 10, 15, and 50% of the maximum voluntary contraction were significantly lower (p muscle contraction and that near infrared spectroscopy is a sensitive technique for detecting deoxygenation noninvasively at low levels of forearm muscle contraction. Our findings have important implications in occupational medicine because oxygen depletion induced by low levels of muscle contraction may be directly linked to muscle fatigue.

  15. Sampling method development and optimization in view of human hand odor analysis by thermal desorption coupled with gas chromatography and mass spectrometry.

    Science.gov (United States)

    Cuzuel, Vincent; Portas, Eglantine; Cognon, Guillaume; Rivals, Isabelle; Heulard, François; Thiébaut, Didier; Vial, Jérôme

    2017-08-01

    Forensic profiling of human odor is challenging and would be useful to support information provided by dogs in courts of justice. Analyses of volatile compounds constitutive of human odor are commonly performed with gas chromatography coupled with mass spectrometry. All developed methods and sampling prototypes have to be easy to use in the field by crime scene investigators. This paper will focus on techniques for human hand odor sampling prior to analysis by a thermodesorption device coupled with gas chromatography and mass spectrometry. Thermodesorption and gas chromatography methods were developed using a sorbent phase spiked with a mixture of 80 compounds representative of human hand odor. Then, the crucial sampling step was performed indirectly with a homemade device based on air suction and trapping on a sorbent. This indirect sampling device was evaluated with the same synthetic mixture for optimization. An innovative polymer sorbent called Sorb-Star(®) was compared to classic Tenax TA(®) packed tubes. Sorb-Star(®) provided similar recovery to Tenax TA(®) packed tubes and a smaller pooled coefficient of variation (6 vs 13%). Thus, it appeared to be fully suited to the indirect sampling of human hand odor. The developed methods were successfully applied to real samples, the ultimate aim being the comparison of a suspect's sample to a sample collected from a crime scene.

  16. [Chronic stress-related compartment syndrome of the forearm].

    Science.gov (United States)

    Kouvalchouk, J F; Watin Augouard, L; Dufour, O; Coudert, X; Paszkowski, A

    1993-01-01

    The chronic anterior compartment syndrome of the forearm is a rare pathology (3 cases have been already published), and of new knowledge. Three new cases on 2 patients (one on both sides) are described here. The authors describe recent advances about physiopathology, exploration and surgical treatment. It is due to strenuous activity using flexor muscles of the forearm without any release period (here motor cyclist competition). The symptom was pain at the anterior forearm similar to cramp. The most important for diagnosis was to measure the pressure after activity. The threshold level read after activity was up to 30 mm of Hg, with a very slow coming back to normal value. The isotopic scanner with hydroxyl methylene di-phosphonate (HMDP), after activity, showed a delay of arrival of the tracer and a stasis. RMI seems to give abnormal modification of the signal. The only treatment was surgical and an open fasciotomy of superficial and deep fascia must be done, with opening of the muscle's perimysium. The patients became painfree and resumed their sport after surgical treatment.

  17. Dual pathology proximal median nerve compression of the forearm.

    LENUS (Irish Health Repository)

    Murphy, Siun M

    2013-12-01

    We report an unusual case of synchronous pathology in the forearm- the coexistence of a large lipoma of the median nerve together with an osteochondroma of the proximal ulna, giving rise to a dual proximal median nerve compression. Proximal median nerve compression neuropathies in the forearm are uncommon compared to the prevalence of distal compression neuropathies (eg Carpal Tunnel Syndrome). Both neural fibrolipomas (Refs. 1,2) and osteochondromas of the proximal ulna (Ref. 3) in isolation are rare but well documented. Unlike that of a distal compression, a proximal compression of the median nerve will often have a definite cause. Neural fibrolipoma, also called fibrolipomatous hamartoma are rare, slow-growing, benign tumours of peripheral nerves, most often occurring in the median nerve of younger patients. To our knowledge, this is the first report of such dual pathology in the same forearm, giving rise to a severe proximal compression of the median nerve. In this case, the nerve was being pushed anteriorly by the osteochondroma, and was being compressed from within by the intraneural lipoma. This unusual case highlights the advantage of preoperative imaging as part of the workup of proximal median nerve compression.

  18. Activation patterns in forearm muscles during archery shooting.

    Science.gov (United States)

    Ertan, H; Kentel, B; Tümer, S T; Korkusuz, F

    2003-02-01

    A contraction and relaxation strategy with regard to forearm muscles during the release of the bowstring has often been observed during archery, but has not well been described. The purpose of this study was to analyze this strategy in archers with different levels of expertise; elite, beginner and non-archers. Electromyography (EMG) activity of the M. flexor digitorum superficialis and the M. extensor digitorum were recorded at a sampling frequency of 500 Hz, together with a pulse synchronized with the clicker snap, for twelve shots by each subject. Raw EMG records, 1-s before and after the clicker pulse, were rectified, integrated and normalized. The data was then averaged for successive shots of each subject and later for each group. All subjects including non-archers developed an active contraction of the M. extensor digitorum and a gradual relaxation of the M. flexor digitorum superficialis with the fall of the clicker. In elite archers release started about 100 ms after the fall of the clicker, whereas in beginners and non-archers release started after about 200 and 300 ms, respectively. Non-archers displayed a preparation phase involving extensive extensor activity before the release of the bowstring, which was not observed in elite and beginner archers. In conclusion, archers released the bowstring by active contraction of the forearm extensors, whereas a clear relaxation of the forearm flexors affecting the release movement was not observed.

  19. Acute dietary nitrate supplementation does not augment submaximal forearm exercise hyperemia in healthy young men.

    Science.gov (United States)

    Kim, Jin-Kwang; Moore, David J; Maurer, David G; Kim-Shapiro, Daniel B; Basu, Swati; Flanagan, Michael P; Skulas-Ray, Ann C; Kris-Etherton, Penny; Proctor, David N

    2015-02-01

    Despite the popularity of dietary nitrate supplementation and the growing evidence base of its potential ergogenic and vascular health benefits, there is no direct information about its effects on exercising limb blood flow in humans. We hypothesized that acute dietary nitrate supplementation from beetroot juice would augment the increases in forearm blood flow, as well as the progressive dilation of the brachial artery, during graded handgrip exercise in healthy young men. In a randomized, double-blind, placebo-controlled crossover study, 12 young (22 ± 2 years) healthy men consumed a beetroot juice (140 mL Beet-It Sport, James White Juice Company) that provided 12.9 mmol (0.8 g) of nitrate or placebo (nitrate-depleted Beet-It Sport) on 2 study visits. At 3 h postconsumption, brachial artery diameter, flow, and blood velocity were measured (Doppler ultrasound) at rest and during 6 exercise intensities. Nitrate supplementation raised plasma nitrate (19.5-fold) and nitrite (1.6-fold) concentrations, and lowered resting arterial pulse wave velocity (PWV) versus placebo (all p nitrate supplementation had no effect on brachial artery diameter, flow, or shear rates at rest (all p ≥ 0.28) or during any exercise workload (all p ≥ 0.18). These findings suggest that acute dietary nitrate supplementation favorably modifies arterial PWV, but does not augment blood flow or brachial artery vasodilation during nonfatiguing forearm exercise in healthy young men.

  20. Redirection of cutaneous sensation from the hand to the chest skin of human amputees with targeted reinnervation

    OpenAIRE

    Kuiken, Todd A.; Marasco, Paul D.; Lock, Blair A.; Harden, R. Norman; Dewald, Julius P.A.

    2007-01-01

    Amputees cannot feel what they touch with their artificial hands, which severely limits usefulness of those hands. We have developed a technique that transfers remaining arm nerves to residual chest muscles after an amputation. This technique allows some sensory nerves from the amputated limb to reinnervate overlying chest skin. When this reinnervated skin is touched, the amputees perceive that they are being touched on their missing limb. We found that touch thresholds of the reinnervated ch...

  1. In vivo study of human skin using pulsed terahertz radiation

    Energy Technology Data Exchange (ETDEWEB)

    Pickwell, E [Semiconductor Physics Group, Cavendish Laboratory, Cambridge University, Madingley Road, Cambridge CB3 0HE (United Kingdom); Cole, B E [TeraView Ltd, Unit 302/4 Cambridge Science Park, Cambridge CB4 0WG (United Kingdom); Fitzgerald, A J [TeraView Ltd, Unit 302/4 Cambridge Science Park, Cambridge CB4 0WG (United Kingdom); Pepper, M [Semiconductor Physics Group, Cavendish Laboratory, Cambridge University, Madingley Road, Cambridge CB3 0HE (United Kingdom); Wallace, V P [TeraView Ltd, Unit 302/4 Cambridge Science Park, Cambridge CB4 0WG (United Kingdom)

    2004-05-07

    Studies in terahertz (THz) imaging have revealed a significant difference between skin cancer (basal cell carcinoma) and healthy tissue. Since water has strong absorptions at THz frequencies and tumours tend to have different water content from normal tissue, a likely contrast mechanism is variation in water content. Thus, we have previously devised a finite difference time-domain (FDTD) model which is able to closely simulate the interaction of THz radiation with water. In this work we investigate the interaction of THz radiation with normal human skin on the forearm and palm of the hand in vivo. We conduct the first ever systematic in vivo study of the response of THz radiation to normal skin. We take in vivo reflection measurements of normal skin on the forearm and palm of the hand of 20 volunteers. We compare individual examples of THz responses with the mean response for the areas of skin under investigation. Using the in vivo data, we demonstrate that the FDTD model can be applied to biological tissue. In particular, we successfully simulate the interaction of THz radiation with the volar forearm. Understanding the interaction of THz radiation with normal skin will form a step towards developing improved imaging algorithms for diagnostic detection of skin cancer and other tissue disorders using THz radiation.

  2. Corrective Osteotomy for Malunited Diaphyseal Forearm Fractures Using Preoperative 3-Dimensional Planning and Patient-Specific Surgical Guides and Implants.

    Science.gov (United States)

    Byrne, Ann-Maria; Impelmans, Bianca; Bertrand, Veronique; Van Haver, Annemieke; Verstreken, Frederik

    2017-07-11

    Three-dimensional planning based on computed tomography images of the malunited and the mirrored contralateral forearm allows preoperative simulations of corrective osteotomies, the fabrication of patient-specific osteotomy guides, and custom-made 3-dimensional printed titanium plates. This study aims to assess the precision and clinical outcome of this technique. This was a prospective pilot study with 5 consecutive patients. The mean age at initial injury was 11 years (range, 4-16 years), and the mean interval from the time of injury to the time of corrective surgery was 32 months (range, 7-107 months). Patient-specific osteotomy guides and custom-made plates were used for multiplanar corrective osteotomies of both forearm bones at the distal level in 1 patient and at the middle-third level in 4 patients. Patients were assessed before and after surgery after a mean follow-up of 42 months (range, 29-51 months). The mean planned angular corrections of the ulna and radius before surgery were 9.9° and 10.0°, respectively. The mean postoperative corrections obtained were 10.1° and 10.8° with corresponding mean errors in correction of 1.8° (range, 0.3°-5.2°) for the ulna and 1.4° (range, 0.2°-3.3°) for the radius. Forearm supination improved significantly from 47° (range, 25°-75°) before surgery to 89° (range, 85°-90°) at final review. Forearm pronation improved from 68° (range, 45°-84°) to 87° (range, 82°-90°). In addition, there was a statistically significant improvement in pain and grip strength. This study demonstrates that 3-dimensional planned patient-specific guides and implants allow the surgeon to perform precise corrective osteotomies of complex multiplanar forearm deformities with satisfactory preliminary results. Therapeutic V. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  3. Hand eczema.

    Science.gov (United States)

    Agarwal, Uma Shankar; Besarwal, Raj Kumar; Gupta, Rahul; Agarwal, Puneet; Napalia, Sheetal

    2014-05-01

    Hand eczema is often a chronic, multifactorial disease. It is usually related to occupational or routine household activities. Exact etiology of the disease is difficult to determine. It may become severe enough and disabling to many of patients in course of time. An estimated 2-10% of population is likely to develop hand eczema at some point of time during life. It appears to be the most common occupational skin disease, comprising 9-35% of all occupational diseases and up to 80% or more of all occupational contact dermatitis. So, it becomes important to find the exact etiology and classification of the disease and to use the appropriate preventive and treatment measures. Despite its importance in the dermatological practice, very few Indian studies have been done till date to investigate the epidemiological trends, etiology, and treatment options for hand eczema. In this review, we tried to find the etiology, epidemiology, and available treatment modalities for chronic hand eczema patients.

  4. [Traumatic pathology of antibrachial interosseous membrane of forearm].

    Science.gov (United States)

    Soubeyrand, Marc; Lafont, Clarisse; De Georges, Renaud; Dumontier, Christian

    2007-12-01

    The antibrachial interosseous membrane (IOM) is taught over an average length of 10.6cm between the diaphyses of the radius and ulna bone. It looks like a stitch with fibers running from the ulna to the radius and from proximal to distal and fibers running from distal to proximal. The central band, which is the middle part of the fibers directed from distal to proximal has mechanical properties similar to those of a ligament and act as a ligamentous structure embedded in the larger membranous complex of the IOM. The interosseous membrane has a double function: it stabilizes transversally the forearm's two bones and stabilizes longitudinally the two bones by transferring loads from the radius to the ulna. Load transmission varies according to the prono-supination position, the varus-valgus constraints on the elbow and the inclination of the wrist, making interpretation of the experimental data difficult. One should consider the forearm as a whole and the interosseous membrane with the two diaphyses should be regarded as a middle radio-ulnar joint, intercalated between the proximal and distal radio-ulnar joint. Those three articulations or links between radius and ulna act synergistically to stabilize and optimize repartition of loads. Functional loss of one of these links, and of course of more than one, will severely modify the forearm function. Essex-Lopresti lesion, which represents the functional loss of all three links, is the most destabilizing forearm lesion. Imaging of the interosseous membrane is difficult. MRI allows for static imaging of the interosseous membrane but there are often artifacts due to previous trauma or surgical procedures. Dynamic sonography helps to visualize all the lesions and will probably be part of the evaluation of every severe forearm injury. Surgical treatment depends on the gravity of the lesions of the different links. Interosseous membrane reconstruction is still the most difficult technique and most of the previously reported

  5. Elastic robust intramedullary nailing for forearm fracture in children

    Directory of Open Access Journals (Sweden)

    Wasem, Jürgen

    2006-01-01

    Full Text Available Background: Forearm fractures are the most common fractures in children (23% of all fractures. Basically there are two treatment options available for diaphyseal forearm fractures in children: closed reduction with cast immobilisation (conservative therapy and the elastic stable intramedullary nailing (ESIN. Treatment decision is influenced by the doctor's estimation of fracture instability. Stable fractures can be treated conservatively whereas instable forearm shaft fractures can be treated according the following three treatment strategies: 1. conservative therapy in an outpatient setting 2. conservative therapy in the operating room in attendance to change to ESIN in case that no stabilisation can be achieved with cast immobilisation 3. immediate treatment with ESIN in the operating room. Objectives: Aim of this Health Technology Assessment (HTA report is to assess and report the published evidence concerning effectiveness and cost-effectiveness of ESIN as a treatment option for diaphyseal forearm fractures in children and to identify future research need. Important parameters for the assessment of effectiveness are objective parameters (axis deviation, losses of motion, and numbers of reductions in case of redislocations and subjective parameters (pain or impairment in quality of life. Furthermore, a health economic evaluation shall be done which refers to the costs of the different therapy strategies. Methods: An extensive, systematic literature search in medical, economic, and HTA literature databases was performed. Relevant data were extracted and synthesised. Results: Three cohort studies and seven case series have been identified. Controlled clinical studies, systematic reviews and/or HTA reports that gave evidence to answer the own study question have not been found. The identified studies partly differed in respect of defined indication for ESIN, study population and treatment strategies. For that reason comparability of results was

  6. A Case of Reverse Palmaris Longus Muscle- An Additional Muscle in the Anterior Compartment of the Forearm

    Science.gov (United States)

    Bhat, Ashwini Lagadamane Sathynarayana; Gadahad, Mohandas Rao Kappettu

    2016-01-01

    It is uncommon to have additional muscles in the upper limb. Some of them may restrict the movements or compress the nerves and vessels, while others may go unnoticed. During the routine dissection for undergraduate medical students, we observed an additional muscle in the anterior compartment of the forearm in about 60-year-old male cadaver. The muscle had a prominent belly and a long tendon. Distally, it was attached to the flexor retinaculum by a short and thick tendon. Proximally, long tendon of the muscle passed between the flexor carpi ulnaris and palmaris longus and was attached to the common aponeurosis shared by the extensor carpi ulnaris and flexor digitorum profundus muscles. The additional muscle belly was supplied by a branch from the anterior interosseous nerve. The ulnar nerve and artery was passing deep to the fleshy belly of the muscle. The muscle reported here might compress the ulnar nerve and artery and may produce neurovascular symptoms. On the other hand, the tendon and fleshy belly of the muscle could be useful in muscle/tendon grafts. The observations made by us in the present case will supplement our knowledge of variations of the muscles in this region which could be useful for surgeons during the forearm and hand surgeries. PMID:27134851

  7. Investigation of the Intra- and Inter-Limb Muscle Coordination of Hands-and-Knees Crawling in Human Adults by Means of Muscle Synergy Analysis

    Directory of Open Access Journals (Sweden)

    Xiang Chen

    2017-05-01

    Full Text Available To investigate the intra- and inter-limb muscle coordination mechanism of human hands-and-knees crawling by means of muscle synergy analysis, surface electromyographic (sEMG signals of 20 human adults were collected bilaterally from 32 limb related muscles during crawling with hands and knees at different speeds. The nonnegative matrix factorization (NMF algorithm was exerted on each limb to extract muscle synergies. The results showed that intra-limb coordination was relatively stable during human hands-and-knees crawling. Two synergies, one relating to the stance phase and the other relating to the swing phase, could be extracted from each limb during a crawling cycle. Synergy structures during different speeds kept good consistency, but the recruitment levels, durations, and phases of muscle synergies were adjusted to adapt the change of crawling speed. Furthermore, the ipsilateral phase lag (IPL value which was used to depict the inter-limb coordination changed with crawling speed for most subjects, and subjects using the no-limb-pairing mode at low speed tended to adopt the trot-like mode or pace-like mode at high speed. The research results could be well explained by the two-level central pattern generator (CPG model consisting of a half-center rhythm generator (RG and a pattern formation (PF circuit. This study sheds light on the underlying control mechanism of human crawling.

  8. The Tromsø Study: artifacts in forearm bone densitometry--prevalence and effect.

    Science.gov (United States)

    Berntsen, G K; Tollan, A; Magnus, J H; Søgaard, A J; Ringberg, T; Fønnebø, V

    1999-01-01

    Suboptimal performance of bone densitometer, operator and/or subject may cause artifacts of consequence both for individual patient management and research. The prevalence and effects of such artifacts are largely unknown in densitometry. A cross-sectional population-based study was carried out of artifacts in forearm bone densitometry with single X-ray Absorptiometry (SXA) of the nondominant hand (distal and ultradistal site). After the screening, all scans were reviewed for artifact detection and reanalysis. The effect on the bone mineral density (BMD) result was found by comparing artifactual scans with a reanalyzed version or with normal repeat scans. All women aged 50-74 years, all men aged 55-74 years and 5-10% samples of other age groups aged >/=25 years attending the fourth Tromso health study were invited to have bone densitometry. The response rate from the background population was 80% (n = 7948). Fourteen percent of subjects had a movement artifact at either the distal or ultradistal site. The individual BMD variation was twice as large in scans with a movement artifact (0.94%) compared with normal scans (0.58%) (p = 0.0027). The radial endplate was inaccurately detected in 74% of the scans. Reanalysis of these scans led to a mean 3.8% decrease in the BMD value and an increase in the prevalence of osteoporosis of 10%. Artifacts were thus common, and their effects were clinically relevant in forearm bone densitometry. Artifacts and their effects need to be characterized in other bone densitometry settings also.

  9. Does computer use pose an occupational hazard for forearm pain; from the NUDATA study

    DEFF Research Database (Denmark)

    Kryger, Ann Isabel; Andersen, JH; Lassen, C. F.

    2003-01-01

    AIMS: To determine the occurrence of pain conditions and disorders in the forearm and to evaluate risk factors for forearm pain in a cohort of computer workers. METHODS: A total of 6943 participants with a wide range of computer use and work tasks were studied. At baseline and at one year follow up...... was associated with use of a mouse device for more than 30 hours per week, and with keyboard use more than 15 hours per week. High job demands and time pressure at baseline were risk factors for onset of forearm pain; women had a twofold increased risk of developing forearm pain. Self reported ergonomic...... workplace factors at baseline did not predict future forearm pain. CONCLUSION: Intensive use of a mouse device, and to a lesser extent keyboard usage, were the main risk factors for forearm pain. The occurrence of clinical disorders was low, suggesting that computer use is not commonly associated with any...

  10. EF-hands at atomic resolution: The structure of human psoriasin (S100A7) solved by MAD phasing

    DEFF Research Database (Denmark)

    Brodersen, Ditlev Egeskov; Etzerodt, Michael; Madsen, Peder Søndergaard

    1998-01-01

    The S100 family consists of small acidic proteins, belonging to the EF-hand class of calcium-binding proteins. They are primarily regulatory proteins, involved in cell growth, cell structure regulation and signal transduction. Psoriasin (S100A7) is an 11.7 kDa protein that is highly upregulated i...... structures of apo forms of S100 proteins. The substitution of Ca2+ ions in EF-hands by lanthanide ions may provide a general vehicle for structure determination of S100 proteins by means of MAD phasing....

  11. [Hand infections].

    Science.gov (United States)

    Schiele, Philippe; Le Nen, Dominique

    2013-11-01

    Superficial and deep hand infections are frequent in general medical practice. Clinical examination is a crucial step for an adapted provided care. Most of the time, surgery is the only way to heal infections. However, in some cases (like bites), empiric antibiotherapy is first indicated to limit infection. Staphyloccocus aureus as well as Group Beta Streptococcus are the most frequently pathogenes associated with hand infections. Methicillin resistant S. Aureus must always be considered in the diagnoses. Whatever treatment is provided, clinical assessement must be repeated within two days. An early adaquated treatment prevent functional complications and in some cases death of the patients.

  12. Regular use of a hand cream can attenuate skin dryness and roughness caused by frequent hand washing

    Directory of Open Access Journals (Sweden)

    Kampf Günter

    2006-02-01

    Full Text Available Abstract Background Aim of the study was to determine the effect of the regular use of a hand cream after washing hands on skin hydration and skin roughness. Methods Twenty-five subjects washed hands and forearms with a neutral soap four times per day, for 2 minutes each time, for a total of two weeks. One part of them used a hand cream after each hand wash, the others did not (cross over design after a wash out period of two weeks. Skin roughness and skin hydration were determined on the forearms on days 2, 7, 9 and 14. For skin roughness, twelve silicon imprint per subject and time point were taken from the stratum corneum and assessed with a 3D skin analyzer for depth of the skin relief. For skin hydration, five measurements per subject and time point were taken with a corneometer. Results Washing hands lead to a gradual increase of skin roughness from 100 (baseline to a maximum of 108.5 after 9 days. Use of a hand cream after each hand wash entailed a decrease of skin roughness which the lowest means after 2 (94.5 and 14 days (94.8. Skin hydration was gradually decreased after washing hands from 79 (baseline to 65.5 after 14 days. The hand wash, followed by use of a hand cream, still decreased skin hydration after 2 days (76.1. Over the next 12 days, however, skin hydration did not change significantly (75.6 after 14 days. Conclusion Repetitive and frequent hand washing increases skin dryness and roughness. Use of a hand cream immediately after each hand wash can confine both skin dryness and skin roughness. Regular use of skin care preparations should therefore help to prevent both dry and rough skin among healthcare workers in clinical practice.

  13. Love and caring. Ethics of face and hand--an invitation to return to the heart and soul of nursing and our deep humanity.

    Science.gov (United States)

    Watson, Jean

    2003-01-01

    This manuscript offers a new view of old and timeless values: the essential ethic of love, informed by contemporary European philosophies, and caring theory, as well as ancient poetry and wisdom traditions. It integrates some of the philosophical views of Levinas and Logstrup with Watson's Transpersonal Caring Theory. The metaphysics, metaphors, and meanings associated with "ethics of face," the "infinity of the human soul," and "holding another's life in our hands" are tied to a deeply ethical foundation for the timeless practice of love and caring, as a means to sustain, not only our shared humanity, but the profession of nursing itself.

  14. Does computer use pose an occupational hazard for forearm pain; from the NUDATA study

    DEFF Research Database (Denmark)

    Kryger, Ann Isabel; Andersen, JH; Lassen, C. F.

    2003-01-01

    workplace factors at baseline did not predict future forearm pain. CONCLUSION: Intensive use of a mouse device, and to a lesser extent keyboard usage, were the main risk factors for forearm pain. The occurrence of clinical disorders was low, suggesting that computer use is not commonly associated with any......AIMS: To determine the occurrence of pain conditions and disorders in the forearm and to evaluate risk factors for forearm pain in a cohort of computer workers. METHODS: A total of 6943 participants with a wide range of computer use and work tasks were studied. At baseline and at one year follow up...

  15. Wrist and forearm postures and motions during typing.

    Science.gov (United States)

    Serina, E R; Tal, R; Rempel, D

    1999-07-01

    Awkward upper extremity postures and repetitive wrist motions have been identified by some studies as risk factors for upper extremity musculoskeletal disorders during keyboard work. However, accurate body postures and joint motions of typists typing on standardized workstations are not known. A laboratory study was conducted to continuously measure wrist and forearm postures and motions of 25 subjects while they typed for 10-15 min at a standard computer workstation adjusted to the subjects' anthropometry. Electrogoniometers continuously recorded wrist and forearm angles. Joint angular velocities and accelerations were calculated from the postural data. The results indicate that wrist and forearm postures during typing were sustained at non-neutral angles; mean wrist extension angle was 23.4 +/- 10.9 degrees on the left and 19.9 +/- 8.6 degrees on the right. Mean ulnar deviation was 14.7 +/- 10.1 degrees on the left and 18.6 +/- 5.8 degrees on the right. More than 73% of subjects typed with the left or right wrist in greater than 15 degrees extension and more than 20% typed with the left or right wrist in greater than 20 degrees ulnar deviation. Joint angles and motions while typing on an adjusted computer workstation were not predictable based on anthropometry or typing speed and varied widely between subjects. Wrist motions are rapid and are similar in magnitude to wrist motions of industrial workers performing jobs having a high risk for developing cumulative trauma disorders. The magnitude of the dynamic components suggests that wrist joint motions may need to be evaluated as a risk factor for musculoskeletal disorders during typing.

  16. Nonunion of forearm fracture: a rare instance in a toddler

    Institute of Scientific and Technical Information of China (English)

    Pramod Saini; Sanjay Meena; Vishal Shekhawat; Tanmay S Kishanpuria

    2012-01-01

    When compared to adults,pediatric fractures unite readily and nonunion is quite rare.Nonunion is often associated with open fractures,operative interventions,infection,pediatric osteogenesis imperfecta and neurofibromatosis.There are only a few studies and reports mentioning nonunion following conservative management of closed pediatric fractures.We report here a case of an eighteen-month-old child who developed nonunion following treatment of fracture of both forearm bones with cast and was successfully treated with plating.To the best of our knowledge,this is the youngest reported case of nonunion following conservative management of closed diaphyseal pediatric fracture.

  17. Epiglottis reconstruction with free radial forearm flap after supraglottic laryngectomy.

    Science.gov (United States)

    Hsiao, Hung-Tao; Leu, Yi-Shing; Tung, Kwang-Yi

    2010-01-01

    A bilobed free radial forearm flap was designed to reconstruct a defect in the epiglottis and tongue base in 2 patients who underwent supraglottic laryngectomy. The flap was initially sutured in the shape of the epiglottis to prevent aspiration during deglutition. Six months after surgery, after a full course of radiation therapy, the flap had flattened and underwent atrophy, but the patients still had good voice production and were able to swallow well without any aspiration. Regardless of the final shape of the reconstructed epiglottis, it will suffice to prevent aspiration if the flap is large enough to occlude the tracheal outlet.

  18. Hand eczema

    Directory of Open Access Journals (Sweden)

    Uma Shankar Agarwal

    2014-01-01

    Full Text Available Hand eczema is often a chronic, multifactorial disease. It is usually related to occupational or routine household activities. Exact etiology of the disease is difficult to determine. It may become severe enough and disabling to many of patients in course of time. An estimated 2-10% of population is likely to develop hand eczema at some point of time during life. It appears to be the most common occupational skin disease, comprising 9-35% of all occupational diseases and up to 80% or more of all occupational contact dermatitis. So, it becomes important to find the exact etiology and classification of the disease and to use the appropriate preventive and treatment measures. Despite its importance in the dermatological practice, very few Indian studies have been done till date to investigate the epidemiological trends, etiology, and treatment options for hand eczema. In this review, we tried to find the etiology, epidemiology, and available treatment modalities for chronic hand eczema patients.

  19. Hand Osteoblastoma

    Directory of Open Access Journals (Sweden)

    M. Farzan

    2006-06-01

    Full Text Available Background and Aim: Osteoblastoma is one of the rarest primary bone tumors. Although, small bones of the hands and feet are the third most common location for this tumor, the hand involvement is very rare and few case observations were published in the English-language literature. Materials and Methods: In this study, we report five cases of benign osteoblastoma of the hand, 3 in metacarpals and two in phalanxes. The clinical feature is not specific. The severe nocturnal, salicylate-responsive pain is not present in patients with osteoblastoma. The pain is dull, persistent and less localized. The clinical course is usually long and there is often symptoms for months before medical attention are sought. Swelling is a more persistent finding in osteoblastoma of the hand that we found in all of our patients. The radiologic findings are indistinctive, so preoperative diagnosis based on X-ray appearance is difficult. In all of our 5 cases, we fail to consider osteoblastoma as primary diagnosis. Pathologically, osteoblastoma consisting of a well-vascularized connective tissue stroma in which there is active production of osteoid and primitive woven bone. Treatment depends on the stage and localization of the tumor. Curettage and bone grafting is sufficient in stage 1 or stage 2, but in stage 3 wide resection is necessary for prevention of recurrence. Osteosarcoma is the most important differential diagnosis that may lead to inappropriate operation.

  20. Hand eczema

    DEFF Research Database (Denmark)

    Ibler, K.S.; Jemec, G.B.E.; Flyvholm, M.-A.

    2012-01-01

    /materials/methods. A survey of 3181 healthcare workers was performed. Data were analysed with logistic regression. Data on sick leave and notification to the authorities were obtained. Results. The response rate was 71% (2274 of 3181). The 1-year prevalence of hand eczema was 21%, and was positively associated with atopic...

  1. A restrained-torque-based motion instructor: forearm flexion/extension-driving exoskeleton

    Science.gov (United States)

    Nishimura, Takuya; Nomura, Yoshihiko; Sakamoto, Ryota

    2013-01-01

    When learning complicated movements by ourselves, we encounter such problems as a self-rightness. The self-rightness results in a lack of detail and objectivity, and it may cause to miss essences and even twist the essences. Thus, we sometimes fall into the habits of doing inappropriate motions. To solve these problems or to alleviate the problems as could as possible, we have been developed mechanical man-machine human interfaces to support us learning such motions as cultural gestures and sports form. One of the promising interfaces is a wearable exoskeleton mechanical system. As of the first try, we have made a prototype of a 2-link 1-DOF rotational elbow joint interface that is applied for teaching extension-flexion operations with forearms and have found its potential abilities for teaching the initiating and continuing flection motion of the elbow.

  2. Relative Efficacy of Human Social Interaction and Food as Reinforcers for Domestic Dogs and Hand-Reared Wolves

    Science.gov (United States)

    Feuerbacher, Erica; Wynne, Clive D. L.

    2012-01-01

    Despite the intimate relationship dogs share with humans in Western society, we know relatively little about the variables that produce and maintain dog social behavior towards humans. One possibility is that human social interaction is itself a reinforcer for dog behavior. As an initial assessment of the variables that might maintain dog social…

  3. Relative Efficacy of Human Social Interaction and Food as Reinforcers for Domestic Dogs and Hand-Reared Wolves

    Science.gov (United States)

    Feuerbacher, Erica; Wynne, Clive D. L.

    2012-01-01

    Despite the intimate relationship dogs share with humans in Western society, we know relatively little about the variables that produce and maintain dog social behavior towards humans. One possibility is that human social interaction is itself a reinforcer for dog behavior. As an initial assessment of the variables that might maintain dog social…

  4. Assessment of electrosurgical hand controls integrated into a laparoscopic grasper.

    Science.gov (United States)

    Brown-Clerk, Bernadette; Rousek, Justin B; Lowndes, Bethany R; Eikhout, Sandra M; Balogh, Bradley J; Hallbeck, M Susan

    2011-12-01

    The aim of this study was to quantitatively and qualitatively determine the optimal ergonomic placement of novel electrosurgical hand controls integrated into a standard laparoscopic grasper to optimize functionality. This device will allow laparoscopic surgeons to hand-operate standard electrosurgical equipment, eliminating the use of electrosurgical foot pedals, which are prone to activation errors and cause uncomfortable body positions for the physician. Three hand control designs were evaluated by 26 participants during the performance of four basic inanimate laparoscopic electrosurgical tasks. Task completion time, actuation force, forearm electromyography (EMG) and user preference were evaluated for each hand control design. Task speed was controlled using a metronome to minimize subject variability, and resulted in no significant completion time differences between task types (P > 0.05). Hand control design 1 (CD 1) resulted in the ability to generate significantly greater actuation force for three of the four tasks (P electrosurgical hand controls.

  5. Long-term results of surgery for forearm deformities in patients with multiple cartilaginous exostoses.

    Science.gov (United States)

    Akita, Shosuke; Murase, Tsuyoshi; Yonenobu, Kazuo; Shimada, Kozo; Masada, Kazuhiro; Yoshikawa, Hideki

    2007-09-01

    Surgical treatment of forearm deformities in patients with multiple cartilaginous exostoses remains controversial. The purpose of the present study was to determine the reasonable indications for operative treatment and to evaluate long-term results of forearm surgery in these patients. We retrospectively reviewed twenty-three patients (thirty-one forearms) after a mean duration of follow-up of nearly thirteen years. The mean age at the time of the initial procedure was eleven years. The patients underwent a variety of surgical procedures, including excision of exostoses; corrective procedures (lengthening of the radius or ulna and/or corrective osteotomy of the radius and/or ulna) and open reduction or excision of a dislocated radial head. Clinical evaluation involved the assessment of pain, activities of daily living, the cosmetic outcome, and the ranges of motion of the wrist, forearm, and elbow. The radiographic parameters that were assessed were ulnar variance, the radial articular angle, and carpal slip. Four patients had mild pain, and five patients had mild restriction of daily activities at the time of follow-up. Eight patients stated that the appearance of the forearm was unsatisfactory. Radiographic parameters (ulnar variance, radial articular angle, carpal slip) were initially improved; however, at the time of the final follow-up visit, the deformities had again progressed and showed no significant improvement. The only procedure that was associated with complications was ulnar lengthening. Complications included nonunion (three forearms), fracture of callus at the site of lengthening (two forearms), and temporary radial nerve paresis following an ulnar distraction osteotomy (one forearm). Excision of exostoses significantly improved the range of pronation (p = 0.036). In our patients with multiple cartilaginous exostoses, corrective osteotomy and/or lengthening of forearm bones was not beneficial. The most beneficial procedure was excision of exostoses

  6. Total Lip Reconstruction with Tendinofasciocutaneous Radial Forearm Flap

    Directory of Open Access Journals (Sweden)

    Eldad Silberstein

    2014-01-01

    Full Text Available Introduction. Squamous cell carcinoma is a common tumour of lower lip. Small defects created by surgical resection may be readily reconstructed by linear closure or with local flaps. However, large tumours resection often results with microstomia and oral incompetence, drooling, and speech incomprehension. The goal of this study is to describe our experience with composite free radial forearm-palmaris longus tendon flap for total or near total lower lip reconstruction. Patients and Methods. This procedure was used in 5 patients with 80–100% lip defect resulting from Squamous cell carcinoma. Patients’ age ranged from 46 to 82 years. They are three male patients and two female. In 3 cases chin skin was reconstructed as well and in one case a 5 cm segment of mandible was reconstructed using radius bone. In one case where palmaris longus was missing hemi-flexor carpi radialis tendon was used instead. All patients tolerated the procedure well. Results. All flaps totally survived. No patient suffered from drooling. All patients regained normal diet and normal speech. Cosmetic result was fair to good in all patients accept one. Conclusion. We conclude that tendino-fasciocutaneous radial forearm flap for total lower lip reconstruction is safe. Functional and aesthetic result approaches reconstructive goals.

  7. Electromyographical Study on Muscle Fatigue in Repetitive Forearm Tasks

    Institute of Scientific and Technical Information of China (English)

    DAI Wentao; ZHAO Xiaorong; WANG Zhenglun; YANG Lei

    2007-01-01

    The purpose of this study was to examine whether repetitive muscle tasks in low weight load might influence the fatigue of forearm muscles, and to identify ergonomic risk factors of forearm muscle fatigue in these tasks. Sixteen healthy male volunteers performed eight wrist extensions in different frequency, weight and angle loads while being instructed to keep a dominant upper limb posture as constant as possible. Surface electromyograph (sEMG) was recorded from right extensors digitorium (ED), flexor carpi radialis (FCR), flexor carpi ulnaris (FCU) and extensor carpi ulnaris (ECU) during the task performance. Our results showed that mean power frequency (MPF) and median frequency (MF) values of ED, FCR and FCU were significantly lower (P<0.05) at high frequency load level than at low load level. However, MPF and MF values of ED were significantly lower (P<0.01) in higher load groups of frequency, angle and weight than in lower load groups. These results indicated that the fatigue of muscles varied in the same task, and the number-one risk factor of ECU, ED and FCR was angle load.

  8. Prehospital Dextrose Extravasation Causing Forearm Compartment Syndrome: A Case Report.

    Science.gov (United States)

    Chinn, Matthew; Colella, M Riccardo

    2017-01-01

    A 57-year-old woman was found at home by paramedics to be hypoglycemic with altered mental status. She had multiple attempts at IV access and eventually a 22G IV was established and D50 was infused into her right forearm. Extravasation of the dextrose was noted after approximately 12 g of the medication was infused. She was given a dose of glucagon intramuscularly and her mental status improved. Shortly after her arrival to the emergency department, she was noted to have findings of compartment syndrome of her forearm at the site of the dextrose extravasation. She was evaluated by plastic surgery and taken to the operating room for emergent fasciotomy. She recovered well from the operation. D50 is well known to cause phlebitis and local skin necrosis as a complication. This case illustrates the danger of compartment syndrome after D50 extravasation. It is the first documented case of prehospital dextrose extravasation leading to compartment syndrome. There may be safer alternatives to D50 administration and providers must be acutely aware to monitor for D50 infusion complications.

  9. Simultaneous formation of right- and left-handed anti-parallel coiled-coil interfaces by a coil2 fragment of human lamin A.

    Science.gov (United States)

    Kapinos, Larisa E; Burkhard, Peter; Herrmann, Harald; Aebi, Ueli; Strelkov, Sergei V

    2011-04-22

    The elementary building block of all intermediate filaments (IFs) is a dimer featuring a central α-helical rod domain flanked by the N- and C-terminal end domains. In nuclear IF proteins (lamins), the rod domain consists of two coiled-coil segments, coil1 and coil2, that are connected by a short non-helical linker. Coil1 and the C-terminal part of coil2 contain the two highly conserved IF consensus motifs involved in the longitudinal assembly of dimers. The previously solved crystal structure of a lamin A fragment (residues 305-387) corresponding to the second half of coil2 has yielded a parallel left-handed coiled coil. Here, we present the crystal structure and solution properties of another human lamin A fragment (residues 328-398), which is largely overlapping with fragment 305-387 but harbors a short segment of the tail domain. Unexpectedly, no parallel coiled coil forms within the crystal. Instead, the α-helices are arranged such that two anti-parallel coiled-coil interfaces are formed. The most significant interface has a right-handed geometry, which is accounted for by a characteristic 15-residue repeat pattern that overlays with the canonical heptad repeat pattern. The second interface is a left-handed anti-parallel coiled coil based on the predicted heptad repeat pattern. In solution, the fragment reveals only a weak dimerization propensity. We speculate that the C-terminus of coil2 might unzip, thereby allowing for a right-handed coiled-coil interface to form between two laterally aligned dimers. Such an interface might co-exist with a heterotetrameric left-handed coiled-coil assembly, which is expected to be responsible for the longitudinal A(CN) contact.

  10. Primary shortening of the forearm and Sauvé-Kapandji for severely comminuted fractures of the distal forearm in elderly patients: a case report.

    Science.gov (United States)

    Goorens, Chul Ki; Geurts, Ghislain; Goubau, Jean F

    2013-01-01

    We report a case of an elderly female who sustained a severely comminuted distal radial and ulnar fracture, treated by shortening of the forearm, combined with a primary Sauvé-Kapandji procedure and volar plating of the distal radius.

  11. 78 FR 68907 - Agency Information Collection (Elbow and Forearm Conditions Disability Benefits Questionnaire...

    Science.gov (United States)

    2013-11-15

    ... AFFAIRS Agency Information Collection (Elbow and Forearm Conditions Disability Benefits Questionnaire... electronic mail to oira_submission@omb.eop.gov . Please refer to ``OMB Control No. 2900- NEW (Elbow and... Control No. 2900-NEW (Elbow and Forearm Conditions Disability Benefits Questionnaire)''....

  12. [Chronic compartment syndrome of the flexor muscles in the forearm due to motocross].

    Science.gov (United States)

    Jeschke, J; Baur, E M; Piza-Katzer, H

    2006-04-01

    A case of a mechanic and motorcyclist is reported who developed unilateral chronic exertional compartment syndrome of the flexor muscles in the forearm. After years of discomfort and medical check-ups, a subcutaneous fasciotomy of the superficial compartments of the flexor muscles in the forearm led to a complete relief of symptoms, which allowed the patient unrestricted activity.

  13. Estimation of height of an individual from forearm length on the population of Eastern India

    National Research Council Canada - National Science Library

    Biswa Bhusan Mohanty; Divya Agrawal; Kunal Mishra; Pusparaj Samantsinghar; Prafulla Kumar Chinara

    2013-01-01

    ... calculate the height of a person precisely and reproducibly from forearm length. 300 students (M = 206, F = 94) aged 18-25 years, - who had no disability, were studied at SCB Medical College, Cuttack. Height & forearm lengths were measured. Prediction equation for height was derived using linear equation method. [PUBLICATION ABSTRACT

  14. A molecular exploration of human DNA/RNA co-extracted from the palmar surface of the hands and fingers.

    Science.gov (United States)

    Lacerenza, D; Aneli, S; Omedei, M; Gino, S; Pasino, S; Berchialla, P; Robino, C

    2016-05-01

    "Touch DNA" refers to the DNA that is left behind when a person touches or comes into contact with an item. However, the source of touch DNA is still debated and the large variability in DNA yield from casework samples suggests that, besides skin, various body fluids can be transferred through contact. Another important issue concerning touch DNA is the possible occurrence of secondary transfer, but the data published in the literature in relation to the background levels of foreign DNA present on the hand surfaces of the general population are very limited. As the present study aimed at better understanding the nature and characteristics of touch DNA, samples were collected from the palmar surface of the hands and fingers ("PHF" samples) of 30 male and 30 female donors by tape-lifting/swabbing and subjected to DNA/RNA co-extraction. Multiplex mRNA profiling showed that cellular material different from skin could be observed in 15% of the PHF samples. The total amount of DNA recovered from these samples (median 5.1 ng) was significantly higher than that obtained from samples containing skin cells only (median 1.6 ng). The integrity of the DNA isolated from the donors' hands and fingers as well as the prevalence of DNA mixtures were evaluated by STR typing and compared with reference STR profiles from buccal swabs. DNA integrity appeared significantly higher in the male rather than in the female subsample, as the average percentage of the donors' alleles effectively detected in PHF profiles was 75.1% and 60.1%, respectively. The prevalence of mixtures with a foreign DNA contribution ≥20% was 19.2% (30.0% in the female PHF samples and 8.3% in the male PHF samples). The obtained results support the hypothesis that transfer of cellular material different from skin may underlie the occasional recovery of quality STR profiles from handled items. These results also suggest that gender may represent an important factor influencing the propensity of individuals to carry

  15. Older women with dementia can perform fast alternating forearm movements and performance is correlated with tests of lower extremity function

    Directory of Open Access Journals (Sweden)

    Bramell-Risberg E

    2013-02-01

    Full Text Available Eva Bramell-Risberg,1 Gun-Britt Jarnlo,2 Sölve Elmståhl11Division of Geriatric Medicine, 2Division of Physiotherapy, Department of Health Sciences, Lund University, Lund, SwedenBackground: The purpose of this work was to study the performance and reliability of a test of fast alternating forearm movements and its relationship with measures of lower extremity function in older women with dementia.Methods: Fast alternating movements was studied in 26 female patients (mean age 81.7 ± 5.9 years with dementia and 34 controls (mean age 87.5 ± 4.7 years. Subgroup analyses for those aged 80–89 years were performed due to significant differences in the mean ages of the study groups. Test–retest reliability for alternating forearm movements was studied in 11 patients (mean age 80.3 ± 6.7 years and 10 controls (mean age 87.4 ± 1.6 years. Pulses generated were transformed to an analog signal shown on a modified electrocardiogram. Numbers of cycles at 10 and 15 seconds were calculated for the right and left hand. Walking 2 × 15 m and the Get-Up-and Go (GUG test were performed at self-selected and maximal speed. Associations between tests of upper and lower extremity function were sought in eight patients (mean age 85 ± 2.7 years and 16 controls (mean age 85.1 ± 2.8 years and also according to types of dementia in nine patients with probable Alzheimer's disease and 10 patients with other types of dementia.Results: Patients with dementia could perform the test and had significantly fewer cycles (P = 0.02–0.006 at both 10 and 15 seconds compared with controls after age adjustment. A higher number of cycles was associated with higher self-selected walking speeds in patients (r = -0.79. Test–retest reliability for alternating forearm movements was high for both patients (intraclass correlation 0.88–0.94 and controls (intraclass correlation 0.74–0.94.Conclusion: Alternating forearm movements at fast speed can be used as a reliable test in both

  16. Effect of specific resistance training on forearm pain and work disability in industrial technicians: cluster randomised controlled trial

    DEFF Research Database (Denmark)

    Andersen, Lars Louis; Jakobsen, Markus D; Pedersen, Mogens Theisen

    2012-01-01

    To determine the effect of specific resistance training on forearm pain and work disability in industrial technicians.......To determine the effect of specific resistance training on forearm pain and work disability in industrial technicians....

  17. Multiple osteochondromas (MO in the forearm: a 12-year single-centre experience

    Directory of Open Access Journals (Sweden)

    John Ham

    2016-10-01

    Full Text Available Abstract Multiple osteochondromas (MO are a rare autosomal dominant disorder characterized by the presence of osteochondromas located on the long bones and axial skeleton. Patients present with growth disturbances and angular deformities of the long bones as well as limited motion of affected joints. Forearm involvement is found in a considerable number of patients and may vary from the presence of a simple osteochondroma to severe forearm deformities and radial head dislocation. Patients encounter a variety of problems and symptoms e.g., pain, functional impairment, loss of strength and cosmetic concerns. Several surgical procedures are offered from excision of symptomatic osteochondromas to challenging reconstructions of forearm deformities. We describe visualizing, planning and treating these forearm deformities in MO and, in particular, a detailed account of the surgical correction of Masada type I and Masada type II MO forearm deformities.

  18. Mirror activity in the human brain while observing hand movements: a comparison between EEG desynchronization in the mu-range and previous fMRI results.

    Science.gov (United States)

    Perry, Anat; Bentin, Shlomo

    2009-07-28

    Mu (mu) rhythms are EEG oscillations between 8-13 Hz distinguished from alpha by having more anterior distribution and being desynchronized by motor rather than visual activity. Evidence accumulating during the last decade suggests that the desynchronization of mu rhythms (mu suppression) might be also a manifestation of a human Mirror Neuron System (MNS). To further explore this hypothesis we used a paradigm that, in a previous fMRI study, successfully activated this putative MNS in humans. Our direct goal was to provide further support for a link between modulation of mu rhythms and the MNS, by finding parallels between the reported patterns of fMRI activations and patterns of mu suppression. The EEG power in the mu range has been recorded while participants passively observed either a left or a right hand, reaching to and grasping objects, and compared it with that recorded while participants observed the movement of a ball, and while observing static grasping scenes or still objects. Mirroring fMRI results (Shmuelof, L., Zohary, E., 2005. Dissociation between ventral and dorsal fMRI activation during object and action recognition. Neuron 47, 457-470), mu suppression was larger in the hemisphere contra-lateral to the moving hand and larger when the hands grasped different objects in different ways than when the movement was repetitive. No suppression was found while participants observed still objects but mu suppression was also found while seeing static grasping postures. These data are discussed in light of similar parallels between modulations of alpha waves and fMRI while recording EEG in the magnet. The present data support a link between mu suppression and a human MNS.

  19. Hand preference, performance abilities and hand selection in children

    Directory of Open Access Journals (Sweden)

    Sara Marie Scharoun

    2014-02-01

    Full Text Available It is widely know that the pattern of human handedness is such that approximately 90% of the population is right handed with the remainder being left handed, at least in the adult population. What is less well understood is how handedness develops and at what age adult-like handedness patterns emerge. Quantified in terms of both preference and performance, a plethora of different behavioural assessments are currently in use with both children and adults. Handedness questionnaires are commonly used; however, these possess inherent limitations, considering their subjective nature. Hand performance measures have also been implemented; however, such tasks appear to measure different components of handedness. In addition to these traditional measures, handedness has been successfully assessed through observation of hand selection in reaching, which has proven to be a unique and effective manner in understanding the development of handedness in children. Research over the past several decades has demonstrated that young children display weak, inconsistent hand preference tendencies and are slower with both hands. Performance differences between the hands are larger for young children, and consistency improves with age. However, there remains some controversy surrounding the age at which hand preference and hand performance abilities can be considered fully developed. The following paper will provide a review of the literature pertaining to hand preference, performance abilities and hand selection in children in an attempt to ascertain the age at which adult-like patterns of hand preference and performance emerge.

  20. Human health risk assessment of chloroxylenol in liquid hand soap and dishwashing soap used by consumers and health-care professionals.

    Science.gov (United States)

    Yost, Lisa J; Rodricks, Joseph D; Turnbull, Duncan; DeLeo, Paul C; Nash, J Frank; Quiñones-Rivera, Antonio; Carlson, Pete A

    2016-10-01

    A quantitative human risk assessment of chloroxylenol was conducted for liquid hand and dishwashing soap products used by consumers and health-care workers. The toxicological data for chloroxylenol indicate lack of genotoxicity, no evidence of carcinogenicity, and minimal systemic toxicity. No observed adverse effect levels (NOAEL) were established from chronic toxicity studies, specifically a carcinogenicity study that found no cancer excess (18 mg/kg-day) and studies of developmental and reproductive toxicity (100 mg/kg-day). Exposure to chloroxylenol for adults and children was estimated for two types of rinse-off cleaning products, one liquid hand soap, and two dishwashing products. The identified NOAELs were used together with exposure estimates to derive margin of exposure (MOE) estimates for chloroxylenol (i.e., estimates of exposure over NOAELs). These estimates were designed with conservative assumptions and likely overestimate exposure and risk (i.e., highest frequency, 100% dermal penetration). The resulting MOEs ranged from 178 to over 100, 000, 000 indicating negligibly small potential for harm related to consumer or health-care worker exposure to chloroxylenol in liquid soaps used in dish washing and hand washing. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Resonance tuning in a neuro-musculo-skeletal model of the forearm.

    Science.gov (United States)

    Verdaasdonk, B W; Koopman, H F J M; Van der Helm, F C T

    2007-02-01

    In rhythmic movements, humans activate their muscles in a robust and energy efficient way. These activation patterns are oscillatory and seem to originate from neural networks in the spinal cord, called central pattern generators (CPGs). Evidence for the existence of CPGs was found for instance in lampreys, cats and rats. There are indications that CPGs exist in humans as well, but this is not proven yet. Energy efficiency is achieved by resonance tuning: the central nervous system is able to tune into the resonance frequency of the limb, which is determined by the local reflex gains. The goal of this study is to investigate if the existence of a CPG in the human spine can explain the resonance tuning behavior, observed in human rhythmic limb movement. A neuro-musculo-skeletal model of the forearm is proposed, in which a CPG is organized in parallel to the local reflexloop. The afferent and efferent connections to the CPG are based on clues about the organization of the CPG, found in literature. The model is kept as simple as possible (i.e., lumped muscle models, groups of neurons are lumped into half-centers, simple reflex model), but incorporates enough of the essential dynamics to explain behavior-such as resonance tuning-in a qualitative way. Resonance tuning is achieved above, at and below the endogenous frequency of the CPG in a highly non-linear neuro- musculo-skeletal model. Afferent feedback of muscle lengthening to the CPG is necessary to accomplish resonance tuning above the endogenous frequency of the CPG, while feedback of muscle velocity is necessary to compensate for the phase lag, caused by the time delay in the loop coupling the limb to the CPG. This afferent feedback of muscle lengthening and velocity represents the Ia and II fibers, which-according to literature-is the input to the CPG. An internal process of the CPG, which integrates the delayed muscle lengthening and feeds it to the half-center model, provides resonance tuning below the

  2. Dynamic Hand Gesture Recognition Using the Skeleton of the Hand

    OpenAIRE

    Vasile Buzuloiu; Patrick Lambert; Didier Coquin; Bogdan Ionescu

    2005-01-01

    This paper discusses the use of the computer vision in the interpretation of human gestures. Hand gestures would be an intuitive and ideal way of exchanging information with other people in a virtual space, guiding some robots to perform certain tasks in a hostile environment, or interacting with computers. Hand gestures can be divided into two main categories: static gestures and dynamic gestures. In this paper, a novel dynamic hand gesture recognition technique is proposed. It is based on ...

  3. [Clinical anatomy of the fat body in the forearm and in the palm].

    Science.gov (United States)

    Reidenbach, M M; Schmidt, H M

    1993-02-01

    In the hand the space between the deep flexor tendons and the interosseous fascia is named the midpalmar space, spatium palmare medianum. A fat body, Corpus adiposum palmare profundum, can be found there regularly. Despite the anatomical narrowness in this region, it reaches up into the carpal canal. Also in the deep forearm space there is always a fat body, Corpus adiposum profundum antebrachii, located dorsally to the deep flexor tendons, lying on the palmar fascia of the pronator quadratus muscle. Usually it is not connected to the Corpus adiposum palmare profundum. The regular occurrence of both fat bodies indicates their functional importance. It is to be supposed that they serve as a gliding layer for the deep flexor tendons. Especially the Corpus adiposum palmare profundum may provide an essential protecting function to the dorsally located deep branch of the ulnar nerve and deep palmar arch. In contrast there is a higher risk of mechanical irritation and compression of the deep branches of the ulnar nerve and artery during their more proximal course through the opponens muscle of the little finger ("opponens-canal") and the ulnar marginal septum. Characteristic features of dimensions and location of the Corpus adiposum profundum antebrachii and the Corpus adiposum palmare profundum and of the deep branches of the ulnar nerve and artery are described. The clinical relevance is discussed.

  4. The role of the interosseous membrane and triangular fibrocartilage complex in forearm stability.

    Science.gov (United States)

    Rabinowitz, R S; Light, T R; Havey, R M; Gourineni, P; Patwardhan, A G; Sartori, M J; Vrbos, L

    1994-05-01

    This study investigated the relative roles of the interosseous membrane (IOM) and triangular fibrocartilage complex (TFCC) in the transmission of force from the hand to the humerus. Our findings suggest a spectrum of forearm destabilizing injuries. The intact radius abutting the capitellum provides the primary restraint to proximal migration of the radius. After radial head excision, up to 7 mm of proximal radial migration can occur under axial compression. If the TFCC or the IOM alone is disrupted, little alteration in load or displacement is evident. When both the midportion of the IOM and TFCC are incompetent, however, further proximal radial migration occurs, the radial stump abuts the humerus, and load is shifted back to the radial column. These data suggest that the central portion of the IOM is the crucial structural subdivision within the IOM acting as a restraint to proximal radial migration. The TFCC also resists proximal radial migration and participates in load transfer. We propose that clinical migration of the radius under an axial load greater than 7 mm implies disruption of both the midportion of the IOM and TFCC.

  5. Mucormycosis infection following intravenous access in the forearm.

    Science.gov (United States)

    Wollstein, Ronit; Palekar, Alka

    2010-01-01

    Mucormycosis is an opportunistic infection that is often fatal, requiring aggressive local control as well as systemic therapy. A rare case of a forearm infection originating in a traumatic intravenous access portal is described in the present study. The Mucor species infection prevented liver transplant, and the patient passed away. In the present case, it was decided to limit the resection to the skin and subcutaneous tissue based on a frozen section and the viability of the biopsied tissue. With consistently rising numbers of immunocompromised patients, awareness and familiarity with mucormycosis in the extremities is important. Knowing that a minimal traumatic event may precede the infection could assist in prevention and early diagnosis. Guidelines for pathological and clinical diagnosis and treatment need to be further clarified.

  6. [The laterocranial fascia structures in the upper and forearm and the differences in the insertion of the M. biceps brachii in domestic mammals].

    Science.gov (United States)

    Künzel, W; Forstenpointner, G; Skolek-Winnisch, R

    1993-03-01

    The laterocranial fascia of the upper arm and forearm, as well as aponeurotic relationships of the Musculus biceps brachii were investigated on each of ten forelimbs from horses, cattle and swine. Ten canine biceps were also investigated. Equine and bovine fascia contain elastic components. An as-yet undescribed ligament-like aponeuroses of the laterocranial forearm fascia to the Fossa radialis humeri was seen in all three species studied. The laterocranial fascia of the upper and forearm form a common passage for the Musculi brachialis et extensor carpi radialis. In the case of the horse, the ulnar aponeurotic tendon of the biceps muscle crosses below the Ligamentum collaterale cubiti medialis. In cattle, on the other hand, it runs between the two branches of the collateral ligament, to attach on the olecranon. This portion of the equine tendon protrudes into the joint. It has connective tissue character in young animals, but becomes fibrocartilaginous in older horses. The radial aponeuroses of the canine biceps exhibits two branches. A situation similar to that seen for the ulnar aponeuroses of the equine Musculus biceps brachii is observed on the inside surface of the porcine Ligamentum cubiti mediale, in which a wedge of connective tissue protrudes into the joint, taking on fibrocartilaginous character in older animals.

  7. Task-dependent modulation of functional connectivity between hand motor cortices and neuronal networks underlying language and music: a transcranial magnetic stimulation study in humans.

    Science.gov (United States)

    Sparing, R; Meister, I G; Wienemann, M; Buelte, D; Staedtgen, M; Boroojerdi, B

    2007-01-01

    Although language functions are, in general, attributed to the left hemisphere, it is still a matter of debate to what extent the cognitive functions underlying the processing of music are lateralized in the human brain. To investigate hemispheric specialization we evaluated the effect of different overt musical and linguistic tasks on the excitability of both left and right hand motor cortices using transcranial magnetic stimulation (TMS). Task-dependent changes of the size of the TMS-elicited motor evoked potentials were recorded in 12 right-handed, musically naive subjects during and after overt speech, singing and humming, i.e. the production of melody without word articulation. The articulation of meaningless syllables served as control condition. We found reciprocal lateralized effects of overt speech and musical tasks on motor cortex excitability. During overt speech, the corticospinal projection of the left (i.e. dominant) hemisphere to the right hand was facilitated. In contrast, excitability of the right motor cortex increased during both overt singing and humming, whereas no effect was observed on the left hemisphere. Although the traditional concept of hemispheric lateralization of music has been challenged by recent neuroimaging studies, our findings demonstrate that right-hemisphere preponderance of music is nevertheless present. We discuss our results in terms of the recent concepts on evolution of language and gesture, which hypothesize that cerebral networks mediating hand movement and those subserving language processing are functionally linked. TMS may constitute a useful tool to further investigate the relationship between cortical representations of motor functions, music and language using comparative approaches.

  8. THE TREATMENT OF THE FOREARM FRACTURES IN DOGS

    Directory of Open Access Journals (Sweden)

    E. Lika

    2011-12-01

    Full Text Available The practical implementation of this study was enabled by taking into consideration all the traumatized cases accompanied by fractures, presented at the Clinic of the Faculty of Veterinary Medicine during the period of March 2006 - March 2010. Special help for the implementation of this study was even offered by some private clinics in Tirana, from which we took a considerable number of valuable data. The cases of traumatized dogs were numerous and in different situations. Thus from this high number of the traumatizations accompanied by different fractures (altogether 115 dogs, 34 of them had fractures in the forearms bones. All these cases underwent surgical treatment through osteosynthesis with blood and external immobilization. We also treated cases of complications in healing these fractures after surgical treatment. The complications in the recovery of the fractures of the long bones in dogs are frequent. Above all they are first noticed in the bones of the forearm. Different problems might be identified such as’ mal joints, lack of joints, retarded joints and osteomyelitis. These because of the limited covering of the focus of the fracture by the soft tissues, lack of blood supply of the region as well as of the characteristic anatomo-topographic structure that this region has. Specifically the data that were taken into consideration included the period of recovery, the characteristics of the fracture, the type of surgical treatment and the final result. The fractures are often presented as closed fractures and less as transverse and oblique fractures. The most frequent treatment is the conservative one through external immobilization and in some cases of fractures of the radius the treatment was performed with endomedullar rods.

  9. The single-bout forearm critical force test: a new method to establish forearm aerobic metabolic exercise intensity and capacity.

    Directory of Open Access Journals (Sweden)

    J Mikhail Kellawan

    Full Text Available No non-invasive test exists for forearm exercise that allows identification of power-time relationship parameters (W', critical power and thereby identification of the heavy-severe exercise intensity boundary and scaling of aerobic metabolic exercise intensity. The aim of this study was to develop a maximal effort handgrip exercise test to estimate forearm critical force (fCF; force analog of power and establish its repeatability and validity. Ten healthy males (20-43 years completed two maximal effort rhythmic handgrip exercise tests (repeated maximal voluntary contractions (MVC; 1 s contraction-2 s relaxation for 600 s on separate days. Exercise intensity was quantified via peak contraction force and contraction impulse. There was no systematic difference between test 1 and 2 for fCF(peak force (p = 0.11 or fCF(impulse (p = 0.76. Typical error was small for both fCF(peak force (15.3 N, 5.5% and fCF(impulse (15.7 N ⋅ s, 6.8%, and test re-test correlations were strong (fCF(peak force, r = 0.91, ICC = 0.94, pfCF(peak force. TTE predicted by W' showed good agreement with actual TTE during the TTE tests (r = 0.97, ICC = 0.97, P<0.01; typical error 0.98 min, 12%; regression fit slope = 0.99 and y intercept not different from 0, p = 0.31. MVC did not predict fCF(peak force (p = 0.37, fCF(impulse (p = 0.49 or W' (p = 0.15. In conclusion, the poor relationship between MVC and fCF or W' illustrates the serious limitation of MVC in identifying metabolism-based exercise intensity zones. The maximal effort handgrip exercise test provides repeatable and valid estimates of fCF and should be used to normalize forearm aerobic metabolic exercise intensity instead of MVC.

  10. Knowledge Gaps in Rodent Pancreas Biology: Taking Human Pluripotent Stem Cell-Derived Pancreatic Beta Cells into Our Own Hands.

    Science.gov (United States)

    Santosa, Munirah Mohamad; Low, Blaise Su Jun; Pek, Nicole Min Qian; Teo, Adrian Kee Keong

    2015-01-01

    In the field of stem cell biology and diabetes, we and others seek to derive mature and functional human pancreatic β cells for disease modeling and cell replacement therapy. Traditionally, knowledge gathered from rodents is extended to human pancreas developmental biology research involving human pluripotent stem cells (hPSCs). While much has been learnt from rodent pancreas biology in the early steps toward Pdx1(+) pancreatic progenitors, much less is known about the transition toward Ngn3(+) pancreatic endocrine progenitors. Essentially, the later steps of pancreatic β cell development and maturation remain elusive to date. As a result, the most recent advances in the stem cell and diabetes field have relied upon combinatorial testing of numerous growth factors and chemical compounds in an arbitrary trial-and-error fashion to derive mature and functional human pancreatic β cells from hPSCs. Although this hit-or-miss approach appears to have made some headway in maturing human pancreatic β cells in vitro, its underlying biology is vaguely understood. Therefore, in this mini-review, we discuss some of these late-stage signaling pathways that are involved in human pancreatic β cell differentiation and highlight our current understanding of their relevance in rodent pancreas biology. Our efforts here unravel several novel signaling pathways that can be further studied to shed light on unexplored aspects of rodent pancreas biology. New investigations into these signaling pathways are expected to advance our knowledge in human pancreas developmental biology and to aid in the translation of stem cell biology in the context of diabetes treatments.

  11. Differential effects of type of keyboard playing task and tempo on surface EMG amplitudes of forearm muscles

    Directory of Open Access Journals (Sweden)

    Hyun Ju eChong

    2015-09-01

    Full Text Available Despite increasing interest in keyboard playing as a strategy for repetitive finger exercises in fine motor skill development and hand rehabilitation, comparative analysis of task-specific finger movements relevant to keyboard playing has been less extensive. This study examined whether there were differences in surface EMG activity levels of forearm muscles associated with different keyboard playing tasks. Results demonstrated higher muscle activity with sequential keyboard playing in a random pattern compared to individuated playing or sequential playing in a successive pattern. Also, the speed of finger movements was found as a factor that affect muscle activity levels, demonstrating that faster tempo elicited significantly greater muscle activity than self-paced tempo. The results inform our understanding of the type of finger movements involved in different types of keyboard playing at different tempi so as to consider the efficacy and fatigue level of keyboard playing as an intervention for amateur pianists or individuals with impaired fine motor skills.

  12. Differential effects of type of keyboard playing task and tempo on surface EMG amplitudes of forearm muscles.

    Science.gov (United States)

    Chong, Hyun Ju; Kim, Soo Ji; Yoo, Ga Eul

    2015-01-01

    Despite increasing interest in keyboard playing as a strategy for repetitive finger exercises in fine motor skill development and hand rehabilitation, comparative analysis of task-specific finger movements relevant to keyboard playing has been less extensive. This study examined, whether there were differences in surface EMG activity levels of forearm muscles associated with different keyboard playing tasks. Results demonstrated higher muscle activity with sequential keyboard playing in a random pattern compared to individuated playing or sequential playing in a successive pattern. Also, the speed of finger movements was found as a factor that affect muscle activity levels, demonstrating that faster tempo elicited significantly greater muscle activity than self-paced tempo. The results inform our understanding of the type of finger movements involved in different types of keyboard playing at different tempi. This helps to consider the efficacy and fatigue level of keyboard playing tasks when being used as an intervention for amateur pianists or individuals with impaired fine motor skills.

  13. Hand-Ground Nanoscale Zn(II) -Based Coordination Polymers Derived from NSAIDs: Cell Migration Inhibition of Human Breast Cancer Cells.

    Science.gov (United States)

    Paul, Mithun; Sarkar, Koushik; Deb, Jolly; Dastidar, Parthasarathi

    2017-04-27

    Increased levels of intracellular prostaglandin E2 (PGE2 ) have been linked with the unregulated cancer cell migration that often leads to metastasis. Non-steroidal anti-inflammatory drugs (NSAIDs) are known inhibitors of cyclooxygenase (COX) enzymes, which are responsible for the increased PGE2 concentration in inflamed as well as cancer cells. Here, we demonstrate that NSAID-derived Zn(II) -based coordination polymers are able to inhibit cell migration of human breast cancer cells. Various NSAIDs were anchored to a series of 1D Zn(II) coordination polymers through carboxylate-Zn coordination, and these structures were fully characterized by single-crystal X-ray diffraction. Hand grinding in a pestle and mortar resulted in the first reported example of nanoscale coordination polymers that were suitable for biological studies. Two such hand-ground nanoscale coordination polymers NCP1 a and NCP2 a, which contained naproxen (a well-studied NSAID), were successfully internalized by the human breast cancer cells MDA-MB-231, as was evident from cellular imaging by using a fluorescence microscope. They were able to kill the cancer cells (MTT assay) more efficiently than the corresponding mother drug naproxen, and most importantly, they significantly inhibited cancer cell migration thereby displaying anticancer activity. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Bio-inspired mechanical design of a tendon-driven dexterous prosthetic hand.

    Science.gov (United States)

    Controzzi, Marco; Cipriani, Christian; Jehenne, Beryl; Donati, Marco; Carrozza, Maria Chiara

    2010-01-01

    This paper presents the preliminary design of a new dexterous upper-limb prosthesis provided with a novel anthropomorphic hand, a compact wrist based on bevel gears and a modular forearm able to cover different levels of upper-limb amputations. The hand has 20 DoFs and 11 motors, with a dexterous three fingered subsystem composed by a fully actuated thumb, and an hybrid index and middle fingers to enable dexterous manipulation and enhance grasp performance.

  15. Afferent-induced facilitation of primary motor cortex excitability in the region controlling hand muscles in humans.

    Science.gov (United States)

    Devanne, H; Degardin, A; Tyvaert, L; Bocquillon, P; Houdayer, E; Manceaux, A; Derambure, P; Cassim, F

    2009-08-01

    Sensory inputs from cutaneous and limb receptors are known to influence motor cortex network excitability. Although most recent studies have focused on the inhibitory influences of afferent inputs on arm motor responses evoked by transcranial magnetic stimulation (TMS), facilitatory effects are rarely considered. In the present work, we sought to establish how proprioceptive sensory inputs modulate the excitability of the primary motor cortex region controlling certain hand and wrist muscles. Suprathreshold TMS pulses were preceded either by median nerve stimulation (MNS) or index finger stimulation with interstimulus intervals (ISIs) ranging from 20 to 200 ms (with particular focus on 40-80 ms). Motor-evoked potentials recorded in the abductor pollicis brevis (APB), first dorsalis interosseus and extensor carpi radialis muscles were strongly facilitated (by up to 150%) by MNS with ISIs of around 60 ms, whereas digit stimulation had only a weak effect. When MNS was delivered at the interval that evoked the optimal facilitatory effect, the H-reflex amplitude remained unchanged and APB motor responses evoked with transcranial electric stimulation were not increased as compared with TMS. Afferent-induced facilitation and short-latency intracortical inhibition (SICI) and intracortical facilitation (ICF) mechanisms are likely to interact in cortical circuits, as suggested by the strong facilitation observed when MNS was delivered concurrently with ICF and the reduction of SICI following MNS. We conclude that afferent-induced facilitation is a mechanism which probably involves muscle spindle afferents and should be considered when studying sensorimotor integration mechanisms in healthy and disease situations.

  16. Motor unit activity in biceps brachii of left-handed humans during sustained contractions with two load types.

    Science.gov (United States)

    Gould, Jeffrey R; Cleland, Brice T; Mani, Diba; Amiridis, Ioannis G; Enoka, Roger M

    2016-09-01

    The purpose of the study was to compare the discharge characteristics of single motor units during sustained isometric contractions that required either force or position control in left-handed individuals. The target force for the two sustained contractions (24.9 ± 10.5% maximal force) was identical for each biceps brachii motor unit (n = 32) and set at 4.7 ± 2.0% of maximal voluntary contraction (MVC) force above its recruitment threshold (range: 0.5-41.2% MVC force). The contractions were not sustained to task failure, but the duration (range: 60-330 s) was identical for each motor unit and the decline in MVC force immediately after the sustained contractions was similar for the two tasks (force: 11.1% ± 13.7%; position: 11.6% ± 9.9%). Despite a greater increase in the rating of perceived exertion during the position task (task × time interaction, P contractions requiring either force or position control.

  17. The Work of the Hand

    Science.gov (United States)

    Ludick, Pat

    2013-01-01

    Recognizing Maria and Mario Montessori's reverence for the hand, Pat Ludick takes the reader into the wonder of the human body, mind, and spirit and across the planes of education, into the making of a whole personality and grounded intelligence that is ready for the adult world. Putting the hand front and center, she lyrically evolves an overview…

  18. Assessment and Planning for a Pediatric Bilateral Hand Transplant Using 3-Dimensional Modeling: Case Report.

    Science.gov (United States)

    Gálvez, Jorge A; Gralewski, Kevin; McAndrew, Christine; Rehman, Mohamed A; Chang, Benjamin; Levin, L Scott

    2016-03-01

    Children are not typically considered for hand transplantation for various reasons, including the difficulty of finding an appropriate donor. Matching donor-recipient hands and forearms based on size is critically important. If the donor's hands are too large, the recipient may not be able to move the fingers effectively. Conversely, if the donor's hands are too small, the appearance may not be appropriate. We present an 8-year-old child evaluated for a bilateral hand transplant following bilateral amputation. The recipient forearms and model hands were modeled from computed tomography imaging studies and replicated as anatomic models with a 3-dimensional printer. We modified the scale of the printed hand to produce 3 proportions, 80%, 100% and 120%. The transplant team used the anatomical models during evaluation of a donor for appropriate match based on size. The donor's hand size matched the 100%-scale anatomical model hand and the transplant team was activated. In addition to assisting in appropriate donor selection by the transplant team, the 100%-scale anatomical model hand was used to create molds for prosthetic hands for the donor.

  19. The role of ultrasound and magnetic resonance imaging in the evaluation of the forearm interosseous membrane. A review

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Martin, Juan [Infanta Leonor University Hospital, Trauma and Orthopaedics, Shoulder and Elbow Unit, Madrid (Spain); Pretell-Mazzini, Juan [The Children' s Hospital of Philadelphia, Pediatric Orthopaedic Fellow, Division of Orthopaedic Surgery, Philadelphia, PA (United States)

    2011-12-15

    The interosseous membrane of the forearm is an important structure to consider in cases of elbow and forearm trauma; it can be injured after elbow or forearm fractures, leading to longitudinal forearm instability. Diagnosis of interosseous membrane injuries is challenging, and failure in diagnosis may result in poor clinical outcomes and complications. Magnetic resonance imaging and ultrasound have shown to be valuable methods for the evaluation of this important structure. Both techniques have advantages and limitations, and its use should be adapted to each specific clinical scenario. This article presents an up-to-date literature review regarding the use of ultrasound and magnetic resonance imaging in the forearm interosseous membrane evaluation. (orig.)

  20. Maternal dietary patterns during pregnancy in relation to offspring forearm fractures

    DEFF Research Database (Denmark)

    Petersen, Sesilje Elise Bondo; Rasmussen, Morten Arendt; Olsen, Sjurdur F;

    2015-01-01

    Limited evidence exists for an association between maternal diet during pregnancy and offspring bone health. In a prospective study, we examined the association between dietary patterns in mid-pregnancy and offspring forearm fractures. In total, 101,042 pregnancies were recruited to the Danish...... associated with offspring forearm fractures (p = 0.02). In the large prospective DNBC high mid-pregnancy consumption of Western diet and artificially sweetened soft drinks, respectively, indicated positive associations with offspring forearm fractures, which provides interesting hypotheses for future...

  1. Free radial forearm adiposo-fascial flap for inferior maxillectomy defect reconstruction

    Directory of Open Access Journals (Sweden)

    Thankappan Krishnakumar

    2009-01-01

    Full Text Available A free radial forearm fascial flap has been described for intraoral reconstruction. Adiposo-fascial flap harvesting involves few technical modifications from the conventional radial forearm fascio-cutaneous free flap harvesting. We report a case of inferior maxillectomy defect reconstruction in a 42-year-old male with a free radial forearm adiposo-fascial flap with good aesthetic and functional outcome with minimal primary and donor site morbidity. The technique of raising the flap and closing the donor site needs to be meticulous in order to achieve good cosmetic and functional outcome.

  2. Muscle fatigue in relation to forearm pain and tenderness among professional computer users

    DEFF Research Database (Denmark)

    Thomsen, GF; Johnson, PW; Svendsen, Susanne Wulff

    2007-01-01

    and twenty gender and age matched referents without such complaints were enrolled from the Danish NUDATA study of neck and upper extremity disorders among technical assistants and machine technicians. Fatigue of the right forearm extensor muscles was assessed by muscle twitch forces in response to low...... response was not explained by differences in the MVC or body mass index. CONCLUSION: Computer users with forearm pain and moderate to severe palpation tenderness had diminished forearm extensor muscle fatigue response. Additional studies are necessary to determine whether this result reflects an adaptive...... response to exposure without any pathophysiological significance, or represents a part of a causal pathway leading to pain....

  3. Nudge, nudge, wink, wink: love, sex and gay men with intellectual disabilities - a helping hand or a human right?

    Science.gov (United States)

    Abbott, D

    2013-11-01

    How do human rights help us with the experiences of people with intellectual disabilities (ID) who face discrimination and barriers in their sexual lives? Men with ID who are gay face a whole range of rights violations when it comes to exercising their sexual identity. How can such a seemingly marginalised group draw on rights based claims for better and equal treatment? This paper explores how the power of men's own stories may usefully challenge prevailing social norms and in turn strengthen human rights claims in this area. It also reflects on the challenges posed to such an agenda by current economic difficulties and changes in the organisation of adult social care in the UK. The paper draws on empirical research with gay men with ID completed in the UK in 2005 and briefly revisits some key messages from the data. It also considers the wider literature on the power and possibilities of human rights, 'intimate stories' and translating human rights into everyday change. Gay men with ID tell powerful stories of love, longing and exclusion. Such stories have the capacity to transform wider social attitudes and in turn strengthen the rights claims of this marginalised groups. There are question marks about the possibility of such change in a time of austerity and the broader move in the UK's welfare state from the collective to the individual consumer of services. However, the telling of men's 'intimate stories' creates an almost unassailable challenge to current discriminatory practices and norms. © 2012 The Author. Journal of Intellectual Disability Research © 2012 John Wiley & Sons Ltd, MENCAP & IASSID.

  4. Thermography-based blood flow imaging in human skin of the hands and feet: a spectral filtering approach.

    Science.gov (United States)

    Sagaidachnyi, A A; Fomin, A V; Usanov, D A; Skripal, A V

    2017-02-01

    The determination of the relationship between skin blood flow and skin temperature dynamics is the main problem in thermography-based blood flow imaging. Oscillations in skin blood flow are the source of thermal waves propagating from micro-vessels toward the skin's surface, as assumed in this study. This hypothesis allows us to use equations for the attenuation and dispersion of thermal waves for converting the temperature signal into the blood flow signal, and vice versa. We developed a spectral filtering approach (SFA), which is a new technique for thermography-based blood flow imaging. In contrast to other processing techniques, the SFA implies calculations in the spectral domain rather than in the time domain. Therefore, it eliminates the need to solve differential equations. The developed technique was verified within 0.005-0.1 Hz, including the endothelial, neurogenic and myogenic frequency bands of blood flow oscillations. The algorithm for an inverse conversion of the blood flow signal into the skin temperature signal is addressed. The examples of blood flow imaging of hands during cuff occlusion and feet during heating of the back are illustrated. The processing of infrared (IR) thermograms using the SFA allowed us to restore the blood flow signals and achieve correlations of about 0.8 with a waveform of a photoplethysmographic signal. The prospective applications of the thermography-based blood flow imaging technique include non-contact monitoring of the blood supply during engraftment of skin flaps and burns healing, as well the use of contact temperature sensors to monitor low-frequency oscillations of peripheral blood flow.

  5. On Semantic Development of HAND

    Institute of Scientific and Technical Information of China (English)

    黎金娥

    2015-01-01

    The body-part term, HAND, ranks 48 in Swadesh's 100-Word List.This paper discusses the origin and meanings, and then the rules of semantic development in the HAND semantic field by comparing with other languages.The word itself does not only denote the body part but also things resembling hands in shape, position, function and things associated with hands.Plenty of linguistic evidence can be found to illustrate that all human beings regard their bodies as the basis and starting point of recognition of the whole world.

  6. The properties of human body phantoms used in calculations of electromagnetic fields exposure by wireless communication handsets or hand-operated industrial devices.

    Science.gov (United States)

    Zradziński, Patryk

    2013-06-01

    According to international guidelines, the assessment of biophysical effects of exposure to electromagnetic fields (EMF) generated by hand-operated sources needs the evaluation of induced electric field (E(in)) or specific energy absorption rate (SAR) caused by EMF inside a worker's body and is usually done by the numerical simulations with different protocols applied to these two exposure cases. The crucial element of these simulations is the numerical phantom of the human body. Procedures of E(in) and SAR evaluation due to compliance analysis with exposure limits have been defined in Institute of Electrical and Electronics Engineers standards and International Commission on Non-Ionizing Radiation Protection guidelines, but a detailed specification of human body phantoms has not been described. An analysis of the properties of over 30 human body numerical phantoms was performed which has been used in recently published investigations related to the assessment of EMF exposure by various sources. The differences in applicability of these phantoms in the evaluation of E(in) and SAR while operating industrial devices and SAR while using mobile communication handsets are discussed. The whole human body numerical phantom dimensions, posture, spatial resolution and electric contact with the ground constitute the key parameters in modeling the exposure related to industrial devices, while modeling the exposure from mobile communication handsets, which needs only to represent the exposed part of the human body nearest to the handset, mainly depends on spatial resolution of the phantom. The specification and standardization of these parameters of numerical human body phantoms are key requirements to achieve comparable and reliable results from numerical simulations carried out for compliance analysis against exposure limits or within the exposure assessment in EMF-related epidemiological studies.

  7. Bipaddle radial forearm flap for head and neck reconstruction.

    Science.gov (United States)

    Zhang, Yi Xin; Xi, Wenjing; Lazzeri, Davide; Zhou, Xiao; Li, Zan; Nicoli, Fabio; Zenn, Michael R; Torresetti, Matteo; Grassetti, Luca; Spinelli, Giuseppe

    2015-03-01

    Although the radial forearm free flap has become a workhorse flap in head and neck reconstruction, the skin grafting of the donor is the main drawback resulting in an unacceptable contour deformity and an unsightly appearance. Several technical modifications have been therefore applied to the radial forearm (RF) flap marking, elevation, and inset to overcome this major shortcoming. In this article, we report our clinical series with the bipaddle RF flap. The authors described their 11 cases of head and neck oncologic reconstruction with the bipaddle RF flap. The skin island is designed longer and narrower and split into 2 separate skin paddles each nourished by a proximal and a distal independent perforators raising from the radial artery so that the donor site could be closed directly. The narrow design of the skin paddle and the subsequent splitting in its 2 components applying the "perforator-pedicle propeller flap method" allow for the changing of the flap shape according to the shape of the recipient site defect. From 2007 to 2013, the bipaddle RF flap method was used in 11 patients to restore head and neck defects following cancer ablation. The mean age of the patients was 43 years, ranging from 31 to 50 years. The location of the defects was the tongue (n = 7) and the intraoral region (n = 4). The defect sizes varied from 4 × 5 cm to 5 × 6 cm, and the flap maximum width was 3 cm with mean area of 26.4 cm. The healing was uneventful in all patients with excellent cosmetic and functional results of both donor site and recipient site after 20 months of mean follow-up. The bipaddle RF free flap is a reliable and versatile option for the reconstruction of a wide range of soft tissue defects of head and neck region. This method allows for a customized resurfacing of the defect because of its large variability in shape and size. The harvesting site is closed primarily, and a second donor site for skin graft is avoided.Clinical Question, Level of Evidence

  8. The evaluation of human hand odor volatiles on various textiles: a comparison between contact and noncontact sampling methods.

    Science.gov (United States)

    Prada, Paola A; Curran, Allison M; Furton, Kenneth G

    2011-07-01

    The focus of this study is to compare contact and noncontact human scent collection procedures across an array of textiles (cotton, rayon, polyester, and wool) to determine an optimized collection method for human scent evidence. Six subjects were sampled in triplicate for each textile and collection mode, and the samples were then analyzed through headspace solid-phase micro-extraction in combination with gas chromatography/mass spectrometry (SPME-GC/MS). Contact sampling with cotton material has been shown to be the collection method that yielded the greatest number of volatile compounds and the highest scent mass amounts. Through Spearman rank correlations, it was shown that an individual's scent profile is more reproducible within samples collected on the same textile type than between different materials. Furthermore, contact sampling with cotton fabric demonstrated the greatest reproducibility producing the lowest amount of type I and type II errors with 90.85% of the samples distinguished at the 0.9 match/no match threshold.

  9. Ergonomic Evaluation of Biomechanical Hand Function

    OpenAIRE

    Lee, Kyung-Sun; Jung, Myung-Chul

    2014-01-01

    The human hand is a complex structure that performs various functions for activities of daily living and occupations. This paper presents a literature review on the methodologies used to evaluate hand functions from a biomechanics standpoint, including anthropometry, kinematics, kinetics, and electromyography (EMG). Anthropometry describes the dimensions and measurements of the hand. Kinematics includes hand movements and the range of motion of finger joints. Kinetics includes hand models for...

  10. Hand Detection Using HSV Model

    Directory of Open Access Journals (Sweden)

    Uzma Noreen

    2015-08-01

    Full Text Available Natural Human Computer Interaction HCI is the demand of todays technology oriented world. Detecting and tracking of face and hands are important for gesture recognition. Skin detection is a very popular and useful technique for detecting and tracking human-body parts. It has been much attention mainly because of its vast range of applications such as face detection and tracking naked people detection hand detection and tracking people retrieval in databases and Internet etc. Many models and algorithms are being used for detection of face hand and its gesture. Hand detection using model or classification is to build a decision rule that will discriminate between skin and non-skin pixels. Identifying skin color pixels involves finding the range of values for which most skin pixels would fall in a given color space. All external factors will be eliminated to detect the hand and its color in the image in complex background.

  11. 3D Printed Robotic Hand

    Science.gov (United States)

    Pizarro, Yaritzmar Rosario; Schuler, Jason M.; Lippitt, Thomas C.

    2013-01-01

    Dexterous robotic hands are changing the way robots and humans interact and use common tools. Unfortunately, the complexity of the joints and actuations drive up the manufacturing cost. Some cutting edge and commercially available rapid prototyping machines now have the ability to print multiple materials and even combine these materials in the same job. A 3D model of a robotic hand was designed using Creo Parametric 2.0. Combining "hard" and "soft" materials, the model was printed on the Object Connex350 3D printer with the purpose of resembling as much as possible the human appearance and mobility of a real hand while needing no assembly. After printing the prototype, strings where installed as actuators to test mobility. Based on printing materials, the manufacturing cost of the hand was $167, significantly lower than other robotic hands without the actuators since they have more complex assembly processes.

  12. Reconstruction of hand contracture by reverse ulnar perforator flap

    Directory of Open Access Journals (Sweden)

    Cengiz Eser

    2016-04-01

    Full Text Available Hand burn scar contractures affect patients in aesthetic and functional aspects. After releasing these scars, the defects should be repaired. The reconstruction methods include primary suturation, Z plasty, skin grafting, local or free flaps, etc. All methods have their own advantages and disadvantages. One of the most useful flaps is the reverse ulnar perforator flap. We performed a two-staged procedure for repairing a post-burn contracture release defect in a 40-year-old male. In the first stage we applied reverse ulnar perforator flap for the hand defect, and ulnar artery and vein repair in the second stage. In conclusion, this two-staged procedure is a non-primary but useful option for hand and finger defects and prevents major vascular structure damage of the forearm. [Hand Microsurg 2016; 5(1.000: 40-43

  13. On the control of a robot hand by extracting neural signals from the PNS: preliminary results from a human implantation.

    Science.gov (United States)

    Micera, S; Rigosa, J; Carpaneto, J; Citi, L; Raspopovic, S; Guglielmelli, E; Benvenuto, A; Rossini, L; Di Pino, G; Cavallo, G; Carrozza, M C; Cipriani, C; Hoffmann, K P; Dario, P; Rossini, P M

    2009-01-01

    The development of hybrid neuroprosthetic systems (HBSs) linking the human nervous system with artificial devices is an important area of research that is currently addressed by several groups to restore sensorimotor function in people affected by different disabilities. It is particularly important to establish a fast, intuitive, bidirectional flow of information between the nervous system of the user and the smart robotic device. Among the possible solutions to achieve this goal, interfaces with the peripheral nervous system and in particular intraneural electrodes can represent an interesting choice. In the present study, thin-film longitudinal intra-fascicular electrodes were implanted in the median and ulnar nerves of an amputee. The possibility of restoring the bidirectional link between the subject and the external world was investigated during a 4 week trial. The result showed that both the extraction of motor information and the restoration of sensory function are possible.

  14. Measurement of the subcutaneous fat in the distal forearm by single photon absorptiometry

    Energy Technology Data Exchange (ETDEWEB)

    Hassager, C.; Borg, J.; Christiansen, C.

    1989-02-01

    The influence of subcutaneous fat on single photon (/sup 125/I) absorptiometry (SPA) measurement of bone mineral content of the distal forearm was investigated. A fat correction model was tested by measurements on eight lean subjects with different amounts of porcine fat around their forearm, and further validated from measurements on 128 females. In addition, it is shown that the fat content in the distal forearm can be measured by SPA with a short-term precision at 1.9% in an obese subject and that it correlates well with total body fat (r2 = .7) measured by dual photon absorptiometry, skinfold thickness (r2 = .5), and body mass index (r2 = .6). By using this method in a double-blind placebo-controlled trial, hormonal substitutional therapy significantly decreased the forearm fat content without affecting the body weight in postmenopausal osteoporotic women.

  15. Double bilobed radial forearm free flap for anterior tongue and floor-of-mouth reconstruction

    National Research Council Canada - National Science Library

    Ko, Alvin B; Lavertu, Pierre; Rezaee, Rod P

    2010-01-01

    We describe what is, to the best of our knowledge, the first use of a double bilobed radial forearm free flap in reconstructive surgery of the tongue and floor of the mouth following bilateral tumor resection...

  16. Functional assessment: Free thin anterolateral thigh flap versus free radial forearm reconstruction for hemiglossectomy defects

    National Research Council Canada - National Science Library

    Lu, Mingxing; Sun, Guowen; Hu, Qingang; Tang, Enyi; Wang, Yujia

    2015-01-01

    To compare free thin anterolateral thigh (ALT) flap with free radial forearm (FRF) flap in the reconstruction of hemiglossectomy defects, and to introduce our methods and experience in the tongue reconstruction with free thin ALT flap...

  17. Crystallization of the Zalpha domain of the human editing enzyme ADAR1 complexed with a DNA-RNA chimeric oligonucleotide in the left-handed Z-conformation.

    Science.gov (United States)

    Brown, Bernard A; Athanasiadis, Alekos; Hanlon, Eugene B; Lowenhaupt, Ky; Wilbert, Christina M; Rich, Alexander

    2002-01-01

    The Zalpha domain of human double-stranded RNA adenosine deaminase (ADAR1) has been crystallized with a hexanucleotide containing alternating deoxyribose and ribose furanose sugars. Solution circular dichroism experiments show that this double-stranded chimera (dCrG)(3) initially adopts the right-handed A-conformation. However, addition of stoichiometric amounts of Zalpha causes a rapid transition to the Z-conformation. Raman spectroscopy of crystals of the Zalpha-(dCrG)(3) complex confirm that the chimeric oligonucleotide is stabilized in the Z-conformation. A complete data set has been obtained at 2.5 A resolution. The Zalpha-(dCrG)(3) crystals belong to the tetragonal I422 space group, with unit-cell parameters a = b = 104.2, c = 117.6 A. Work is under way to solve the structure by molecular replacement.

  18. Male-female differences in forearm skin tissue dielectric constant.

    Science.gov (United States)

    Mayrovitz, Harvey N; Carson, Sophia; Luis, Michelle

    2010-09-01

    Tissue dielectric constant (TDC) measurements at 300 MHz via the coaxial line reflection method are useful to evaluate local skin tissue water and its change, but virtually all available data relate to measurements on women. Because TDC values in part depend on skin thickness, we hypothesized that differences in male-female skin may be associated with male-female differences in TDC. To test this hypothesis, we compared TDC values in volar forearm skin of 60 young adult volunteers (30 men, 25.0 +/- 2.5 years, 30 women, 27.4 +/- 6.6 years) in the seated position using a probe with an effective measurement depth of 1.5 mm. Results showed that TDC values (mean +/- SD) for men were significantly greater than for women (33.2 +/- 4.0 versus 29.4 +/- 2.7, PTDC measurements are used in research or clinical studies in which both men and women are included in a common study population, it would be prudent to consider this difference in both experimental design and data interpretation. This is especially true if absolute TDC values are of interest in contrast to changes in TDC values on the same subject subsequent to time passage or secondary to an intervention. Despite greater TDC values measured in men, calculations of the impact of a greater male skin thickness indicate that the greater TDC values of men may or may not reflect a greater relative local skin tissue water in men compared to women.

  19. Microvascular radial forearm fasciocutaneous free flap in hard palate reconstruction.

    Science.gov (United States)

    Duflo, S; Lief, F; Paris, J; Giovanni, A; Thibeault, S; Zanaret, M

    2005-09-01

    To report the reconstruction of palatal defects by microvascular radial forearm fasciocutaneous free flap (RFFF) and to report patient's quality of life outcomes after this procedure. During the period 1990-2002, 30 cases of palatal defects were reconstructed using RFFF in our institution. RFFF allowed restoration of a vestibular sulcus to maintain dental prostheses. Outcome measurements included post-operative assessment of speech, swallowing and diet evaluation 6 months, 1 year and 2 years after reconstruction. Quality of life outcomes were measured 1 and 2 years post-reconstruction. RFFF surgery was successful in 28 cases. Six months after resection 28 patients reported satisfactory speech and swallowing. Two years after surgery, 92% (n=26) of patients resumed a normal diet. All patients underwent dental evaluation and 68% (n=19) of patients required dental rehabilitation over a post-operative period of 3-18 months. Patients self assessed their quality of life on a scale of 0-2. First year post-operatively, 21 patients reported a good quality of life (score=2). After the second year, 26 patients reported a good quality of life and the remaining two patients reported an intermediate quality of life (score=1) because they did not resume a normal diet. RFFF for palatal reconstruction is a reliable technique and provides a definitive separation between oral and sinusonasal cavities. Furthermore, it improves quality of life by improving speech, swallowing and chewing. It should be considered an integral component of head and neck cancer therapy and rehabilitation.

  20. Functional Assessments in Patients Undergoing Radial Forearm Flap Following Hemiglossectomy.

    Science.gov (United States)

    Li, Xiangru; Sun, Qiang; Guo, Shu

    2016-03-01

    Our goal was to evaluate the functional outcomes following radial forearm free-flap reconstruction with a focus on radiotherapy. A 2-year prospective study was performed. A total of 47 patients were enrolled finally. They were asked to complete the swallowing, chewing, speech domains of the University of Washington Quality of Life questionnaire preoperatively and at 2 years postoperatively. Swallowing capacity was apparently affected after surgery, but no patients reported there was chokes cough during eating, the mean score was 51.1 (SD: 21.3). Most patients (70.2%) presented their articulation was good enough for everyday life, and the mean score was 60.0 (SD: 21.1). As for chewing, only 7 (14.9%) patients complained there was negative effect, and the mean score was as high as 92.6 (SD: 18.0). Compared to patients with surgery only, patients with postoperative radiotherapy only had significantly worse swallowing and speech capacity. Compared with patients with postoperative radiotherapy only, patients with both preoperative and postoperative radiotherapy tended to have better swallowing and speech. No significant differences were found between chewing and radiotherapy. In most patients, the results of swallowing, speech, and chewing are favorable. Postoperative radiotherapy has an apparent impact on functional impairment, but preoperative tends to preserve the original tongue function.

  1. Facilitation from hand muscles innervated by the ulnar nerve to the extensor carpi radialis motoneurone pool in humans: a study with an electromyogram-averaging technique.

    Science.gov (United States)

    Suzuki, Katsuhiko; Ogawa, Keiichi; Sato, Toshiaki; Nakano, Haruki; Fujii, Hiromi; Shindo, Masaomi; Naito, Akira

    2012-10-01

    Effects of low-threshold afferents of hand muscles innervated by the ulnar nerve on an excitability of the extensor carpi radialis (ECR) motoneurone pool in humans were examined using an electromyogram-averaging (EMG-A) technique. Changes of EMG-A of ECR exhibiting 10% of the maximum contraction by electrical stimulation to the ulnar nerve at the wrist (ES-UN) and mechanical stimulation to the hypothenar muscles (MS-HTM) and first dorsal interosseus (MS-FDI) were evaluated in eight normal human subjects. The ES-UN with the intensity immediately below the motor threshold and MS-HTM and -FDI with the intensity below the threshold of the tendon(T)-reflex were delivered. Early and significant peaks in EMG-A were produced by ES-UN, MS-HTM, and MS-FDI in eight of eight subjects. The mean amplitudes of the peaks by ES-UN, MS-HTM, and MS-FDI were, respectively, 121.9%, 139.3%, and 149.9% of the control EMG (100%). The difference between latencies of the peaks by ES-UN and MS-HTM, and ES-UN and MS-FDI was almost equivalent to that of the Hoffmann(H)- and T-reflexes of HTM and FDI, respectively. The peaks by ES-UN, MS-HTM, and MS-FDI diminished with tonic vibration stimulation (TVS) to HTM and FDI, respectively. These findings suggest that group Ia afferents of the hand muscles facilitate the ECR motoneurone pool.

  2. Control and postural thixotropy of the forearm muscles: changes caused by cold.

    OpenAIRE

    Lakie, M; Walsh, E G; Wright, G W

    1986-01-01

    The forearm was cooled in water at 5-10 degrees C while wrist biodynamics were investigated. Pronounced loosening following a perturbation (thixotropy) was no longer seen. The wrist became stiffer for large or moderate but not small movements; EMG activity did not increase. Cooling the wrist alone, or opposite forearm, was without effect. The ability to make rapid reciprocating movements was reduced and muscle relaxation time was increased. Single movements were not affected.

  3. Resistance exercise with different volumes: blood pressure response and forearm blood flow in the hypertensive elderly

    Science.gov (United States)

    Brito, Aline de Freitas; de Oliveira, Caio Victor Coutinho; Brasileiro-Santos, Maria do Socorro; Santos, Amilton da Cruz

    2014-01-01

    Background The purpose of this study was to evaluate the effect of two sessions of resistance exercise with different volumes on post-exercise hypotension, forearm blood flow, and forearm vascular resistance in hypertensive elderly subjects. Methods The study was conducted with ten hypertensive elderly (65±3 years, 28.7±3 kg/m2) subjected to three experimental sessions, ie, a control session, exercise with a set (S1), and exercise with three sets (S3). For each session, the subjects were evaluated before and after intervention. In the pre-intervention period, blood pressure, forearm blood flow, and forearm vascular resistance were measured after 10 minutes of rest in the supine position. Thereafter, the subjects were taken to the gym to perform their exercise sessions or remained at rest during the same time period. Both S1 and S3 comprised a set of ten repetitions of ten exercises, with an interval of 90 seconds between exercises. Subsequently, the measurements were again performed at 10, 30, 50, 70, and 90 minutes of recovery (post-intervention) in the supine position. Results Post-exercise hypotension was greater in S3 than in S1 (systolic blood pressure, −26.5±4.2 mmHg versus −17.9±4.7 mmHg; diastolic blood pressure, −13.8±4.9 mmHg versus −7.7±5 mmHg, P<0.05). Similarly, forearm blood flow and forearm vascular resistance changed significantly in both sessions with an increase and decrease, respectively, that was more evident in S3 than in S1 (P<0.05). Conclusion Resistance exercises with higher volume were more effective in causing post-exercise hypotension, being accompanied by an increase in forearm blood flow and a reduction of forearm vascular resistance. PMID:25540580

  4. Surgical trainees neuropraxia? An unusual case of compression of the lateral cutaneous nerve of the forearm.

    LENUS (Irish Health Repository)

    Seoighe, D M

    2010-09-01

    Compression of the lateral cutaneous nerve of the forearm is an uncommon diagnosis but has been associated with strenuous upper limb activity. We report the unique case of a 32-year-old male orthopaedic trainee who suffered this nerve palsy as a result of prolonged elbow extension and forearm pronation while the single assistant during a hip resurfacing procedure. Conservative measures were sufficient for sensory recovery to be clinically detectable after 12 weeks.

  5. Ergonomic Evaluation of Biomechanical Hand Function

    Directory of Open Access Journals (Sweden)

    Kyung-Sun Lee

    2015-03-01

    Full Text Available The human hand is a complex structure that performs various functions for activities of daily living and occupations. This paper presents a literature review on the methodologies used to evaluate hand functions from a biomechanics standpoint, including anthropometry, kinematics, kinetics, and electromyography (EMG. Anthropometry describes the dimensions and measurements of the hand. Kinematics includes hand movements and the range of motion of finger joints. Kinetics includes hand models for tendon and joint force analysis. EMG is used on hand muscles associated with hand functions and with signal-processing technology.

  6. Role of nitric oxide and adenosine in the onset of vasodilation during dynamic forearm exercise.

    Science.gov (United States)

    Casey, Darren P; Mohamed, Essa A; Joyner, Michael J

    2013-02-01

    We tested the hypothesis that nitric oxide (NO) and adenosine contribute to the onset of vasodilation during dynamic forearm exercise. Twenty-two subjects performed rhythmic forearm exercise (20 % of maximum) during control and NO synthase (NOS) inhibition (N (G)-monomethyl-L-arginine; L-NMMA) trials. A subset of subjects performed a third trial of forearm exercise during combined inhibition of NOS and adenosine (aminophylline; n = 9). Additionally, a separate group of subjects (n = 7) performed rhythmic forearm exercise during control, inhibition of adenosine alone and combined inhibition of adenosine and NOS. Forearm vascular conductance (FVC; ml min(-1) · 100 mmHg(-1)) was calculated from blood flow and mean arterial pressure (mmHg). The onset of vasodilation was assessed by calculating the slope of the FVC response for every duty cycle between baseline and steady state, and the number of duty cycles (1-s contraction/2-s relaxation) to reach steady state. NOS inhibition blunted vasodilation at the onset of exercise (11.1 ± 0.8 vs. 8.5 ± 0.6 FVC units/duty cycle; P Vasodilation was blunted further with combined inhibition of NOS and adenosine (7.5 ± 0.6 vs. 6.2 ± 0.8 FVC units/duty cycle; P vasodilation during dynamic forearm exercise.

  7. First permanent implant of nerve stimulation leads activated by surface electrodes, enabling hand grasp and release: the stimulus router neuroprosthesis.

    Science.gov (United States)

    Gan, Liu Shi; Ravid, Einat; Kowalczewski, Jan Andrzej; Olson, Jaret Lawrence; Morhart, Michael; Prochazka, Arthur

    2012-05-01

    . More than 150 000 neuroprostheses (NPs) have been implanted in people to restore bodily function in a variety of neural disorders. The authors developed a novel NP, the Stimulus Router System (SRS), in which only passive leads are implanted. Each lead picks up a portion of the current delivered through the skin by an external stimulator. . The authors report on the first human implant of an SRS. . The recipient was a tetraplegic man with bilateral hand paralysis. Three SRS leads were implanted in his right forearm to activate the finger extensors, finger flexors, and thumb flexor. A wristlet containing a surface stimulator and electrodes was used to pass trains of electrical pulses through the skin to each lead. Hand opening and grasp were controlled via a wireless earpiece that sensed small tooth-clicks and transmitted signals to the wristlet. . The current required to activate the muscles was less than half that required prior to implantation and below perceptual threshold. Maximal grip force and hand opening aperture were both larger using the SRS. The implanted leads have remained functional for 3 years. The recipient reported various tasks of daily life that improved during SRS usage. An electronic counter revealed mean monthly usage of 18.5 hours, equivalent to 55 hours of continuous manual activity. . This first implant of the SRS indicates that it can be effective and reliable and has potential to provide an alternative to existing NPs.

  8. Cross-talk in mechanomyographic signals from the forearm muscles during sub-maximal to maximal isometric grip force.

    Directory of Open Access Journals (Sweden)

    Md Anamul Islam

    Full Text Available PURPOSE: This study aimed: i to examine the relationship between the magnitude of cross-talk in mechanomyographic (MMG signals generated by the extensor digitorum (ED, extensor carpi ulnaris (ECU, and flexor carpi ulnaris (FCU muscles with the sub-maximal to maximal isometric grip force, and with the anthropometric parameters of the forearm, and ii to quantify the distribution of the cross-talk in the MMG signal to determine if it appears due to the signal component of intramuscular pressure waves produced by the muscle fibers geometrical changes or due to the limb tremor. METHODS: Twenty, right-handed healthy men (mean ± SD: age  = 26.7±3.83 y; height  = 174.47±6.3 cm; mass  = 72.79±14.36 kg performed isometric muscle actions in 20% increment from 20% to 100% of the maximum voluntary isometric contraction (MVIC. During each muscle action, MMG signals generated by each muscle were detected using three separate accelerometers. The peak cross-correlations were used to quantify the cross-talk between two muscles. RESULTS: The magnitude of cross-talk in the MMG signals among the muscle groups ranged from, R2(x, y = 2.45-62.28%. Linear regression analysis showed that the magnitude of cross-talk increased linearly (r2 = 0.857-0.90 with the levels of grip force for all the muscle groups. The amount of cross-talk showed weak positive and negative correlations (r2 = 0.016-0.216 with the circumference and length of the forearm respectively, between the muscles at 100% MVIC. The cross-talk values significantly differed among the MMG signals due to: limb tremor (MMGTF, slow firing motor unit fibers (MMGSF and fast firing motor unit fibers (MMGFF between the muscles at 100% MVIC (p<0.05, η2 = 0.47-0.80. SIGNIFICANCE: The results of this study may be used to improve our understanding of the mechanics of the forearm muscles during different levels of the grip force.

  9. Species-specific differences and similarities in the behavior of hand-raised dog and wolf pups in social situations with humans.

    Science.gov (United States)

    Gácsi, Márta; Gyori, Borbála; Miklósi, Adám; Virányi, Zsófia; Kubinyi, Eniko; Topál, József; Csányi, Vilmos

    2005-09-01

    In order to reveal early species-specific differences, we observed the behavior of dog puppies (n = 11) and wolf pups (n = 13) hand raised and intensively socialized in an identical way. The pups were studied in two object-preference tests at age 3, 4, and 5 weeks. After a short isolation, we observed the subjects' behavior in the presence of a pair of objects, one was always the subject's human foster parent (caregiver) and the other was varied; nursing bottle (3 weeks), unfamiliar adult dog (3 and 5 weeks), unfamiliar experimenter (4 and 5 weeks), and familiar conspecific age mate (4 weeks). Dogs and wolves did not differ in their general activity level during the tests. Wolf pups showed preference for the proximity of the caregiver in two of the tests; Bottle-Caregiver at the age of 3 weeks and Experimenter-Caregiver at the age of 5 weeks, while dogs showed preference to the caregiver in three tests; conspecific Pup-Caregiver and Experimenter-Caregiver at the age of 4 weeks and dog-caregiver at the age of 5. Compared to wolves, dogs tended to display more communicative signals that could potentially facilitate social interactions, such as distress vocalization, tail wagging, and gazing at the humans' face. In contrast to dog puppies, wolf pups showed aggressive behavior toward a familiar experimenter and also seemed to be more prone to avoidance. Our results demonstrate that already at this early age--despite unprecedented intensity of socialization and the comparable social (human) environment during early development--there are specific behavioral differences between wolves and dogs mostly with regard to their interactions with humans.

  10. On the origins of human handedness and language: a comparative review of hand preferences for bimanual coordinated actions and gestural communication in nonhuman primates.

    Science.gov (United States)

    Meguerditchian, Adrien; Vauclair, Jacques; Hopkins, William D

    2013-09-01

    Within the evolutionary framework about the origin of human handedness and hemispheric specialization for language, the question of expression of population-level manual biases in nonhuman primates and their potential continuities with humans remains controversial. Nevertheless, there is a growing body of evidence showing consistent population-level handedness particularly for complex manual behaviors in both monkeys and apes. In the present article, within a large comparative approach among primates, we will review our contribution to the field and the handedness literature related to two particular sophisticated manual behaviors regarding their potential and specific implications for the origins of hemispheric specialization in humans: bimanual coordinated actions and gestural communication. Whereas bimanual coordinated actions seem to elicit predominance of left-handedness in arboreal primates and of right-handedness in terrestrial primates, all handedness studies that have investigated gestural communication in several primate species have reported stronger degree of population-level right-handedness compared to noncommunicative actions. Communicative gestures and bimanual actions seem to affect differently manual asymmetries in both human and nonhuman primates and to be related to different lateralized brain substrates. We will discuss (1) how the data of hand preferences for bimanual coordinated actions highlight the role of ecological factors in the evolution of handedness and provide additional support the postural origin theory of handedness proposed by MacNeilage [MacNeilage [2007]. Present status of the postural origins theory. In W. D. Hopkins (Ed.), The evolution of hemispheric specialization in primates (pp. 59-91). London: Elsevier/Academic Press] and (2) the hypothesis that the emergence of gestural communication might have affected lateralization in our ancestor and may constitute the precursors of the hemispheric specialization for language.

  11. Contact transfer of anions from hands as a function of the use of hand lotions

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    Welker, R. W.; Schulman, M.

    2001-01-01

    Contact transfer of anions from human hands can result in contamination of materials, increasing their rate of corrosion. Two types of hand lotion were applied to the hands: one was specially formulated for cleanroom use and the other was a popular commercial lotion. The effect on contact transfer of anions was measured versus anion transfer from washed hands without lotions.

  12. Treatment of split-thickness skin graft-related forearm scar contractures with a carbon dioxide laser protocol: 3 case reports.

    Science.gov (United States)

    Kroonen, Leo; Shumaker, Peter R; Kwan, Julia M; Uebelhoer, Nathan; Hofmeister, Eric

    2013-11-01

    Split-thickness skin grafts in the forearm can lead to motion restriction and disability through the dense scarring of the skin and formation of graft-tendon adhesions. Three patients were referred for laser treatment of motion-limiting scar-associated split-thickness skin grafts to the forearm. All patients had reached a plateau in range of motion despite aggressive hand therapy and underwent serial laser scar treatments at 6- to 8-week intervals. Treatments were performed in a clinic setting and were initiated 2 to 5 months after reconstructive surgery. Rapid subjective functional and objective improvements in range of motion were noted after laser therapy. Results were cumulative and durable at final follow-up ranging from 10 to 15 months after the initial treatment. No complications were noted. Fractionated carbon dioxide laser therapy is a promising adjunct to hand therapy when the main restraint to motion is superficial skin scarring and skin-tendon adhesions.

  13. Tactile display on the remaining hand for unilateral hand amputees

    Directory of Open Access Journals (Sweden)

    Li Tao

    2016-09-01

    Full Text Available Human rely profoundly on tactile feedback from fingertips to interact with the environment, whereas most hand prostheses used in clinics provide no tactile feedback. In this study we demonstrate the feasibility to use a tactile display glove that can be worn by a unilateral hand amputee on the remaining healthy hand to display tactile feedback from a hand prosthesis. The main benefit is that users could easily distinguish the feedback for each finger, even without training. The claimed advantage is supported by preliminary tests with healthy subjects. This approach may lead to the development of effective and affordable tactile display devices that provide tactile feedback for individual fingertip of hand prostheses.

  14. Dynamic Hand Gesture Recognition Using the Skeleton of the Hand

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    Coquin Didier

    2005-01-01

    Full Text Available This paper discusses the use of the computer vision in the interpretation of human gestures. Hand gestures would be an intuitive and ideal way of exchanging information with other people in a virtual space, guiding some robots to perform certain tasks in a hostile environment, or interacting with computers. Hand gestures can be divided into two main categories: static gestures and dynamic gestures. In this paper, a novel dynamic hand gesture recognition technique is proposed. It is based on the 2D skeleton representation of the hand. For each gesture, the hand skeletons of each posture are superposed providing a single image which is the dynamic signature of the gesture. The recognition is performed by comparing this signature with the ones from a gesture alphabet, using Baddeley's distance as a measure of dissimilarities between model parameters.

  15. Dynamic Hand Gesture Recognition Using the Skeleton of the Hand

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    Ionescu, Bogdan; Coquin, Didier; Lambert, Patrick; Buzuloiu, Vasile

    2005-12-01

    This paper discusses the use of the computer vision in the interpretation of human gestures. Hand gestures would be an intuitive and ideal way of exchanging information with other people in a virtual space, guiding some robots to perform certain tasks in a hostile environment, or interacting with computers. Hand gestures can be divided into two main categories: static gestures and dynamic gestures. In this paper, a novel dynamic hand gesture recognition technique is proposed. It is based on the 2D skeleton representation of the hand. For each gesture, the hand skeletons of each posture are superposed providing a single image which is the dynamic signature of the gesture. The recognition is performed by comparing this signature with the ones from a gesture alphabet, using Baddeley's distance as a measure of dissimilarities between model parameters.

  16. Accuracy and Early Clinical Outcome of 3-Dimensional Planned and Guided Single-Cut Osteotomies of Malunited Forearm Bones.

    Science.gov (United States)

    Roner, Simon; Vlachopoulos, Lazaros; Nagy, Ladislav; Schweizer, Andreas; Fürnstahl, Philipp

    2017-09-06

    To investigate the reduction accuracy of 3-dimensional planned single-cut osteotomies (SCOTs) of the forearm that were performed using patient-specific guides. A retrospective analysis of SCOTs performed between 2012 and 2014 was performed. Ten patients (age, 15-59 years) with 6 malunions of the ulna and 6 malunions of the radius were identified. The reduction accuracy was assessed by comparing the 3-dimensional preoperative plan of each osteotomy with the superimposed bone model extracted from postoperative computed tomography data. The difference was assessed by 3-dimensional angle and in all 6 degrees of freedom (3 translations, 3 rotations) with respect to an anatomical coordinate system. Wrist range of motion and grip strength was assessed after a mean of 16.7 months and compared with the preoperative measurements. On average, the 12 SCOTs demonstrated excellent accuracy of the reduction with respect to rotation (ie, pronation/supination, 4.9°; flexion/extension, 1.7°; ulnar/radial angulation, 2.0°) and translation (ie, proximal/distal, 0.8 mm; radial/ulnar, 0.8 mm; dorsal/palmar, 0.8 mm). A mean residual 3-dimensional angle of 5.8° (SD, 3.6°) was measured after surgery. All 6 patients operated on for reasons of a reduced range of motion demonstrated improved symptoms and increased movement (from 20° to 80°). In the patients with unstable/painful distal radioulnar joint, 3 were totally free of complaints and 1 patient showed residual pain during sports. A SCOT combined with patient-specific guides is an accurate and reliable technique to restore normal anatomy in multiplanar deformities of the forearm. Therapeutic IV. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  17. fMRI reveals a lower visual field preference for hand actions in human superior parieto-occipital cortex (SPOC) and precuneus.

    Science.gov (United States)

    Rossit, Stéphanie; McAdam, Teresa; McLean, D Adam; Goodale, Melvyn A; Culham, Jody C

    2013-10-01

    Humans are more efficient when performing actions towards objects presented in the lower visual field (VF) than in the upper VF. The present study used slow event-related functional magnetic resonance imaging (fMRI) to examine whether human brain areas implicated in action would show such VF preferences. Participants were asked to fixate one of four different positions allowing objects to be presented in the upper left, upper right, lower left or lower right VF. In some trials they reached to grasp the object with the right hand while in others they passively viewed the object. Crucially, by manipulating the fixation position, rather than the position of the objects, the biomechanics of the movements did not differ across conditions. The superior parieto-occipital cortex (SPOC) and the left precuneus, brain areas implicated in the control of reaching, were significantly more activated when participants grasped objects presented in the lower VF relative to the upper VF. Importantly, no such VF preferences were observed in these regions during passive viewing. This finding fits well with evidence from the macaque neurophysiology that neurons within visuomotor regions over-represent the lower VF relative to the upper VF and indicate that the neural responses within these regions may reflect a functional lower VF advantage during visually-guided actions.

  18. A biomechanical analysis of pronation-supination of the forearm using magnetic resonance imaging; Dynamic changes of the interosseous membrane of the forearm during pronation-supination

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    Nakamura, Toshiyasu; Yabe, Yutaka; Horiuchi, Yukio (Keio Univ., Tokyo (Japan). School of Medicine)

    1994-01-01

    A magnetic resonance (MR) study was performed using a 0.5 tesla system to investigate the behavior of the interosseous membrane of the forearm during pronation-supination and to evaluate the influence of pronation-supination loading in the neutral position. The right forearm was examined in twenty volunteers at the proximal fourth part, middle part and distal fourth part of the forearm. Slices were examined at maximum pronation, 45deg pronation, neutral, 45deg supination and at maximum supination. A 0.1 Nm torque in both rotational directions was added in the neutral position. The MR image of the interosseous membrane of the forearm was a thin line with low contrast in the neutral position. The tendinous portion and membranous portions of the interosseous membrane could be differentiated. At maximum pronation and at maximum supination, the interosseous membrane was flexed, caused mainly by the relaxation in the membranous portion. The radius shifted slightly volarly to the ulna at maximum pronation, caused by the incongruity of the distal radioulnar joint. The radius shifted dorsally with pronation loading, and shifted volarly with supination loading. The inelasticity of the membranous portion of the interosseous membrane may be responsible for pronation-supination contracture, while rotational loading may be a cause of the distal radioulnar joint dislocation. These studies suggest that this technique is useful for further in vivo studies of kinesiology. (author).

  19. Forearm muscle oxygenation during sustained isometric contractions in rock climbers

    Directory of Open Access Journals (Sweden)

    Jan Kodejška

    2016-02-01

    Full Text Available Background. Bouldering and lead climbing are divergent disciplines of the sport of rock climbing. Bouldering moves are short and powerful, whilst sport climbing is longer and require a greater degree of endurance. Aim. The aim of this study was to compare forearm muscle oxygenation during sustained isometric contraction between lead climbers (LC and boulderers (BO. Methods. Eight BO and twelve LC completed maximal finger flexor strength test and sustained contractions to exhaustion at 60% of maximum voluntary contraction (MVC. Differences between BO and LC in maximal strength, time to exhaustion, force time integral (FTI, and tissue oxygenation (SmO2 were assessed by t-test for independent samples. Results. LC showed significantly lower level of average tissue oxygenation (BO 38.9% SmO2, s = 7.4; LC 28.7% SmO2, s = 7.1 and maximal tissue deoxygenation (BO 25.6% SmO2, s = 8.2; LC 13.5% SmO2, s = 8.5. LC demonstrated significantly lower finger flexor strength (519 N, s = 72 than BO (621 N, s = 142. LC sustained a longer time of contraction (not significantly (BO 52.2 s, s = 11.5; LC 60.6 s, s = 13 and achieved a similar value of FTI (BO 17421 Ns, s = 4291; LO 17476 Ns, s = 5036 in the endurance test. Conclusions. The results showed lower deoxygenation during sustained contraction in BO than LC despite similar FTI, indicating different local metabolic pathways in both groups.

  20. Human Driving Forces and Their Impacts on Land Use/Land Cover. Hands-On! Developing Active Learning Modules on the Human Dimensions of Global Change.

    Science.gov (United States)

    Moser, Susanne

    This learning module aims to engage students in problem solving, critical thinking, scientific inquiry, and cooperative learning. The module is appropriate for use in any introductory or intermediate undergraduate course that focuses on human-environment relationships. The module explains that land use/cover change has occurred at all times in all…