Science.gov

Sample records for rasmus grip jan-gunnar

  1. Gripping device

    NASA Technical Reports Server (NTRS)

    Parma, George F. (Inventor)

    1989-01-01

    This invention relates to a gripping device, and more particularly to one with a large moment carrying capability for handling long workpieces of various diameters and which can be particularly used as an end effector on a robotic arm.

  2. GRIPPING TOOL

    DOEpatents

    Sandrock, R.J.

    1961-12-12

    A self-actuated gripping tool is described for transferring fuel elements and the like into reactors and other inaccessible locations. The tool will grasp or release the load only when properly positioned for this purpose. In addition, the load cannot be released except when unsupported by the tool, so that jarring or contact will not bring about accidental release of the load. The gripping members or jaws of the device are cam-actuated by an axially slidable shaft which has two lockable positions. A spring urges the shaft into one position and a solenoid is provided to overcome the spring and move it into the other position. The weight of the tool operates a sleeve to lock the shaft in its existing position. Only when the cable supporting the tool is slack is the device capable of being actuated either to grasp or release its load. (AEC)

  3. Wire Test Grip Fixture

    NASA Technical Reports Server (NTRS)

    Burke, Christopher S.

    2011-01-01

    Wire-testing issues, such as the gripping strains imposed on the wire, play a critical role in obtaining clean data. In a standard test frame fitted with flat wedge grips, the gripping action alone creates stresses on the wire specimen that cause the wire to fail at the grip location. A new test frame, which is outfitted with a vacuum chamber, negated the use of any conventional commercially available wire test fixtures, as only 7 in. (17.8 cm) existed between the grip faces. An innovative grip fixture was designed to test thin gauge wire for a variety of applications in an existing Instron test frame outfitted with a vacuum chamber.

  4. 22. GRIP RACK: View to east showing Eppelsheimer bottom grips ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. GRIP RACK: View to east showing Eppelsheimer bottom grips standing in grip rack on the first floor of the Washington and Mason Street powerhouse. - San Francisco Cable Railway, Washington & Mason Streets, San Francisco, San Francisco County, CA

  5. Timelapse: GRIPS Assembly

    NASA Video Gallery

    The GRIPS team integrated and tested their balloon payload at NASA’s Columbia Scientific Balloon Facility in Palestine, Texas, July 18-Aug. 28, 2015. After putting the finishing touches on the payl...

  6. NASA Hurricane Mission - GRIP

    NASA Video Gallery

    This is an overview of NASA's hurricane research campaign called Genesis and Rapid Intensification Processes (GRIP). The six-week mission was conducted in coordination with NOAA and the National Sc...

  7. Bi-stem gripping apparatus

    NASA Technical Reports Server (NTRS)

    Sanders, Fred G. (Inventor)

    1988-01-01

    This invention relates to devices which grip cylindrical structures and more particularly to a device which has three arcuate gripping members having frictional surfaces for gripping and compressing a bi-stem. The bi-stem gripping apparatus is constructed having a pair of side gripping members, and an intermediate gripping member disposed between them. Sheets of a gum stock silicone rubber with frictional gripping surfaces are bonded to the inner region of the gripping members and provide frictional engagement between the bi-stem and the apparatus. A latch secures the gripping apparatus to a bi-stem, and removable handles are attached, allowing an astronaut to pull the bi-stem from its cassette. A tethering ring on the outside of the gripping apparatus provides a convenient point to which a lanyard may be attached.

  8. Grip and slip

    PubMed Central

    Whitney, Heather M; Federle, Walter

    2009-01-01

    Flowers interact simultaneously with a variety of insect visitors, including mutualistic pollinators and antagonists such as florivores, nectar robbers and pollinator predators. The plant epidermis produces a range of structures, such as conical or papillate cells, that can help mutualists to grip the flower, while a variety of other structures, such as slippery wax crystals on the flowers or on the stems leading to them, are able to deter non-beneficial insects or behaviors. Modification of the floral surface can also aid pollination in unusual ways in some highly specialized interactions. In the case of the trap-flowers in species of Arisaema, conical cells aid pollination by being present on the spathe surface, but here they are modified in such a way as to decrease the pollinating insect’s grip. We discuss a variety of these floral structural features that influence insect stability on the plant. PMID:20195456

  9. GRIPPING DEVICE FOR CYLINDRICAL OBJECTS

    DOEpatents

    Pilger, J.P.

    1964-01-21

    A gripping device is designed for fragile cylindrical objects such as for drawing thin-walled tubes. The gripping is done by multiple jaw members held in position by two sets of slots, one defined by keystone-shaped extensions of the outer shell of the device and the other in a movable sleeve held slidably by the extensions. Forward movement oi the sleeve advances the jaws, thereby exerting a controlled, radial pressure on the object being gripped. (AEC)

  10. Computing Gravity's Strongest Grip

    NASA Astrophysics Data System (ADS)

    Shoemaker, Deirdre

    2008-04-01

    Gravitational physics is entering a new era, one driven by observation, that will begin once gravitational wave interferometers such as LIGO make their first detections. The gravitational waves are produced during violent events such as the merger of two black holes. The detection of these waves or ripples in the fabric of spacetime is a formidable undertaking, requiring innovative engineering, powerful data analysis tools and careful theoretical modeling. In support of this theoretical modeling, recent breakthroughs in numerical relativity have lead to the development of computational tools that allow us to explore where and how gravitational wave observations can constrain or inform our understanding of gravity and astrophysical phenomena. I will review these latest developments, focusing on binary black hole simulations and the role these simulations play in our new understanding of physics and astronomy where gravity exhibits its strongest grip on our spacetime.

  11. Conformal gripping device

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2009-01-01

    The present invention relates to a conformal gripping device. In an embodiment of the present invention a conformal gripper device may be disclosed comprising a frame that includes an array of movable pins. The device may also include a roller locking and unlocking system within the frame. The system may comprise a pair of locking rollers for each row of gripper pins to facilitate locking and unlocking the array of gripper pins on a column-by-column basis. The system may also include a striker element that may force the locking rollers to roll along an angled roll surface to facilitate unlocking of the array of pins on a column-by-column basis. The system may further include an electromagnetic actuator or solenoid and permanent magnets to facilitate movement of the striker element and the locking rollers.

  12. The Grip of Gravity

    NASA Astrophysics Data System (ADS)

    Gondhalekar, Prabhakar

    2001-09-01

    Gravity is one of the most inexplicable forces of nature, controlling everything, from the expansion of the Universe to the ebb and flow of ocean tides. The search for the laws of motion and gravitation began more than two thousand years ago, a quest that Prabhakar Gondhalekar recounts in The Grip of Gravity. Beginning with Aristotle and concluding with Planck, Gondhalekar outlines a 'genealogy' of gravity and lucidly explains how previous explanations have shaped the most recent development in the field, string theory. In this work, physicist and astronomer Gondhalekar describes experiments, both planned and proposed, and clearly explains natural phenomena like ocean tides, seasons, ice ages, the formation of planets, stars, and exotic objects like black holes and neutron stars, which are all controlled by gravity. Including anecdotes and thumb-nail sketches of the personalities involved, The Grip of Gravity provides an introduction to the foundation of modern physics and shows how the current developments in string theory may lead to a new and radical interpretation of gravity. Prabhakar Gondhalekar is an Honorary Fellow in the Department of Physics and Astronomy, University College, London. Until his retirement in 1998, he was the head of the Space Astronomy Group at the Rutherford Appleton Laboratory, where he had been a researcher for 18 years. His research has included a number of topics in galactic and extragalactic astronomy, with his major work focusing on the interstellar medium and active galactic nuclei. Gondhalekar has been awarded Royal Society, Leverhulme Trust, and NATO Research Fellowships to do research in universities in the United States and Israel.

  13. Robot Hand Grips Cylinders Securely

    NASA Technical Reports Server (NTRS)

    Parma, George F.

    1989-01-01

    Jaws and linkage accommodate various sizes. Robot hand includes two pairs of parallel jaws that grasp rods, pipes, tubes, struts, and other long, heavy cylindrical objects. Hand features compact rotary drive and butterfly configuration simplifying approach and gripping maneuvers of robot. Parallelogram linkages maintain alignment of each jaw with other jaws. One bar of each linkage connected to one of two concentric, counterrotating shafts; rotation of shafts moves jaws in each pair toward or away from each other to grasp or release workpiece. Each jaw includes rigid gripping pad lined with rubber to give firm grip and to prevent damage to workpiece. Inner cylindrical surface (corner) of each jaw tapers off to flat sides. Enables jaw to grasp workpieces with diameters larger than or equal to twice the corner radius.

  14. Measuring Grip Pressure during the Golf Swing.

    ERIC Educational Resources Information Center

    Budney, David R.

    1979-01-01

    With the use of a special instrumented golf club, grip pressure measurements can be used by the instructor to quantify and discuss the effects of grip pressure in relation to instructional points. (MM)

  15. Well casing grip assurance system

    SciTech Connect

    Mosing, D.E.; Webre, C.M.

    1987-06-30

    An apparatus is described for assuring that at least one of the elevator or the spider of well casing installation apparatus is fully closed in gripping connection about a well casing before the other of the elevator or the spider may be released from fully closed gripping connection about the well casing, the continuation comprising: (a) two-position elevator valve means connected to admit fluid pressure and to optionally direct it to open and close the elevator; (b) two-position spider valve means connected to admit fluid pressure into the spider and to optionally direct the fluid pressure to open and to close the spider; (c) two-position spider position valve means connected to the elevator valve means. The spider position valve means is mechanically connected for passing the fluid pressure to the elevator valve means only when the spider is fully closed into gripping position; and (d) two-position elevator position valve means connected to the spider valve means. The elevator position valve is mechanically connected to the elevator for passing fluid pressure to the spider valve when the elevator is fully closed into gripping position.

  16. Tensile testing grips ensure uniform loading of bimetal tubing specimens

    NASA Technical Reports Server (NTRS)

    Driscol, S. D.; Hunt, V.

    1968-01-01

    Tensile testing grip uniformly distributes stresses to the internal and external tube of bimetal tubing specimens. The grip is comprised of a slotted external tube grip, a slotted internal tube grip, a machine bolt and nut, an internal grip expansion cone, and an external grip compression nut.

  17. Hydraulically Driven Grips For Hot Tensile Specimens

    NASA Technical Reports Server (NTRS)

    Bird, R. Keith; Johnson, George W.

    1994-01-01

    Pair of grips for tensile and compressive test specimens operate at temperatures up to 1,500 degrees F. Grips include wedges holding specimen inside furnace, where heated to uniform temperature. Hydraulic pistons drive wedges, causing them to exert clamping force. Hydraulic pistons and hydraulic fluid remain outside furnace, at room temperature. Cooling water flows through parts of grips to reduce heat transferred to external components. Advantages over older devices for gripping specimens in high-temperature tests; no need to drill holes in specimens, maintains constant gripping force on specimens, and heated to same temperature as that of specimen without risk of heating hydraulic fluid and acuator components.

  18. Constraints on grip-selection: minimizing awkwardness.

    PubMed

    Fischman, M G

    1998-02-01

    In picking up and manipulating an object, the selection of an initial grip (overhand versus underhand) often depends on how comfortable the hand and arm will be at the end of the movement. This effect has been called "end-state comfort" and seems to be an important constraint in grip-selection. The present experiment further explored this effect by selecting a task that would ensure a comfortable ending position regardless of the initial choice of grip. 206 undergraduates picked up a cardboard paper-towel roll from a horizontal position and placed one end down on a table. Analysis showed a clear preference for the overhand grip, as 78% of the participants chose this grip. In addition, more women preferred the overhand grip than men. The findings indicate that people may be sensitive to minimizing awkwardness in both terminal and initial positions. PMID:9530757

  19. Factors affecting maximal momentary grip strength.

    PubMed

    Martin, S; Neale, G; Elia, M

    1985-03-01

    Maximal voluntary grip strength has been measured in normal adults aged 18-70 years (17 f, 18 m) and compared with other indices of body muscle mass. Grip strength (dominant side) was directly proportional to creatinine excretion (r = 0.81); to forearm muscle area (r = 0.73); to upper arm muscle area (r = 0.71) and to lean body mass (r = 0.65). Grip strength relative to forearm muscle area decreased with age. The study of a subgroup of normal subjects revealed a small but significant postural and circadian effect on grip strength. The effect on maximal voluntary grip strength of sedatives in elderly subjects undergoing routine endoscopy (n = 6), and of acute infections in otherwise healthy individuals (n = 6), severe illness in patients requiring intensive care (n = 6), chronic renal failure (n = 7) and anorexia nervosa (n = 6) has been assessed. Intravenous diazepam and buscopan produced a 50 per cent reduction in grip strength which returned to normal within the next 2-3 h. Acute infections reduced grip strength by a mean of 35 per cent and severe illness in patients in intensive care by 60 per cent. In patients with chronic renal failure grip strength was 80-85 per cent of that predicted from forearm 'muscle area' (P less than 0.05). In anorectic patients the values were appropriate for their forearm muscle area. Nevertheless nutritional rehabilitation of one anorectic patient did not lead to a consistent improvement in grip strength. PMID:3926728

  20. Cardiovascular responses to isometric hand grip vs. relaxed hand grip in sustained cycling efforts.

    PubMed

    Canivel, Randy G; Wyatt, Frank B; Baker, Julien S

    2012-11-01

    Peripheral isometric contractions may lead to enhanced performance. Previous research using hand grip protocols indicates increased stabilization and peak power outputs. Research is lacking with the grip vs. no-grip protocol during sustained efforts. The purpose of this study is to determine cardiovascular reactions (i.e., heart rate [HR], blood pressure [BP], and rate pressure product [RPP]) during sustained cycling via an isometric and relaxed hand grip. Nine (n = 9) recreational cyclists participated in this study. After signing a medical and physical readiness questionnaire, the subjects were randomly assigned to 1 of 2 different protocols. Preexercising values of the HR (beats per minute), BP (miilimeters of mercury), height (centimeters), weight (kilograms), and age (years) were assessed before testing. A Monark bicycle ergometer was used for testing. Grip was substantiated through the use of a hand grip dynamometer at 20 kg of tension. Protocol 1 used an isometric "Hand Grip" scenario at 150 W for 20 minutes. Protocol 2 used a "Relaxed Hand Grip" at the same power and time. During the 20-minute exercise test, HR (POLAR), BP (stethoscope and sphygmomanometer), and calculated RPP (HR × systolic BP [SPB]/100) were recorded every minute. Statistical measures included mean and SDs between protocols, and dependent samples t-tests were used to examine differences between grip and no-grip protocols. At an alpha of ≤0.05, SBP did show a significant increase when using no grip, 161.4 (5.1) mm Hg vs. grip, 154.1 (6.6) mm Hg. However, rate pressure product and heart rate showed no significant differences between protocols. Our data suggested that the use of an isometric hand grip is transient and diminishes over time. PMID:22105053

  1. Task Dependency of Grip Stiffness—A Study of Human Grip Force and Grip Stiffness Dependency during Two Different Tasks with Same Grip Forces

    PubMed Central

    Höppner, Hannes; McIntyre, Joseph; van der Smagt, Patrick

    2013-01-01

    It is widely known that the pinch-grip forces of the human hand are linearly related to the weight of the grasped object. Less is known about the relationship between grip force and grip stiffness. We set out to determine variations to these dependencies in different tasks with and without visual feedback. In two different settings, subjects were asked to (a) grasp and hold a stiffness-measuring manipulandum with a predefined grip force, differing from experiment to experiment, or (b) grasp and hold this manipulandum of which we varied the weight between trials in a more natural task. Both situations led to grip forces in comparable ranges. As the measured grip stiffness is the result of muscle and tendon properties, and since muscle/tendon stiffness increases more-or-less linearly as a function of muscle force, we found, as might be predicted, a linear relationship between grip force and grip stiffness. However, the measured stiffness ranges and the increase of stiffness with grip force varied significantly between the two tasks. Furthermore, we found a strong correlation between regression slope and mean stiffness for the force task which we ascribe to a force stiffness curve going through the origin. Based on a biomechanical model, we attributed the difference between both tasks to changes in wrist configuration, rather than to changes in cocontraction. In a new set of experiments where we prevent the wrist from moving by fixing it and resting it on a pedestal, we found subjects exhibiting similar stiffness/force characteristics in both tasks. PMID:24324643

  2. NASA Gets 'GRIP' on Hurricane Formation

    NASA Video Gallery

    NASA's GRIP 2010 hurricane mission is in full force. During this year's Atlantic hurricane season, researchers using powerful instruments onboard three aircraft will be able to "see"" below the clo...

  3. Grip strength in post-stroke hemiplegia

    PubMed Central

    Park, Soohee; Park, Joo-Young

    2016-01-01

    [Purpose] This study was performed in order to investigate the grip strength of the unaffected hand of hemiplegic post-stroke patients. [Subjects] This study conducted on 83 hemiplegic post-stroke patients from May to August 2012. [Methods] This study was measured the mean grip strength of the unaffected hand of patients with hemiplegia and comparatively analyzed this with the mean normal grip strength. [Results] The grip strength of the unaffected hand of patients with hemiplegia was weaker compared to the of normal. [Conclusion] Patients with hemiplegia demonstrated problems in both their unaffected and affected sides. Based on the results of this study, it is necessary to expand treatment from the affected to unaffected areas of patients with hemiplegia. PMID:27065562

  4. GRIPS - The Geostationary Remote Infrared Pollution Sounder

    NASA Astrophysics Data System (ADS)

    Spackman, Ryan; Dickerson, Russell; Schoeberl, Mark; Bloom, Hal; Gordley, Larry; McHugh, Martin; Thompson, Anne; Burrows, John; Zeng, Ning; Marshall, Tom; Fish, Chad; Kim, Jhoon; Park, Rokjin; Warner, Juying; Bhartia, Pawan; Kollonige, Debra

    2013-04-01

    Climate change and air quality are the most pressing environmental issues of the 21st century for America and for the world as a whole. Despite decades of research, the sources and sinks of key greenhouse gases and other pollutants remain highly uncertain making atmospheric composition predictions difficult. The Geostationary Remote Infrared Pollution Sounder (GRIPS) will measure carbon dioxide (CO2), carbon monoxide (CO), and methane (CH4). By using measurements of nitrous oxide (N2O) and the O2 A-band to help correct for clouds and aerosols, GRIPS will achieve unprecedented precision. Together these gases account for about 85% of all climate forcing and they impact atmospheric ozone (O3). GRIPS, employing gas-filter correlation radiometry, uses the target gases themselves in place of dispersive elements to achieve outstanding throughput, sensitivity, and specificity. Because it uses a combination of reflected and thermal IR, GRIPS will detect trace gas concentrations right down to the Earth's surface. When flown in parallel to a UV/VIS sensor such as GEMS on GEO-KOMPSAT-2B over East Asia or the Sentinel 4 on MTG over Europe/Africa, the combination offers powerful finger-printing capabilities to distinguish and quantify diverse pollution sources such as electricity generation, biomass burning, and motor vehicles. From geostationary orbit, GRIPS will be able to focus on important targets to quantify sources, net flux, diurnal cycles, and long-range transport of these key components in the Earth's radiative balance and air quality.

  5. GRIPS - The Geostationary Remote Infrared Pollution Sounder

    NASA Astrophysics Data System (ADS)

    Dickerson, R. R.; Schoeberl, M. R.; Gordley, L. L.; McHugh, M. J.; Thompson, A. M.; Burrows, J. P.; Zeng, N.; Marshall, B. T.; Fish, C. S.; Spackman, J. R.; Kim, J.; Park, R.; Warner, J. X.; Bhartia, P. K.; Kollonige, D. E.

    2012-12-01

    Climate change and air quality are the most pressing environmental issues of the 21st century - for America and for the world as a whole. Despite decades of research, the sources and sinks of key greenhouse gases and other pollutants remain highly uncertain making atmospheric composition predictions difficult. The Geostationary Remote Infrared Pollution Sounder (GRIPS) will measure carbon dioxide (CO2), carbon monoxide (CO), and methane (CH4). By using measurements of nitrous oxide (N2O) and the O2 A-band to help correct for clouds and aerosols, GRIPS will achieve unprecedented precision. Together these gases account for about 85% of all climate forcing and they impact atmospheric ozone (O3). GRIPS, employing gas-filter correlation radiometry, uses the target gases themselves in place of dispersive elements to achieve outstanding throughput, sensitivity, and specificity. Because it uses a combination of reflected and thermal IR, GRIPS will detect trace gas concentrations right down to the Earth's surface. When flown in parallel to a UV/VIS sensor such as GEMS on GEO-KOMPSAT-2B over East Asia or the Sentinel 4 on MTG over Europe/Africa, the combination offers powerful finger-printing capabilities to distinguish and quantify diverse pollution sources such as electricity generation, biomass burning, and motor vehicles. From geostationary orbit, GRIPS will be able to focus on important targets to quantify sources, net flux, diurnal cycles, and long-range transport of these key components in the Earth's radiative balance and air quality.

  6. Selective Influences of Precision and Power Grips on Speech Categorization.

    PubMed

    Tiainen, Mikko; Tiippana, Kaisa; Vainio, Martti; Peromaa, Tarja; Komeilipoor, Naeem; Vainio, Lari

    2016-01-01

    Recent studies have shown that articulatory gestures are systematically associated with specific manual grip actions. Here we show that executing such actions can influence performance on a speech-categorization task. Participants watched and/or listened to speech stimuli while executing either a power or a precision grip. Grip performance influenced the syllable categorization by increasing the proportion of responses of the syllable congruent with the executed grip (power grip-[ke] and precision grip-[te]). Two follow-up experiments indicated that the effect was based on action-induced bias in selecting the syllable. PMID:26978074

  7. 23. POWELLTYPE CAR THROUGH GRIP REMOVAL DOOR: View looking through ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. POWELL-TYPE CAR THROUGH GRIP REMOVAL DOOR: View looking through grip removal door into interior of a Powell-type cable car. - San Francisco Cable Railway, Washington & Mason Streets, San Francisco, San Francisco County, CA

  8. Lifting clamp positively grips structural shapes

    NASA Technical Reports Server (NTRS)

    Reinhardt, E. C.

    1966-01-01

    Welded steel clamps securely grip structural shapes of various sizes for crane operations. The clamp has adjustable clamping jaws and screw-operated internal v-jaws and provides greater safety than hoisting slings presently used. The structural member can be rotated in any manner, angle, or direction without being released by the clamp.

  9. Kinetics of crimp and slope grip in rock climbing.

    PubMed

    Schweizer, Andreas; Hudek, Robert

    2011-05-01

    The aim was to investigate differences of the kinetics of the crimp and the slope grip used in rock climbing. Nine cadaver fingers were prepared and fixated with the proximal phalanx in a frame. The superficial (FDS) and deep (FDP) flexor tendons were loaded selectively and together with 40 N in the crimp grip (PIP joint flexed 90°/DIP joint hyperextended) and the slope grip position (<25° flexed/50° flexed respectively). Five different grip sizes were tested and the flexion force which was generated to the grip was measured. In the crimp grip the FDP generated more flexion force in small sized holds whereas the FDS generated more force in the larger holds. During the slope grip the FDP was more effective than the FDS. While both tendons were loaded, the flexion force was always greater during crimp grip compared with the slope grip. The FDP seems to be most important for very small holds using the crimp grip but also during slope grip holds whereas the FDS is more important for larger flat holds. PMID:21576719

  10. Status of The SPARC-GRIPS Initiative

    NASA Technical Reports Server (NTRS)

    Pawson, Steven; Kodera, Kunihiko; Einaudi, Franco (Technical Monitor)

    2000-01-01

    The GCM-Reality Intercomparison Project for the Symbolic Processing Algorithmic Research Computer (SPARC) is an initiative designed to provide a comprehensive assessment of our ability to model the present-day climate and the impacts of different physical perturbations. This poster will show the different scientific experiments being conducted in the general purpose rocket instrumentation and payload system (GRIPS) and include some summaries of the results. The three concurrent aspects of GRIPS are: (1) studies of the climate and transient features simulated by the models; (2) examinations of different parametrizations and their impacts on the model climate; (3) studies of the impact of physical perturbations, such as solar forcing, volcanic aerosols and ozone change. Sample results from a number of these areas will be presented, with discussion of their implications for our ability to model the climate of the present and future atmosphere.

  11. Effect of grip strength and grip strengthening exercises on instantaneous bat velocity of collegiate baseball players.

    PubMed

    Hughes, Shawn S; Lyons, Brian C; Mayo, Jerry J

    2004-05-01

    Bat velocity is considered to be an important factor for successful hitting. The relationship between grip strength and bat velocity has not been conclusively established. The purposes of this study were to determine the relationship of grip strength to bat velocity and to ascertain whether the performance of resistance training exercises designed to specifically target the forearms and grip would significantly alter bat velocity. The subjects for this study were 23 male members (mean +/- SD, age = 19.7 +/- 1.3 years, height = 182.5 +/- 5.9 cm, weight = 85.4 +/- 15.5 kg, experience = 14.4 +/- 1.7 years) of a varsity baseball team at a National Collegiate Athletic Association Division II school. The Jamar hand dynamometer was used to test grip strength, and the SETPRO Rookie was used to measure instantaneous bat velocity at the point of contact with the ball. Subjects were randomly divided into an experimental group and a control group. For 6 weeks, both groups participated in their usual baseball practice sessions, but the experimental group also performed extra forearm and grip strengthening exercises, whereas the control group did not. Pretest and posttest correlations between grip strength and bat velocity revealed no significant relationship between grip strength and bat velocity (pretest r = 0.054, p = 0.807; posttest r = 0.315, p = 0.145). A dependent t-test performed on all subjects revealed that a significant (p = 0.001) increase in bat velocity did occur over the course of the study. A covariate analysis, employing pretest bat velocity as the covariate, revealed no significant difference (p = 0.795) in posttest bat velocity scores between the experimental and control groups. Thus, increases in bat velocity occurred, but the differences were similar for both the experimental and control groups. The findings of this study suggest that grip strength and bat velocity are not significantly related, and that the allocation of time and energy for added training

  12. Claw grip contact probe for flat packs

    NASA Astrophysics Data System (ADS)

    Shearer, J. W., Jr.

    1985-09-01

    A probe device including a unitary body 2 and a sliding plate means 44 for testing and diagnosing multi-lead electrical flat packs. The sliding plate means contains two sets of holes 52 into which are inserted spring-loaded electrical contact probes for making contact with the leads of the electrical flat pack. The unitary body 2 includes comb teeth for orienting the unitary body over the leads of the electrical flat pack, as well as gripping means having hook ends for securely fastening the probe device to the electrical flat pack being tested or diagnosed. The gripping means include an outwardly flared portion against which the sliding plate means exerts inward lateral pressure causing the hook ends to grip underneath the electrical flat pack at each corner thereof to securely clamp it in place. Included in unitary body 2 is at least one threaded hole which is sufficiently large to allow a size 4 to 40 machine screw to pass therethrough.

  13. Handle Shape Affects the Grip Force Distribution and the Muscle Loadings During Power Grip Tasks.

    PubMed

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

    2015-12-01

    The objectives of this study were to investigate the effect of handle shape on the grip force distribution in the hand and on the muscle forces during maximal power grip tasks. Eleven subjects maximally grasped 3 handles with different external shapes (circular, elliptic, and double-frustum). A handle dynamometer, equipped with both a force sensor and a pressure map, was used to record the forces exerted at the hand/handle interface. The finger and wrist joint postures were also computed from synchronized kinematic measurement. These processed data were then used as input of a biomechanical hand model to estimate muscle forces. The results showed that handle shape influences the maximal grip force, the grip force distribution, and the finger joint postures. Particularly, we observed that the elliptical shape resulted in a 6.6% lower maximal grip force compared with the circular and double-frustum handle. Concomitantly, the estimated muscle forces also varied significantly according to the handle shape, with up to 48% differences for the flexor digitorum superficialis muscle for example. Interestingly, different muscle coordination strategies were observed depending on the handle shape, therefore suggesting a potential influence of these geometrical characteristics on pathological risks such as tendonitis. PMID:26214057

  14. Systems and Methods for Gravity-Independent Gripping and Drilling

    NASA Technical Reports Server (NTRS)

    Parness, Aaron (Inventor); Frost, Matthew A. (Inventor); Thatte, Nitish (Inventor); King, Jonathan P. (Inventor)

    2016-01-01

    Systems and methods for gravity independent gripping and drilling are described. The gripping device can also comprise a drill or sampling devices for drilling and/or sampling in microgravity environments, or on vertical or inverted surfaces in environments where gravity is present. A robotic system can be connected with the gripping and drilling devices via an ankle interface adapted to distribute the forces realized from the robotic system.

  15. Microspine Gripping Mechanism for Asteroid Capture

    NASA Technical Reports Server (NTRS)

    Merriam, Ezekiel G.; Berg, Andrew B.; Willig, Andrew; Parness, Aaron; Frey, Tim; Howell, Larry L.

    2016-01-01

    This paper details the development and early testing of a compliant suspension for a microspine gripper device for asteroid capture or micro-gravity percussive drilling. The microspine gripper architecture is reviewed, and a proposed microspine suspension design is presented and discussed. Prototyping methods are discussed, as well as testing methods and results. A path forward is identified from the results of the testing completed thus far. Key findings include: the microspine concept has been established as a valid architecture and the compliant suspension exhibits the desired stiffness characteristics for good gripping behavior. These developments will aid in developing the capability to grasp irregularly shaped boulders in micro-gravity.

  16. Selective Influences of Precision and Power Grips on Speech Categorization

    PubMed Central

    Tiainen, Mikko; Tiippana, Kaisa; Vainio, Martti; Peromaa, Tarja; Komeilipoor, Naeem; Vainio, Lari

    2016-01-01

    Recent studies have shown that articulatory gestures are systematically associated with specific manual grip actions. Here we show that executing such actions can influence performance on a speech-categorization task. Participants watched and/or listened to speech stimuli while executing either a power or a precision grip. Grip performance influenced the syllable categorization by increasing the proportion of responses of the syllable congruent with the executed grip (power grip—[ke] and precision grip—[te]). Two follow-up experiments indicated that the effect was based on action-induced bias in selecting the syllable. PMID:26978074

  17. Anticipatory Vibrotactile Cueing Facilitates Grip Force Adjustment during Perturbative Loading.

    PubMed

    Okamoto, Shogo; Wiertlewski, Michael; Hayward, Vincent

    2016-01-01

    Grip force applied to an object held between the thumb and index finger is automatically and unconsciously adjusted upon perception of an external disturbance to the object. Typically, this adjustment occurs within approximately 100 ms. Here, we investigated the effect of anticipatory vibrotactile cues prior to a perturbative force, which the central nervous system may use for rapid grip re-stabilization. We asked participants to grip and hold an instrumented, actuated handle between the thumb and index finger. Under computer control, the handle could suddenly be pulled away from a static grip and could independently provide vibration to the gripping fingers. The mean latency of corrective motor action was 139 ms. When vibrotactile stimulation was applied 50 ms before application of tractive force, the latency was reduced to 117 ms, whereas the mean latency of the conscious response to vibrotactile stimuli alone was 229 ms. This suggests that vibrotactile stimulation can influence reflex-like actions. We also examined the effects of anticipatory cues using a set of perturbative loads with different rising rates. As expected, facilitation of grip force adjustment was observed for moderate loads. In contrast, anticipatory cues had an insignificant effect on rapid loads that evoked an adjustment within 60-80 ms, which approaches the minimum latency of human grip adjustment. Understanding the facilitative effects of anticipatory cues on human reactive grip can aid the development of human-machine interfaces to enhance human behavior. PMID:26887013

  18. 21. UNDERSIDE OF EPPELSHEIMER BOTTOM GRIP: Photocopy of 1905 photograph ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. UNDERSIDE OF EPPELSHEIMER BOTTOM GRIP: Photocopy of 1905 photograph showing the underside of an Eppelsheimer bottom grip. The position of the cable between the jaws is clearly evident. Photograph taken at the Washington and Mason Street powerhouse. - San Francisco Cable Railway, Washington & Mason Streets, San Francisco, San Francisco County, CA

  19. Tensile testing grips are easily assembled under liquid nitrogen

    NASA Technical Reports Server (NTRS)

    Skalka, R. J.; Vandergrift, E. F.

    1967-01-01

    Split-screw grips for tensile testing provide uniform loading on the specimen shoulders. Holes in the heads enable the screws and specimen to be threaded as an assembly into a grip body, closely controlled guides and seats afford positive seating, and precision machining of mating surfaces minimizes misalignment effects.

  20. Personality and Grip Strength Relationships Between Monozygous and Dizygous Twins.

    ERIC Educational Resources Information Center

    Fisher, A. Craig; And Others

    The purposes of this study were a) to investigate the relationship between grip strength and the measures of age, height, weight, and the personality traits revealed by the Comrey Personality and Attitude Factor Scales and b) to assess the influence of heredity on height, weight, and grip strength. Fifty-eight pairs of twins (MZ, 30 and DZ, 28)…

  1. 30 CFR 18.40 - Cable clamps and grips.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Requirements § 18.40 Cable clamps and grips. Insulated clamps shall be provided for all portable (trailing) cables to prevent strain on the cable terminals of a machine. Also insulated clamps shall be provided to... mounted component. Cable grips anchored to the cable may be used in lieu of insulated strain...

  2. 30 CFR 18.40 - Cable clamps and grips.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Requirements § 18.40 Cable clamps and grips. Insulated clamps shall be provided for all portable (trailing) cables to prevent strain on the cable terminals of a machine. Also insulated clamps shall be provided to... mounted component. Cable grips anchored to the cable may be used in lieu of insulated strain...

  3. 30 CFR 18.40 - Cable clamps and grips.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Requirements § 18.40 Cable clamps and grips. Insulated clamps shall be provided for all portable (trailing) cables to prevent strain on the cable terminals of a machine. Also insulated clamps shall be provided to... mounted component. Cable grips anchored to the cable may be used in lieu of insulated strain...

  4. 30 CFR 18.40 - Cable clamps and grips.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Requirements § 18.40 Cable clamps and grips. Insulated clamps shall be provided for all portable (trailing) cables to prevent strain on the cable terminals of a machine. Also insulated clamps shall be provided to... mounted component. Cable grips anchored to the cable may be used in lieu of insulated strain...

  5. Alterations in grip strength during male sexual arousal.

    PubMed

    Jiao, C; Turman, B; Weerakoon, P; Knight, P

    2006-01-01

    Although it is known that alterations in grip strength occur under a number of conditions, little is known about relationships between grip strength and sexual arousal. This relationship was investigated in 30 healthy heterosexual males, who viewed both erotic and nonerotic videos. A questionnaire was used to assess the extent of sexual arousal. The grip strengths of both hands were measured with a five-position (P1-P5) dynamometer, before and after watching the videos. After watching the erotic video, there was a statistically significant reduction in grip strength for the P2 position, with nonsignificant overall reductions in grip strength for all other positions tested. No such effect was observed in control tests. The results indicate that during sexual arousal, the neural system is likely to reduce the output to muscles not directly related to sexual function, presumably to enhance the physiological responses of sexual arousal. PMID:16254571

  6. Pistol grip power tool handle and trigger size effects on grip exertions and operator preference.

    PubMed

    Oh, S; Radwin, R G

    1993-09-01

    Finger and palmar forces were measured during actual pneumatic nutrunner operation using a strain gauge dynamometer. Eighteen student subjects were assigned to one of three categories based on hand length. Two triggers and four handle spans were presented randomly. Handle span affected maximal and submaximal grip force. As span increased from 4 cm to 7 cm, average peak finger force increased 24%, peak palmar force increased 22%, and average finger and palmar tool-holding forces increased 20%. When an extended trigger was used, average peak finger force decreased 9%, peak palmar force decreased 8%, finger tool-holding force decreased 65%, and palmar tool-holding force decreased 48%. Hand size affected grip strength (MVC), grip force, and exertion level (force/MVC). Holding exertion level was maximum for large-handed subjects using a 4-cm handle and for small-handed subjects using a 7-cm handle. Subjective handle span preference increased as hand size increased. A similar experiment was performed using 11 factory workers. PMID:8244414

  7. Effects of bat grip on baseball hitting kinematics.

    PubMed

    Escamilla, Rafael F; Fleisig, Glenn S; DeRenne, Coop; Taylor, Marcus K; Moorman, Claude T; Imamura, Rodney; Barakatt, Edward; Andrews, James R

    2009-08-01

    A motion system collected 120-Hz data from 14 baseball adult hitters using normal and choke-up bat grips. Six swings were digitized for each hitter, and temporal and kinematic parameters were calculated. Compared with a normal grip, the choke-up grip resulted in 1) less time during stride phase and swing; 2) the upper torso more opened at lead foot contact; 3) the pelvis more closed and less bat linear velocity at bat-ball contact; 4) less range of motion of the upper torso and pelvis during swing; 5) greater elbow flexion at lead foot contact; and 6) greater peak right elbow extension angular velocity. The decreased time during the stride phase when using a choke-up grip implies that hitters quicken their stride when they choke up. Less swing time duration and less upper torso and pelvis rotation range of motion using the choke-up grip supports the belief of many coaches and players that using a choke-up grip results in a "quicker" swing. However, the belief that using a choke-up grip leads to a faster moving bat was not supported by the results of this study. PMID:19827469

  8. Gripped by Gout: Avoiding the Ache and Agony

    MedlinePlus

    ... please review our exit disclaimer . Subscribe Gripped by Gout Avoiding the Ache and Agony Sudden, painful swelling ... toe is often the first warning sign of gout. It can affect other joints as well. Without ...

  9. Effects of pretest stimulative and sedative music on grip strength.

    PubMed

    Karageorghis, C I; Drew, K M; Terry, P C

    1996-12-01

    The purpose of the present study was to investigate the effects of stimulative (energizing) and sedative (relaxing) music on grip strength. A 2 x 3 (gender x condition) repeated-measures analysis of variance and post hoc tests showed that participants (N = 50) evidenced higher grip strength after listening to stimulative music (M = 43.94 kg.force) than after sedative music or a white noise control condition. Sedative music yielded lower scores than white noise. Men evidenced higher grip strength than women, but there was no interaction between gender and music condition. It was concluded that a simple motoric task such as grip strength provides a sensitive measure of psychophysical responses to music. PMID:9017751

  10. Long term consistency of handwriting grip kinetics in adults.

    PubMed

    Ghali, Bassma; Mamun, Khondaker A; Chau, Tom

    2014-04-01

    While there is growing interest in clinical applications of handwriting grip kinetics, the consistency of these forces over time is not well-understood at present. In this study, we investigated the short- and long-term intra-participant consistency and inter-participant differences in grip kinetics associated with adult signature writing. Grip data were collected from 20 adult participants using a digitizing tablet and an instrumented pen. The first phase of data collection occurred over 10 separate days within a three week period. To ascertain long-term consistency, a second phase of data collection followed, one day per month over several months. In both phases, data were collected three times a day. After pre-processing and feature extraction, nonparametric statistical tests were used to compare the within-participant grip force variation between the two phases. Participant classification based on grip force features was used to determine the relative magnitude of inter-participant versus intra-participant differences. The misclassification rate for the longitudinal data were used as an indication of long term kinetic consistency. Intra-participant analysis revealed significant changes in grip kinetic features between the two phases for many participants. However, the misclassification rate, on average, remained stable, despite different demarcations of training, and testing data. This finding suggests that while signature writing grip forces may evolve over time, inter-participant kinetic differences consistently exceeds within-participant force changes in the long-term. These results bear implications on the collection, modeling and interpretation of grip kinetics in clinical applications. PMID:24510237

  11. Effect of Syllable Articulation on Precision and Power Grip Performance

    PubMed Central

    Vainio, Lari; Schulman, Mirjam; Tiippana, Kaisa; Vainio, Martti

    2013-01-01

    The present study was motivated by a theory, which proposes that speech includes articulatory gestures that are connected to particular hand actions. We hypothesized that certain articulatory gestures would be more associated with the precision grip than with the power grip, and vice versa. In the study, the participants pronounced a syllable and performed simultaneously a precision or power grip that was theorized to be either congruent or incongruent with the syllable. Relatively fast precision grip responses were associated with articulatory gestures in which the tip of the tongue contacted the alveolar ridge ([te]) or the aperture of the vocal tract remained small ([hi]), as well as gestures that required lip protrusion ([pu]). In contrast, relatively fast power grip responses were associated with gestures that were produced by moving the back of the tongue against the velum ([ke]) or in which the aperture of the vocal tract remained large ([hα]). In addition to demonstrating that certain articulatory gestures are systematically connected to different grip types, the study may shed some light on discussion concerning sound symbolism and evolution of speech. PMID:23326381

  12. GRIP Collaboration Portal: Information Management for a Hurricane Field Campaign

    NASA Astrophysics Data System (ADS)

    Conover, H.; Kulkarni, A.; Garrett, M.; Smith, T.; Goodman, H. M.

    2010-12-01

    NASA’s Genesis and Rapid Intensification Processes (GRIP) experiment, carried out in August and September of 2010, was a complex operation, involving three aircraft and their crews based at different airports, a dozen instrument teams, mission scientists, weather forecasters, project coordinators and a variety of other participants. In addition, GRIP was coordinated with concurrent airborne missions: NOAA’s IFEX and then NSF-funded PREDICT. The GRIP Collaboration Portal was developed to facilitate communication within and between the different teams and serve as an information repository for the field campaign, providing a single access point for project documents, plans, weather forecasts, flight reports and quicklook data. The portal was developed using the Drupal open source content management framework. This presentation will cover both technology and participation issues. Specific examples include: Drupal’s large and diverse open source developer community is an advantage in that we were able to reuse many modules rather than develop capabilities from scratch, but integrating multiple modules developed by many people adds to the overall complexity of the site. Many of the communication capabilities provided by the site, such as discussion forums and blogs, were not used. Participants were diligent about posting necessary documents, but the favored communication method remained email. Drupal's developer-friendly nature allowed for quick development of the customized functionality needed to accommodate the rapidly changing requirements of GRIP experiment. DC-8 Overflight of Hurricane Earl during GRIP Mission

  13. Grip-load force coordination in cerebellar patients.

    PubMed

    Serrien, D J; Wiesendanger, M

    1999-09-01

    The study examined the anticipatory grip force modulations to load force changes during a drawer-opening task. An impact force was induced by a mechanical stop which abruptly arrested movement of the pulling hand. In performing this task, normal subjects generated a typical grip force profile characterized by an initial force impulse related to drawer movement onset, followed by a ramp-like grip force increase prior to the impending load perturbation. Finally, a reactive response was triggered by the impact. In patients with bilateral cerebellar dysfunction, the drawer-opening task was performed with an alternative control strategy. During pulling, grip force was increased to a high (overestimated) default level. The latter suggests that cerebellar patients were unable to adjust and to scale precisely the grip force according to the load force. In addition, the latency between impact and reactive activity was prolonged in the patients, suggesting an impaired cerebellar transmission of the long-latency responses. In conclusion, these data demonstrate the involvement of cerebellar circuits in both proactive and reactive mechanisms in view of predictable load perturbations during manipulative behavior. PMID:10473743

  14. Comparison of Rolyan and Jamar dynamometers for measuring grip strength.

    PubMed

    Mathiowetz, Virgil

    2002-01-01

    This study compared the Jamar and Rolyan hydraulic dynamometers to determine their concurrent validity with known weights as well as their inter-instrument reliability and concurrent validity for measuring grip strength in a clinical setting. Thirty females and 30 males were tested on these two grip strength measurement devices using a repeated measure design. Results showed that the Jamar and Rolyan dynamometers have acceptable concurrent validity with known weights (that is, correlation coefficients were r > or = 0.9994), excellent inter-instrument reliability (that is, intraclass correlation coefficients ranged from 0.90 to 0.97) and strong concurrent validity (that is, no significant differences between dynamometers' scores). Data indicate that Jamar and Rolyan dynamometers measure grip strength equivalently and can be used interchangeably. Thus, therapists using the Rolyan dynamometer are justified in using published normative data, which were collected with the Jamar dynamometer. PMID:12374997

  15. Two-handed grip on a mobile phone affords greater thumb motor performance, decreased variability, and a more extended thumb posture than a one-handed grip.

    PubMed

    Trudeau, Matthieu B; Asakawa, Deanna S; Jindrich, Devin L; Dennerlein, Jack T

    2016-01-01

    Holding a mobile computing device with two hands may affect thumb motor performance, joint postures, and device stability compared to holding the device and tapping the touchscreen with the thumb of the holding hand. We tested the hypotheses that holding a touchscreen mobile phone with two hands lead to increased thumb motor performance, different thumb postures, and decreased device movement relative to using one hand. Ten right-handed participants completed reciprocal thumb tapping tasks between emulated keys on a smartphone in either a one- (portrait) or two-handed (landscape) grip configuration. Effective index of performance measured from Fitts' Law was 9% greater (p < 0.001), movement time 7% faster (p < 0.001), and taps were 4% more precise (p < 0.016) for the two-handed grip. Tapping with a two-handed grip involved significantly different wrist and thumb postures than a one-handed grip. Variability of the computing device's movement was 36-63% lower for the two-handed grip compared to the one-handed grip condition (p < 0.001). The support for our hypotheses suggests that a two-handed grip results in increased performance and more extended wrist and thumb postures than a single-handed grip. Device designs that allow two-handed grips may afford increased performance relative to a one-handed grip. PMID:26360191

  16. Hand Grip Strength Vs. Sprint Effectiveness in Amputee Soccer Players

    PubMed Central

    Wieczorek, Marta; Wiliński, Wojciech; Struzik, Artur; Rokita, Andrzej

    2015-01-01

    Amputee soccer is one of the types of soccer designed for the disabled, especially those who have undergone amputations, as well as those with extremity dysfunction. The objective of the study was to find the relationship between hand grip strength and sprint time in amputee soccer players. Thirteen field amputee soccer players participated in the study. A SAEHAN hydraulic hand dynamometer manufactured by Jamar was used for hand grip strength measurements. The sprint running test was conducted over a distance of 30 m. The Fusion Smart Speed System was employed for running time measurements. No statistically significant relationships were found between hand grip strength of the left or right hand, and sprint times over 1, 5, 10, 15, 20, 25 and 30 m. Analysis of the running velocity curve of the subjects showed an interesting profile characterized by a 15 meter-long acceleration phase and a significant velocity increase over a distance of 20 – 25 m. The study suggests that there is no relationship between hand grip strength and sprint effectiveness in amputee soccer players. The specificity of locomotion with the use of elbow crutches among elite Polish amputee soccer players probably accounts for the profile of the sprint velocity curve. Extension of the acceleration phase in the sprint run and a velocity increase in the subsequent part of the run were observed. PMID:26834881

  17. Grip strength at four years in relation to birth weight

    PubMed Central

    Dodds, R.; Macdonald-Wallis, C.; Kapasi, T.; Sayer, A. A.; Robinson, S.; Godfrey, K.; Cooper, C.; Harvey, N.; Inskip, H.

    2013-01-01

    Consistent positive relationships have been found between birth weight and grip strength in adults but evidence in children is limited. In a prospective general population birth cohort (Southampton Women’s Survey) grip strength and anthropometry (height and weight) were measured in 968 children at age 4 years. Mean (standard deviation (S.D.)) birth weight was 3.48 (0.52) kg. Birth weight, adjusted for sex and gestational age, was positively associated with grip strength (β = 0.22 kg/S.D. increase in adjusted birth weight; 95% CI 0.11, 0.34). The relationship was attenuated after adjustment for current height and weight such that it became non-significant (β = 0.03 kg/S.D. increase in adjusted birth weight; 95% CI −0.08, 0.14), suggesting that body size may be on the causal pathway. Early influences on muscle development appear to impact on grip strength in children as well as adults. PMID:24294479

  18. Get a Grip! A Middle School Engineering Challenge

    ERIC Educational Resources Information Center

    Olds, Suzanne A.; Harrell, Deborah A.; Valente, Michael E.

    2006-01-01

    Investigating the field of engineering offers the opportunity for interdisciplinary, hands-on, inquiry-based units that integrate real-world applications. However, many K-12 students are not exposed to engineering until they enter college. Get a Grip! is a problem-based unit that places middle school students in the role of engineers who are…

  19. Hand Grip Strength Vs. Sprint Effectiveness in Amputee Soccer Players.

    PubMed

    Wieczorek, Marta; Wiliński, Wojciech; Struzik, Artur; Rokita, Andrzej

    2015-11-22

    Amputee soccer is one of the types of soccer designed for the disabled, especially those who have undergone amputations, as well as those with extremity dysfunction. The objective of the study was to find the relationship between hand grip strength and sprint time in amputee soccer players. Thirteen field amputee soccer players participated in the study. A SAEHAN hydraulic hand dynamometer manufactured by Jamar was used for hand grip strength measurements. The sprint running test was conducted over a distance of 30 m. The Fusion Smart Speed System was employed for running time measurements. No statistically significant relationships were found between hand grip strength of the left or right hand, and sprint times over 1, 5, 10, 15, 20, 25 and 30 m. Analysis of the running velocity curve of the subjects showed an interesting profile characterized by a 15 meter-long acceleration phase and a significant velocity increase over a distance of 20 - 25 m. The study suggests that there is no relationship between hand grip strength and sprint effectiveness in amputee soccer players. The specificity of locomotion with the use of elbow crutches among elite Polish amputee soccer players probably accounts for the profile of the sprint velocity curve. Extension of the acceleration phase in the sprint run and a velocity increase in the subsequent part of the run were observed. PMID:26834881

  20. Coordination of Fingertip Forces During Precision Grip in Premanifest Huntington’s Disease

    PubMed Central

    Rao, Ashwini K.; Gordon, Andrew M.; Marder, Karen S.

    2011-01-01

    Precision grip control is important for accurate object manipulation and requires coordination between horizontal (grip) and vertical (load) fingertip forces. Manifest Huntington’s disease (HD) subjects demonstrate excessive and highly variable grip force and delayed coordination between grip and load forces. Because the onset of these impairments is unknown, we examined precision grip control in premanifest HD (pre-HD) subjects. Fifteen pre-HD and 15 age- and sex-matched controls performed the precision grip task in a seated position. Subjects grasped and lifted an object instrumented with a force transducer that measured horizontal grip and vertical load forces. Outcomes were preload time, loading time, maximum grip force, mean static grip force, and variability for all measures. We compared outcomes across groups and correlated grip measures with the Unified Huntington’s Disease Rating Scale and predicted age of onset. Variability of maximum grip force (P < .0001) and variability of static grip force (P < .00001) were higher for pre-HD subjects. Preload time (P < .007) and variability of preload time (P < .006) were higher in pre-HD subjects. No differences were seen in loading time across groups. Variability of static grip force (r2 = 0.23) and variability of preload time (r2 = 0.59) increased with predicted onset and were correlated with tests of cognitive function. Our results indicate that pre-HD patients have poor regulation of the transition between reach and grasp and higher variability in force application and temporal coordination during the precision grip task. Force and temporal variability may be good markers of disease severity because they were correlated with predicted onset of disease. PMID:21394785

  1. Evolution of the power ("squeeze") grip and its morphological correlates in hominids.

    PubMed

    Marzke, M W; Wullstein, K L; Viegas, S F

    1992-11-01

    The "squeeze" form of power grip is investigated for the purposes of clarifying the hand posture and activities associated with the grip, assessing the potential in chimpanzees for using the grip, and identifying morphological correlates of an effective power grip that may be recognized in fossil hominid species. Our approaches include: (1) the analysis of the human grip, focusing on both the hand posture involved and hand movements associated with use of the grip in hammering; (2) the analysis of similar chimpanzee grips and associated movements; (3) comparative functional analysis of regions in the hand exploited and stressed by the grip and its associated movements in humans; and (4) a review of the literature on the power grip and its morphological correlates. Results of the study indicate that humans use a squeeze form of power grip effectively to wield cylindrical tools forcefully as extensions of the forearm. Several morphological features occur in high frequency among humans which facilitate the grip and are consistent with the large internal and external forces associated with it in hammering and in other tool-using activities. Chimpanzee hand postures resembling this form of human power grip are not fully comparable and lack some of these morphological correlates that facilitate its use. The hand of Australopithecus afarensis does not appear to have been stressed by use of the grip, but there is some evidence for this type of stress in the metacarpals from Sterkfontein Member 4. Hands from Olduvai and Swartkrans do not provide sufficient evidence for assessment of power grip capabilities. PMID:1485637

  2. Effects of hyperthyroidism on hand grip strength and function.

    PubMed

    Erkol İnal, Esra; Çarlı, Alparslan Bayram; Çanak, Sultan; Aksu, Oğuzhan; Köroğlu, Banu Kale; Savaş, Serpil

    2015-01-01

    Hyperthyroidism is a pathologic condition in which the body is exposed to excessive amounts of circulating thyroid hormones. Skeletal muscle is one of the major target organs of thyroid hormones. We evaluated hand grip strength and function in patients with overt hyperthyroidism. Fifty-one patients newly diagnosed with hyperthyroidism and 44 healthy controls participated in this study. Age, height, weight, and dominant hand of all participants were recorded. The diagnosis of hyperthyroidism was confirmed by clinical examination and laboratory tests. Hand grip strength was tested at the dominant hand with a Jamar hand dynamometer. The grooved pegboard test (PGT) was used to evaluate hand dexterity. The Duruöz Hand Index (DHI) was used to assess hand function. No significant differences were found in terms of clinical and demographic findings between the patients with hyperthyroidism and healthy controls (p > 0.05). Significant differences were found between the patients with hyperthyroidism and healthy controls regarding PGT and DHI scores (p < 0.05). Hyperthyroidism seemed to affect hand dexterity and function more than hand grip strength and seemed to be associated with reduced physical function more than muscle strength. This may also indicate that patients with hyperthyroidism should be evaluated by multidisplinary modalities. PMID:26562373

  3. Delayed grip relaxation and altered modulation of intracortical inhibition with aging.

    PubMed

    Motawar, Binal; Stinear, James W; Lauer, Abigail W; Ramakrishnan, Viswanathan; Seo, Na Jin

    2016-04-01

    Grip relaxation is a voluntary action that requires an increase in short-interval intracortical inhibition (SICI) in healthy young adults, rather than a simple termination of excitatory drive. The way aging affects this voluntary inhibitory action and timing of grip relaxation is currently unknown. The objective of this study was to examine aging-related delays in grip relaxation and SICI modulation for the flexor digitorum superficialis muscle during grip relaxation. The main finding was that young adults increased SICI to relax their grips, whereas older adults did not increase SICI with a prolonged grip relaxation time (p < 0.05 for both SICI modulation and grip relaxation time). A secondary experiment showed that both young and older adults did not change H reflex excitability during grip relaxation. Our data suggest that grip relaxation is mediated by increased cortical inhibitory output in young adults, and aging-related impairment in increasing cortical inhibitory output may hamper timely cessation of muscle activity. Our data also suggest a lesser role of the spinal circuits in grip muscle relaxation. This knowledge may contribute to understanding of aging-related movement deterioration and development of interventions for improving modulation of SICI to improve muscle relaxation and movement coordination. PMID:26686531

  4. Control of Precision Grip Force in Lifting and Holding of Low-Mass Objects.

    PubMed

    Hiramatsu, Yuichi; Kimura, Daisuke; Kadota, Koji; Ito, Taro; Kinoshita, Hiroshi

    2015-01-01

    Few studies have investigated the control of grip force when manipulating an object with an extremely small mass using a precision grip, although some related information has been provided by studies conducted in an unusual microgravity environment. Grip-load force coordination was examined while healthy adults (N = 17) held a moveable instrumented apparatus with its mass changed between 6 g and 200 g in 14 steps, with its grip surface set as either sandpaper or rayon. Additional measurements of grip-force-dependent finger-surface contact area and finger skin indentation, as well as a test of weight discrimination, were also performed. For each surface condition, the static grip force was modulated in parallel with load force while holding the object of a mass above 30 g. For objects with mass smaller than 30 g, on the other hand, the parallel relationship was changed, resulting in a progressive increase in grip-to-load force (GF/LF) ratio. The rayon had a higher GF/LF force ratio across all mass levels. The proportion of safety margin in the static grip force and normalized moment-to-moment variability of the static grip force were also elevated towards the lower end of the object mass for both surfaces. These findings indicate that the strategy of grip force control for holding objects with an extremely small mass differs from that with a mass above 30 g. The data for the contact area, skin indentation, and weight discrimination suggest that a decreased level of cutaneous feedback signals from the finger pads could have played some role in a cost function in efficient grip force control with low-mass objects. The elevated grip force variability associated with signal-dependent and internal noises, and anticipated inertial force on the held object due to acceleration of the arm and hand, could also have contributed to the cost function. PMID:26376484

  5. Control of Precision Grip Force in Lifting and Holding of Low-Mass Objects

    PubMed Central

    Kimura, Daisuke; Kadota, Koji; Ito, Taro

    2015-01-01

    Few studies have investigated the control of grip force when manipulating an object with an extremely small mass using a precision grip, although some related information has been provided by studies conducted in an unusual microgravity environment. Grip-load force coordination was examined while healthy adults (N = 17) held a moveable instrumented apparatus with its mass changed between 6 g and 200 g in 14 steps, with its grip surface set as either sandpaper or rayon. Additional measurements of grip-force-dependent finger-surface contact area and finger skin indentation, as well as a test of weight discrimination, were also performed. For each surface condition, the static grip force was modulated in parallel with load force while holding the object of a mass above 30 g. For objects with mass smaller than 30 g, on the other hand, the parallel relationship was changed, resulting in a progressive increase in grip-to-load force (GF/LF) ratio. The rayon had a higher GF/LF force ratio across all mass levels. The proportion of safety margin in the static grip force and normalized moment-to-moment variability of the static grip force were also elevated towards the lower end of the object mass for both surfaces. These findings indicate that the strategy of grip force control for holding objects with an extremely small mass differs from that with a mass above 30 g. The data for the contact area, skin indentation, and weight discrimination suggest that a decreased level of cutaneous feedback signals from the finger pads could have played some role in a cost function in efficient grip force control with low-mass objects. The elevated grip force variability associated with signal-dependent and internal noises, and anticipated inertial force on the held object due to acceleration of the arm and hand, could also have contributed to the cost function. PMID:26376484

  6. Grip force adjustments induced by predictable load perturbations during a manipulative task.

    PubMed

    Serrien, D J; Kaluzny, P; Wicki, U; Wiesendanger, M

    1999-01-01

    The experiment examined the anticipatory modulation of grip force with respect to load force during a drawer opening task. An impact force was introduced by a mechanical stop that arrested movement of the pulling hand. The results showed a typical grip force profile which consisted of two evolving phases, one to control drawer movement onset, and the other to secure grip force at the expected impact. Initially, grip force increased with the load force that was developed to overcome the inertia of the drawer. After the first peak, a small decline was observed, followed by a proactive grip force increase prior to the time of impact. During this ramp-like increase of grip force, load force remained unchanged. In addition, a reactive response was triggered by the impact. That anticipatory control with respect to an impact force is not innate but, rather, is learned by experience was evidenced by a comparison of adults and children. Whereas adults made the characteristic grip force adjustments to anticipate the impact, children used a probing strategy with irregular build-up of force until impact. Furthermore, adults calibrated the second phase of the grip force profile in the initial trials of the task, indicating that grip force was rapidly updated with information related to the impact force. The present results demonstrate that grip-load force coordination during manipulation is a necessity for dealing with destabilizing load perturbations produced by self-induced movement and impact forces. It is concluded that grip force is adjusted automatically, but in a flexible manner, to secure grip in accordance with the characteristics of the pulling synergy. PMID:9928794

  7. Finger pad friction and its role in grip and touch

    PubMed Central

    Adams, Michael J.; Johnson, Simon A.; Lefèvre, Philippe; Lévesque, Vincent; Hayward, Vincent; André, Thibaut; Thonnard, Jean-Louis

    2013-01-01

    Many aspects of both grip function and tactile perception depend on complex frictional interactions occurring in the contact zone of the finger pad, which is the subject of the current review. While it is well established that friction plays a crucial role in grip function, its exact contribution for discriminatory touch involving the sliding of a finger pad is more elusive. For texture discrimination, it is clear that vibrotaction plays an important role in the discriminatory mechanisms. Among other factors, friction impacts the nature of the vibrations generated by the relative movement of the fingertip skin against a probed object. Friction also has a major influence on the perceived tactile pleasantness of a surface. The contact mechanics of a finger pad is governed by the fingerprint ridges and the sweat that is exuded from pores located on these ridges. Counterintuitively, the coefficient of friction can increase by an order of magnitude in a period of tens of seconds when in contact with an impermeably smooth surface, such as glass. In contrast, the value will decrease for a porous surface, such as paper. The increase in friction is attributed to an occlusion mechanism and can be described by first-order kinetics. Surprisingly, the sensitivity of the coefficient of friction to the normal load and sliding velocity is comparatively of second order, yet these dependencies provide the main basis of theoretical models which, to-date, largely ignore the time evolution of the frictional dynamics. One well-known effect on taction is the possibility of inducing stick–slip if the friction decreases with increasing sliding velocity. Moreover, the initial slip of a finger pad occurs by the propagation of an annulus of failure from the perimeter of the contact zone and this phenomenon could be important in tactile perception and grip function. PMID:23256185

  8. Age and Grip Strength Predict Hand Dexterity in Adults

    PubMed Central

    Martin, Jason A.; Ramsay, Jill; Hughes, Christopher; Peters, Derek M.; Edwards, Martin G.

    2015-01-01

    In the scientific literature, there is much evidence of a relationship between age and dexterity, where increased age is related to slower, less nimble and less smooth, less coordinated and less controlled performances. While some suggest that the relationship is a direct consequence of reduced muscle strength associated to increased age, there is a lack of research that has systematically investigated the relationships between age, strength and hand dexterity. Therefore, the aim of this study was to examine the associations between age, grip strength and dexterity. 107 adults (range 18-93 years) completed a series of hand dexterity tasks (i.e. steadiness, line tracking, aiming, and tapping) and a test of maximal grip strength. We performed three phases of analyses. Firstly, we evaluated the simple relationships between pairs of variables; replicating the existing literature; and found significant relationships of increased age and reduced strength; increased age and reduced dexterity, and; reduced strength and reduced dexterity. Secondly, we used standard Multiple Regression (MR) models to determine which of the age and strength factors accounted for the greater variance in dexterity. The results showed that both age and strength made significant contributions to the data variance, but that age explained more of the variance in steadiness and line tracking dexterity, whereas strength explained more of the variance in aiming and tapping dexterity. In a third phase of analysis, we used MR analyses to show an interaction between age and strength on steadiness hand dexterity. Simple Slopes post-hoc analyses showed that the interaction was explained by the middle to older aged adults showing a relationship between reduced strength and reduced hand steadiness, whereas younger aged adults showed no relationship between strength and steadiness hand dexterity. The results are discussed in terms of how age and grip strength predict different types of hand dexterity in

  9. Method and apparatus for gripping uniaxial fibrous composite materials

    NASA Technical Reports Server (NTRS)

    Whittenberger, J. D.; Hurwitz, F. I. (Inventor)

    1984-01-01

    A strip specimen is cut from a unidirectional strong, brittle fiber composite material, and the surfaces of both ends of the specimen are grit blasted. The specimen is then placed between metal load transfer members having grit blasted surfaces. Sufficient compressive stress is applied to the load transfer members to prevent slippage during testing at both elevated temperatures and room temperatures. The need for adhesives, load pads, and other secondary composite processing is eliminated. This gripping system was successful in tensile testing, creep rupture testing, and fatigue testing uniaxial composite materials at 316 C.

  10. Contribution of the Cerebellum in Cue-Dependent Force Changes During an Isometric Precision Grip Task.

    PubMed

    Kutz, Dieter F; Schmid, Barbara C; Meindl, Tobias; Timmann, Dagmar; Kolb, Florian P

    2016-08-01

    The "raspberry task" represents a precision grip task that requires continuous adjustment of grip forces and pull forces. During this task, subjects use a specialised grip rod and have to increase the pull force linearly while the rod is locked. The positions of the fingers are unrestrained and freely selectable. From the finger positions and the geometry of the grip rod, a physical lever was derived which is a comprehensive measurement of the subject's grip behaviour. In this study, the involvement of the cerebellum in establishing cued force changes (CFC) was examined. The auditory stimulus was associated with a motor behaviour that has to be readjusted during an ongoing movement that already started. Moreover, cerebellar involvement on grip behaviour was examined. The results show that patients presenting with degenerating cerebellar disease (CBL) were able to elicit CFC and were additionally able to optimise grip behaviour by minimising the lever. Comparison of the results of CBL with a control group of healthy subjects showed, however, that the CFC incidence was significantly lower and the reduction of the lever was less in CBL. Hence, the cerebellum is involved not only in the classical conditioning of reflexes but also in the association of sensory stimuli with complex changes in motor behaviour. Furthermore, the cerebellum is involved in the optimisation of grip behaviour during ongoing movements. Recent studies lead to the assumption that the cerebello-reticulo-spinal pathway might be important for the reduced optimisation of grip behaviour in CBL. PMID:26208705

  11. Grip pressure measurements during activities of daily life

    NASA Astrophysics Data System (ADS)

    Sanford, Joe; Young, Carolyn; Popa, Dan; Bugnariu, Nicoleta; Patterson, Rita

    2014-06-01

    Research has expanded human-machine communication methods past direct programming and standard hand- held joystick control. Individual force sensors have been used as a simple means of providing environmental information to a robot and research has shown that more advanced sensitive skins can be viable input devices. These touch sensitive surfaces allow for additional modes of interaction between machines in open, undefined environments. These interactions include object detection for navigation and safety but can also be used for recognition of users command gestures by their machine partner. Key to successful implementation of these gestures is the understanding of varied strategies used for communication and interaction and the development of performance limits. Data of dominant hand grip forces was collected using a Tekscan Grip VersaTek Pressure Measurement System during opening of a door. Analysis of data from 10 male and female subjects is presented. The results of qualitative and quantitative analysis of these data show variability in hand configurations between users. Average data over the cohort is reported. These data will be used in future work to provide human metrology constraints and limits for use in simulation and design of new, physical human-robot interaction systems.

  12. Grip Forces During Object Manipulation: Experiment, Mathematical Model & Validation

    PubMed Central

    Slota, Gregory P.; Latash, Mark L.; Zatsiorsky, Vladimir M.

    2011-01-01

    When people transport handheld objects, they change the grip force with the object movement. Circular movement patterns were tested within three planes at two different rates (1.0, 1.5 Hz), and two diameters (20, 40 cm). Subjects performed the task reasonably well, matching frequencies and dynamic ranges of accelerations within expectations. A mathematical model was designed to predict the applied normal forces from kinematic data. The model is based on two hypotheses: (a) the grip force changes during movements along complex trajectories can be represented as the sum of effects of two basic commands associated with the parallel and orthogonal manipulation, respectively; (b) different central commands are sent to the thumb and virtual finger (Vf- four fingers combined). The model predicted the actual normal forces with a total variance accounted for of better than 98%. The effects of the two components of acceleration—along the normal axis and the resultant acceleration within the shear plane—on the digit normal forces are additive. PMID:21735245

  13. Influence of central set on anticipatory and triggered grip-force adjustments

    NASA Technical Reports Server (NTRS)

    Winstein, C. J.; Horak, F. B.; Fisher, B. E.; Peterson, B. W. (Principal Investigator)

    2000-01-01

    The effects of predictability of load magnitude on anticipatory and triggered grip-force adjustments were studied as nine normal subjects used a precision grip to lift, hold, and replace an instrumented test object. Experience with a predictable stimulus has been shown to enhance magnitude scaling of triggered postural responses to different amplitudes of perturbations. However, this phenomenon, known as a central-set effect, has not been tested systematically for grip-force responses in the hand. In our study, predictability was manipulated by applying load perturbations of different magnitudes to the test object under conditions in which the upcoming load magnitude was presented repeatedly or under conditions in which the load magnitudes were presented randomly, each with two different pre-load grip conditions (unconstrained and constrained). In constrained conditions, initial grip forces were maintained near the minimum level necessary to prevent pre-loaded object slippage, while in unconstrained conditions, no initial grip force restrictions were imposed. The effect of predictable (blocked) and unpredictable (random) load presentations on scaling of anticipatory and triggered grip responses was tested by comparing the slopes of linear regressions between the imposed load and grip response magnitude. Anticipatory and triggered grip force responses were scaled to load magnitude in all conditions. However, regardless of pre-load grip force constraint, the gains (slopes) of grip responses relative to load magnitudes were greater when the magnitude of the upcoming load was predictable than when the load increase was unpredictable. In addition, a central-set effect was evidenced by the fewer number of drop trials in the predictable relative to unpredictable load conditions. Pre-load grip forces showed the greatest set effects. However, grip responses showed larger set effects, based on prediction, when pre-load grip force was constrained to lower levels. These

  14. The Effect of Grip Size on the Hitting Force During a Soft Tennis Forehand Stroke

    PubMed Central

    Ohguni, Mika; Aoki, Mitsuhiro; Sato, Hiroki; Imada, Kohdai; Funane, Sota

    2009-01-01

    Background: Grip size of a tennis racquet has been reported to influence performance, but clear evidence of a correlation has yet to be established. Hypothesis: Hitting force during a soft tennis forehand stroke correlates with grip size. Study Design: Controlled clinical study. Methods: A total of 40 healthy volunteers (20 men and 20 women) with a mean age of 21.9 years were enrolled. Of the 40 participants, 20 were experienced soft tennis players (10 men and 10 women) and 20 were nonexperienced soft tennis players (10 men and 10 women). Based on racquets with 5 different grip sizes, the hitting force during a soft tennis forehand stroke was measured with a handheld dynamometer. Correlations between 4 factors (sex, experience, grip and pinch strengths, and middle finger length) and hitting force were evaluated with each grip size. Measurements for each factor were repeated, and a 2-way analysis of variance was performed on the obtained data. Results: The hitting force was greater for male players than for female players and greater for experienced players than for nonexperienced players (P < .01). Men with large grip and pinch strengths demonstrated an increased hitting force with an increase in grip size. Men who had a long middle finger also demonstrated increased hitting force when grip size increased (P < .05). Conclusion: The hypothesis proved accurate for experienced men who had a large grip strength, a large pinch strength, and a long middle finger. Clinical Relevance: Large-grip-sized racquets may result in better forehand stroke performance when used by experienced male soft tennis players with a large grip strength, a large pinch strength, and a long middle finger. PMID:23015889

  15. Development and Application of a Multi-Axis Dynamometer for Measuring Grip Force

    PubMed Central

    Irwin, C.B.; Towles, J.D; Radwin, R.G.

    2013-01-01

    Objective This article describes the development and application of a novel multi-axis hand dynamometer for quantifying two-dimensional grip force magnitude and direction in the flexion-extension plane of the fingers. Methods A three-beam reconfigurable form dynamometer, containing two active beams for measuring orthogonal forces and moments regardless of point of force application, was designed, fabricated and tested. Maximum grip exertions were evaluated for sixteen subjects gripping cylindrical handles varying in diameter. Results Mean grip force magnitudes were 231 N (SD=67.7 N), 236 N (72.9 N), 208 N (72.5 N), and 158 N (45.7 N) for 3.81 cm, 5.08 cm, 6.35 cm and 7.62 cm diameter handles, respectively. Grip force direction rotated clockwise and the centre of pressure moved upward along the handle as handle diameter increased. Conclusions Given that the multi-axis dynamometer simultaneously measures planar grip force magnitude and direction, and centre of pressure along the handle, this novel sensor design provides more grip force characteristics than current sensor designs that would improve evaluation of grip characteristics and model-driven calculations of musculoskeletal forces from dynamometer data. PMID:24134054

  16. 16 CFR Figure 5 to Part 1512 - Typical Handbrake Actuator Showing Grip Dimension

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Typical Handbrake Actuator Showing Grip Dimension 5 Figure 5 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS... Actuator Showing Grip Dimension EC03OC91.072...

  17. 16 CFR Figure 5 to Part 1512 - Typical Handbrake Actuator Showing Grip Dimension

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Typical Handbrake Actuator Showing Grip Dimension 5 Figure 5 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS... Actuator Showing Grip Dimension EC03OC91.072...

  18. Effect of Feedback during Virtual Training of Grip Force Control with a Myoelectric Prosthesis

    PubMed Central

    Bouwsema, Hanneke; van der Sluis, Corry K.; Bongers, Raoul M.

    2014-01-01

    The aim of this study was to determine whether virtual training improves grip force control in prosthesis use, and to examine which type of augmented feedback facilitates its learning most. Thirty-two able-bodied participants trained grip force with a virtual ball-throwing game for five sessions in a two-week period, using a myoelectric simulator. They received either feedback on movement outcome or on movement execution. Sixteen controls received training that did not focus on force control. Variability over learning was examined with the Tolerance-Noise-Covariation approach, and the transfer of grip force control was assessed in five test-tasks that assessed different aspects of force control in a pretest, a posttest and a retention test. During training performance increased while the variability in performance was decreased, mainly by reduction in noise. Grip force control only improved in the test-tasks that provided information on performance. Starting the training with a task that required low force production showed no transfer of the learned grip force. Feedback on movement execution was detrimental to grip force control, whereas feedback on movement outcome enhanced transfer of grip force control to tasks other than trained. Clinical implications of these results regarding virtual training of grip force control are discussed. PMID:24865570

  19. Grip force control during virtual object interaction: effect of force feedback,accuracy demands, and training.

    PubMed

    Gibo, Tricia L; Bastian, Amy J; Okamura, Allison M

    2014-03-01

    When grasping and manipulating objects, people are able to efficiently modulate their grip force according to the experienced load force. Effective grip force control involves providing enough grip force to prevent the object from slipping, while avoiding excessive force to avoid damage and fatigue. During indirect object manipulation via teleoperation systems or in virtual environments, users often receive limited somatosensory feedback about objects with which they interact. This study examines the effects of force feedback, accuracy demands, and training on grip force control during object interaction in a virtual environment. The task required subjects to grasp and move a virtual object while tracking a target. When force feedback was not provided, subjects failed to couple grip and load force, a capability fundamental to direct object interaction. Subjects also exerted larger grip force without force feedback and when accuracy demands of the tracking task were high. In addition, the presence or absence of force feedback during training affected subsequent performance, even when the feedback condition was switched. Subjects' grip force control remained reminiscent of their employed grip during the initial training. These results motivate the use of force feedback during telemanipulation and highlight the effect of force feedback during training. PMID:24845744

  20. Age-Related and Sex-Related Differences in Hand and Pinch Grip Strength in Adults

    ERIC Educational Resources Information Center

    Puh, Urska

    2010-01-01

    The purpose of the study was to quantify age-related changes in hand grip strength and three types of pinch grip strength (key pinch, tip pinch, and palmar pinch) among male and female participants. The study included 199 healthy participants (100 females, 99 males) aged 20-79 years, who were divided into four age groups. The Baseline Hydraulic…

  1. Grip strength is potentially an early indicator of age-related decline in mice.

    PubMed

    Ge, Xuan; Cho, Anthony; Ciol, Marcia A; Pettan-Brewer, Christina; Snyder, Jessica; Rabinovitch, Peter; Ladiges, Warren

    2016-01-01

    The hand grip test has been correlated with mobility and physical performance in older people and has been shown to be a long-term predictor of mortality. Implementation of new strategies for enhancing healthy aging and maintaining independent living are dependent on predictable preclinical studies. The mouse is used extensively as a model in these types of studies, and the paw grip strength test is similar to the hand grip test for people in that it assesses the ability to grip a device with the paw, is non-invasive and easy to perform, and provides reproducible information. However, little has been reported on how grip strength declines with increasing age in mice. This report shows that grip strength was decreased in C57BL/6 (B6) NIA and C57BL/6×BALB/c F1 (CB6F1) NIA male mice at 12 months of age compared to 8-month-old mice, and continued a robust decline to 20 months and then 28 months of age, when the study was terminated. The decline was not related to lean muscle mass, but extensive age-related carpal and digital exostosis could help explain the decreased grip strength times with increasing age. In conclusion, the grip strength test could be useful in mouse preclinical studies to help make translational predictions on treatment strategies to enhance healthy aging. PMID:27613499

  2. The Effect of Handedness on Grip Strength in Older Adults with Intellectual Disabilities

    ERIC Educational Resources Information Center

    Oppewal, Alyt; Hilgenkamp, Thessa I. M.; van Wijck, Ruud; Evenhuis, Heleen M.

    2013-01-01

    Grip strength is an important predictor of several health outcomes in the general older population. Grip strength assessment is feasible and reliable in older adults with intellectual disabilities (ID), which makes it a valuable measurement for application in this population. The purpose of this study was to investigate the effect of handedness on…

  3. Do changes in hand grip strength correlate with shoulder rotator cuff function?

    PubMed Central

    Herrington, Lee; Hoyle, Rebecca; Prescott, Evie; Bellamy, Nathan

    2016-01-01

    Background Shoulder pain as a result of rotator cuff pathology is one of the most common musculoskeletal complaints presenting within primary care. Assessment of hand grip strength has been proposed as an indicator of rotator cuff function. This experimental study assessed the relationship between grip strength and shoulder lateral rotator muscle strength in a number of different shoulder positions, aiming to investigate whether such a relationship existed and whether grip strength could be used as a functional assessment tool for the posterior cuff. Methods Twenty-seven healthy, physically active, volunteers (19 males, eight females) with no history of shoulder, upper limb or neck injury comprised the study group. The mean (SD) age was 19.8 (5.7) years (range 18 years to 23 years). Grip strength (measured with hand grip dynamometer) and lateral rotator strength (measured with a hand held dynamometer) was measured at neutral, 90° abduction, and 90° abduction with 90° external rotation. Results The correlation between grip strength and shoulder lateral rotation strength ranged between r = 0.91 (r2 = 0.84) and r = 0.72 (r2 = 0.52) across all positions. Conclusions A strong correlation between grip strength and lateral rotator strength was shown at all positions for both left and right hands, suggesting that assessment of grip strength could be used as a rotator cuff monitor of recruitment function. PMID:27583010

  4. I forgot when I lost my grip-strong associations between cognition and grip strength in level of performance and change across time in relation to impending death.

    PubMed

    Praetorius Björk, Marcus; Johansson, Boo; Hassing, Linda B

    2016-02-01

    An association between level of cognitive function and grip strength is well established, whereas evidence for longitudinal associations of change in the 2 functions is still unclear. We examined associations between cognition and grip strength in levels of performance and in longitudinal change in late life in a population-based sample, aged ≥80 years at baseline, followed until death. The sample consisted of 449 nondemented individuals drawn from the OCTO-Twin Study. A test battery assessing 6 cognitive domains and grip strength was administered at 5 occasions with measurements intervals of 2 years. We fitted time to death bivariate growth curve models, adjusted for age, education, and sex which resulted in associations between grip strength and cognition in both levels of performance (across all cognitive domains) and rates of change (in 4 of 6 domains). These results show that cognition and grip strength change conjointly in later life and that the association between cognition and grip strength is stronger before death than earlier in life. PMID:26827644

  5. The laboratory station for tyres grip testing on different surfaces

    NASA Astrophysics Data System (ADS)

    Kalinowski, K.; Grabowik, C.; Janik, W.; Ćwikła, G.; Skowera, M.

    2015-11-01

    The paper presents the conception of the device for tyre grip testing in the laboratory conditions. The main purpose is to provide a device working in confined spaces, which enables rapid changes of the tested samples of the road surfaces. Among the key assumptions the minimization of the device dimensions and the relative ease of transportation and mobility - the ability to quick assemble and disassemble were also assumed. The main components of the projected workstation includes: the replaceable platform for mounting samples of a road surface, the roller conveyor, the drive of the platform, the wheel mounting assembly and the axial force measuring system. At the design the station a morphological structure method has been used, particular elements have been optimized individually.

  6. NBL Pistol Grip Tool for Underwater Training of Astronauts

    NASA Technical Reports Server (NTRS)

    Liszka, Michael; Ashmore, Matthew; Behnke, Mark; Smith, Walter; Waterman, Tod

    2011-01-01

    A document discusses a lightweight, functional mockup of the Pistol Grip Tool for use during underwater astronaut training. Previous training tools have caused shoulder injuries. This new version is more than 50 percent lighter [in water, weight is 2.4 lb (=1.1 kg)], and can operate for a six-hour training session after 30 minutes of prep for submersion. Innovations in the design include the use of lightweight materials (aluminum and Delrin(Registered TradeMark)), creating a thinner housing, and the optimization of internal space with the removal of as much excess material as possible. This reduces tool weight and maximizes buoyancy. Another innovation for this tool is the application of a vacuum that seats the Orings in place and has shown to be reliable in allowing underwater usage for up to six hours.

  7. Utilizing cryogenic grips for dynamic tension testing of human placenta tissue.

    PubMed

    Manoogian, Sarah; McNally, Craig; Calloway, Britt; Duma, Stefan; Mertz, Heather

    2007-01-01

    Computational models are used to investigate placental abruption in motor vehicle crashes, which is the leading cause of traumatic fetal injury mortality in the United States. Material parameters for computational modeling of pregnant occupant kinematics come from early research on placenta tissue at quasi-static loading rates. The purpose of this research is to develop a methodology for using cryogenic grips to test placenta specimens in uniaxial tension at a rate normally seen in a motor vehicle crash. For dynamic testing of placental tissue, implementing and adapting a cryogenic grip mechanism provides the ability to grip the tissue throughout the thickness and eliminates potential slipping of the tissue in the grip during the dynamic test. The validation for using the cryogenic grips is presented with video images of a typical test event showing the tissue failing in the active area. Additionally, local and global strain measures are compared to confirm the tissue strain is similar throughout the specimen. The cryogenic grips provide a low-cost and effective method of gripping and pulling a thick soft tissue in uniaxial tension. As a result, these methods can be used to acquire the material properties of placenta tissue loaded at a dynamic rate to apply in a computational pregnant model. PMID:17487107

  8. Effects of kinesio tape compared with non-elastic tape on hand grip strength.

    PubMed

    Kim, Ji Young; Kim, Seong Yeol

    2016-05-01

    [Purpose] Many assumptions have been made about taping and several studies have considered tape application methods; however, the true effect of taping on muscle strength remains unclear. Most previous studies compared application techniques using Kinesio tape (KT), but studies that compared muscle strength using non-elastic tape (NT) are limited. Moreover, no studies have applied KT and NT in the same way to assess grip strength in normal subjects. The purpose of this study was to evaluate the immediate effect of application of two tapes with different elastic properties on maximal grip strength in healthy adults. [Subjects and Methods] Twenty healthy adults were divided into two groups (KT and NT). Maximal grip strength was measured with a dynamometer. Forearm extensor muscles of the dominant hand were then taped and subjects were immediately asked to perform hand grip movement with maximum strength in the same standardized manner. [Results] In the KT group, maximal grip strength was significantly increased compared to the initial value; however, in the NT group, there was no significant difference in maximal grip strength. [Conclusion] This study suggests that only Kinesio tape can increase maximal grip strength immediately after application on the extensor region of the forearm. PMID:27313372

  9. Using Hand Grip Force as a Correlate of Longitudinal Acceleration Comfort for Rapid Transit Trains

    PubMed Central

    Guo, Beiyuan; Gan, Weide; Fang, Weining

    2015-01-01

    Longitudinal acceleration comfort is one of the essential metrics used to evaluate the ride comfort of train. The aim of this study was to investigate the effectiveness of using hand grip force as a correlate of longitudinal acceleration comfort of rapid transit trains. In the paper, a motion simulation system was set up and a two-stage experiment was designed to investigate the role of the grip force on the longitudinal comfort of rapid transit trains. The results of the experiment show that the incremental grip force was linearly correlated with the longitudinal acceleration value, while the incremental grip force had no correlation with the direction of the longitudinal acceleration vector. The results also show that the effects of incremental grip force and acceleration duration on the longitudinal comfort of rapid transit trains were significant. Based on multiple regression analysis, a step function model was established to predict the longitudinal comfort of rapid transit trains using the incremental grip force and the acceleration duration. The feasibility and practicably of the model was verified by a field test. Furthermore, a comparative analysis shows that the motion simulation system and the grip force based model were valid to support the laboratory studies on the longitudinal comfort of rapid transit trains. PMID:26147730

  10. Effect of hold depth and grip technique on maximal finger forces in rock climbing.

    PubMed

    Amca, Arif Mithat; Vigouroux, Laurent; Aritan, Serdar; Berton, Eric

    2012-01-01

    The aim of this study was to understand how the commonly used climbing-specific grip techniques and hold depths influence the finger force capacities. Ten advanced climbers performed maximal voluntary force on four different hold depths (from 1 to 4 cm) and in two force directions (antero-posterior and vertical) using three grip techniques (slope, half crimp and full crimp). A specially designed platform instrumented with a 6-degrees-of-freedom (DoF) force/torque sensor was used to record force values. Results showed that the maximal vertical forces differed significantly according to the hold depth and the grip technique (ranged from 350.8 N to 575.7 N). The maximal vertical forces increased according to the hold depth but the form of this increase differed depending on grip technique. These results seemed to be more associated with finger-hold contact/interaction than with internal biomechanical factors. Similar results were revealed for antero-posterior forces (ranged from 69.9 N to 138.0 N) but, it was additionally noted that climbers have different hand-forearm posture strategies with slope and crimp grip techniques when applying antero-posterior forces. This point is important as it could influence the body position adopted during climbing according to the chosen grip technique. For trainers and designers, a polynomial regression model was proposed in order to predict the mean maximal force based on hold depth and adopted grip technique. PMID:22339482

  11. The effects of acute cortical somatosensory deafferentation on grip force control.

    PubMed

    Richardson, Andrew G; Attiah, Mark A; Berman, Jeffrey I; Chen, H Isaac; Liu, Xilin; Zhang, Milin; Van der Spiegel, Jan; Lucas, Timothy H

    2016-01-01

    Grip force control involves mechanisms to adjust to unpredictable and predictable changes in loads during manual manipulation. Somatosensory feedback is critical not just to reactive, feedback control but also to updating the internal representations needed for proactive, feedforward control. The role of primary somatosensory cortex (S1) in these control strategies is not well established. Here we investigated grip force control in a rare case of acute central deafferentation following resection of S1. The subject had complete loss of somatosensation in the right arm without any deficit in muscle strength or reflexes. In the first task, the subject was asked to maintain a constant grip force with and without visual feedback. The subject was able to attain the target force with visual feedback but not maintain that force for more than a few seconds after visual feedback was removed. In the second task, the subject was asked to grip and move an instrumented object. The induced acceleration-dependent loads were countered by adjustments in grip force. Both amplitude and timing of the grip force modulation were not affected by deafferentation. The dissociation of these effects demonstrates the differential contribution of S1 to the mechanisms of grip force control. PMID:26587914

  12. Effects of kinesio tape compared with non-elastic tape on hand grip strength

    PubMed Central

    Kim, Ji Young; Kim, Seong Yeol

    2016-01-01

    [Purpose] Many assumptions have been made about taping and several studies have considered tape application methods; however, the true effect of taping on muscle strength remains unclear. Most previous studies compared application techniques using Kinesio tape (KT), but studies that compared muscle strength using non-elastic tape (NT) are limited. Moreover, no studies have applied KT and NT in the same way to assess grip strength in normal subjects. The purpose of this study was to evaluate the immediate effect of application of two tapes with different elastic properties on maximal grip strength in healthy adults. [Subjects and Methods] Twenty healthy adults were divided into two groups (KT and NT). Maximal grip strength was measured with a dynamometer. Forearm extensor muscles of the dominant hand were then taped and subjects were immediately asked to perform hand grip movement with maximum strength in the same standardized manner. [Results] In the KT group, maximal grip strength was significantly increased compared to the initial value; however, in the NT group, there was no significant difference in maximal grip strength. [Conclusion] This study suggests that only Kinesio tape can increase maximal grip strength immediately after application on the extensor region of the forearm. PMID:27313372

  13. Grips and hand movements of chimpanzees during feeding in Mahale Mountains National Park, Tanzania.

    PubMed

    Marzke, Mary W; Marchant, Linda F; McGrew, William C; Reece, Sandra P

    2015-03-01

    It has long been assumed that stone tool making was a major factor in the evolution of derived hominin hand morphology. However, stresses on the hand associated with food retrieval and processing also have been recognized as relevant early hominin behaviors that should be investigated. To this end, chimpanzee food manipulation was videotaped in the Mahale Mountains National Park, Tanzania. Grips and hand movements by 39 chimpanzees were analyzed for arboreal and terrestrial feeding involving 10 food-types and associated vegetation. It was predicted that (1) new grips would be found that had not been observed in captivity, (2) forceful precision grips would be absent from the repertoire, as in captivity, and (3) precision handling would be observed. New grips involving the full thumb and buttressed index finger, and a new integrated pattern of grips and forceful hand movements were discovered, associated with feeding on large fruits and meat. Participation of the full thumb in these grips, rather than the distal thumb and fingers, throws light on feeding behaviors that may have become increasingly significant factors in the evolution of derived hominin thumb morphology. The proximal thumb stabilizes food with the flexed index finger against the pull of the teeth and provides leverage in breaking food into portions. Isolated qualitative observations of possibly forceful pinch by the thumb and side of the index finger highlight the need for comparative quantitative data to test whether humans are unique in forceful precision gripping capability. Precision handling was not seen. PMID:25363236

  14. Grip forces during fast point-to-point and continuous hand movements.

    PubMed

    Viviani, Paolo; Lacquaniti, Francesco

    2015-11-01

    Three experiments investigated the grip force exerted by the fingers on an object displaced actively in the near-body space. In one condition (unimanual) the object was held by one hand with the tripod grip and was moved briskly back and forth along one of the three coordinate directions (up-down, left-right, near-far). In the second condition (bimanual) the same point-to-point movements were performed while holding the object with the index and middle fingers of both hands. In the third condition (bimanual) the object was held as in the second condition and moved along a circular path lying in one of the three coordinate planes (horizontal, frontal, sagittal). In all conditions participants were asked to exert a baseline level of grip force largely exceeding the safety margin against slippage. Both grip forces and hand displacements were measured with high accuracy. As reported in previous studies, in the two point-to-point conditions we observed an upsurge of the grip force at the onset and at the end the movements. However, the timing of the transient increases of the grip force relative to hand kinematics did not confirm the hypothesis set forth by several previous studies that grip modulation is a pre-planned action based on an internal model of the expected effects of the movement. In the third condition, the systematic modulation of the grip force also for circular movements was again at variance with the internal model hypothesis because it cannot be construed as a pre-planned action aiming at countering large changes in dynamic load. We argue that a parsimonious account of the covariations of load and grip forces can be offered by taking into account the visco-elastic properties of the neuromuscular system. PMID:26223578

  15. Computational model of precision grip in Parkinson's disease: a utility based approach

    PubMed Central

    Gupta, Ankur; Balasubramani, Pragathi P.; Chakravarthy, V. Srinivasa

    2013-01-01

    We propose a computational model of Precision Grip (PG) performance in normal subjects and Parkinson's Disease (PD) patients. Prior studies on grip force generation in PD patients show an increase in grip force during ON medication and an increase in the variability of the grip force during OFF medication (Ingvarsson et al., 1997; Fellows et al., 1998). Changes in grip force generation in dopamine-deficient PD conditions strongly suggest contribution of the Basal Ganglia, a deep brain system having a crucial role in translating dopamine signals to decision making. The present approach is to treat the problem of modeling grip force generation as a problem of action selection, which is one of the key functions of the Basal Ganglia. The model consists of two components: (1) the sensory-motor loop component, and (2) the Basal Ganglia component. The sensory-motor loop component converts a reference position and a reference grip force, into lift force and grip force profiles, respectively. These two forces cooperate in grip-lifting a load. The sensory-motor loop component also includes a plant model that represents the interaction between two fingers involved in PG, and the object to be lifted. The Basal Ganglia component is modeled using Reinforcement Learning with the significant difference that the action selection is performed using utility distribution instead of using purely Value-based distribution, thereby incorporating risk-based decision making. The proposed model is able to account for the PG results from normal and PD patients accurately (Ingvarsson et al., 1997; Fellows et al., 1998). To our knowledge the model is the first model of PG in PD conditions. PMID:24348373

  16. Computational model of precision grip in Parkinson's disease: a utility based approach.

    PubMed

    Gupta, Ankur; Balasubramani, Pragathi P; Chakravarthy, V Srinivasa

    2013-01-01

    We propose a computational model of Precision Grip (PG) performance in normal subjects and Parkinson's Disease (PD) patients. Prior studies on grip force generation in PD patients show an increase in grip force during ON medication and an increase in the variability of the grip force during OFF medication (Ingvarsson et al., 1997; Fellows et al., 1998). Changes in grip force generation in dopamine-deficient PD conditions strongly suggest contribution of the Basal Ganglia, a deep brain system having a crucial role in translating dopamine signals to decision making. The present approach is to treat the problem of modeling grip force generation as a problem of action selection, which is one of the key functions of the Basal Ganglia. The model consists of two components: (1) the sensory-motor loop component, and (2) the Basal Ganglia component. The sensory-motor loop component converts a reference position and a reference grip force, into lift force and grip force profiles, respectively. These two forces cooperate in grip-lifting a load. The sensory-motor loop component also includes a plant model that represents the interaction between two fingers involved in PG, and the object to be lifted. The Basal Ganglia component is modeled using Reinforcement Learning with the significant difference that the action selection is performed using utility distribution instead of using purely Value-based distribution, thereby incorporating risk-based decision making. The proposed model is able to account for the PG results from normal and PD patients accurately (Ingvarsson et al., 1997; Fellows et al., 1998). To our knowledge the model is the first model of PG in PD conditions. PMID:24348373

  17. Hand-Grip Strength Cut-Points to Screen Older Persons at Risk for Mobility Limitation

    PubMed Central

    Sallinen, Janne; Stenholm, Sari; Rantanen, Taina; Heliövaara, Markku; Sainio, Päivi; Koskinen, Seppo

    2010-01-01

    Objectives To determine optimal hand-grip strength cut-points for increased likelihood for mobility limitation among older people and to study whether these cut-points differ according to body mass index (BMI). Design and setting Cross-sectional analysis of data collected in the Finnish population-based Health 2000 Survey. Participants and measurements 1 084 men and 1 562 women aged 55 years and older with complete data on anthropometry, hand-grip strength and self-reported mobility. Mobility limitation was defined as difficulties in walking 0.5-km or climbing stairs. Receiver Operating Characteristics analysis was used to estimate hand-grip strength cut-points for increased likelihood for mobility limitation. Results The overall hand-grip strength cut-points for increased likelihood for mobility limitation were 37 kg (sensitivity 62% and specificity 76%) for men and 21 kg (67% and 73%) for women. Hand-grip strength by BMI interaction on mobility limitation was significant among men (p = 0.022), while no such interaction was observed among women (p = 0.156). Among men, most optimal cut-offs were 33 kg (73% and 79%) for normal-weight men, 39 kg (67% and 71%) for overweight men and 40 kg (57% and 68%) for obese men. Among women, BMI-specific hand-grip strength cut-off values did not markedly increase accuracy over the overall cut-off value. Conclusion Hand-grip strength test is a useful tool to identify persons with increased risk for mobility limitation. Among men, the hand-grip strength cut-points for mobility increased along with BMI, while among women only one hand-grip strength threshold was identified. PMID:20863331

  18. Anticipatory grip force between 1 and 3g

    NASA Astrophysics Data System (ADS)

    White, Olivier; Van Loon, ing.. Jack J. W. A.; Thonnard, Jean-Louis; Hermsdorfer, Joachim; Lefevre, Philippe

    One remarkable capacity of utilizing common tools appropriately as soon as we grasp them relies on the ability to determine in advance the grip force (GF) required to handle them in relation to their mechanical properties and the surrounding environment. This anticipatory strategy avoids the uncompressible delays in the feedback system. The predictive control of GF is made possible because the nervous system can learn, store and then select the internal representations of the dynamics of innumerable objects, known as internal models. Beside this flexibility, the nervous system's ability to learn different task dynamics is often limited in classical robotic experiments The environment itself can be profoundly modified in altered gravity or centrifugation. The few studies that investigated motor adaptation in such contexts did not consider the interaction between gravitational phases and even less the transitions across environments. Here, we tested subject's abilities to adapt to levels of gravitational fields generated by a human centrifuge. In Experiment 1, seven subjects performed 4 lifting trials in each gravitational phase (1 to 2.5g and then 2.5 to 1g by steps of 0.5g) with a 0.12 kg instrumented object. In Experiment 2, six subjects performed vertical oscillations of the object during transitions between 1 and 3g (0.5g steps, ascending and descending phases, profile repeated twice). We continuously measured GF, load force (LF) and ambient gravity. We hypothesized that participants were able to predictively adjust GF to the new environment. In Experiment 1, participants adjusted their GF proportionally to gravity and decreased GF across trials within a given gravitational environment. Preload phases decreased over time from 300ms to 50ms irrespective of gravity. We quantified the abilities of participants to switch across environments by subtracting GF recorded in the last trial in the current gravity level from GF during the first trial in the new environment

  19. JPL Genesis and Rapid Intensification Processes (GRIP) Portal

    NASA Technical Reports Server (NTRS)

    Knosp, Brian W.; Li, P. Peggy; Vu, Quoc A.; Turk, Francis J.; Shen, Tsae-Pyng J.; Hristova-Veleva, Svetla M.; Licata, Stephen J.; Poulsen, William L.

    2012-01-01

    Satellite observations can play a very important role in airborne field campaigns, since they provide a comprehensive description of the environment that is essential for the experiment design, flight planning, and post-experiment scientific data analysis. In the past, it has been difficult to fully utilize data from multiple NASA satellites due to the large data volume, the complexity of accessing NASA s data in near-real-time (NRT), as well as the lack of software tools to interact with multi-sensor information. The JPL GRIP Portal is a Web portal that serves a comprehensive set of NRT observation data sets from NASA and NOAA satellites describing the atmospheric and oceanic environments related to the genesis and intensification of the tropical storms in the North Atlantic Ocean. Together with the model forecast data from four major global atmospheric models, this portal provides a useful tool for the scientists and forecasters in planning and monitoring the NASA GRIP field campaign during the 2010 Atlantic Ocean hurricane season. This portal uses the Google Earth plug-in to visualize various types of data sets, such as 2D maps, wind vectors, streamlines, 3D data sets presented at series of vertical cross-sections or pointwise vertical profiles, and hurricane best tracks and forecast tracks. Additionally, it allows users to overlap multiple data sets, change the opacity of each image layer, generate animations on the fly with selected data sets, and compare the observation data with the model forecast using two independent calendars. The portal also provides the capability to identify the geographic location of any point of interest. In addition to supporting the airborne mission planning, the NRT data and portal will serve as a very rich source of information during the post-field campaign analysis stage of the airborne experiment. By including a diverse set of satellite observations and model forecasts, it provides a good spatial and temporal context for the

  20. Climatological Structures of the GRIPS Models: Mean States and Forcing

    NASA Technical Reports Server (NTRS)

    Pawson, Steven

    1999-01-01

    The GCM-Reality Intercomparison Project for SPARC (GRIPS) is assessing and monitoring the performance of state-of-the-art general circulation models (GCMs). A wide variety of tasks have been initiated. These are designed to: (1) assess the ability of the GCMs to represent the current climatological structure of the troposphere and middle atmosphere,(2) to compare their response to imposed forcing anomalies, and (3) to estimate the certainty with which future climate perturbations can be predicted. This paper is concerned with assessments of the climatological states in the GCM simulations. Comparing the simulations with observational datasets reveals considerable discrepancies in the modelled fields. While it might be anticipated that certain types of biases in the model simulations might be related to the formulation of different aspects of the numerical package (dynamical schemes, cloud schemes, radiation transfer, inclusion of gravity wave drag), there is no clear relationship between these features. This paper attempts to draw a more comprehensive picture of the GCMs'performance than has previously been shown, by comparing the dominant forcing mechanisms in the models with observational estimates, and relating model deficiencies to the differences in the physical mechanisms in the GCMS.

  1. Butterfly survival on an isolated island by improved grip.

    PubMed

    Duplouy, Anne; Hanski, Ilkka

    2013-04-23

    On small isolated islands, natural selection is expected to reduce the dispersal capacity of organisms, as short distances do not require a high rate of dispersal, which might lead to accidental emigration from the population. In addition, individuals foregoing the high cost of maintaining flight capacity may instead allocate resources to other functions. However, in butterflies and many other insects, flight is necessary not only for dispersal but also for most other activities. A weakly flying individual would probably do worse and have an elevated rather than reduced probability of accidental emigration. Here, we report results consistent with the hypothesis that a butterfly population on an isolated island, instead of having lost its flight capacity, has evolved better grip to resist the force of wind and to avoid being blown off the island. Our study suggests that local adaptation has occurred in this population in spite of its very small size (Ne ∼ 100), complete isolation, low genetic variation and high genetic load. PMID:23445946

  2. Gripping during climbing of arboreal snakes may be safe but not economical

    PubMed Central

    Byrnes, Greg; Jayne, Bruce C.

    2014-01-01

    On the steep surfaces that are common in arboreal environments, many types of animals without claws or adhesive structures must use muscular force to generate sufficient normal force to prevent slipping and climb successfully. Unlike many limbed arboreal animals that have discrete gripping regions on the feet, the elongate bodies of snakes allow for considerable modulation of both the size and orientation of the gripping region. We quantified the gripping forces of snakes climbing a vertical cylinder to determine the extent to which their force production favoured economy or safety. Our sample included four boid species and one colubrid. Nearly all of the gripping forces that we observed for each snake exceeded our estimate of the minimum required, and snakes commonly produced more than three times the normal force required to support their body weight. This suggests that a large safety factor to avoid slipping and falling is more important than locomotor economy. PMID:25142200

  3. Grip Strength across the Life Course: Normative Data from Twelve British Studies

    PubMed Central

    Dodds, Richard M.; Syddall, Holly E.; Cooper, Rachel; Benzeval, Michaela; Deary, Ian J.; Dennison, Elaine M.; Der, Geoff; Gale, Catharine R.; Inskip, Hazel M.; Jagger, Carol; Kirkwood, Thomas B.; Lawlor, Debbie A.; Robinson, Sian M.; Starr, John M.; Steptoe, Andrew; Tilling, Kate; Kuh, Diana; Cooper, Cyrus; Sayer, Avan Aihie

    2014-01-01

    Introduction Epidemiological studies have shown that weaker grip strength in later life is associated with disability, morbidity, and mortality. Grip strength is a key component of the sarcopenia and frailty phenotypes and yet it is unclear how individual measurements should be interpreted. Our objective was to produce cross-sectional centile values for grip strength across the life course. A secondary objective was to examine the impact of different aspects of measurement protocol. Methods We combined 60,803 observations from 49,964 participants (26,687 female) of 12 general population studies in Great Britain. We produced centile curves for ages 4 to 90 and investigated the prevalence of weak grip, defined as strength at least 2.5 SDs below the gender-specific peak mean. We carried out a series of sensitivity analyses to assess the impact of dynamometer type and measurement position (seated or standing). Results Our results suggested three overall periods: an increase to peak in early adult life, maintenance through to midlife, and decline from midlife onwards. Males were on average stronger than females from adolescence onwards: males’ peak median grip was 51 kg between ages 29 and 39, compared to 31 kg in females between ages 26 and 42. Weak grip strength, defined as strength at least 2.5 SDs below the gender-specific peak mean, increased sharply with age, reaching a prevalence of 23% in males and 27% in females by age 80. Sensitivity analyses suggested our findings were robust to differences in dynamometer type and measurement position. Conclusion This is the first study to provide normative data for grip strength across the life course. These centile values have the potential to inform the clinical assessment of grip strength which is recognised as an important part of the identification of people with sarcopenia and frailty. PMID:25474696

  4. Grip force variability and its effects on children's handwriting legibility, form, and strokes.

    PubMed

    Falk, Tiago H; Tam, Cynthia; Schwellnus, Heidi; Chau, Tom

    2010-11-01

    A comprehensive understanding of the underlying biomechanical processes during handwriting is needed to accurately guide clinical interventions. To date, quantitative measurement of such biomechanical processes has largely excluded measurements of the forces exerted radially on the barrel of the writing utensil (grip forces) and how they vary over time during a handwriting task. An instrumented writing utensil was deployed for a direct measurement of kinematic and temporal information during a writing task, as well as forces exerted on the writing surface and on the barrel of the pen. The writing utensil was used by a cohort of 35 students (19 males), 16 in first grade and 19 in second grade, as they performed the Minnesota Handwriting Assessment (MHA) test. Quantitative grip force variability measures were computed and tested as correlates of handwriting legibility, form, and strokes. Grip force variability was shown to correlate strongly with handwriting quality, in particular for students classified by the MHA as nonproficient writers. More specifically, static grip force patterns were shown to result in poor handwriting quality and in greater variation in handwriting stroke durations. Grip force variability throughout the writing task was shown to be significantly lower for nonproficient writers (t-test, p<0.01) while the number of strokes and per-stroke durations were shown to be higher (p<0.03). The results suggest that grip force dynamics play a key role in determining handwriting quality and stroke characteristics. In particular, students with writing difficulties exhibited more static grip force patterns, lower legibility and form scores, as well as increased variation in stroke durations. These findings shed light on the underlying processes of handwriting and grip force modulation and may help to improve intervention planning. PMID:21034156

  5. The effects of grip width on sticking region in bench press.

    PubMed

    Gomo, Olav; Van Den Tillaar, Roland

    2016-01-01

    The aim of this study was to examine the occurrence of the sticking region by examining how three different grip widths affect the sticking region in powerlifters' bench press performance. It was hypothesised that the sticking region would occur at the same joint angle of the elbow and shoulder independent of grip width, indicating a poor mechanical region for vertical force production at these joint angles. Twelve male experienced powerlifters (age 27.7 ± 8.8 years, mass 91.9 ± 15.4 kg) were tested in one repetition maximum (1-RM) bench press with a narrow, medium and wide grip. Joint kinematics, timing, bar position and velocity were measured with a 3D motion capture system. All participants showed a clear sticking region with all three grip widths, but this sticking region was not found to occur at the same joint angles in all three grip widths, thereby rejecting the hypothesis that the sticking region would occur at the same joint angle of the elbow and shoulder independent of grip width. It is suggested that, due to the differences in moment arm of the barbell about the elbow joint in the sticking region, there still might be a poor mechanical region for total force production that is joint angle-specific. PMID:26055260

  6. Role of transcriptional coregulator GRIP1 in the anti-inflammatory actions of glucocorticoids

    PubMed Central

    Chinenov, Yurii; Gupte, Rebecca; Dobrovolna, Jana; Flammer, Jamie R.; Liu, Bill; Michelassi, Francesco E.; Rogatsky, Inez

    2012-01-01

    Inhibition of cytokine gene expression by the hormone-activated glucocorticoid receptor (GR) is the key component of the anti-inflammatory actions of glucocorticoids, yet the underlying molecular mechanisms remain obscure. Here we report that glucocorticoid repression of cytokine genes in primary macrophages is mediated by GR-interacting protein (GRIP)1, a transcriptional coregulator of the p160 family, which is recruited to the p65-occupied genomic NFκB-binding sites in conjunction with liganded GR. We created a mouse strain enabling a conditional hematopoietic cell-restricted deletion of GRIP1 in adult animals. In this model, GRIP1 depletion in macrophages attenuated in a dose-dependent manner repression of NFκB target genes by GR irrespective of the upstream Toll-like receptor pathway responsible for their activation. Furthermore, genome-wide transcriptome analysis revealed a broad derepression of lipopolysaccharide (LPS)-induced glucocorticoid-sensitive targets in GRIP1-depleted macrophages without affecting their activation by LPS. Consistently, conditional GRIP1-deficient mice were sensitized, relative to the wild type, to a systemic inflammatory challenge developing characteristic signs of LPS-induced shock. Thus, by serving as a GR corepressor, GRIP1 facilitates the anti-inflammatory effects of glucocorticoids in vivo. PMID:22753499

  7. Posture, flexibility and grip strength in horse riders.

    PubMed

    Hobbs, Sarah Jane; Baxter, Joanna; Broom, Louise; Rossell, Laura-Ann; Sinclair, Jonathan; Clayton, Hilary M

    2014-09-29

    Since the ability to train the horse to be ambidextrous is considered highly desirable, rider asymmetry is recognized as a negative trait. Acquired postural and functional asymmetry can originate from numerous anatomical regions, so it is difficult to suggest if any is developed due to riding. The aim of this study was therefore to assess symmetry of posture, strength and flexibility in a large population of riders and to determine whether typical traits exist due to riding. 127 right handed riders from the UK and USA were categorized according to years riding (in 20 year increments) and their competition level (using affiliated test levels). Leg length, grip strength and spinal posture were measured and recorded by a physiotherapist. Standing and sitting posture and trunk flexibility were measured with 3-D motion capture technology. Right-left differences were explored in relation to years riding and rider competitive experience. Significant anatomical asymmetry was found for the difference in standing acromion process height for a competition level (-0.07±1.50 cm Intro/Prelim; 0.02±1.31 cm Novice; 0.43±1.27 cm Elementary+; p=0.048) and for sitting iliac crest height for years riding (-0.23±1.36 cm Intro/Prelim; 0.01±1.50 cm Novice; 0.86±0.41 cm Elementary+; p=0.021). For functional asymmetry, a significant interaction was found for lateral bending ROM for years riding x competition level (p=0.047). The demands on dressage riders competing at higher levels may predispose these riders to a higher risk of developing asymmetry and potentially chronic back pain rather than improving their symmetry. PMID:25414745

  8. Posture, Flexibility and Grip Strength in Horse Riders

    PubMed Central

    Hobbs, Sarah Jane; Baxter, Joanna; Broom, Louise; Rossell, Laura-Ann; Sinclair, Jonathan; Clayton, Hilary M

    2014-01-01

    Since the ability to train the horse to be ambidextrous is considered highly desirable, rider asymmetry is recognized as a negative trait. Acquired postural and functional asymmetry can originate from numerous anatomical regions, so it is difficult to suggest if any is developed due to riding. The aim of this study was therefore to assess symmetry of posture, strength and flexibility in a large population of riders and to determine whether typical traits exist due to riding. 127 right handed riders from the UK and USA were categorized according to years riding (in 20 year increments) and their competition level (using affiliated test levels). Leg length, grip strength and spinal posture were measured and recorded by a physiotherapist. Standing and sitting posture and trunk flexibility were measured with 3-D motion capture technology. Right-left differences were explored in relation to years riding and rider competitive experience. Significant anatomical asymmetry was found for the difference in standing acromion process height for a competition level (−0.07±1.50 cm Intro/Prelim; 0.02±1.31 cm Novice; 0.43±1.27 cm Elementary+; p=0.048) and for sitting iliac crest height for years riding (−0.23±1.36 cm Intro/Prelim; 0.01±1.50 cm Novice; 0.86±0.41 cm Elementary+; p=0.021). For functional asymmetry, a significant interaction was found for lateral bending ROM for years riding x competition level (p=0.047). The demands on dressage riders competing at higher levels may predispose these riders to a higher risk of developing asymmetry and potentially chronic back pain rather than improving their symmetry. PMID:25414745

  9. Genetics of hand grip strength in mid to late life.

    PubMed

    Chan, Jessica P L; Thalamuthu, Anbupalam; Oldmeadow, Christopher; Armstrong, Nicola J; Holliday, Elizabeth G; McEvoy, Mark; Kwok, John B; Assareh, Amelia A; Peel, Rosanne; Hancock, Stephen J; Reppermund, Simone; Menant, Jasmine; Trollor, Julian N; Brodaty, Henry; Schofield, Peter R; Attia, John R; Sachdev, Perminder S; Scott, Rodney J; Mather, Karen A

    2015-02-01

    Hand grip strength (GS) is a predictor of mortality in older adults and is moderately to highly heritable, but no genetic variants have been consistently identified. We aimed to identify single nucleotide polymorphisms (SNPs) associated with GS in middle-aged to older adults using a genome-wide association study (GWAS). GS was measured using handheld dynamometry in community-dwelling men and women aged 55-85 from the Hunter Community Study (HCS, N = 2088) and the Sydney Memory and Ageing Study (Sydney MAS, N = 541). Genotyping was undertaken using Affymetrix microarrays with imputation to HapMap2. Analyses were performed using linear regression. No genome-wide significant results were observed in HCS nor were any of the top signals replicated in Sydney MAS. Gene-based analyses in HCS identified two significant genes (ZNF295, C2CD2), but these results were not replicated in Sydney MAS. One out of eight SNPs previously associated with GS, rs550942, located near the CNTF gene, was significantly associated with GS (p = 0.005) in the HCS cohort only. Study differences may explain the lack of consistent results between the studies, including the smaller sample size of the Sydney MAS cohort. Our modest sample size also had limited power to identify variants of small effect. Our results suggest that similar to various other complex traits, many genetic variants of small effect size may influence GS. Future GWAS using larger samples and consistent measures may prove more fruitful at identifying genetic contributors for GS in middle-aged to older adults. PMID:25637336

  10. Genetic Influences on the Development of Grip Strength in Adolescence

    PubMed Central

    Isen, Joshua; McGue, Matt; Iacono, William

    2014-01-01

    Enhanced physical strength is a secondary sex characteristic in males. Sexual dimorphism in physical strength far exceeds sex differences in stature or total body mass, suggesting a legacy of intense sexual selection. Upper-body strength is a particularly promising marker of intra-sexual competitiveness in young men. Consequently, it is assumed that sex-influenced gene expression contributes to the development of physical strength. It is unclear, however, whether the underlying sources of individual differences in strength development are comparable across sex. We obtained three measurements of hand-grip strength (HGS) over a six-year period spanning adolescence in male and female same-sex twins (N= 2,513). Biometrical latent growth models were used to partition the HGS variance at age 11 (intercept) and its growth over time (slope) into genetic and environmental components. Results demonstrated that variance around the intercept was highly heritable in both males and females (88% and 79%, respectively). In males, variance around the slope exceeded that of the intercept, while the reverse held for females. Additive genetic effects accounted for most (80%) of the variance around the slope in males, but were of less importance in females (heritability = 28%). Absolute genetic variance around the slope was nearly nine-fold higher in males. This striking disparity suggests that the developmental processes shaping HGS growth are different between the sexes. We propose that this might account for the sex-specific pattern of associations between HGS and external measures (e.g., digit ratio and physical aggression) typically reported in the literature. Our results underscore the role of endogenous androgenic influences in the development of physical strength. PMID:24936605

  11. Impaired grip-lift synergy in children with unilateral brain lesions.

    PubMed

    Forssberg, H; Eliasson, A C; Redon-Zouitenn, C; Mercuri, E; Dubowitz, L

    1999-06-01

    Children with spastic hemiplegia have impaired dexterity in the affected extremity. The purpose of the present study was to investigate whether the force co-ordination pattern during precision grip in 13 children between 4 and 10 years of age with predominant unilateral brain lesions is related to manual dexterity and to the location and size of the brain lesion. The force co-ordination pattern was investigated by means of a specially designed object that monitored the isometric fingertip forces applied to the contact surfaces during precision grip. Hand function was measured by means of neurological examination, functional hand-grips and dexterity. Brain lesions were identified by series of ultrasound and MRI scans. Normally, the fingertip forces are applied to the object in the initial phase of the lift in an invariant force co-ordination pattern (i.e. grip-lift synergy), in which the grip and load forces are initiated simultaneously and increase in parallel with unimodal force rate trajectories. A majority of children with unilateral brain lesions had not developed the force co-ordination pattern typical for their age, but produced an immature or a pathological pattern. The developmental level of the grip-lift synergy was determined and quantified according to criteria derived from earlier studies on normally developed children. There was a clear relationship between the developmental level of the grip-lift synergy and impaired dexterity, indicating that proper development of the force co-ordination pattern is important for skilled hand function. The grip-lift synergy correlated with the total extent of lesions in the contralateral cortex and white matter and with lesions in the thalamus/basal ganglia, while no correlation was found for isolated cortical lesions. The results suggest that the neural circuits involved in the control of the precision grip are organized in a parallel and distributed system in the hemispheres, and that the basal ganglia are important

  12. A connectionist architecture for view-independent grip-aperture computation.

    PubMed

    Prevete, Roberto; Tessitore, Giovanni; Santoro, Matteo; Catanzariti, Ezio

    2008-08-15

    This paper addresses the problem of extracting view-invariant visual features for the recognition of object-directed actions and introduces a computational model of how these visual features are processed in the brain. In particular, in the test-bed setting of reach-to-grasp actions, grip aperture is identified as a good candidate for inclusion into a parsimonious set of hand high-level features describing overall hand movement during reach-to-grasp actions. The computational model NeGOI (neural network architecture for measuring grip aperture in an observer-independent way) for extracting grip aperture in a view-independent fashion was developed on the basis of functional hypotheses about cortical areas that are involved in visual processing. An assumption built into NeGOI is that grip aperture can be measured from the superposition of a small number of prototypical hand shapes corresponding to predefined grip-aperture sizes. The key idea underlying the NeGOI model is to introduce view-independent units (VIP units) that are selective for prototypical hand shapes, and to integrate the output of VIP units in order to compute grip aperture. The distinguishing traits of the NEGOI architecture are discussed together with results of tests concerning its view-independence and grip-aperture recognition properties. The overall functional organization of NEGOI model is shown to be coherent with current functional models of the ventral visual stream, up to and including temporal area STS. Finally, the functional role of the NeGOI model is examined from the perspective of a biologically plausible architecture which provides a parsimonious set of high-level and view-independent visual features as input to mirror systems. PMID:18538746

  13. Global variation in grip strength: a systematic review and meta-analysis of normative data

    PubMed Central

    Dodds, Richard M.; Syddall, Holly E.; Cooper, Rachel; Kuh, Diana; Cooper, Cyrus; Sayer, Avan Aihie

    2016-01-01

    Background: weak grip strength is a key component of sarcopenia and is associated with subsequent disability and mortality. We have recently established life course normative data for grip strength in Great Britain, but it is unclear whether the cut points we derived for weak grip strength are suitable for use in other settings. Our objective was to investigate differences in grip strength by world region using our data as a reference standard. Methods: we searched MEDLINE and EMBASE for reporting age- and gender-stratified normative data for grip strength. We extracted each item of normative data and converted it on to a Z-score scale relative to our British centiles. We performed meta-regression to pool the Z-scores and compare them by world region. Findings: our search returned 806 abstracts. Sixty papers met inclusion criteria and reported on 63 different samples. Seven UN regions were represented, although most samples (n = 44) were based in developed regions. We extracted 726 normative data items relating to 96,537 grip strength observations. Normative data from developed regions were broadly similar to our British centiles, with a pooled Z-score 0.12 SDs (95% CI: 0.07, 0.17) above the corresponding British centiles. By comparison, normative data from developing regions were clearly lower, with a pooled Z-score of −0.85 SDs (95% CI: −0.94, −0.76). Interpretation: our findings support the use of our British grip strength centiles and their associated cut points in consensus definitions for sarcopenia and frailty across developed regions, but highlight the need for different cut points in developing regions. PMID:26790455

  14. Effects of bat composition, grip firmness, and impact location on postimpact ball velocity.

    PubMed

    Weyrich, A S; Messier, S P; Ruhmann, B S; Berry, M J

    1989-04-01

    The purpose of this investigation was to examine the effects of bat composition (aluminum and wooden), impact location [center of percussion (COP), center of gravity (COG), and end of the bat (E)], and grip firmness [tight (T) and no tension (NT)] on postimpact ball velocity. With the bats placed alternately in NT and T conditions, baseballs were delivered at a speed of 27.1 m.s-1 from a pitching machine positioned 1.5 m from the bat. High-speed photography (400 fps) was performed using a Locam camera positioned 7.54 m from and perpendicular to the principal plane of ball movement. A three-way ANCOVA revealed significant (P less than 0.01) differences in postimpact ball velocity between the three impact locations, with the COP yielding the greatest values, followed by the COG and E. Moreover, there was a significant (P less than 0.01) grip vs bat interaction. A simple-effects procedure revealed the following results: 1) the T grip produced greater (P less than 0.01) velocities than the NT grip across the aluminum (Al) bat; 2) there was no difference (P greater than 0.01) between the T and NT grips across the wooden (W) bat; 3) the W bat produced greater (P less than 0.01) velocities than the Al bat across the NT grip; and 4) there was no difference (P greater than 0.01) between the Al and W bats across the T grip.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2709983

  15. Inertial torque during reaching directly impacts grip-force adaptation to weightless objects.

    PubMed

    Giard, T; Crevecoeur, F; McIntyre, J; Thonnard, J-L; Lefèvre, P

    2015-11-01

    A hallmark of movement control expressed by healthy humans is the ability to gradually improve motor performance through learning. In the context of object manipulation, previous work has shown that the presence of a torque load has a direct impact on grip-force control, characterized by a significantly slower grip-force adjustment across lifting movements. The origin of this slower adaptation rate remains unclear. On the one hand, information about tangential constraints during stationary holding may be difficult to extract in the presence of a torque. On the other hand, inertial torque experienced during movement may also potentially disrupt the grip-force adjustments, as the dynamical constraints clearly differ from the situation when no torque load is present. To address the influence of inertial torque loads, we instructed healthy adults to perform visually guided reaching movements in weightlessness while holding an unbalanced object relative to the grip axis. Weightlessness offered the possibility to remove gravitational constraints and isolate the effect of movement-related feedback on grip force adjustments. Grip-force adaptation rates were compared with a control group who manipulated a balanced object without any torque load and also in weightlessness. Our results clearly show that grip-force adaptation in the presence of a torque load is significantly slower, which suggests that the presence of torque loads experienced during movement may alter our internal estimates of how much force is required to hold an unbalanced object stable. This observation may explain why grasping objects around the expected location of the center of mass is such an important component of planning and control of manipulation tasks. PMID:26265124

  16. The effect of handedness on grip strength in older adults with intellectual disabilities.

    PubMed

    Oppewal, Alyt; Hilgenkamp, Thessa I M; van Wijck, Ruud; Evenhuis, Heleen M

    2013-05-01

    Grip strength is an important predictor of several health outcomes in the general older population. Grip strength assessment is feasible and reliable in older adults with intellectual disabilities (ID), which makes it a valuable measurement for application in this population. The purpose of this study was to investigate the effect of handedness on grip strength in the older population with ID. Handedness and grip strength were assessed in a sample of 1050 older adults (≥ 50 years) with borderline to profound ID. Results showed that 26.2% of the study sample was left-handed. In right-handed participants the dominant hand (right) was on average 8.7% stronger than the non-dominant hand (p<0.001). For lefthanded participants there was no significant difference between the dominant hand (left) and nondominant hand. However, more detailed analyses revealed that 34.5% of the participants were stronger with their non-dominant hand, (on average 16.6% stronger for right-handed and 16.3% stronger for left-handed participants). Because of the large strength ratios, distributed in favor of both the dominant as the non-dominant hand, it is recommended to assess both hands to get a valid result of grip strength in older adults with ID. PMID:23475012

  17. Epidermolysis bullosa and embryonic lethality in mice lacking the multi-PDZ domain protein GRIP1

    PubMed Central

    Bladt, Friedhelm; Tafuri, Anna; Gelkop, Sigal; Langille, Lowell; Pawson, Tony

    2002-01-01

    Glutamate receptor-interacting protein 1 (GRIP1) is an adaptor protein composed of seven PDZ (postsynaptic density-95/Discs large/zona occludens-1) domains, capable of mediating diverse protein–protein interactions. GRIP1 has been implicated in the regulation of neuronal synaptic function, but its physiologic roles have not been defined in vivo. We find that elimination of murine GRIP1 results in embryonic lethality. GRIP1−/− embryos develop abnormalities of the dermo-epidermal junction, resulting in extensive skin blistering around day 12 of embryonic life. Ultra-structural characterization of the blisters (or bullae) revealed cleavage of the dermo-epidermal junction below the lamina densa, an alteration reminiscent of the dystrophic form of human epidermolysis bullosa. Blisters were also observed in the lateral ventricle of the brain and in the meninges covering the cerebral cortex. These genetic data suggest that the GRIP1 scaffolding protein is required for the formation and integrity of the dermo-epidermal junction and reveal the importance of PDZ domains in the organization of supramolecular structures essential for mammalian embryonic development. PMID:11983858

  18. Effects of Taping on Pain, Grip Strength and Wrist Extension Force in Patients with Tennis Elbow

    PubMed Central

    Shamsoddini, Alireza; Hollisaz, Mohammad Taghi

    2013-01-01

    Background Tennis elbow (TE) is a common musculotendinous degenerative disorder of the extensor origin at the lateral humeral epicondyle. Different modes of treatment are used for management of tennis elbow. Objectives This study investigated the effect of the taping technique (TT) on pain, grip strength and wrist extension force in treatment of tennis elbow. Patients and Methods Thirty patients (16 men /14 women with a mean age of 32.2 years) with tennis elbow of their dominant arm participated in this study. Outcome measures were assessment of pain at the lateral aspect of the elbow, grip strength and wrist extension force before and five to ten minutes after application of elbow tape on the affected and unaffected arms. A Visual Analog Scale was used to assess pain. A dynamometer and a hand-held dynamometer were used for evaluation of grip strength and wrist extension force, respectively. Results Among the variables, significant differences were found in wrist extension forces between effected and unaffected arms (P = 0.02). Changes in grip strength showed statically significant improvements in the affected arm compared to the unaffected arm (P = 0.03). Also, in assessment of pain at the lateral epicondyle, the mean change between affected and unaffected arms was significant, with P = 0.001. Conclusions The taping technique, as applied in this study demonstrates an impressive effect on wrist extension force and grip strength of patients with TE. Elbow taping also reduces pain at the lateral aspect of the elbow in these patients. PMID:24350156

  19. Grip pressure distributions and associated variability in golf: a two-club comparison.

    PubMed

    Langlais, Sean M; Broker, Jeffrey P

    2014-06-01

    Teaching and playing professionals offer multiple theories concerning the manner in which forces should be applied to the handle of the club during the golf swing. This study extends recent research concerning grip pressures and forces in golf, with the purpose of exploring the similarities and differences between force profiles for a 7-iron and driver swung by proficient golfers. A secondary purpose was to further analyze the way that golfers use grip forces to manipulate the club. Grip forces were measured on eight low handicap golfers (USGA indexes 0 to 7) swinging their own 7-irons and drivers. In total, lead-hand and trail-hand grip forces were isolated as well as anatomically specific forces within the hands. Force profile variability across multiple swings for each golfer and between golfers characterized consistencies and important differences. Correlations between 7-iron and driver force profiles characterized force 'signatures.' The data highlight large fluctuations in grip forces during the swing. Marked differences between participants were observed, involving force magnitudes and phasing. Dominant forces arose primarily from the lead hand, specifically the last three fingers. Force profiles were highly repeatable across swings for a golfer (standard deviations < 7% of total force) and force profile correlations between 7-iron and driver for a golfer were remarkably high (r2 = 0.86). Notably, within swing force variability was greatest during club acceleration, but dramatically decreased at impact. PMID:25122996

  20. Similar motion of a handheld object may trigger non-similar grip force adjustments

    PubMed Central

    Gao, Fan; Latash, Mark L.; Zatsiorsky, Vladimir M.

    2007-01-01

    The tight coupling between load (L) and grip (G) forces during voluntary manipulation of a hand-held object is well established. The current study is to examine grip-load force coupling when motion of the hand with an object was either self-generated (voluntary) or externally generated. Subjects performed similar cyclic movements of different loads at various frequencies with three types of manipulation: (a) voluntary oscillation, (b) oscillating the right arm via the pulley system by the left leg (self-driven oscillation), (c) oscillating the arm via the pulley system by another person (other-driven oscillation). During the self-generated movements: (a) the grip forces were larger and (b) grip-load force modulation was more pronounced than in the externally generated movements. The G-L adjustments are not completely determined by the mechanics of object motion; non-mechanical factors related to movement performance, for instance perceptual factors, may affect the G-L coupling. Potentially the results of study can be used to provide hand therapists with another way for administering the Rapid Exchange Gripping Test. PMID:17954351

  1. Two cases of firearm grip impressions on the hands of suicide victims.

    PubMed

    Poulos, Christopher K; Peterson, Brian L

    2012-03-01

    Many factors are used to help distinguish firearm suicides from homicides and accidents, including range of fire, location of entrance defects, wound path trajectory, backspatter (blowback), and gunshot residue. Specifically, authors have discussed examination of the hands for backspatter, gunshot residue, cylinder gap effects, iron staining, and trauma as means of supporting a person having held a firearm while committing suicide. Here, we discuss 2 cases where suicidal gunshot wounds were accompanied by unique firearm grip impressions on the hands of the decedents. In 1 case, a "negative"[ impression of a grip pattern was left in a decedent's hand and in another case a grip pattern was left on the decedent's hand in dried blood. Such impressions can be used to provide support for establishing suicide as the manner of death. PMID:20661121

  2. Estimating thumb–index finger precision grip and manipulation potential in extant and fossil primates

    PubMed Central

    Feix, Thomas; Kivell, Tracy L.; Pouydebat, Emmanuelle; Dollar, Aaron M.

    2015-01-01

    Primates, and particularly humans, are characterized by superior manual dexterity compared with other mammals. However, drawing the biomechanical link between hand morphology/behaviour and functional capabilities in non-human primates and fossil taxa has been challenging. We present a kinematic model of thumb–index precision grip and manipulative movement based on bony hand morphology in a broad sample of extant primates and fossil hominins. The model reveals that both joint mobility and digit proportions (scaled to hand size) are critical for determining precision grip and manipulation potential, but that having either a long thumb or great joint mobility alone does not necessarily yield high precision manipulation. The results suggest even the oldest available fossil hominins may have shared comparable precision grip manipulation with modern humans. In particular, the predicted human-like precision manipulation of Australopithecus afarensis, approximately one million years before the first stone tools, supports controversial archaeological evidence of tool-use in this taxon. PMID:25878134

  3. Estimating thumb-index finger precision grip and manipulation potential in extant and fossil primates.

    PubMed

    Feix, Thomas; Kivell, Tracy L; Pouydebat, Emmanuelle; Dollar, Aaron M

    2015-05-01

    Primates, and particularly humans, are characterized by superior manual dexterity compared with other mammals. However, drawing the biomechanical link between hand morphology/behaviour and functional capabilities in non-human primates and fossil taxa has been challenging. We present a kinematic model of thumb-index precision grip and manipulative movement based on bony hand morphology in a broad sample of extant primates and fossil hominins. The model reveals that both joint mobility and digit proportions (scaled to hand size) are critical for determining precision grip and manipulation potential, but that having either a long thumb or great joint mobility alone does not necessarily yield high precision manipulation. The results suggest even the oldest available fossil hominins may have shared comparable precision grip manipulation with modern humans. In particular, the predicted human-like precision manipulation of Australopithecus afarensis, approximately one million years before the first stone tools, supports controversial archaeological evidence of tool-use in this taxon. PMID:25878134

  4. Menstrual cyclicity of finger joint size and grip strength in patients with rheumatoid arthritis.

    PubMed Central

    Rudge, S R; Kowanko, I C; Drury, P L

    1983-01-01

    Daily measurements of finger joint size, grip strength, and body weight have been made throughout 2 complete menstrual cycles in 7 female patients with rheumatoid arthritis and 6 healthy female controls. Sine wave analysis showed significant individual cyclical rhythms (p less than 0.05) for finger joint size (5 patients, 4 controls), nude weight (5 patients, 3 controls), and grip strength (4 patients, 3 controls). In addition analysis of group data, on the assumption of a 28-day cycle, showed a significant cycle for grip strength in the rheumatoid patients, with a nadir at 28 days. In the normal subjects much of the cyclical variation in finger joint size could be explained by changes in weight (median 49.5%), but this was not so in patients with rheumatoid arthritis (median 2.8%). These findings suggest the existence of a cyclical variation in disease activity in rheumatoid arthritis. PMID:6882039

  5. Maximal intermittent handgrip strategy: design and evaluation of an exercise protocol and a grip tool

    PubMed Central

    Bentley, Danielle Christine; Thomas, Scott Gordon

    2016-01-01

    Handgrip (HG) exercise has been prescribed as a lifestyle intervention to successfully reduce resting blood pressure (BP) among heterogeneous groups of participants. Current HG protocols have limited accessibility due to complicated exercise prescriptions and sophisticated required equipment. Therefore, this research describes the design and evaluation of the maximal intermittent (MINT) HG exercise strategy, consisting of both a novel exercise protocol (32×5 seconds maximal grip squeezes separated by 5 seconds of rest between sets) and an original grip tool. This research was a multistep progressive design that included 51 postmenopausal women as participants in three separate research studies. Part 1 of this research focuses on the MINT exercise protocol. A literature-informed rationale for the design of the protocol is described. This includes exercise intensity, work-to-rest ratio, and total exercise duration with reference to the unique physiology (mechanoreflex and metaboreflex) of postmenopausal women. Subsequent experimental analyses of acute responses to the MINT protocol revealed that women produced 50% of their maximum grip force with moderate cardiovascular responses (increases of systolic BP: 41.6 mmHg, diastolic BP: 20.1 mmHg, heart rate: 35.1 bpm) that remained far below the thresholds of concern identified by the American College of Sports Medicine. Part 2 of this research describes the creation of a novel grip tool, beginning with a mixed-methods assessment of participant opinions regarding two distinct in-laboratory grip tools, leading to the creation of four prototype MINT tools. Structured focus groups revealed a strong preference for MINT prototype 1 for all tool design features, including color, shape, size, and foam grip. Collectively, the result of this multistep research is a novel HG exercise strategy with enhanced accessibility by being easy to understand and simple to execute. The long-term training effectiveness of MINT as an exercise

  6. Extraction of time and frequency features from grip force rates during dexterous manipulation.

    PubMed

    Mojtahedi, Keivan; Fu, Qiushi; Santello, Marco

    2015-05-01

    The time course of grip force from object contact to onset of manipulation has been extensively studied to gain insight into the underlying control mechanisms. Of particular interest to the motor neuroscience and clinical communities is the phenomenon of bell-shaped grip force rate (GFR) that has been interpreted as indicative of feedforward force control. However, this feature has not been assessed quantitatively. Furthermore, the time course of grip force may contain additional features that could provide insight into sensorimotor control processes. In this study, we addressed these questions by validating and applying two computational approaches to extract features from GFR in humans: 1) fitting a Gaussian function to GFR and quantifying the goodness of the fit [root-mean-square error, (RMSE)]; and 2) continuous wavelet transform (CWT), where we assessed the correlation of the GFR signal with a Mexican Hat function. Experiment 1 consisted of a classic pseudorandomized presentation of object mass (light or heavy), where grip forces developed to lift a mass heavier than expected are known to exhibit corrective responses. For Experiment 2, we applied our two techniques to analyze grip force exerted for manipulating an inverted T-shaped object whose center of mass was changed across blocks of consecutive trials. For both experiments, subjects were asked to grasp the object at either predetermined or self-selected grasp locations ("constrained" and "unconstrained" task, respectively). Experiment 1 successfully validated the use of RMSE and CWT as they correctly distinguished trials with versus without force corrective responses. RMSE and CWT also revealed that grip force is characterized by more feedback-driven corrections when grasping at self-selected contact points. Future work will examine the application of our analytical approaches to a broader range of tasks, e.g., assessment of recovery of sensorimotor function following clinical intervention, interlimb

  7. Relationship Between Grip and Pinch Strength and Activities of Daily Living in Stroke Patients

    PubMed Central

    Bae, Jung Hyun; Seo, Kyung Mook; Kim, Don-Kyu; Shin, Hyun Iee; Shin, Hye Eun

    2015-01-01

    Objective To investigate the relationship between grip and pinch strength and independence in activities of daily living (ADL) in stroke patients. Methods Medical records of 577 stroke patients from January 2010 to February 2013 were retrospectively reviewed. Patients' grip and pinch strength of both hemiplegic and non-hemiplegic hands and the Korean version of Modified Barthel Index (K-MBI) score were collected. These patients were divided into three groups: group A (onset duration: ≤3 months), group B (onset duration: >3 months and <2 years), and group C (onset duration: ≥2 years). The correlation between grip and pinch strength and the K-MBI score was analyzed. Results In group A (95 patients), the K-MBI score was significantly (p<0.05) correlated with the grip and pinch strength of both hands in patients with right hemiplegia. Significant (p<0.05) correlation between the K-MBI score and the grip and pinch strength of the hemiplegic hand was shown in patients with left hemiplegia. In group B (69 patients) and group C (73 patients), the K-MBI score was significantly (p<0.05) correlated with the grip and pinch strength of the hemiplegic hand. Conclusion Stroke patients in subacute stage mainly performed activities of daily living using their dominant hand. However, independence in ADL was associated with the strength of the affected dominant hand. For stroke patients in chronic and late chronic stages, their hand power of the affected hand was associated with independence in ADL regardless whether the dominant hand was affected. PMID:26605173

  8. Clinical effectiveness of grip strength in predicting ambulation of elderly inpatients

    PubMed Central

    Beseler, MR; Rubio, C; Duarte, E; Hervás, D; Guevara, MC; Giner-Pascual, M; Viosca, E

    2014-01-01

    Background Assessing the clinical effectiveness of measuring grip strength as a prognostic tool in recovering ambulation in bed-confined frail elderly patients. Methods A prospective study was carried out with 50 elderly inpatients (mean age: 81.6 years old). Manual muscle test was used for checking strength of hip flexor muscles, hip abductor muscles and knee extensor muscles. Grip strength was assessed by hydraulic dynamometer. Walking ability was assessed by functional ambulation categories and Functional Classification of Sagunto Hospital Ambulation. Existence of cognitive impairment (Short Portable Mental Status of Pfeiffer) and comorbidity (abbreviated Charlson index) were considered to be confounding variables. Statistical analysis Simple comparisons and mixed models of multiple ordinal regression. Results The sample presented generalized weakness in scapular (mean 4.22) and pelvic (mean 3.82) muscle. Mean hand grip values were similar: 11.98 kg right hand; 11.70 kg left hand. The patients had lost walking ability. After treatment, there was a statistically significant for scapular waist strength (P=0.001), pelvic waist strength (P=0.005) and walking ability (P=0.001). A statistically significant relationship in the regression analysis was found between the grip (right and left hands) and walking ability post-treatment (P=0.009; odds ratio 1.14 and P=0.0014 odds ratio 1.113 for each walking scale). The confounding variables showed no statistical significance in the results. Conclusion Grip strength is associated with walking ability in hospitalized frail elderly. Grip strength assessment by hydraulic dynamometry is useful in patients with poor collaboration. Walking ability training in frail elderly inpatients is useful. PMID:25395842

  9. Grip-force modulation in multi-finger prehension during wrist flexion and extension

    PubMed Central

    Ambike, Satyajit S.; Paclet, Florent; Latash, Mark L.; Zatsiorsky, Vladimir M.

    2013-01-01

    Extrinsic digit muscles contribute to both fingertip forces and wrist movements (FDP and FPL – flexion, EDC - extension). Hence it is expected that finger forces depend on the wrist movement and position. We investigated the relation between grip force and wrist kinematics to examine whether and how the force: (1) scales with wrist flexion-extension (FE) angle; (2) can be predicted from accelerations induced during FE movement. In one experiment subjects naturally held an instrumented handle using a prismatic grasp and performed very slow FE movements. In another experiment, the same movement was performed cyclically at three prescribed frequencies. In quasistatic conditions, the grip force remained constant over the majority of the wrist range of motion. During the cyclic movements, the grip force changed. The changes were described with a linear regression model that represents the thumb and virtual finger (VF = four fingers combined) normal forces as the sum of the effects of the object’s tangential and radial accelerations and an object-weight-dependent constant term. The model explained 99% of the variability in the data. The independence of the grip force from wrist position agrees with the theory that that the thumb and VF forces are controlled with two neural variables that encode referent coordinates for each digit while accounting for changes in the position dependence of muscle forces, rather than a single neural variable like referent aperture. The results of the cyclical movement study extend the principle of superposition (some complex actions can be decomposed into independently controlled elemental actions) for a motor task involving simultaneous grip force exertion and wrist motion with significant length changes of the grip-force producing muscles. PMID:23625077

  10. Maximal intermittent handgrip strategy: design and evaluation of an exercise protocol and a grip tool.

    PubMed

    Bentley, Danielle Christine; Thomas, Scott Gordon

    2016-01-01

    Handgrip (HG) exercise has been prescribed as a lifestyle intervention to successfully reduce resting blood pressure (BP) among heterogeneous groups of participants. Current HG protocols have limited accessibility due to complicated exercise prescriptions and sophisticated required equipment. Therefore, this research describes the design and evaluation of the maximal intermittent (MINT) HG exercise strategy, consisting of both a novel exercise protocol (32×5 seconds maximal grip squeezes separated by 5 seconds of rest between sets) and an original grip tool. This research was a multistep progressive design that included 51 postmenopausal women as participants in three separate research studies. Part 1 of this research focuses on the MINT exercise protocol. A literature-informed rationale for the design of the protocol is described. This includes exercise intensity, work-to-rest ratio, and total exercise duration with reference to the unique physiology (mechanoreflex and metaboreflex) of postmenopausal women. Subsequent experimental analyses of acute responses to the MINT protocol revealed that women produced 50% of their maximum grip force with moderate cardiovascular responses (increases of systolic BP: 41.6 mmHg, diastolic BP: 20.1 mmHg, heart rate: 35.1 bpm) that remained far below the thresholds of concern identified by the American College of Sports Medicine. Part 2 of this research describes the creation of a novel grip tool, beginning with a mixed-methods assessment of participant opinions regarding two distinct in-laboratory grip tools, leading to the creation of four prototype MINT tools. Structured focus groups revealed a strong preference for MINT prototype 1 for all tool design features, including color, shape, size, and foam grip. Collectively, the result of this multistep research is a novel HG exercise strategy with enhanced accessibility by being easy to understand and simple to execute. The long-term training effectiveness of MINT as an exercise

  11. Oxygenator Safety Evaluation: A Focus on Connection Grip Strength and Arterial Temperature Measurement Accuracy

    PubMed Central

    Newland, Richard F.; Baker, Robert A.; Sanderson, Andrew J.; Tuble, Sigrid C.; Tully, Phil J.

    2012-01-01

    Abstract: This report describes the assessment of three specific safety-related specifications in the consideration of an alternate oxygenator; first the grip strength relationship between various oxygenator connectors and SMARxT® tubing, second, the grip strength of various biopassive tubings and an isolated SMARxT® connector, and finally, the accuracy of the arterial outlet temperature measurement. Grip strength experiments for the connections between the SMARxT® tubing and the venous reservoir outlet and the oxygenator venous inlet and oxygenator arterial outlet of the Medtronic Affinity®, Sorin Synthesis®, Sorin Primox®, and Terumo Capiox® RX25 oxygenators were performed. In addition we compared the grip strength of polyvinyl chloride, Physio®, Trillium®, Carmeda®, X-Coating®, and SMARxT® tubing. The accuracy of the integrated arterial outlet temperature probes was determined by comparing the temperatures measured by the integrated probe with a precision reference thermometer. Connector grip strength comparisons for the evaluation oxygenators with SMARxT® tubing showed significant variation between oxygenators and connections (p = .02). Evaluation of the arterial outlet showed significant variation between evaluation oxygenators, while at the venous reservoir outlet and oxygenator inlet, there were no significant differences. Grip strength comparison data for the various tubing types demonstrated a main effect for tubing type F(5, 18) = 8.01, p = .002, ηp2 = .77. Temperature accuracy measurements demonstrated that all oxygenators overread the arterial outlet temperature at 15°C, whilst at temperatures ≥25°C, all oxygenators underread the arterial outlet temperature. The integrity of SMARxT® tubing connection is influenced by the connector type, and may decline over time, highlighting the importance to not consider interchanging components of the bypass circuit as inconsequential. PMID:22893983

  12. Does visually induced self-motion affect grip force when holding an object?

    PubMed

    Bringoux, Lionel; Lepecq, Jean-Claude; Danion, Frédéric

    2012-09-01

    Accurate control of grip force during object manipulation is necessary to prevent the object from slipping, especially to compensate for the action of gravitational and inertial forces resulting from hand/object motion. The goal of the current study was to assess whether the control of grip force was influenced by visually induced self-motion (i.e., vection), which would normally be accompanied by changes in object load. The main task involved holding a 400-g object between the thumb and the index finger while being seated within a virtual immersive environment that simulated the vertical motion of an elevator across floors. Different visual motions were tested, including oscillatory (0.21 Hz) and constant-speed displacements of the virtual scene. Different arm-loading conditions were also tested: with or without the hand-held object and with or without oscillatory arm motion (0.9 Hz). At the perceptual level, ratings from participants showed that both oscillatory and constant-speed motion of the elevator rapidly induced a long-lasting sensation of self-motion. At the sensorimotor level, vection compellingness altered arm movement control. Spectral analyses revealed that arm motion was entrained by the oscillatory motion of the elevator. However, we found no evidence that grip force used to hold the object was visually affected. Specifically, spectral analyses revealed no component in grip force that would mirror the virtual change in object load associated with the oscillatory motion of the elevator, thereby allowing the grip-to-load force coupling to remain unaffected. Altogether, our findings show that the neural mechanisms underlying vection interfere with arm movement control but do not interfere with the delicate modulation of grip force. More generally, those results provide evidence that the strength of the coupling between the sensorimotor system and the perceptual level can be modulated depending on the effector. PMID:22723677

  13. The determination of the operating range of a twin-grip control yoke through biomechanical means

    NASA Technical Reports Server (NTRS)

    Gaertner, K. P.

    1978-01-01

    A twin-grip control yoke was designed as an ergonomic case study that allows dual axis control inputs, both axes being rotational. Inputs are effected by rotating the grips. How the handles were designed with respect to their shape and size and how the angular range of the control yoke in both rotational axes was evaluated. The control yoke which requires two-hand operation was tested to determine its operating range. The intention of this investigation was to find out the optimal form of the control yoke and the maximum permissible range in both rotating axes. In these experiments controls had no spring resistance.

  14. Association between floating toe and toe grip strength in school age children: a cross-sectional study

    PubMed Central

    Tasaka, Seishiro; Matsubara, Keisuke; Nishiguchi, Shu; Fukutani, Naoto; Tashiro, Yuto; Shirooka, Hidehiko; Nozaki, Yuma; Hirata, Hinako; Yamaguchi, Moe; Matsushita, Tomofumi; Fukumoto, Takahiko; Aoyama, Tomoki

    2016-01-01

    [Purpose] This study investigated the association between floating toe and toe grip strength. [Subjects and Methods] A total of 635 Japanese children aged 9–11 years participated in this study. Floating toe was evaluated using footprint images, while toe grip strength was measured using a toe grip dynamometer. All 1,270 feet were classified into a floating toe group and a normal toe group according to visual evaluation of the footprint images. Intergroup differences in toe grip strength were analyzed using the unpaired t-test and logistic regression analysis adjusted for age, gender, and Rohrer Index. [Results] There were 512 feet (40.3%) in the floating toe group. Mean toe grip strength of the feet with floating toe was significantly lower than that of normal feet (floating toe group, 12.9 ± 3.7 kg; normal toe group, 13.6 ± 4.1 kg). In addition, lower toe grip strength was associated with floating toe on logistic regression analysis after adjustment for age, gender, and Rohrer Index (odds ratio, 0.954; 95% confidence interval, 0.925–0.984). [Conclusion] This study revealed that lower toe grip strength was significantly associated with floating toe. Therefore, increasing toe grip strength may play a role in preventing floating toe in school age children.

  15. Activity-dependent synaptic GRIP1 accumulation drives synaptic scaling up in response to action potential blockade

    PubMed Central

    Gainey, Melanie A.; Tatavarty, Vedakumar; Nahmani, Marc; Lin, Heather; Turrigiano, Gina G.

    2015-01-01

    Synaptic scaling is a form of homeostatic plasticity that stabilizes neuronal firing in response to changes in synapse number and strength. Scaling up in response to action-potential blockade is accomplished through increased synaptic accumulation of GluA2-containing AMPA receptors (AMPAR), but the receptor trafficking steps that drive this process remain largely obscure. Here, we show that the AMPAR-binding protein glutamate receptor-interacting protein-1 (GRIP1) is essential for regulated synaptic AMPAR accumulation during scaling up. Synaptic abundance of GRIP1 was enhanced by activity deprivation, directly increasing synaptic GRIP1 abundance through overexpression increased the amplitude of AMPA miniature excitatory postsynaptic currents (mEPSCs), and shRNA-mediated GRIP1 knockdown prevented scaling up of AMPA mEPSCs. Furthermore, knockdown and replace experiments targeting either GRIP1 or GluA2 revealed that scaling up requires the interaction between GRIP1 and GluA2. Finally, GRIP1 synaptic accumulation during scaling up did not require GluA2 binding. Taken together, our data support a model in which activity-dependent trafficking of GRIP1 to synaptic sites drives the forward trafficking and enhanced synaptic accumulation of GluA2-containing AMPAR during synaptic scaling up. PMID:26109571

  16. Frimand Needle Holder Reduces Suturing Time and Surgical Stress When Suturing in Palm Grip.

    PubMed

    Frimand Rönnow, Carl-Fredrik; Jeppsson, Bengt; Thorlacius, Henrik

    2016-06-01

    Purpose The Frimand needle holder (FNH) was developed to facilitate palm grip suturing. In the present study, we wanted to examine the impact of the FNH compared with a conventional Hegar-styled needle holder (HSNH) on suture time and surgical stress. Methods Thirty-two surgeons were enrolled and they performed sets of 3 continuous sutures on a polyurethane pad with premarked insert and exit points and the time for suturing was measured. Surgical stress was quantified by having the surgeons to perform 10 release maneuvers with the FNH and the HSNH on a needle attached to a scale. The scale sent 5 values per second to a computer. The first measurement of each series was regarded as the starting weight and all subsequent measurements were either regarded as neutral, pressure or traction. The sum of these measurements represented total surgical stress. Results We found that all surgeons reduced their median suturing time by 16% when using FNH for palm grip suturing with no difference between junior and senior surgeons. Moreover, it was observed that FNH decreased median surgical stress by 62% for all surgeons performing palm grip suturing compared with a conventional HSNH. Conclusion We conclude that the FNH reduces suture time and surgical stress compared with HSNH when performing palm grip suturing. These findings warrant studies in surgical patients in order to evaluate the potential clinical impact of FNH. PMID:26474606

  17. The effect of precision and power grips on activations in human auditory cortex

    PubMed Central

    Wikman, Patrik A.; Vainio, Lari; Rinne, Teemu

    2015-01-01

    The neuroanatomical pathways interconnecting auditory and motor cortices play a key role in current models of human auditory cortex (AC). Evidently, auditory-motor interaction is important in speech and music production, but the significance of these cortical pathways in other auditory processing is not well known. We investigated the general effects of motor responding on AC activations to sounds during auditory and visual tasks (motor regions were not imaged). During all task blocks, subjects detected targets in the designated modality, reported the relative number of targets at the end of the block, and ignored the stimuli presented in the opposite modality. In each block, they were also instructed to respond to targets either using a precision grip, power grip, or to give no overt target responses. We found that motor responding strongly modulated AC activations. First, during both visual and auditory tasks, activations in widespread regions of AC decreased when subjects made precision and power grip responses to targets. Second, activations in AC were modulated by grip type during the auditory but not during the visual task. Further, the motor effects were distinct from the present strong attention-related modulations in AC. These results are consistent with the idea that operations in AC are shaped by its connections with motor cortical regions. PMID:26528121

  18. Motor command for precision grip in the macaque monkey can be mediated by spinal interneurons.

    PubMed

    Alstermark, B; Pettersson, L G; Nishimura, Y; Yoshino-Saito, K; Tsuboi, F; Takahashi, M; Isa, T

    2011-07-01

    In motor control, the general view is still that spinal interneurons mainly contribute to reflexes and automatic movements. The question raised here is whether spinal interneurons can mediate the cortical command for independent finger movements, like a precision grip between the thumb and index finger in the macaque monkey, or if this function depends exclusively on a direct corticomotoneuronal pathway. This study is a followup of a previous report (Sasaki et al. J Neurophysiol 92: 3142-3147, 2004) in which we trained macaque monkeys to pick a small piece of sweet potato from a cylinder by a precision grip between the index finger and thumb. We have now isolated one spinal interneuronal system, the C3-C4 propriospinal interneurons with projection to hand and arm motoneurons. In the previous study, the lateral corticospinal tract (CST) was interrupted in C4/C5 (input intact to the C3-C4 propriospinal interneurons), and in this study, the CST was interrupted in C2 (input abolished). The precision grip could be performed within the first 15 days after a CST lesion in C4/C5 but not in C2. We conclude that C3-C4 propriospinal interneurons also can carry the command for precision grip. PMID:21511706

  19. The effect of precision and power grips on activations in human auditory cortex.

    PubMed

    Wikman, Patrik A; Vainio, Lari; Rinne, Teemu

    2015-01-01

    The neuroanatomical pathways interconnecting auditory and motor cortices play a key role in current models of human auditory cortex (AC). Evidently, auditory-motor interaction is important in speech and music production, but the significance of these cortical pathways in other auditory processing is not well known. We investigated the general effects of motor responding on AC activations to sounds during auditory and visual tasks (motor regions were not imaged). During all task blocks, subjects detected targets in the designated modality, reported the relative number of targets at the end of the block, and ignored the stimuli presented in the opposite modality. In each block, they were also instructed to respond to targets either using a precision grip, power grip, or to give no overt target responses. We found that motor responding strongly modulated AC activations. First, during both visual and auditory tasks, activations in widespread regions of AC decreased when subjects made precision and power grip responses to targets. Second, activations in AC were modulated by grip type during the auditory but not during the visual task. Further, the motor effects were distinct from the present strong attention-related modulations in AC. These results are consistent with the idea that operations in AC are shaped by its connections with motor cortical regions. PMID:26528121

  20. Grip Force Control Is Dependent on Task Constraints in Children with and without Developmental Coordination Disorder

    ERIC Educational Resources Information Center

    Law, Sui-Heung; Lo, Sing Kai; Chow, Susanna; Cheing, Gladys L.Y.

    2011-01-01

    Excessive grip force (GF) is often found in children with developmental coordination disorder (DCD). However, their GF control may vary when task constraints are imposed upon their motor performance. This study aimed to investigate how their GF control changes in response to task demands, and to examine their tactile sensitivity. Twenty-one…

  1. 16 CFR Figure 5 to Part 1512 - Typical Handbrake Actuator Showing Grip Dimension

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Typical Handbrake Actuator Showing Grip Dimension 5 Figure 5 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 5 Figure 5 to Part 1512—Typical...

  2. 16 CFR Figure 5 to Part 1512 - Typical Handbrake Actuator Showing Grip Dimension

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Typical Handbrake Actuator Showing Grip Dimension 5 Figure 5 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 5 Figure 5 to Part 1512—Typical...

  3. 16 CFR Figure 5 to Part 1512 - Typical Handbrake Actuator Showing Grip Dimension

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Typical Handbrake Actuator Showing Grip Dimension 5 Figure 5 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 5 Figure 5 to Part 1512—Typical...

  4. Automated pressure map segmentation for quantifying phalangeal kinetics during cylindrical gripping.

    PubMed

    Sinsel, Erik W; Gloekler, Daniel S; Wimer, Bryan M; Warren, Christopher M; Wu, John Z; Buczek, Frank L

    2016-02-01

    Inverse dynamics models used to investigate musculoskeletal disorders associated with handle gripping require accurate phalangeal kinetics. Cylindrical handles wrapped with pressure film grids have been used in studies of gripping kinetics. We present a method fusing six degree-of-freedom hand kinematics and a kinematic calibration of a cylinder-wrapped pressure film. Phalanges are modeled as conic frusta and projected onto the pressure grid, automatically segmenting the pressure map into regions of interest (ROIs). To demonstrate the method, segmented pressure maps are presented from two subjects with substantially different hand length and body mass, gripping cylinders 50 and 70 mm in diameter. For each ROI, surface-normal force vectors were summed to create a reaction force vector and center of pressure location. Phalangeal force magnitudes for a data sample were similar to that reported in previous studies. To evaluate our method, a surrogate was designed for each handle such that when modeled as a phalanx it would generate a ROI around the cells under its supports; the classification F-score was above 0.95 for both handles. Both the human subject results and the surrogate evaluation suggest that the approach can be used to automatically segment the pressure map for quantifying phalangeal kinetics of the fingers during cylindrical gripping. PMID:26709291

  5. How Predictive Is Grip Force Control in the Complete Absence of Somatosensory Feedback?

    ERIC Educational Resources Information Center

    Nowak, Dennis A.; Glasauer, Stefan; Hermsdorfer, Joachim

    2004-01-01

    Grip force control relies on accurate internal models of the dynamics of our motor system and the external objects we manipulate. Internal models are not fixed entities, but rather are trained and updated by sensory experience. Sensory feedback signals relevant object properties and mechanical events, e.g. at the skin-object interface, to modify…

  6. The transcriptional coregulator GRIP1 controls macrophage polarization and metabolic homeostasis.

    PubMed

    Coppo, Maddalena; Chinenov, Yurii; Sacta, Maria A; Rogatsky, Inez

    2016-01-01

    Diet-induced obesity causes chronic macrophage-driven inflammation in white adipose tissue (WAT) leading to insulin resistance. WAT macrophages, however, differ in their origin, gene expression and activities: unlike infiltrating monocyte-derived inflammatory macrophages, WAT-resident macrophages counteract inflammation and insulin resistance, yet, the mechanisms underlying their transcriptional programming remain poorly understood. We recently reported that a nuclear receptor cofactor-glucocorticoid receptor (GR)-interacting protein (GRIP)1-cooperates with GR to repress inflammatory genes. Here, we show that GRIP1 facilitates macrophage programming in response to IL4 via a GR-independent pathway by serving as a coactivator for Kruppel-like factor (KLF)4-a driver of tissue-resident macrophage differentiation. Moreover, obese mice conditionally lacking GRIP1 in macrophages develop massive macrophage infiltration and inflammation in metabolic tissues, fatty livers, hyperglycaemia and insulin resistance recapitulating metabolic disease. Thus, GRIP1 is a critical regulator of immunometabolism, which engages distinct transcriptional mechanisms to coordinate the balance between macrophage populations and ultimately promote metabolic homeostasis. PMID:27464507

  7. Infants' grip strength predicts mu rhythm attenuation during observation of lifting actions with weighted blocks.

    PubMed

    Upshaw, Michaela B; Bernier, Raphael A; Sommerville, Jessica A

    2016-03-01

    Research has established that the body is fundamentally involved in perception: bodily experience influences activation of the shared neural system underlying action perception and production during action observation, and bodily characteristics influence perception of the spatial environment. However, whether bodily characteristics influence action perception and its underlying neural system is unknown, particularly in early ontogeny. We measured grip strength in 12-month-old infants and investigated relations with mu rhythm attenuation, an electroencephalographic correlate of the neural system underlying action perception, during observation of lifting actions performed with differently weighted blocks. We found that infants with higher grip strength exhibited significant mu attenuation during observation of lifting actions, whereas infants with lower grip strength did not. Moreover, a progressively strong relation between grip strength and mu attenuation during observation of lifts was found with increased block weight. We propose that this relation is attributable to differences in infants' ability to recognize the effort associated with lifting objects of different weights, as a consequence of their developing strength. Together, our results extend the body's role in perception by demonstrating that bodily characteristics influence action perception by shaping the activation of its underlying neural system. PMID:25939632

  8. The transcriptional coregulator GRIP1 controls macrophage polarization and metabolic homeostasis

    PubMed Central

    Coppo, Maddalena; Chinenov, Yurii; Sacta, Maria A.; Rogatsky, Inez

    2016-01-01

    Diet-induced obesity causes chronic macrophage-driven inflammation in white adipose tissue (WAT) leading to insulin resistance. WAT macrophages, however, differ in their origin, gene expression and activities: unlike infiltrating monocyte-derived inflammatory macrophages, WAT-resident macrophages counteract inflammation and insulin resistance, yet, the mechanisms underlying their transcriptional programming remain poorly understood. We recently reported that a nuclear receptor cofactor—glucocorticoid receptor (GR)-interacting protein (GRIP)1—cooperates with GR to repress inflammatory genes. Here, we show that GRIP1 facilitates macrophage programming in response to IL4 via a GR-independent pathway by serving as a coactivator for Kruppel-like factor (KLF)4—a driver of tissue-resident macrophage differentiation. Moreover, obese mice conditionally lacking GRIP1 in macrophages develop massive macrophage infiltration and inflammation in metabolic tissues, fatty livers, hyperglycaemia and insulin resistance recapitulating metabolic disease. Thus, GRIP1 is a critical regulator of immunometabolism, which engages distinct transcriptional mechanisms to coordinate the balance between macrophage populations and ultimately promote metabolic homeostasis. PMID:27464507

  9. Precision Grip in Congenital and Acquired Hemiparesis: Similarities in Impairments and Implications for Neurorehabilitation

    PubMed Central

    Bleyenheuft, Yannick; Gordon, Andrew M.

    2014-01-01

    Background: Patients with congenital and acquired hemiparesis incur long-term functional deficits, among which the loss of prehension that may impact their functional independence. Identifying, understanding, and comparing the underlying mechanisms of prehension impairments represent an opportunity to better adapt neurorehabilitation. Objective: The present review aims to provide a better understanding of precision grip deficits in congenital and acquired hemiparesis and to determine whether the severity and type of fine motor control impairments depend on whether or not the lesions are congenital or acquired in adulthood. Methods: Using combinations of the following key words: fingertip force, grip force, precision grip, cerebral palsy, stroke, PubMed, and Scopus databases were used to search studies from 1984 to 2013. Results: Individuals with both congenital and acquired hemiparesis were able to some extent to use anticipatory motor control in precision grip tasks, even if this control was impaired in the paretic hand. In both congenital and acquired hemiparesis, the ability to plan efficient anticipatory motor control when the less-affected hand is used provides a possibility to remediate impairments in anticipatory motor control of the paretic hand. Conclusion: Surprisingly, we observed very few differences between the results of studies in children with congenital hemiplegia and stroke patients. We suggest that the underlying specific strategies of neurorehabilitation developed for each one could benefit the other. PMID:25071502

  10. Fingerboard in Competitive Bouldering: Training Effects on Grip Strength and Endurance.

    PubMed

    Medernach, Jerry P J; Kleinöder, Heinz; Lötzerich, Helmut H H

    2015-08-01

    Bouldering (BL) is an independent discipline of sport climbing, with grip strength and endurance as key factors. Although the sport has grown increasingly popular and competitive, limited research has been conducted on commonly used training methods to maximize BL performance. The purpose of this study was to investigate the training effects of 4 weeks of fingerboarding (FB) on grip strength and endurance in competitive BL. Twenty-three highly advanced male boulderers (25.6 ± 4.4 y; 1.78 ± 0.05 m; 70.1 ± 5.4 kg; 6.2 ± 2.8 y climbing; 7b+ Fb mean ability) were randomly allocated to a 4-week FB (n = 11) or BL (n = 12) training regimen. Pretests and posttests (50-min duration) involved (a) handheld dynamometry (GS) to assess grip strength, (b) dead hangs (DH), and (c) intermittent finger hangs (IFH) to assess grip endurance. After the 4-week regimen, GS increased significantly in the FB group (2.5 ± 1.4 kg, p < 0.001) but not in the BL group (1.4 ± 2.8 kg, p = 0.109). The mean increase in DH ranged from 5.4 to 6.7 seconds in the FB group and was significantly (p ≤ 0.05) higher than that in the BL group (3.0-3.9 seconds). Finally, significantly higher IFH gains were observed in the FB group (p = 0.004), with a mean gain of 26 seconds, but not in the BL group (p = 0.168). These results suggest that FB is highly effective in increasing grip strength and endurance in competitive BL. PMID:26203738

  11. Precision grip responses to unexpected rotational perturbations scale with axis of rotation.

    PubMed

    De Gregorio, Michael; Santos, Veronica J

    2013-04-01

    It has been established that rapid, pulse-like increases in precision grip forces ("catch-up responses") are elicited by unexpected translational perturbations and that response latency and strength scale according to the direction of linear slip relative to the hand as well as gravity. To determine if catch-up responses are elicited by unexpected rotational perturbations and are strength-, axis-, and/or direction-dependent, we imposed step torque loads about each of two axes which were defined relative to the subject's hand: the distal-proximal axis away from and towards the subject's palm, and the grip axis which connects the two fingertips. Precision grip responses were dominated initially by passive mechanics and then by active, unimodal catch-up responses. First dorsal interosseous activity, marking the start of the catch-up response, began 71-89 ms after the onset of perturbation. The onset latency, shape, and duration (217-231 ms) of the catch-up response were not affected by the axis, direction, or magnitude of the rotational perturbation, while strength was scaled by axis of rotation and slip conditions. Rotations about the grip axis that tilted the object away from the palm and induced rotational slip elicited stronger catch-up responses than rotations about the distal-proximal axis that twisted the object between the digits. To our knowledge, this study is the first to investigate grip responses to unexpected torque loads and to show characteristic, yet axis-dependent, catch-up responses for conditions other than pure linear slip. PMID:23499162

  12. Hand grip strength and associated factors in non-institutionalised men and women 50 years and older in South Africa

    PubMed Central

    2014-01-01

    Background Little is known about the prevalence, predictors and gender differences in hand grip strength of older adults in Africa. This study aims to investigate social and health differences in hand grip strength among older adults in a national probability sample of older South Africans who participated in the Study of Global Ageing and Adults Health (SAGE wave 1) in 2008. Methods We conducted a national population-based cross-sectional study with a sample of 3840 men and women aged 50 years or older in South Africa. The questionnaire included socio-demographic characteristics, health variables, and anthropometric measurements. Linear multivariate regression analysis was performed to assess the association of social factors, health variables and grip strength. Results The mean overall hand grip strength was 37.9 kgs for men (mean age 61.1 years, SD = 9.1) and 31.5 kgs for women (mean age 62.0 years, SD = 9.7). In multivariate analysis among men, greater height, not being underweight and lower functional disability was associated with greater grip strength, and among women, greater height, better cognitive functioning, and lower functional disability were associated with greater grip strength. Conclusions Greater height and lower functional disability were found for both older South African men and women to be significantly associated with grip strength. PMID:24393403

  13. An electromyographic study of the effect of hand grip sizes on forearm muscle activity and golf performance.

    PubMed

    Sorbie, Graeme G; Hunter, Henry H; Grace, Fergal M; Gu, Yaodong; Baker, Julien S; Ugbolue, Ukadike Chris

    2016-01-01

    The study describes the differences in surface electromyography (EMG) activity of two forearm muscles in the lead and trail arm at specific phases of the golf swing using a 7-iron with three different grip sizes among amateur and professional golfers. Fifteen right-handed male golfers performed five golf swings using golf clubs with three different grip sizes. Surface EMG was used to measure muscle activity of the extensor carpi radialis brevis (ECRB) and flexor digitorum superficialis (FDS) on both forearms. There were no significant differences in forearm muscle activity when using the three golf grips within the group of 15 golfers (p > 0.05). When using the undersize grip, club head speed significantly increased (p = 0.044). During the backswing and downswing phases, amateurs produced significantly greater forearm muscle activity with all three grip sizes (p < 0.05). In conclusion, forearm muscle activity is not affected by grip sizes. However, club head speed increases when using undersize grips. PMID:27267082

  14. Respiratory performance and grip strength tests in Indian school bodys of different socio-economic status.

    PubMed Central

    De, A. K.; Debnath, P. K.; Dey, N. K.; Nagchaudhuri, J.

    1980-01-01

    Physical efficiency tests were performed on urban school boys drawn from high socio-economic status in comparison to rural school boys. The height and weight records of the subjects indicating growing process showed that the rural boys attained less physical growth than their urban counterparts. The Vital Capacity and Peak Expiratory Flow Rate data expressed either per unit of height or body surface area were significantly lower in rual boys. these findings indicated a poor development of the thorax in the rural group. However, the determined grip strengths for both the group were similar. The grip test might reflect improvement of muscle mass in case of rural boys as a result of regular physical activity employing the arm muscles. Images p145-a p145-b PMID:7407454

  15. Serotonergic-postsynaptic receptors modulate gripping-induced immobility episodes in male taiep rats.

    PubMed

    Eguibar, José R; Cortés, M C; Ita, M L

    2009-09-01

    The Taiep rat is a myelin mutant with a motor syndrome characterized by tremor, ataxia, immobility, epilepsy, and paralysis. The rat shows a hypomyelination followed by a progressive demyelination. During immobilities taiep rats show a REM-like sleep pattern and a disorganized sleep-wake pattern suggesting taiep rats as a model of narcolepsy-cataplexy. Our study analyzed the role of postsynaptic serotonin receptors in the expression of gripping-induced immobility episodes (IEs) in 8-month-old male taiep rats. The specific postsynaptic serotonin agonist +/-1-(2,5-dimethoxy-4-iodoamphetamine hydrochloride (+/-DOI) decreased the frequency of gripping-induced IEs, but that was not the case with alpha-methyl-serotonin maleate (alpha-methyl-5HT), a nonspecific postsynaptic agonist. Although the serotonin antagonists, ketanserine and metergoline, produced a biphasic effect, first a decrease followed by an increase with higher doses, similar effects were obtained with a mean duration of gripping-induced IEs. These findings correlate with the pharmacological observations in narcoleptic dogs and humans in which serotonin-reuptake inhibitors improve cataplexy, particularly in long-term treatment that could change the serotonin receptor levels. Polysomnographic recordings showed an increase in the awakening time and a decrease in the slow wave and rapid eye movement sleep concomitant with a decrease in immobilities after use of +/-DOI, this being stronger with the highest dose. Taken together, our results show that postsynaptic serotonin receptors are involved in the modulation in gripping-induced IEs caused by the changes in the organization of the sleep-wake cycle in taiep rats. It is possible that specific agonists, without side effects, could be a useful treatment in human narcoleptic patients. PMID:19484723

  16. Tension free open inguinal hernia repair using an innovative self gripping semi-resorbable mesh

    PubMed Central

    Chastan, Philippe

    2006-01-01

    Aims: Inguinal hernia repair according to Lichtenstein technique has become the most common procedure performed by general surgeons. Heavy weight polypropylene meshes have been reported to stimulate inflammatory reaction responsible for mesh shrinkage when scar tissue evolved. Additionally, some concerns remain regarding the relationship between chronic pain and mesh fixation technique. In order to reduce those drawbacks, we have developed a new mesh for anterior tension free inguinal hernia repair which exhibits self-gripping absorbable properties. Materials and Methods: 52 patients (69 hernias) were prospectivly operated with this mesh (SOFRADIM-France) made of low-weight isoelastic large pores knitted fabric which incorporated resorbable micro hooks that provides self gripping properties to the mesh during the first months post-implantation. The fixation of the mesh onto the tissues is significantly facilitated. The mesh is secured around the cord with a self gripping flap. After complete tissular ingrowth and resorption of the PLA hooks, the low-weight (40 g/m2) polypropylene mesh insures the long term wall reinforcement. Results: Peroperativly, no complication was reported, the mesh was easy to handle and to fix. Discharge was obtained at Day 1. No perioperative complication occurred, return to daily activities was obtained at Day 5.5. At one month, no neurological pain or other complications were described. Conclusions: Based on the first results of this clinical study, this unique concept of low density self gripping mesh should allows an efficient treatment of inguinal hernia. It should reduce postoperative complications and the extent of required suture fixation, making the procedure more reproducible PMID:21187984

  17. Arm function after stroke. An evaluation of grip strength as a measure of recovery and a prognostic indicator.

    PubMed Central

    Sunderland, A; Tinson, D; Bradley, L; Hewer, R L

    1989-01-01

    The value of strength of voluntary grip as an indicator of recovery of arm function was assessed by testing 38 recent stroke patients using a sensitive electronic dynamometer, and comparing the results with those from five other arm movement and function tests (Motricity Index, Motor Club Assessment, Nine Hole Peg Test, and Frenchay Arm Test). This procedure allowed measurement of grip in a large proportion of patients, and strength correlated highly with performance on the other tests. Measuring grip over a six month follow up period was a sensitive method of charting intrinsic neurological recovery. The presence of voluntary grip at one month indicates that there will be some functional recovery at six months. PMID:2592969

  18. The Great Lakes Runoff Intercomparison Project (GRIP): Phase II, Lake Ontario

    NASA Astrophysics Data System (ADS)

    Gronewold, A.; Tolson, B.; Gaborit, E.; Fortin, V.; Fry, L. M.; Hunter, T.

    2015-12-01

    The Great Lakes runoff intercomparison project (GRIP) was established to assess a suite of models used primarily for simulating and forecasting flows from all of the major tributaries within the Great Lakes basin. These models are somewhat unique, in part because they were developed to overcome challenges of assimilating data across an international border, and in part because they are often an integral component of regional water budget models that also include simulations of over-lake precipitation and over-lake evaporation (both of which are, on annual time scales, of the same magnitude as runoff). Here, we present the next step in the evolution of GRIP (following GRIP-M, the first phase of the project that focused on Lake Michigan) with a comparison between different hydrological models (including GR4J and the NOAA large basin runoff model) and different regional precipitation data sources across the Lake Ontario basin. Results of our analysis provide insights that underscore the importance of the spatial and temporal resolution of a model domain and its forcings, along with their connections to model skill and selected objective criteria. Perhaps more importantly, our results are expected to assist in the advancement of regional hydrological models not only for improved forecasts of the Great Lakes water cycle, but in other large international freshwater basins as well.

  19. Examining the effect of the Flextend Orthotic Device on grip strength: a pilot study.

    PubMed

    James, Debra M; Branson, Bonnie G; Simmer-Beck, Melanie; Bray, Kimberly K

    2010-01-01

    Strengthening exercises like those used to treat carpal tunnel syndrome have been recommended for prevention however their effectiveness when used in this manner are not known. The purpose of this study was to determine the effects of the Flextend Orthotic Device on grip strength of dental hygiene students. This study used a convenience sample of 24 (n=24) first year dental hygiene students. Students were randomly assigned to either the Flextend Orthotic Exercise glove group or a control group. A series of grip strength measurements were taken periodically throughout the study using a hydraulic hand dynamometer. In a repeated measures analysis of covariance there were no significant effects for study group (p=0.812) time (p=0.954), nor was there a significant interaction between group and time (p=0.858). Use of the Flextend Orthotic Device did not additionally increase grip strength among dental hygiene students over the eight week time period. In none of the weeks post baseline was there a significant difference between the Flextend Orthotic Device group and control groups. PMID:20448327

  20. Flash Detection Efficiencies of Long Range Lightning Detection Networks During GRIP

    NASA Technical Reports Server (NTRS)

    Mach, Douglas M.; Bateman, Monte G.; Blakeslee, Richard J.

    2012-01-01

    We flew our Lightning Instrument Package (LIP) on the NASA Global Hawk as a part of the Genesis and Rapid Intensification Processes (GRIP) field program. The GRIP program was a NASA Earth science field experiment during the months of August and September, 2010. During the program, the LIP detected lighting from 48 of the 213 of the storms overflown by the Global Hawk. The time and location of tagged LIP flashes can be used as a "ground truth" dataset for checking the detection efficiency of the various long or extended range ground-based lightning detection systems available during the GRIP program. The systems analyzed included Vaisala Long Range (LR), Vaisala GLD360, the World Wide Lightning Location Network (WWLLN), and the Earth Networks Total Lightning Network (ENTLN). The long term goal of our research is to help understand the advantages and limitations of these systems so that we can utilize them for both proxy data applications and cross sensor validation of the GOES-R Geostationary Lightning Mapper (GLM) sensor when it is launched in the 2015 timeframe.

  1. Observations During GRIP from HIRAD: Ocean Surface Wind Speed and Rain Rate

    NASA Technical Reports Server (NTRS)

    Miller, Timothy L.; James, M. W.; Jones, L.; Ruf, C. S.; Uhlhorn, E. W.; Bailey, M. C.; Buckley, C. D.; Simmons, D. E.; Johnstone, S.; Peterson, A.; Schultz, L. A.; Biewas, S.; Johnson, J. W.; Shah, G.; Feingstein, D.; Cleveland, W. H.; Johnson, J.; Hood, R. E.

    2011-01-01

    HIRAD (Hurricane Imaging Radiometer) flew on the WB-57 during NASA's GRIP (Genesis and Rapid Intensification Processes) campaign in August - September of 2010. HIRAD is a new C-band radiometer using a synthetic thinned array radiometer (STAR) technology to obtain cross-track resolution of approximately 3 degrees, out to approximately 60 degrees to each side of nadir. By obtaining measurements of emissions at 4, 5, 6, and 6.6 GHz, observations of ocean surface wind speed and rain rate can be inferred. This technique has been used for many years by precursor instruments, including the Stepped Frequency Microwave Radiometer (SFMR), which has been flying on the NOAA and USAF hurricane reconnaissance aircraft for several years. The advantage of HIRAD over SFMR is that HIRAD can observe a +/- 60-degree swath, rather than a single footprint at nadir angle. Results from the flights during the GRIP campaign will be shown, including images of brightness temperatures, wind speed, and rain rate. To the extent possible, comparisons will be made with observations from other instruments on the GRIP campaign, for which HIRAD observations are either directly comparable or are complementary. Potential impacts on operational ocean surface wind analyses and on numerical weather forecasts will also be discussed.

  2. Getting a grip on other minds: mirror neurons, intention understanding, and cognitive empathy.

    PubMed

    Kaplan, Jonas T; Iacoboni, Marco

    2006-01-01

    We have previously shown that a right inferior frontal mirror neuron area for grasping responds differently to observed grasping actions embedded in contexts that suggest different intentions, such as drinking and cleaning (Iacoboni, Molnar-Szakacs, Gallese, Buccino, Mazziotta, & Rizzolatti, 2005). Information about intentions, however, may be conveyed also by the grasping action itself: for instance, people typically drink by grasping the handle of a cup with a precision grip. In this fMRI experiment, subjects watched precision grips and whole-hand prehensions embedded in a drinking or an eating context. Indeed, in the right inferior frontal mirror neuron area there was higher activity for observed precision grips in the drinking context. Signal changes in the right inferior frontal mirror neuron area were also significantly correlated with scores on Empathic Concern subscale of the Interpersonal Reactivity Index, a measure of emotional empathy. These data suggest that human mirror neuron areas use both contextual and grasping type information to predict the intentions of others. They also suggest that mirror neuron activity is strongly linked to social competence. PMID:18633786

  3. Substrate diameter and compliance affect the gripping strategies and locomotor mode of climbing boa constrictors.

    PubMed

    Byrnes, Greg; Jayne, Bruce C

    2010-12-15

    Arboreal habitats pose unique challenges for locomotion as a result of their narrow cylindrical surfaces and discontinuities between branches. Decreased diameter of branches increases compliance, which can pose additional challenges, including effects on stability and energy damping. However, the combined effects of substrate diameter and compliance are poorly understood for any animal. We quantified performance, kinematics and substrate deformation while boa constrictors (Boa constrictor) climbed vertical ropes with three diameters (3, 6 and 9 mm) and four tensions (0.5, 1.0, 1.5 and 2.0 body weights). Mean forward velocity decreased significantly with both decreased diameter and increased compliance. Both diameter and compliance had numerous effects on locomotor kinematics, but diameter had larger and more pervasive effects than compliance. Locomotion on the largest diameter had a larger forward excursion per cycle, and the locomotor mode and gripping strategy differed from that on the smaller diameters. On larger diameters, snakes primarily applied opposing forces at the same location on the rope to grip. By contrast, on smaller diameters forces were applied in opposite directions at different locations along the rope, resulting in increased rope deformation. Although energy is likely to be lost during deformation, snakes might use increased surface deformation as a strategy to enhance their ability to grip. PMID:21113006

  4. A three-dimensional finite element model of maximal grip loading in the human wrist.

    PubMed

    Gislason, M K; Nash, D H; Nicol, A; Kanellopoulos, A; Bransby-Zachary, M; Hems, T; Condon, B; Stansfield, B

    2009-10-01

    The aim of this work was to create an anatomically accurate three-dimensional finite element model of the wrist, applying subject-specific loading and quantifying the internal load transfer through the joint during maximal grip. For three subjects, representing the anatomical variation at the wrist, loading on each digit was measured during a maximal grip strength test with simultaneous motion capture. The internal metacarpophalangeal joint load was calculated using a biomechanical model. High-resolution magnetic resonance scans were acquired to quantify bone geometry. Finite element analysis was performed, with ligaments and tendons added, to calculate the internal load distribution. It was found that for the maximal grip the thumb carried the highest load, an average of 72.2 +/- 20.1 N in the neutral position. Results from the finite element model suggested that the highest regions of stress were located at the radial aspect of the carpus. Most of the load was transmitted through the radius, 87.5 per cent, as opposed to 12.5 per cent through the ulna with the wrist in a neutral position. A fully three-dimensional finite element analysis of the wrist using subject-specific anatomy and loading conditions was performed. The study emphasizes the importance of modelling a large ensemble of subjects in order to capture the spectrum of the load transfer through the wrist due to anatomical variation. PMID:19908424

  5. Control of grip force when tilting objects: effect of curvature of grasped surfaces and applied tangential torque.

    PubMed

    Goodwin, A W; Jenmalm, P; Johansson, R S

    1998-12-15

    When we manipulate objects in everyday tasks, there are variations in the shape of the grasped surfaces, and the loads that potentially destabilize the grasp include time-varying linear forces and torques tangential to the grasped surfaces. Previous studies of the control of fingertip forces for grasp stability have dealt principally with flat grip surfaces and linear force loads. Here, we studied the regulation of grip force with changes in curvature of grasped surfaces and changes in tangential torque applied by the index finger and thumb when humans lifted an object and rotated it about the horizontal grip axis through an angle of 65 degrees. The curvatures of the matched pair of spherical surfaces varied from -50 m-1 (concave with radius 20 mm) to 200 m-1 (convex with radius 5 mm). The applied tangential torque at the orientation of 65 degrees was varied sixfold. Regardless of the values of curvature and end torque, grip force and tangential torque were coordinated, increasing in parallel throughout the tilt with an approximately linear relationship; the slope of the line increased progressively with increasing surface curvature. This parametric scaling of grip force was directly related to the minimum grip force required to prevent rotational slip, resulting in an adequate safety margin against slip in all cases. We conclude that surface curvature parametrically influences grip force regulation when the digits are exposed to torsional loads. Furthermore, the sensorimotor programs that control the grip force apparently predict the effect of the total load comprising linear forces and tangential torques. PMID:9852607

  6. Associations between grip strength of parents and their 4 year old children: findings from the Southampton Women’s Survey

    PubMed Central

    Inskip, Hazel; Macdonald-Wallis, Corrie; Kapasi, Tasneem; Robinson, Siân; Godfrey, Keith; Cooper, Cyrus; Harvey, Nicholas; Sayer, Avan Aihie

    2013-01-01

    Summary Relationships between birthweight and grip strength throughout the lifecourse suggest that early influences on the growth and development of muscle are important for long-term muscle function. However, little is known about parental influences on children’s grip strength. We have explored this in the Southampton Women’s Survey, a prospective general population cohort study from before conception through childhood. Grip strength was measured using a Jamar handgrip dynamometer in the mother at 19 weeks’ gestation and her partner, and in the child at age four years. Pre-pregnancy heights and weights were measured in the mothers; reported weights and measured heights were available for the fathers. Complete data on parents and children were available for 444 trios. In univariate analyses, both parents’ grip strengths were significantly associated with that of the child (r=0.17, p<0.001 for mothers, r=0.15, p=0.002 for fathers). These correlations were similar to that between the grip strength of the mothers and the father (r=0.17, P<0.001). In the multivariate model, after adjustment for child’s height and physical activity, the correlations with the child’s grip strength were attenuated, being 0.10 (P=0.02) and 0.11 (P=0.01) for mothers’ and fathers’ grip strength respectively. The findings show that grip strength of both parents is associated with that of their child, indicating that heritable influences and the shared family environment influence the development of muscle strength. This contributes to our understanding of the role of heritable and environmental factors on early muscle growth and development, which are important for muscle function across the lifecourse. PMID:22150705

  7. Assessment of grip strength with the modified sphygmomanometer test: association between upper limb global strength and motor function

    PubMed Central

    Martins, Júlia C.; Aguiar, Larissa T.; Lara, Eliza M.; Teixeira-Salmela, Luci F.; Faria, Christina D. C. M.

    2015-01-01

    ABSTRACT Background: Grip strength, commonly evaluated with the handgrip dynamometer, is a good indicator of upper limb (UL) function in stroke subjects and may reflect the global strength deficits of the whole paretic UL. The Modified Sphygmomanometer Test (MST) also provides objective and adequate measures at low-cost. Objective: To assess whether grip strength values obtained by using the MST and those obtained by using a handgrip dynamometer would present similar correlations with the global strength and motor function of the paretic UL in subjects with stroke, both in the subacute and chronic phases. Method: Measures of grip strength (MST and handgrip dynamometer), UL global strength (MST and hand-held dynamometer), and UL motor function (Fugl-Meyer motor assessment scale) were obtained with 33 subacute and 44 chronic stroke subjects. Pearson and Spearman correlation coefficients were calculated and Stepwise multiple regression analyses were performed to investigate predictor variables of grip strength (α=0.05). Results: Significant correlations of similar magnitude were found between measures of global strength of the paretic UL and grip strength assessed with both the MST (0.66≤r≤0.78) and handgrip dynamometer (0.66≤r≤0.78) and between UL motor function and grip strength assessed with both the MST (0.50≤rs≤0.51) and hand-held dynamometer (0.50≤rs≤0.63) in subacute and chronic stroke subjects. Only global strength remained as a significant predictor variable of grip strength for the MST (0.43≤R2≤0.61) and for the handgrip dynamometer (0.44≤R2≤0.61) for both stroke subgroups. Conclusion: Grip strength assessed with the MST could be used to report paretic UL global strength. PMID:26647752

  8. The Association of Levels of and Decline in Grip Strength in Old Age with Trajectories of Life Course Occupational Position

    PubMed Central

    Fritzell, Johan; Hoffmann, Rasmus

    2016-01-01

    Background The study of the influence of life course occupational position (OP) on health in old age demands analysis of time patterns in both OP and health. We study associations between life course time patterns of OP and decline in grip strength in old age. Methods We analyze 5 waves from the Survey of Health Ageing and Retirement in Europe (n = 5108, ages 65–90). We use a pattern-mixture latent growth model to predict the level and decline in grip strength in old age by trajectory of life course OP. We extend and generalize the structured regression approach to establish the explanatory power of different life course models for both the level and decline of grip strength. Results Grip strength declined linearly by 0.70 kg (95% CI -0.74;-0.66) for men and 0.42 kg (95% CI -0.45;-0.39) for women per year. The level of men’s grip strength can best be explained by a critical period during midlife, with those exposed to low OP during this period having 1.67 kg (95% CI -2.33;-1.00) less grip strength. These differences remain constant over age. For women, no association between OP and levels of or decline in grip strength was found. Conclusions Men’s OP in midlife seems to be a critical period for the level of grip strength in old age. Inequalities remain constant over age. The integration of the structured regression approach and latent growth modelling offers new possibilities for life course epidemiology. PMID:27232696

  9. In vivo bite and grip forces, morphology and prey-killing behavior of North American accipiters (Accipitridae) and falcons (Falconidae).

    PubMed

    Sustaita, Diego; Hertel, Fritz

    2010-08-01

    Raptors exhibit a diversity of strategies to procure their prey but ultimately kill using their beaks and/or talons. Thus, bite and grip forces are ecologically important variables that have direct survival implications. Whereas hawks rely primarily on their feet for killing prey, falcons tend to employ their beaks. Consequently, falcons are expected to achieve relatively greater bite forces, and hawks are expected to generate relatively greater grip forces. Force estimates predicted from musculoskeletal morphology in a previous study indicated that falcons (Falco spp.) possess greater jaw force capabilities than accipiters (Accipiter spp.) but there were no clear differences in predicted grip-force capacity outside of differences in scaling. The objective of this study was to complement those results with measurements of in vivo forces by inducing captive and wild accipiters and falcons to bite and grasp force transducers. Bite force increased isometrically in both groups whereas grip force tended toward positive allometry. After adjusting for body mass, falcons produced greater bite forces, and accipiters produced greater grip forces. Thus, previous anatomical estimates of forces predicted the expected direction and magnitude of differences in bite forces but the overall greater in vivo grip forces of accipiters deviated from the pattern obtained from biomechanical estimates. Although the scaling relationships were similar between data sets, forces generated by live birds were consistently lower than those predicted from biomechanics. Estimated and in vivo jaw and digital forces were nevertheless correlated, and therefore provide an important link between morphology and killing behavior in these raptors. PMID:20639423

  10. The interdigital brace and other grips for termite nest perforation by chimpanzees of the Goualougo Triangle, Republic of Congo.

    PubMed

    Lesnik, Julie J; Sanz, Crickette M; Morgan, David B

    2015-06-01

    Studies of chimpanzee termite foraging enlighten our understanding of early hominin tool use not only by modeling the cognitive ability of our ancestors but also by emphasizing the possible role of social insects in the hominin diet. The chimpanzees of the Goualougo Triangle are known to have one of the largest and most complex tool repertoires reported for wild chimpanzees. One tool set habitually used by this population includes a perforating tool to penetrate the hard outer crust of elevated termite nests before fishing for termite prey with an herbaceous stem. Here, we report the variation present in the grips used on the perforating tool. Our analysis of video recordings of chimpanzee visitation to termite nests over a 3-year period shows that these chimpanzees use a variety of grips to navigate the challenges encountered in opening a termite nest. For situations in which the soil is most hardened, perforating requires force and a power grip is often used. When the soil in the passageway is loose, precision grips are suitable for the task. One of the preferred grips reported here is an interdigital brace, which has previously been described in studies of how some people hold a pencil. In this study, for the first time, the interdigital brace has been thoroughly described for chimpanzees. The various strategies and grips used during perforation emphasize the importance of termites as a nutritional resource that should be considered more strongly as a food used by early hominins. PMID:25916822

  11. Relationship Between Grip, Pinch Strengths and Anthropometric Variables, Types of Pitch Throwing Among Japanese High School Baseball Pitchers

    PubMed Central

    Tajika, Tsuyoshi; Kobayashi, Tsutomu; Yamamoto, Atsushi; Shitara, Hitoshi; Ichinose, Tsuyoshi; Shimoyama, Daisuke; Okura, Chisa; Kanazawa, Saeko; Nagai, Ayako; Takagishi, Kenji

    2015-01-01

    Background: Grip and pinch strength are crucially important attributes and standard parameters related to the functional integrity of the hand. It seems significant to investigate normative data for grip and pinch strength of baseball players to evaluate their performance and condition. Nevertheless, few reports have explained the association between grip and pinch strength and anthropometric variables and types of pitch throwing for baseball pitchers. Objectives: The aim of this study was to measure and evaluate clinical normative data for grip and tip, key, palmar pinch strength and to assess the relationship between these data and anthropometric variables and types of pitch throwing among Japanese high-school baseball pitchers. Materials and Methods: One hundred-thirty three healthy high school baseball pitchers were examined and had completed a self-administered questionnaire including items related to age, hand dominance, throwing ratio of type of pitch. A digital dynamometer was used to measure grip strength and a pinch gauge to measure tip, key and palmer pinch in both dominant and nondominant side. Body composition was measured by the multi frequency segmental body composition analyzer. Results: Grip strength and tip and palmer pinch strength in dominant side were statistically greater than them in nondominant side (P < 0.05). There were significant associations between grip strength and height (r = 0.33, P < 0.001), body mass (r = 0.50, P < 0.001), BMI (r = 0.37, P < 0.001), muscle mass of upper extremity (r = 0.56, P < 0.001), fat free mass (r = 0.57, P < 0.001), fat mass (r = 0.22, P < 0.05) in dominant side. A stepwise multiple regression analysis revealed that fat free mass and tip, palmer, key pinch strength were predictors of grip strength in dominant side. No statistical significant correlations were found between the throwing ratio of types of pitches thrown and grip strength and tip, key, palmar pinch strength. Conclusions: Our result provides

  12. Gloss, colour and grip: multifunctional epidermal cell shapes in bee- and bird-pollinated flowers.

    PubMed

    Papiorek, Sarah; Junker, Robert R; Lunau, Klaus

    2014-01-01

    Flowers bear the function of filters supporting the attraction of pollinators as well as the deterrence of floral antagonists. The effect of epidermal cell shape on the visual display and tactile properties of flowers has been evaluated only recently. In this study we quantitatively measured epidermal cell shape, gloss and spectral reflectance of flowers pollinated by either bees or birds testing three hypotheses: The first two hypotheses imply that bee-pollinated flowers might benefit from rough surfaces on visually-active parts produced by conical epidermal cells, as they may enhance the colour signal of flowers as well as the grip on flowers for bees. In contrast, bird-pollinated flowers might benefit from flat surfaces produced by flat epidermal cells, by avoiding frequent visitation from non-pollinating bees due to a reduced colour signal, as birds do not rely on specific colour parameters while foraging. Moreover, flat petal surfaces in bird-pollinated flowers may hamper grip for bees that do not touch anthers and stigmas while consuming nectar and thus, are considered as nectar thieves. Beside this, the third hypothesis implies that those flower parts which are vulnerable to nectar robbing of bee- as well as bird-pollinated flowers benefit from flat epidermal cells, hampering grip for nectar robbing bees. Our comparative data show in fact that conical epidermal cells are restricted to visually-active parts of bee-pollinated flowers, whereas robbing-sensitive parts of bee-pollinated as well as the entire floral surface of bird-pollinated flowers possess on average flat epidermal cells. However, direct correlations between epidermal cell shape and colour parameters have not been found. Our results together with published experimental studies show that epidermal cell shape as a largely neglected flower trait might act as an important feature in pollinator attraction and avoidance of antagonists, and thus may contribute to the partitioning of flower

  13. The Gamma-Ray Imager/Polarimeter for Solar Flares (GRIPS)

    NASA Technical Reports Server (NTRS)

    Shih, Albert Y.; Lin, Robert P.; Hurford, Gordon J.; Duncan, Nicole A.; Saint-Hilaire, Pascal; Bain, Hazel M.; Boggs, Steven E.; Zoglauer, Andreas C.; Smith, David M.; Tajima, Hiroyasu; Amman, Mark S.; Takahashi, Tadayuki

    2012-01-01

    The balloon-borne Gamma-Ray Imager/Polarimeter for Solar flares (GRIPS) instrument will provide a near-optimal combination of high-resolution imaging, spectroscopy, and polarimetry of solar-flare gamma-ray/hard X-ray emissions from approximately 20 keV to greater than approximately 10 MeV. GRIPS will address questions raised by recent solar flare observations regarding particle acceleration and energy release, such as: What causes the spatial separation between energetic electrons producing hard X-rays and energetic ions producing gamma-ray lines? How anisotropic are the relativistic electrons, and why can they dominate in the corona? How do the compositions of accelerated and ambient material vary with space and time, and why? The spectrometer/polarimeter consists of sixteen 3D position-sensitive germanium detectors (3D-GeDs), where each energy deposition is individually recorded with an energy resolution of a few keV FWHM and a spatial resolution of less than 0.1 cubic millimeter. Imaging is accomplished by a single multi-pitch rotating modulator (MPRM), a 2.5-centimeter thick tungsten alloy slit/slat grid with pitches that range quasi-continuously from 1 to 13 millimeters. The MPRM is situated 8 meters from the spectrometer to provide excellent image quality and unparalleled angular resolution at gamma-ray energies (12.5 arcsec FWHM), sufficient to separate 2.2 MeV footpoint sources for almost all flares. Polarimetry is accomplished by analyzing the anisotropy of reconstructed Compton scattering in the 3D-GeDs (i.e., as an active scatterer), with an estimated minimum detectable polarization of a few percent at 150-650 keV in an X-class flare. GRIPS is scheduled for a continental-US engineering test flight in fall 2013, followed by long or ultra-long duration balloon flights in Antarctica.

  14. Effects of anodal transcranial direct current stimulation on visually guided learning of grip force control.

    PubMed

    Minarik, Tamas; Sauseng, Paul; Dunne, Lewis; Berger, Barbara; Sterr, Annette

    2015-01-01

    Anodal transcranial Direct Current Stimulation (tDCS) has been shown to be an effective non-invasive brain stimulation method for improving cognitive and motor functioning in patients with neurological deficits. tDCS over motor cortex (M1), for instance, facilitates motor learning in stroke patients. However, the literature on anodal tDCS effects on motor learning in healthy participants is inconclusive, and the effects of tDCS on visuo-motor integration are not well understood. In the present study we examined whether tDCS over the contralateral motor cortex enhances learning of grip-force output in a visually guided feedback task in young and neurologically healthy volunteers. Twenty minutes of 1 mA anodal tDCS were applied over the primary motor cortex (M1) contralateral to the dominant (right) hand, during the first half of a 40 min power-grip task. This task required the control of a visual signal by modulating the strength of the power-grip for six seconds per trial. Each participant completed a two-session sham-controlled crossover protocol. The stimulation conditions were counterbalanced across participants and the sessions were one week apart. Performance measures comprised time-on-target and target-deviation, and were calculated for the periods of stimulation (or sham) and during the afterphase respectively. Statistical analyses revealed significant performance improvements over the stimulation and the afterphase, but this learning effect was not modulated by tDCS condition. This suggests that the form of visuomotor learning taking place in the present task was not sensitive to neurostimulation. These null effects, together with similar reports for other types of motor tasks, lead to the proposition that tDCS facilitation of motor learning might be restricted to cases or situations where the motor system is challenged, such as motor deficits, advanced age, or very high task demand. PMID:25738809

  15. Gloss, Colour and Grip: Multifunctional Epidermal Cell Shapes in Bee- and Bird-Pollinated Flowers

    PubMed Central

    Papiorek, Sarah; Junker, Robert R.; Lunau, Klaus

    2014-01-01

    Flowers bear the function of filters supporting the attraction of pollinators as well as the deterrence of floral antagonists. The effect of epidermal cell shape on the visual display and tactile properties of flowers has been evaluated only recently. In this study we quantitatively measured epidermal cell shape, gloss and spectral reflectance of flowers pollinated by either bees or birds testing three hypotheses: The first two hypotheses imply that bee-pollinated flowers might benefit from rough surfaces on visually-active parts produced by conical epidermal cells, as they may enhance the colour signal of flowers as well as the grip on flowers for bees. In contrast, bird-pollinated flowers might benefit from flat surfaces produced by flat epidermal cells, by avoiding frequent visitation from non-pollinating bees due to a reduced colour signal, as birds do not rely on specific colour parameters while foraging. Moreover, flat petal surfaces in bird-pollinated flowers may hamper grip for bees that do not touch anthers and stigmas while consuming nectar and thus, are considered as nectar thieves. Beside this, the third hypothesis implies that those flower parts which are vulnerable to nectar robbing of bee- as well as bird-pollinated flowers benefit from flat epidermal cells, hampering grip for nectar robbing bees. Our comparative data show in fact that conical epidermal cells are restricted to visually-active parts of bee-pollinated flowers, whereas robbing-sensitive parts of bee-pollinated as well as the entire floral surface of bird-pollinated flowers possess on average flat epidermal cells. However, direct correlations between epidermal cell shape and colour parameters have not been found. Our results together with published experimental studies show that epidermal cell shape as a largely neglected flower trait might act as an important feature in pollinator attraction and avoidance of antagonists, and thus may contribute to the partitioning of flower

  16. First flight of the Gamma-Ray Imager/Polarimeter for Solar flares (GRIPS)

    NASA Astrophysics Data System (ADS)

    Saint-Hilaire, Pascal; Shih, Albert Y.; Duncan, Nicole; Bain, Hazel; Maruca, Bennett A.; Kelley, Nicole; Godbole, Niharika; Kaufmann, Pierre; Caspi, Amir; Sample, John; Hoberman, Jane; Mochizuki, Brent; Olson, Jerry; Boggs, Steven E.; Zoglauer, Andreas; Hurford, Gordon J.; Smith, David M.; Tajima, Hiroyasu; Amman, Mark

    2016-05-01

    The Gamma-Ray Imager/Polarimeter for Solar flares (GRIPS) high altitude balloon payload was successfully flown in January 2016 from Antarctica (Jan 19 to Jan 30).GRIPS provides a near-optimal combination of high-resolution imaging, spectroscopy, and polarimetry of solar-flare gamma ray/hard X-ray emissions from ~20 keV to >~10 MeV. GRIPS’s goal is to address questions raised by recent solar flare observations regarding particle acceleration and energy release, such as: What causes the spatial separation between energetic electrons producing hard X-rays and energetic ions producing gamma-ray lines? How anisotropic are the relativistic electrons, and why can they dominate in the corona? How do the compositions of accelerated and ambient material vary with space and time, and why? The spectrometer/polarimeter consists of six 3D position-sensitive germanium detectors (3D-GeDs), where each energy deposition is individually recorded with an energy resolution of a few keV FWHM and a spatial resolution <0.1 mm3. Imaging is accomplished by a single multi-pitch rotating modulator (MPRM), a 2.5-cm thick tungsten alloy slit/slat grid with pitches that range quasi-continuously from 1 to 13 mm. The MPRM is situated 8 meters from the spectrometer to provide excellent image quality and unparalleled angular resolution at gamma-ray energies (12.5 arcsec FWHM), sufficient to separate 2.2 MeV footpoint sources for almost all flares. Polarimetry is accomplished by analyzing the anisotropy of reconstructed Compton scattering in the 3D-GeDs, with an estimated minimum detectable polarization of a few percent at 150-650 keV in an X-class flare. GRIPS was also equipped with active BGO shields, and three piggy-back instruments: a solar terahertz radiometer (Solar-T), a hard X-ray spectrometer (SMASH), and a sonic anemometer (TILDAE).We will present an overview of GRIPS's first flight, the performance of its instruments and subsystems, including the solar pointing and aspect systems, and

  17. Effect of Three Different Grip Angles on Physiological Parameters During Laboratory Handcycling Test in Able-Bodied Participants

    PubMed Central

    Abel, Thomas; Burkett, Brendan; Thees, Barbara; Schneider, Stefan; Askew, Christopher D.; Strüder, Heiko K.

    2015-01-01

    Introduction: Handcycling is a relatively new wheelchair sport that has gained increased popularity for people with lower limb disabilities. The aim of this study was to examine the effect of three different grip positions on physical parameters during handcycling in a laboratory setting. Methods: Twenty one able-bodied participants performed three maximum incremental handcycling tests until exhaustion, each with a different grip angle. The angle between the grip and the crank was randomly set at 90° (horizontal), 0° (vertical), or 10° (diagonal). The initial load was 20 W and increased by 20 W each 5 min. In addition, participants performed a 20 s maximum effort. Results: The relative peak functional performance (W/kg), peak heart rate (bpm), associated lactate concentrations (mmol/l) and peak oxygen uptake per kilogram body weight (ml.min−1.kg−1) for the different grip positions during the stage test were: (a) Horizontal: 1.43 ± 0.21 W/kg, 170.14 ± 12.81 bpm, 9.54 ± 1.93 mmol/l, 30.86 ± 4.57 ml/kg; (b) Vertical: 1.38 ± 0.20 W/kg, 171.81 ± 13.87 bpm, 9.91 ± 2.29 mmol/l, 29.75 ± 5.13 ml/kg; (c) Diagonal: 1.40 ± 0.22 W/kg, 169.19 ± 13.31 bpm, 9.34 ± 2.36 mmol/l, 29.39 ± 4.70 ml/kg. Statistically significant (p < 0.05) differences could only be found for lactate concentration between the vertical grip position and the other grips during submaximal handcycling. Conclusion: The orientation of three different grip angles made no difference to the peak load achieved during an incremental handcycling test and a 20 s maximum effort. At submaximal load, higher lactate concentrations were found when the vertical grip position was used, suggesting that this position may be less efficient than the alternative diagonal or horizontal grip positions. PMID:26635617

  18. Palmitoylation by DHHC5/8 targets GRIP1 to dendritic endosomes to regulate AMPA-R trafficking

    PubMed Central

    Thomas, Gareth M.; Hayashi, Takashi; Chen, Chih-Ming; Chiu, Shu-Ling; Huganir, Richard L.

    2012-01-01

    Summary Palmitoylation, a key regulatory mechanism controlling protein targeting, is catalyzed by DHHC-family palmitoyl acyltransferases (PATs). Impaired PAT activity is linked to several neurodevelopmental and neuropsychiatric disorders, suggesting critical roles for palmitoylation in neuronal function. However, few substrates for specific PATs are known, and functional consequences of specific palmitoylation events are frequently uncharacterized. Here, we identify two related PATs, DHHC5 and DHHC8, as specific regulators of the PDZ domain protein GRIP1b. Binding, palmitoylation and dendritic targeting of GRIP1b require a DHHC5/8 PDZ ligand that is absent in all other PATs. Palmitoylated GRIP1b is targeted to trafficking endosomes, and may link endosomes to kinesin motors. Consistent with this trafficking role, GRIP1b's palmitoylation turnover rate approaches the highest of all reported proteins, and palmitoylation increases GRIP1b's ability to accelerate AMPA-R recycling. These findings identify the first neuronal DHHC5/8 substrate, define novel mechanisms controlling palmitoylation specificity, and suggest further links between dysregulated palmitoylation and neurodevelopmental / neuropsychiatric conditions. PMID:22325201

  19. Low haemoglobin levels contribute to low grip strength independent of low-grade inflammation in Japanese elderly women.

    PubMed

    Yamada, Eriko; Takeuchi, Mika; Kurata, Miki; Tsuboi, Ayaka; Kazumi, Tsutomu; Fukuo, Keisuke

    2015-01-01

    Muscle strength declines with age. However, factors that contribute to such declines are not well documented and have not been extensively studied in elderly populations of Asian origin. Correlations of grip strength with a broad range of factors associated with declines in muscle strength were examined in 202 community-living elderly Japanese women. After adjustment for age, grip strength was positively correlated with body weight, height, serum albumin, haemoglobin, high-density lipoprotein cholesterol (HDL-C) and serum iron and inversely with serum copper, and log high-sensitivity C-reactive protein (hsCRP). Multiple linear regression analysis with grip strength as a dependent variable showed that 47.0% of variability of grip strength could be accounted for by height, age and haemoglobin in order of increasing R2. In conclusion, low haemoglobin may contribute to low muscle strength independently of age, anthropometric, nutritional, and inflammatory markers in the elderly, and may represent an important confounder of the association between grip strength and functional decline in community- living Japanese elderly women. PMID:26420185

  20. Grip strength comparison in immune-mediated neuropathies: Vigorimeter vs. Jamar.

    PubMed

    Draak, Thomas H P; Pruppers, Mariëlle H J; van Nes, Sonja I; Vanhoutte, Els K; Bakkers, Mayienne; Gorson, Kenneth C; Van der Pol, W-Ludo; Lewis, Richard A; Notermans, Nicolette C; Nobile-Orazio, Eduardo; Léger, Jean-Marc; Van den Bergh, Peter Y K; Lauria, Giuseppe; Bril, Vera; Katzberg, Hans; Lunn, Michael P T; Pouget, Jean; van der Kooi, Anneke J; van den Berg, Leonard H; van Doorn, Pieter A; Cornblath, David R; Hahn, Angelika F; Faber, Catharina G; Merkies, Ingemar S J

    2015-09-01

    The Jamar dynamometer and Vigorimeter have been used to assess grip strength in immune-mediated neuropathies, but have never been compared to each other. Therefore, we performed a comparison study between these two devices in patients with immune-mediated neuropathies. Grip strength data were collected in 102 cross-sectional stable and 163 longitudinal (new diagnoses or changing condition) patients with Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), gammopathy-related polyneuropathy (MGUSP), and multifocal motor neuropathy (MMN). Stable patients were assessed twice (validity/reliability studies). Longitudinal patients were assessed 3-5 times during 1 year. Responsiveness comparison between the two tools was examined using combined anchor-/distribution-based minimum clinically important difference (MCID) techniques. Patients were asked to indicate their preference for the Jamar or Vigorimeter. Both tools correlated highly with each other (ρ = 0.86, p < 0.0001) and showed good intra-class correlation coefficients (Jamar [Right/Left hands]: ICC 0.997/0.96; Vigori: ICC 0.95/0.98). Meaningful changes were comparable between the two instruments, being higher in GBS compared to CIDP patients. In MGUSP/MMN poor responsiveness was seen. Significant more patients preferred the Vigorimeter. In conclusion, validity, reliability, and responsiveness aspects were comparable between the Jamar dynamometer and Vigorimeter. However, based on patients' preference, the Vigorimeter is recommended in future studies in immune-mediated neuropathies. PMID:26115516

  1. Gripping Mechanisms for Microgravity and Extreme Terrain and Vertical Climbing Micro Ground Vehicle

    NASA Technical Reports Server (NTRS)

    McKenzie, Clifford; Parness, Aaron

    2011-01-01

    Asteroids and comets may provide insight into the origins of our solar system and the precursors to life on our planet. Near Earth objects offer an accessible target of opportunity, but are small and lack the gravity necessary for conventional wheeled travel. Therefore, it is necessary to develop alternative methods for maneuvering in these environments. This project researched and developed a method for gripping rock surfaces. Work has been completed on the design and prototyping of several possible hooked gripping mechanisms. Future work includes quantitative testing, downselection to a final design, and attachment to the robotic platform, Lemur IIb. A second project focuses on the development of a 100g, crash-proof robot capable of climbing vertical surfaces using a novel silicone adhesive. Capable of carrying video/audio payloads the robot may serve as a surveillance tool for the Department of Defense or as a method of pre-flight spacecraft inspections. A specialized track was developed to provide the specific loading conditions necessary for proper engagement of the adhesive. Both of these projects rely heavily on the shape deposition manufacturing process, being researched at JPL, and 3D printing.

  2. The brain adjusts grip forces differently according to gravity and inertia: a parabolic flight experiment

    PubMed Central

    White, Olivier

    2015-01-01

    In everyday life, one of the most frequent activities involves accelerating and decelerating an object held in precision grip. In many contexts, humans scale and synchronize their grip force (GF), normal to the finger/object contact, in anticipation of the expected tangential load force (LF), resulting from the combination of the gravitational and the inertial forces. In many contexts, GF and LF are linearly coupled. A few studies have examined how we adjust the parameters–gain and offset–of this linear relationship. However, the question remains open as to how the brain adjusts GF regardless of whether LF is generated by different combinations of weight and inertia. Here, we designed conditions to generate equivalent magnitudes of LF by independently varying mass and movement frequency. In a control experiment, we directly manipulated gravity in parabolic flights, while other factors remained constant. We show with a simple computational approach that, to adjust GF, the brain is sensitive to how LFs are produced at the fingertips. This provides clear evidence that the analysis of the origin of LF is performed centrally, and not only at the periphery. PMID:25717293

  3. Complex interaction of Drosophila GRIP PDZ domains and Echinoid during muscle morphogenesis.

    PubMed

    Swan, Laura E; Schmidt, Manuela; Schwarz, Tobias; Ponimaskin, Evgeni; Prange, Ulrike; Boeckers, Tobias; Thomas, Ulrich; Sigrist, Stephan J

    2006-08-01

    Glutamate receptor interacting protein (GRIP) homologues, initially characterized in synaptic glutamate receptor trafficking, consist of seven PDZ domains (PDZDs), whose conserved arrangement is of unknown significance. The Drosophila GRIP homologue (DGrip) is needed for proper guidance of embryonic somatic muscles towards epidermal attachment sites, with both excessive and reduced DGrip activity producing specific phenotypes in separate muscle groups. These phenotypes were utilized to analyze the molecular architecture underlying DGrip signaling function in vivo. Surprisingly, removing PDZDs 1-3 (DGripDelta1-3) or deleting ligand binding in PDZDs 1 or 2 convert DGrip to excessive in vivo activity mediated by ligand binding to PDZD 7. Yeast two-hybrid screening identifies the cell adhesion protein Echinoid's (Ed) type II PDZD-interaction motif as binding PDZDs 1, 2 and 7 of DGrip. ed loss-of-function alleles exhibit muscle defects, enhance defects caused by reduced DGrip activity and suppress the dominant DGripDelta1-3 effect during embryonic muscle formation. We propose that Ed and DGrip form a signaling complex, where competition between N-terminal and the C-terminal PDZDs of DGrip for Ed binding controls signaling function. PMID:16858411

  4. Electric Field Measurements During the Genesis and Rapid Intensification Processes (GRIP) Field Program

    NASA Technical Reports Server (NTRS)

    Bateman, Monte G.; Blakeslee, Richard J.; Mach, Douglas M.

    2010-01-01

    During the Genesis and Rapid Intensification Processes (GRIP) field program, a system of 6 electric field mills was flown on one of NASA's Global Hawk aircraft. We placed several mills on the aircraft to enable us to measure the vector electric field. We created a distributed, ethernet-connected system so that each sensor has its own embedded Linux system, complete with web server. This makes our current generation system fully "sensor web enabled." The Global Hawk has several unique qualities, but relevant to quality storm electric field measurements are high altitude (20 km) and long duration (20-30 hours) flights. There are several aircraft participating in the GRIP program, and coordinated measurements are happening. Lightning and electric field measurements will be used to study the relationships between lightning and other storm characteristics. It has been long understood that lightning can be used as a marker for strong convective activity. Past research and field programs suggest that lightning flash rate may serve as an indicator and precursor for rapid intensification change in tropical cyclones and hurricanes. We have the opportunity to sample hurricanes for many hours at a time and observe intensification (or de-intensification) periods. The electrical properties of hurricanes during such periods are not well known. American

  5. Interpretations of Wrist/Grip Operations From SEMG Signals at Different Locations on Arm.

    PubMed

    Ryait, H S; Arora, A S; Agarwal, R

    2010-04-01

    Surface electromyogram (SEMG) is a common method of measurement of muscle activity. It is noninvasive and is measured with minimal risk to the subject. The analysis of SEMG signal depends on a number of factors, such as amplitude as well as time- and frequency-domain properties. In the present investigation, the study of SEMG signals at different below elbow muscles for four operations of the hand wrist/grip-like opening (op)/closing (cl)/down (d)/up (u) was carried out. Myoelectric signals were extracted by using a single-channel SEMG amplifier consisting of a differential amplifier, noninverting amplifier, and interface module. Matlab softscope was used to acquire the SEMG signal from the hardware. After acquiring the data from six selected locations, interpretations were made for the estimation of parameters of the SEMG using the Matlab-filter algorithm and the fast Fourier transform technique. An interpretation of wrist/grip operations using principal component analysis (PCA) was carried out. PCA was used to identify the best SEMG signal capturing system out of two-channel, three-channel, and four-channel systems. Two acupressure points (on wrist) were also selected for the analysis with other points on the arm. SEMG signal's study at different locations, including pressure points, will be a very helpful tool for the researchers in understanding the behavior of SEMG for the development of the prosthetic hand. PMID:23853317

  6. Hurricane Imaging Radiometer Wind Speed and Rain Rate Retrievals during the 2010 GRIP Flight Experiment

    NASA Technical Reports Server (NTRS)

    Sahawneh, Saleem; Farrar, Spencer; Johnson, James; Jones, W. Linwood; Roberts, Jason; Biswas, Sayak; Cecil, Daniel

    2014-01-01

    Microwave remote sensing observations of hurricanes, from NOAA and USAF hurricane surveillance aircraft, provide vital data for hurricane research and operations, for forecasting the intensity and track of tropical storms. The current operational standard for hurricane wind speed and rain rate measurements is the Stepped Frequency Microwave Radiometer (SFMR), which is a nadir viewing passive microwave airborne remote sensor. The Hurricane Imaging Radiometer, HIRAD, will extend the nadir viewing SFMR capability to provide wide swath images of wind speed and rain rate, while flying on a high altitude aircraft. HIRAD was first flown in the Genesis and Rapid Intensification Processes, GRIP, NASA hurricane field experiment in 2010. This paper reports on geophysical retrieval results and provides hurricane images from GRIP flights. An overview of the HIRAD instrument and the radiative transfer theory based, wind speed/rain rate retrieval algorithm is included. Results are presented for hurricane wind speed and rain rate for Earl and Karl, with comparison to collocated SFMR retrievals and WP3D Fuselage Radar images for validation purposes.

  7. Effect of skin hydration on the dynamics of fingertip gripping contact

    PubMed Central

    André, T.; Lévesque, V.; Hayward, V.; Lefèvre, P.; Thonnard, J.-L.

    2011-01-01

    The dynamics of fingertip contact manifest themselves in the complex skin movements observed during the transition from a stuck state to a fully developed slip. While investigating this transition, we found that it depended on skin hydration. To quantify this dependency, we asked subjects to slide their index fingertip on a glass surface while keeping the normal component of the interaction force constant with the help of visual feedback. Skin deformation inside the contact region was imaged with an optical apparatus that allowed us to quantify the relative sizes of the slipping and sticking regions. The ratio of the stuck skin area to the total contact area decreased linearly from 1 to 0 when the tangential force component increased from 0 to a maximum. The slope of this relationship was inversely correlated to the normal force component. The skin hydration level dramatically affected the dynamics of the contact encapsulated in the course of evolution from sticking to slipping. The specific effect was to reduce the tendency of a contact to slip, regardless of the variations of the coefficient of friction. Since grips were more unstable under dry skin conditions, our results suggest that the nervous system responds to dry skin by exaggerated grip forces that cannot be simply explained by a change in the coefficient of friction. PMID:21490002

  8. Haptic feedback enhances grip force control of sEMG-controlled prosthetic hands in targeted reinnervation amputees.

    PubMed

    Kim, Keehoon; Colgate, J Edward

    2012-11-01

    In this study, we hypothesized that haptic feedback would enhance grip force control of surface electromyography (sEMG)-controlled prosthetic hands for targeted reinnervation (TR) amputees. A new miniature haptic device, a tactor, that can deliver touch, pressure, shear, and temperature sensation, allows modality-matching haptic feedback. TR surgery that creates sensory regions on the patient's skin that refer to the surface of the missing limb allows somatotopic-matching haptic feedback. This paper evaluates the hypothesis via an sEMG-controlled virtual prosthetic arm operated by TR amputees under diverse haptic feedback conditions. The results indicate that the grip force control is significantly enhanced via the haptic feedback. However, the simultaneous display of two haptic channels (pressure and shear) does not enhance, but instead degrades, grip force control. PMID:22855230

  9. Modeling the Maturation of Grip Selection Planning and Action Representation: Insights from Typical and Atypical Motor Development.

    PubMed

    Fuelscher, Ian; Williams, Jacqueline; Wilmut, Kate; Enticott, Peter G; Hyde, Christian

    2016-01-01

    We investigated the purported association between developmental changes in grip selection planning and improvements in an individual's capacity to represent action at an internal level [i.e., motor imagery (MI)]. Participants were groups of healthy children aged 6-7 years and 8-12 years respectively, while a group of adolescents (13-17 years) and adults (18-34 years) allowed for consideration of childhood development in the broader context of motor maturation. A group of children aged 8-12 years with probable DCD (pDCD) was included as a reference group for atypical motor development. Participants' proficiency to generate and/or engage internal action representations was inferred from performance on the hand rotation task, a well-validated measure of MI. A grip selection task designed to elicit the end-state comfort (ESC) effect provided a window into the integrity of grip selection planning. Consistent with earlier accounts, the efficiency of grip selection planning followed a non-linear developmental progression in neurotypical individuals. As expected, analysis confirmed that these developmental improvements were predicted by an increased capacity to generate and/or engage internal action representations. The profile of this association remained stable throughout the (typical) developmental spectrum. These findings are consistent with computational accounts of action planning that argue that internal action representations are associated with the expression and development of grip selection planning across typical development. However, no such association was found for our sample of children with pDCD, suggesting that individuals with atypical motor skill may adopt an alternative, sub-optimal strategy to plan their grip selection compared to their same-age control peers. PMID:26903915

  10. Modeling the Maturation of Grip Selection Planning and Action Representation: Insights from Typical and Atypical Motor Development

    PubMed Central

    Fuelscher, Ian; Williams, Jacqueline; Wilmut, Kate; Enticott, Peter G.; Hyde, Christian

    2016-01-01

    We investigated the purported association between developmental changes in grip selection planning and improvements in an individual’s capacity to represent action at an internal level [i.e., motor imagery (MI)]. Participants were groups of healthy children aged 6–7 years and 8–12 years respectively, while a group of adolescents (13–17 years) and adults (18–34 years) allowed for consideration of childhood development in the broader context of motor maturation. A group of children aged 8–12 years with probable DCD (pDCD) was included as a reference group for atypical motor development. Participants’ proficiency to generate and/or engage internal action representations was inferred from performance on the hand rotation task, a well-validated measure of MI. A grip selection task designed to elicit the end-state comfort (ESC) effect provided a window into the integrity of grip selection planning. Consistent with earlier accounts, the efficiency of grip selection planning followed a non-linear developmental progression in neurotypical individuals. As expected, analysis confirmed that these developmental improvements were predicted by an increased capacity to generate and/or engage internal action representations. The profile of this association remained stable throughout the (typical) developmental spectrum. These findings are consistent with computational accounts of action planning that argue that internal action representations are associated with the expression and development of grip selection planning across typical development. However, no such association was found for our sample of children with pDCD, suggesting that individuals with atypical motor skill may adopt an alternative, sub-optimal strategy to plan their grip selection compared to their same-age control peers. PMID:26903915

  11. Normative static grip strength of population of Turkey, effects of various factors and a comparison with international norms.

    PubMed

    Ekşioğlu, Mahmut

    2016-01-01

    Normative data are of importance in ergonomics and clinical settings. Applying normative data internationally is questionable. To this end, this study aimed to establish gender- and age-specific reference values for static (isometric) hand grip strength of normal population of Turkey with special regard to occupational demand, and compare them with the international norms. The secondary aims were to investigate the effects of gender, age-group, weight-group, job-group, hand and several anthropometric variables on static grip strength. A sample of 211 (128 male and 83 female) volunteers aged between 18 and 69 with various occupations participated in the study. Grip strength data were collected using a Jamar dynamometer with standard testing position, protocol and instructions. The mean and std deviation of maximum voluntary static grip strength values (in N) for dominant and non-dominant hands respectively were 455.2 ± 73.6 and 441.5 ± 72.6 for males, and 258 ± 46.1 and 246.2 ± 49.1 for females. The mean female strength was about 57% of the mean male strength value for both dominant and non-dominant hands. There was a curvilinear relationship of grip strength to age, significant differences between genders, hands, and some age-groups, and a correlation to height, body-mass, BMI and hand dimensions depending on the gender. The comparisons with the norms of other world populations indicate that there are cross-national grip strength variations among some nations but not all. PMID:26360189

  12. Fast-adapting mechanoreceptors are important for force control in precision grip but not for sensorimotor memory.

    PubMed

    Park, Susanna B; Davare, Marco; Falla, Marika; Kennedy, William R; Selim, Mona M; Wendelschafer-Crabb, Gwen; Koltzenburg, Martin

    2016-06-01

    Sensory feedback from cutaneous mechanoreceptors in the fingertips is important in effective object manipulation, allowing appropriate scaling of grip and load forces during precision grip. However, the role of mechanoreceptor subtypes in these tasks remains incompletely understood. To address this issue, psychophysical tasks that may specifically assess function of type I fast-adapting (FAI) and slowly adapting (SAI) mechanoreceptors were used with object manipulation experiments to examine the regulation of grip force control in an experimental model of graded reduction in tactile sensitivity (healthy volunteers wearing 2 layers of latex gloves). With gloves, tactile sensitivity decreased significantly from 1.9 ± 0.4 to 12.3 ± 2.2 μm in the Bumps task assessing function of FAI afferents but not in a grating orientation task assessing SAI afferents (1.6 ± 0.1 to 1.8 ± 0.2 mm). Six axis force/torque sensors measured peak grip (PGF) and load (PLF) forces generated by the fingertips during a grip-lift task. With gloves there was a significant increase of PGF (14 ± 6%), PLF (17 ± 5%), and grip and load force rates (26 ± 8%, 20 ± 8%). A variable-weight series task was used to examine sensorimotor memory. There was a 20% increase in PGF when the lift of a light object was preceded by a heavy relative to a light object. This relationship was not significantly altered when lifting with gloves, suggesting that the addition of gloves did not change sensorimotor memory effects. We conclude that FAI fibers may be important for the online force scaling but not for the buildup of a sensorimotor memory. PMID:27052582

  13. Corrosion caused by elevator and spider marks on CRA pipe: Comparison of conventional inserts and a new gripping system

    SciTech Connect

    1997-05-01

    Corrosion-resistant alloys (CRA) are used to reduce corrosion damage to casing and tubing strings and prolong the life span of the well pipe. An analysis of various corrosion mechanisms shows that surface integrity is an important factor in corrosion prevention. Surface damage caused by inappropriate handling or conventional slip markings contribute directly to the development and propagation of corrosion. A newly developed gripping system distributes the load equally onto a large number of small peaks, minimizing the indentation of each single peak. The new gripping system does not damage the surface integrity of the pipe, virtually eliminating the corrosion potential.

  14. G.R.I.P.S activities in the development of direct use of geothermal resources and small scale geothermal power development

    NASA Astrophysics Data System (ADS)

    1981-10-01

    The activities of the geothermal research information and planning services (G.R.I.P.S.) in the four Geysers-Calistoga KGRA counties (i.e., Lake, Mendocino, Napa, Sonoma) in California are reported. Activities in the G.R.I.P.S. information and outreach program, workshop presentations, pilot project development, permit processing improvements and Department of Energy reporting are described.

  15. Recent Developments: The Gamma Ray Imager/Polarimeter for Solar Flares (GRIPS) Imaging and Detector systems

    NASA Astrophysics Data System (ADS)

    Duncan, Nicole; Shih, A. Y.; Hurford, G. J.; Saint-Hilaire, P.; Bain, H.; Zoglauer, A.; Lin, R. P.; Boggs, S. E.

    2013-07-01

    In two of the best-observed flares of the last cycle, the Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) satellite found the centroids of ion and relativistic electron emission to have a significant displacement. This result is surprising; co-spatially accelerated ions and electrons are thought to be transported along the same field lines, implying they would enter the chromosphere together and have similar emission locations. The Gamma-Ray Imager/Polarimeter for Solar Flares (GRIPS) balloon instrument will investigate particle transport in solar flares by providing enhanced imaging, spectroscopy and polarimetry of gamma/HXR flare emission (20keV - 10MeV). GRIPS’ key technological improvements over the solar state of the art in HXR/gamma ray energies (RHESSI) include three-dimensional position-sensitive germanium detectors (3D-GeDs) and a single-grid modulating collimator, the multi-pitch rotating modulator (MPRM). The 3D-GeDs allow GRIPS to Compton track energy deposition within the crystal. This capability (1) enables the MPRM design by acting as a second modulation grid, (2) provides significant background rejection and (3) makes solar polarization measurements possible. The MPRM imager provides quasi-continuous resolution from 12.5 - 162 arcsecs with 2x the throughput of a dual grid collimator system like RHESSI. This spatial resolution can resolve the separate footpoints of many flare sizes. In comparison, RHESSI images with a minimum of 35 arcsecs for gamma-rays, making these footpoints resolvable in only the largest flares. Here, we present the intial calibration of GRIPS’ 3D-GED detectors using laboratory radioactive sources. We evaluate charge sharing between adjacent strips, the detection of coincidences and preliminary depth measurements. The detectors have been shown to have a linear response and resolve line emission. The MPRM modulation grid is constructed and we present initial results from calibration. GRIPS is scheduled for a

  16. Latest Progress on the Gamma-Ray Imager/Polarimeter for Solar Flares (GRIPS)

    NASA Technical Reports Server (NTRS)

    Shih, Albert Y.; Lin, Robert P.; Hurford, Gordon J.; Duncan, Nicole A.; Saint-Hilaire, Pascal; Smith, David Miles; Tajima, Hiroyasu; Amman, Mark

    2011-01-01

    We present the latest progress on building the balloon-borne Gamma-Ray Imager/Polarimeter for Solar flares (GRIPS) instrument, including testing and calibration of the detectors and development of the imaging and aspect systems. A continental-US test flight is slated for fall 2012. GRIPS will provide a near-optimal combination of high-resolution imaging, spectroscopy, and polarimetry of solar-flare gamma-ray/hard X-ray emissions from approx.20. keV to > approx.10 MeV. The spectrometer/polarimeter consists of sixteen 3D position-sensitive germanium detectors (3D-GeDs), where each energy deposition is individually recorded with an energy resolution of a few keV FWHM and a spatial resolution to within <0.1 cu mm. Imaging is accomplished by a single multi-pitch rotating modulator (MPRM), a 2.5-cm thick tungsten-alloy grid with pitches that range quasi-continuously from 1 to 13 mm. With the MPRM situated 8 meters from the spectrometer, this instrument will provide excellent image quality and unparalleled angular resolution at gamma-ray energies (12.5 arcsec FWHM), sufficient to separate the 2.2 MeV footpoint sources for almost all flares. Polarimetry is accomplished by analyzing the anisotropy of reconstructed Compton scattering in the 3D-GeDs (i.e. as an active scatterer), with an estimated minimum detectable polarization of a few percent at 150-650 keV in an X-class flare. GRIPS will address questions relevant to particle acceleration and energy release that ha-.e been raised by recent solar flare observations, such as: What causes the spatial separation between energetic electron producing hard X-rays and energetic ions producing gamma-ray lines? How anisotropic are the accelerated electrons, and why do relativistic electron dominate in the corona? How does the composition of accelerated and ambient material vary with space and time, and why?

  17. Functional dimorphism and characteristics of maximal hand grip force in top level female athletes.

    PubMed

    Ivanović, Jelena; Dopsaj, Milivoj

    2012-12-01

    The aim of this work is to determine functional dimorphism (F(max)Nd/DoHG(iso)) and model characteristics at maximal isometric hand grip force (F(max)HG(iso)) in top level female athletes. 275 top level female athletes were tested from Taekwondo, Synchronised Swimming, Track and field, Table tennis, Volleyball, Karate, Skiing, Handball, well-trained students (students of the Academy for Criminalistic and Police studies - ACPS) and Control group. In order to assess the F(max)HG(iso), we used standardised equipment, i.e., a sliding device that measures isometric finger flexor force, with a tensiometric probe fixed inside the device. The average values of F(max)HG(iso) and relative force measured by allometric and classic method for dominant and non-dominant hand grip for the total sample were 381.87 +/- 60.28, 344.63 +/- 55.60 N; 24.06 +/- 3.50, 21.72 +/- 3.28 N/BM0.667; 0.62 +/- 0.10, 0.56 +/- 0.09 N/BM. The average value of F(max)Nd/DoHG(iso) was 0.9030 +/- 0.0797. General Significant difference was established between subsamples for the measurement characteristics at the level of Wilks' Lambda 0.476, F = 3.276, p = 0.000. Maximal average value F(max)HG(iso) for non-dominant and dominant hand is found in Karate (372.04 +/- 46.71, 407.04 +/- 71.31 N) and minimal in Table tennis (282.00 +/- 56.00, 304.00 +/- 58.51 N). The minimal index value of F(max)Nd/DoHG(iso) was found in Control group 0.8771 +/- 0.0877. Considering defined classification of F(max)Nd/ DoHG(iso), we classified the examinees from different sports in 4 groups: dominant symmetry of functional hand grip relations (Skiing > 0.9595); symmetry (Table tennis and Taekwondo 0.9288 to 0.9594); average (Karate, Volleyball, ACPS, Track and field 0.8980 to 0.9287); asymmetry (Control, Synchronised swimming and Handball 0.8674 to 0.8979). The results obtained can be used to determine criteria decisions from the aspect of diagnostic procedures, metric aspect, medical aspect. PMID:23390816

  18. The JPL GRIP Portal - Serving Near Real-time Observation and Model Forecast for Hurricane Study

    NASA Astrophysics Data System (ADS)

    Li, P.; Hristova-Veleva, S. M.; Turk, F. J.; Vu, Q.; Knosp, B. W.; Lambrigtsen, B.; Poulsen, W. L.; Shen, T. J.; Licata, S. J.

    2010-12-01

    NASA conducted a field experiment, the Genesis and Rapid Intensification Processes (GRIP), in the summer of 2010 to better understand how tropical storms form and develop into major hurricanes. The DC-8 aircraft and the Global Hawk Unmanned Airborne System (UAS) were deployed loaded with instruments for measurements including lightning, temperature, 3D wind, precipitation, liquid and ice water contents, aerosol and cloud profiles. JPL created a web portal to collect, process and display both the satellite and the airborne observations in near real-time (NRT) and integrated then with the hurricane forecast models. The objective of the JPL GRIP portal is to provide environmental context and temporal continuity for the field campaign observations to help: (1) mission planning, (2) understanding of the physical processes, and (3) improving models through validation and data assimilation. Built on top of the JPL Tropical Cyclone Information System (TCIS) infrastructure, we developed a GRIP portal presenting a near-real time (NRT) basin-scale view of the atmospheric and surface conditions over the Atlantic, characterizing large-scale and storm-scale processes, as depicted by satellites and models. Using Google Earth embedded in the web browser and two independent calendars, we provide 3D visualization of a comprehensive collection of observations and model results as overlapping image overlays, wind vectors, curtain plots, or clickable tracks. We also provide Google Earth time animations of multiple data and model variables. In the portal, we offer more than two dozen NRT satellite products from a wide variety of instruments, model forecasts from four large-scale models (i.e., NOGAPS, GFS, ECMWF, and UKMET), and the best tracks and the forecast tracks from National Hurricane Center’s ATCF models. As they become available, we also display the airborne observations from HAMSR, APR2 and Dropsonde. It is a great challenge to set up a reliable infrastructure to collect data

  19. Effect of blocking tactile information from the fingertips on adaptation and execution of grip forces to friction at the grasping surface.

    PubMed

    Bilaloglu, Seda; Lu, Ying; Geller, Daniel; Rizzo, John Ross; Aluru, Viswanath; Gardner, Esther P; Raghavan, Preeti

    2016-03-01

    Adaptation of fingertip forces to friction at the grasping surface is necessary to prevent use of inadequate or excessive grip forces. In the current study we investigated the effect of blocking tactile information from the fingertips noninvasively on the adaptation and efficiency of grip forces to surface friction during precision grasp. Ten neurologically intact subjects grasped and lifted an instrumented grip device with 18 different frictional surfaces under three conditions: with bare hands or with a thin layer of plastic (Tegaderm) or an additional layer of foam affixed to the fingertips. The coefficient of friction at the finger-object interface of each surface was obtained for each subject with bare hands and Tegaderm by measuring the slip ratio (grip force/load force) at the moment of slip. We found that the foam layer reduced sensibility for two-point discrimination and pressure sensitivity at the fingertips, but Tegaderm did not. However, Tegaderm reduced static, but not dynamic, tactile discrimination. Adaptation of fingertip grip forces to surface friction measured by the rate of change of peak grip force, and grip force efficiency measured by the grip-load force ratio at lift, showed a proportional relationship with bare hands but were impaired with Tegaderm and foam. Activation of muscles engaged in precision grip also varied with the frictional surface with bare hands but not with Tegaderm and foam. The results suggest that sensitivity for static tactile discrimination is necessary for feedforward and feedback control of grip forces and for adaptive modulation of muscle activity during precision grasp. PMID:26655820

  20. Computer vision-based classification of hand grip variations in neurorehabilitation.

    PubMed

    Zariffa, José; Steeves, John D

    2011-01-01

    The complexity of hand function is such that most existing upper limb rehabilitation robotic devices use only simplified hand interfaces. This is in contrast to the importance of the hand in regaining function after neurological injury. Computer vision technology has been used to identify hand posture in the field of Human Computer Interaction, but this approach has not been translated to the rehabilitation context. We describe a computer vision-based classifier that can be used to discriminate rehabilitation-relevant hand postures, and could be integrated into a virtual reality-based upper limb rehabilitation system. The proposed system was tested on a set of video recordings from able-bodied individuals performing cylindrical grasps, lateral key grips, and tip-to-tip pinches. The overall classification success rate was 91.2%, and was above 98% for 6 out of the 10 subjects. PMID:22275622

  1. Is hand-grip another culprit for the risk of fractures in HIV-positive patients?

    PubMed

    Postorino, Maria Concetta; Torti, Carlo; Carè, Ilaria; Pisani, Vincenzo; Strazzulla, Alessio; Vaccaro, Vittoria; Costa, Chiara; Provenzano, Francesco; Mazzitelli, Maria; Pujia, Arturo; Montalcini, Tiziana

    2016-01-01

    Risk of bone fractures in patients with HIV infection is greater than in the general population, particularly in those co-infected with hepatitis viruses. We compared bone mineral density (BMD) and muscular strength, measured by hand grip test (HG), in HIV mono-infected and co-infected patients. T-score values were lower in HIV patients co-infected with hepatitis viruses vs. mono-infected individuals. Since no significant correlations between HG and T-scores were found, we hypothesize that these factors belong, at least in part, to independent pathways, so both should be taken into account as risks for fragility fractures. Larger prospective studies are needed to confirm this hypothesis. PMID:26922987

  2. Observations of C-band Brightness Temperature from the Hurricane Imaging Radiometer (HIRAD) During GRIP

    NASA Technical Reports Server (NTRS)

    Miller, Timothy L.; James, M. W.; Roberts, J. B.; Buckley, C. D.; Jones, W. L.; Biswas, S.; May, C.; Ruf, C. S.; Uhlhorn, E. W.; Atlas, R.; Albers, C.; Black, Peter G.

    2012-01-01

    HIRAD is a new technology developed by NASA/MSFC, in partnership with NOAA and the Universities of Central Florida, Michigan, and Alabama-Huntsville. HIRAD is designed to measure wind speed and rain rate over a wide swath in heavy-rain, strong-wind conditions. HIRAD is expected to eventually fly routinely on unmanned aerial vehicles (UAVs) such as Global Hawk over hurricanes threatening the U.S. coast and other Atlantic basin areas, and possibly in the Western Pacific as well. HIRAD first flew on GRIP in 2010 and is planned to fly 2012-14 on the NASA Hurricane and Severe Storm Sentinel (HS3) missions on the Global Hawk, a high-altitude UAV. HIRAD technology will eventually be used on a satellite platform to extend the dynamical range of Ocean Surface Wind (OSV) observations from space.

  3. Role of the Visuomotor System in On-Line Attenuation of a Premovement Illusory Bias in Grip Aperture

    ERIC Educational Resources Information Center

    Heath, M.; Rival, C.

    2005-01-01

    In this investigation participants formulated a grip aperture (GA) consistent with the size of an object embedded within a Muller-Lyer (ML) figure prior to initiating visually guided grasping movements. The accuracy of the grasping response was emphasized to determine whether or not the visuomotor system might resolve the premovement bias in GA…

  4. Stretch calculated from grip distance accurately approximates mid-specimen stretch in large elastic arteries in uniaxial tensile tests.

    PubMed

    Tian, Lian; Henningsen, Joseph; Salick, Max R; Crone, Wendy C; Gunderson, McLean; Dailey, Seth H; Chesler, Naomi C

    2015-07-01

    The mechanical properties of vascular tissues affect hemodynamics and can alter disease progression. The uniaxial tensile test is a simple and effective method for determining the stress-strain relationship in arterial tissue ex vivo. To enable calculation of strain, stretch can be measured directly with image tracking of markers on the tissue or indirectly from the distance between the grips used to hold the specimen. While the imaging technique is generally considered more accurate, it also requires more analysis, and the grip distance method is more widely used. The purpose of this study is to compare the stretch of the testing specimen calculated from the grip distance method to that obtained from the imaging method for canine descending aortas and large proximal pulmonary arteries. Our results showed a significant difference in stretch between the two methods; however, this difference was consistently less than 2%. Therefore, the grip distance method is an accurate approximation of the stretch in large elastic arteries in the uniaxial tensile test. PMID:25881308

  5. Stretch calculated from grip distance accurately approximates mid-specimen stretch in large elastic arteries in uniaxial tensile tests

    PubMed Central

    Tian, Lian; Henningsen, Joseph; Salick, Max R.; Crone, Wendy C.; Gunderson, McLean; Dailey, Seth H.; Chesler, Naomi C.

    2015-01-01

    The mechanical properties of vascular tissues affect hemodynamics and can alter disease progression. The uniaxial tensile test is a simple and effective method for determining the stress-strain relationship in arterial tissue ex vivo. To enable calculation of strain, stretch can be measured directly with image tracking of markers on the tissue or indirectly from the distance between the grips used to hold the specimen. While the imaging technique is generally considered more accurate, it also requires more analysis, and the grip distance method is more widely used. The purpose of this study is to compare the stretch of the testing specimen calculated from the grip distance method to that obtained from the imaging method for canine descending aortas and large proximal pulmonary arteries. Our results showed a significant difference in stretch between the two methods; however, this difference was consistently less than 2%. Therefore, the grip distance method is an accurate approximation of the stretch in large elastic arteries in the uniaxial tensile test. PMID:25881308

  6. An ergonomic evaluation of manual Cleco plier designs: effects of rubber grip, spring recoil, and worksurface angle.

    PubMed

    You, Heecheon; Kumar, Anil; Young, Ronda; Veluswamy, Prabaharan; Malzahn, Don E

    2005-09-01

    The present study evaluated two design modifications (rubber grip and torsion spring) to the conventional manual Cleco pliers by electromyography (EMG), hand discomfort, and design satisfaction. This study also surveyed workers' satisfaction with selected design features of the pliers for ergonomic improvement. A two-way (plier design x worksurface angle) within-subject (nested within gender and hand size) design was employed. Eleven workers simulated the plier task in an adjustable workstation for different plier designs and worksurface angles (0 degrees , 60 degrees , and 90 degrees ). Lower EMG values were obtained for the pliers with rubber grip and at 60 degrees of worksurface angle. EMG values varied significantly between the participants, but showed low correlations (Spearman's rank correlation = -0.27 approximately -0.58) with their work experience with the pliers. The hand discomfort and design satisfaction evaluations identified that the grip span (max = 14.0 cm) and grip force requirement (peak = 220.5 N) of the current pliers need ergonomic modification. The present study shows the needs of both the ergonomic design of a hand tool and the training of a proper work method to control work-related musculoskeletal disorders at the workplace. PMID:15970202

  7. The Effect of Repetitive Rhythmic Precision Grip Task-Oriented Rehabilitation in Chronic Stroke Patients: A Pilot Study

    ERIC Educational Resources Information Center

    Dispa, Delphine; Lejeune, Thierry; Thonnard, Jean-Louis

    2013-01-01

    Most chronic stroke patients present with difficulty in the manipulation of objects. The aim of this study was to test whether an intensive program of precision grip training could improve hand functioning of patients at more than 6 months after a stroke. This was a cross-over study; hence, at inclusion, the patients were randomly divided into two…

  8. Associations Between Bone Mineral Density, Grip Strength, and Lead Body Burden Among Older Men

    PubMed Central

    Khalil, Naila; Faulkner, Kimberly A.; Greenspan, Susan L.; Cauley, Jane A.

    2013-01-01

    Objectives To study the association of blood lead concentration (BPb) to bone mineral density (BMD), physical, and cognitive function in non-institutionalized community dwelling older men. Design Cross sectional study. Setting University of Pittsburgh clinic, Pittsburgh, PA. Participants Non-Hispanic Caucasian men aged 65 or older (N=445) recruited as a subset of a prospective cohort Osteoporotic Fractures in Men (MrOS) study. Measurement BPb was measured in 2007-2008. From 2007-2009 BMD (g/cm2) was measured using dual energy x-ray absorptiometry (DXA). At the same time physical performance was measured with five tests: grip strength, leg extension power, walking speed, narrow-walk pace, and chair stands. Cognitive performance was assessed using the Modified Mini-Mental State Examination and the Trail Making Test Part B. Participants were categorized into quartiles of BPb. Multivariate regression analysis was used to evaluate independent relationship between BPb, BMD, cognitive and physical function. Results Mean ±sd BPb was 2.25±1.20 μg/dL (median =2 μg/dL, range 1-10). In multivariable adjusted models, men in higher BPb quartiles had lower BMD at femoral neck, and total hip (p-trend =<0.001 for both). Men with higher BPb had lower age adjusted score for grip strength (p-trend<0.001). However, this association was not significant in multivariate adjusted models (p-trend <0.148). BPb was not associated with lumbar spine BMD, cognition, leg extension power, walking speed, narrow-walk pace, and chair stands. Conclusion Environmental lead exposure may adversely affect bone health in older men. These findings support consideration of environmental exposures in age associated bone fragility. PMID:24383935

  9. Grip force, EDL contractile properties, and voluntary wheel running after postdevelopmental myostatin depletion in mice.

    PubMed

    Personius, Kirkwood E; Jayaram, Aditi; Krull, David; Brown, Roger; Xu, Tianshun; Han, Bajin; Burgess, Kerri; Storey, Christopher; Shah, Bharati; Tawil, Rabi; Welle, Stephen

    2010-09-01

    There is no consensus about whether making muscles abnormally large by reducing myostatin activity affects force-generating capacity or the ability to perform activities requiring muscular endurance. We therefore examined grip force, contractile properties of extensor digitorum longus (EDL) muscles, and voluntary wheel running in mice in which myostatin was depleted after normal muscle development. Cre recombinase activity was induced to knock out exon 3 of the myostatin gene in 4-mo-old mice in which this exon was flanked by loxP sequences (Mstn[f/f]). Control mice with normal myostatin genes (Mstn[w/w]) received the same Cre-activating treatment. Myostatin depletion increased the mass of all muscles that were examined (gastrocnemius, quadriceps, tibialis anterior, EDL, soleus, triceps) by approximately 20-40%. Grip force, measured multiple times 2-22 wk after myostatin knockout, was not consistently greater in the myostatin-deficient mice. EDL contractile properties were determined 7-13 mo after myostatin knockout. Twitch force tended to be greater in myostatin-deficient muscles (+24%; P=0.09), whereas tetanic force was not consistently elevated (mean +11%; P=0.36), even though EDL mass was greater than normal in all myostatin-deficient mice (mean +36%; P<0.001). The force deficit induced by eccentric contractions was approximately twofold greater in myostatin-deficient than in normal EDL muscles (31% vs. 16% after five eccentric contractions; P=0.02). Myostatin-deficient mice ran 19% less distance (P<0.01) than control mice during the 12 wk following myostatin depletion, primarily because of fewer running bouts per night rather than diminished running speed or bout duration. Reduced specific tension (ratio of force to mass) and reduced running have been observed after muscle hypertrophy was induced by other means, suggesting that they are characteristics generally associated with abnormally large muscles rather than unique effects of myostatin deficiency. PMID

  10. Seropositivity for CMV and IL-6 levels are associated with grip strength and muscle size in the elderly

    PubMed Central

    2013-01-01

    Background Sarcopenia is an important cause of morbidity and mortality in older adults, with immunosenescence and inflammation being possible underlying mechanisms. We investigated the relationship between latent cytomegalovirus (CMV) infection, Interleukin 6 (IL-6) levels, muscle size and strength in a group of healthy older community-dwelling people. Methods Participants were healthy volunteers from the Lothian Birth Cohort 1936 study. Participants had IL-6 level and CMV antibody titre measured at age 70 years and grip strength and a volumetric T1-weighted MRI brain scan (allowing measurement of neck muscle cross-sectional area (CSA)) at age 73. Markers of childhood deprivation were adjusted for in the analysis due to correlations between childhood deprivation and latent CMV infection. Results 866 participants were studied; 448 men (mean age 72.48 years, sd 0.70) and 418 women (mean age 72.51 years, sd 0.72). In men, CMV seropositivity was associated with smaller neck muscle CSA (p = 0.03, partial eta squared = 0.01), even after adjustment for IL-6 levels. Neck muscle CSA was not associated with CMV seropositivity in women, or CMV antibody titre or IL-6 level in either sex. Grip strength associated negatively with IL-6 level (right grip strength p<0.00001, partial eta squared 0.032 and left grip strength p<0.00001, partial eta squared 0.027) with or without adjustment for CMV serostatus or antibody titre. CMV status and antibody titre were not significantly associated with grip strength in either hand. Conclusion These findings support the hypothesis that there is a relationship between markers of immunosenescence (i.e. CMV serostatus and IL6 level) and low muscle mass and strength and longitudinal studies in older cohorts are now required to investigate these relationships further. PMID:23938060

  11. Body composition and grip strength are improved in transgenic sickle mice fed a high-protein diet.

    PubMed

    Capers, Patrice L; Hyacinth, Hyacinth I; Cue, Shayla; Chappa, Prasanthi; Vikulina, Tatyana; Roser-Page, Susanne; Weitzmann, M Neale; Archer, David R; Newman, Gale W; Quarshie, Alexander; Stiles, Jonathan K; Hibbert, Jacqueline M

    2015-01-01

    Key pathophysiology of sickle cell anaemia includes compensatory erythropoiesis, vascular injury and chronic inflammation, which divert amino acids from tissue deposition for growth/weight gain and muscle formation. We hypothesised that sickle mice maintained on an isoenergetic diet with a high percentage of energy derived from protein (35 %), as opposed to a standard diet with 20 % of energy derived from protein, would improve body composition, bone mass and grip strength. Male Berkeley transgenic sickle mice (S; n 8-12) were fed either 20 % (S20) or 35 % (S35) diets for 3 months. Grip strength (BIOSEB meter) and body composition (dual-energy X-ray absorptiometry scan) were measured. After 3 months, control mice had the highest bone mineral density (BMD) and bone mineral content (BMC) (P < 0·005). S35 mice had the largest increase in grip strength. A two-way ANOVA of change in grip strength (P = 0·043) attributed this difference to genotype (P = 0·025) and a trend in type of diet (P = 0·067). l-Arginine (l-Arg) supplementation of the 20 % diet was explored, as a possible mechanism for improvement obtained with the 35 % diet. Townes transgenic sickle mice (TS; n 6-9) received 0·8, 1·6, 3·2 or 6·4 % l-Arg based on the same protocol and outcome measures used for the S mice. TS mice fed 1·6 % l-Arg for 3 months (TS1.6) had the highest weight gain, BMD, BMC and lean body mass compared with other groups. TS3.2 mice showed significantly more improvement in grip strength than TS0·8 and TS1.6 mice (P < 0·05). In conclusion, the high-protein diet improved body composition and grip strength. Outcomes observed with TS1.6 and TS3.2 mice, respectively, confirm the hypothesis and reveal l-Arg as part of the mechanism. PMID:26090102

  12. SAO and Kelvin Waves in the EuroGRIPS GCMS and the UK Meteorological Offices Analyses

    NASA Technical Reports Server (NTRS)

    Amodei, M.; Pawson, S.; Scaife, A. A.; Lahoz, W.; Langematz, U.; Li, Ding Min; Simon, P.

    2000-01-01

    This work is an intercomparison of four tropospheric-stratospheric climate models, the Unified Model (UM) of the U.K. Meteorological Office (UKMO), the model of the Free University in Berlin (FUB). the ARPEGE-climat model of the National Center for Meteorological Research (CNRM), and the Extended UGAMP GCM (EUGCM) of the Center for Global Atmospheric Modelling (CGAM), against the UKMO analyses. This comparison has been made in the framework of the "GSM-Reality Intercomparison Project for SPARC" (GRIPS). SPARC (Stratospheric Processes and their Role in Climate) aims are to investigate the effects of the middle atmosphere on climate and the GRIPS purpose is to organized a comprehensive assessment of current Middle Atmosphere-Climate Models (MACMs). The models integrations were made without identical contraints e.g. boundary conditions, incoming solar radiation). All models are able to represent the dominant features of the extratropical circulation. In this paper, the structure of the tropical winds and the strengths of the Kelvin waves are examined. Explanations for the differences exhibited. between the models. as well as between models and analyses, are also proposed. In the analyses a rich spectrum of waves (eastward and westward) is present and contributes to drive the SAO (SemiAnnual Oscillation) and the QBO (Quasi-Biennal Oscillation). The amplitude of the Kelvin waves is close to the one observed in UARS (Upper Atmosphere Research Satellite) data. In agreement with observations, the Kelvin waves generated in the models propagate into the middle atmosphere as wave packets which underlines convective forcing origin. In most models, slow Kelvin waves propagate too high and are hence overestimated in the upper stratosphere and in the mesosphere, except for the UM which is more diffusive. These waves are not sufficient to force realistic westerlies of the QBO or SAO westerly phases. If the SAO is represented by all models only two of them are able to generate

  13. Effort, performance, and motivation: insights from robot-assisted training of human golf putting and rat grip strength.

    PubMed

    Duarte, Jaime E; Gebrekristos, Berkenesh; Perez, Sergi; Rowe, Justin B; Sharp, Kelli; Reinkensmeyer, David J

    2013-06-01

    Robotic devices can modulate success rates and required effort levels during motor training, but it is unclear how this affects performance gains and motivation. Here we present results from training unimpaired humans in a virtual golf-putting task, and training spinal cord injured (SCI) rats in a grip strength task using robotically modulated success rates and effort levels. Robotic assistance in golf practice increased trainees feelings of competence, and, paradoxically, increased their sense effort, even though it had mixed effects on learning. Reducing effort during a grip strength training task led rats with SCI to practice the task more frequently. However, the more frequent practice of these rats did not cause them to exceed the strength gains achieved by rats that exercised less often at higher required effort levels. These results show that increasing success and decreasing effort with robots increases motivation, but has mixed effects on performance gains. PMID:24187278

  14. LASE system upgrade and measurements from the NASA GRIP field experiment

    NASA Astrophysics Data System (ADS)

    Kooi, S.; Ismail, S.; Ferrare, R. A.; Hair, J. W.; Notari, A.; Collins, J. E.; Nehrir, A. R.; Butler, C. F.; Halverson, J.

    2010-12-01

    The Lidar Atmospheric Sensing Experiment (LASE) system has operated on the NASA ER-2, P-3, and DC-8 aircraft during the past 16 years and participated in 13 field experiments. This system provides vertical profiles of water vapor mixing ratio and aerosol and cloud backscattering. A brief overview is presented on the upgrade of LASE that included refurbishment of laser diode seeding, control and data system, and zenith receiver system. These developments have enhanced the operational reliability of the system and improved its performance. The LASE system was deployed on the NASA DC-8 aircraft recently for the NASA GRIP (Genesis and Rapid Intensification Processes) field experiment, which was conducted during August and September 2010 from operational bases in Fort Lauderdale, FL and St. Croix, VI. Initial measurements from this field experiment are presented including distributions of water vapor, aerosol, and clouds. Temperature profiles from DC-8 dropsondes and nearby radiosondes are used to derive relative humidity profiles from the LASE water vapor mixing ratio profiles. Comparisons of LASE water vapor mixing ratio profiles with those measured by the new AVAPS-II dropsondes from the NASA DC-8 are also presented.

  15. Device for gripping and detaching a top nozzle subassembly from a reconstitutable fuel assembly

    SciTech Connect

    Wilson, J.F.; Gjersten, R.K.

    1987-03-03

    This patent describes a reconstitutable fuel assembly including a top nozzle subassembly and guide thimbles. The top nozzle subassembly has a lower adapter plate, hold-down springs and an upper hold-down plate with coolant flow openings defined therethrough. The guide thimbles have upper end portions slidably mounting the lower adapter plate and upper hold-down plate for movement therealong between lower and upper limits. A device is described for gripping and detaching the top nozzle subassembly from the guide thimble upper end portions, comprising: (a) a central spider disposable in overlying relation to the upper hold-down plate; (b) locating lugs disposed radially outwardly from the spider and arranged for alignment with and insertion into the plurality of coolant flow openings in the upper hold-down plate. Each of the locating lugs has an elongated central bore; (c) collars interconnected to the spider, each collar connected to one of the locating lugs and bearing on the hold-down plate when the locating lug is inserted in its respective flow opening; and (d) elongated members received through and rotatable within the respective central bores of the locating lugs.

  16. DAWN Coherent Wind Profiling Lidar Flights on NASA's DC-8 During GRIP

    NASA Technical Reports Server (NTRS)

    Kavaya, Michael J.; Beyon, Jeffrey Y.; Creary, Garfield A.; Koch, Grady J.; Petros, Mulugeta; Petzar, Paul J.; Singh, Upendra N.; Trieu, Bo C.; Yu, Jirong

    2011-01-01

    Almost from their invention, lasers have been used to measure the velocity of wind and objects; over distances of cm to 10s of km. Long distance (remote) sensing of wind has been accomplished with continuous-wave (CW), focused pulsed, and collimated pulsed lasers; with direct and coherent (heterodyne) optical detection; and with a multitude of laser wavelengths. Airborne measurement of wind with pulsed, coherent-detection lidar was first performed in 1971 with a CW CO2 laser1, in 1972 with a pulsed CO2 laser2, in 1993 with a pulsed 2-micron laser3, and in 1999 with a pulsed CO2 laser and nadir-centered conical scanning4. Of course there were many other firsts and many other groups doing lidar wind remote sensing with coherent and direct detection. A very large FOM coherent wind lidar has been built by LaRC and flown on a DC-8. However a burn on the telescope secondary mirror prevented the full demonstration of high FOM. Both the GRIP science product and the technology and technique demonstration from aircraft are important to NASA. The technology and technique demonstrations contribute to our readiness for the 3D Winds space mission. The data analysis is beginning and we hope to present results at the conference.

  17. The influence of object height on maximum grip aperture in empirical and modeled data.

    PubMed

    Borchers, Svenja; Verheij, Rebekka; Smeets, Jeroen B J; Himmelbach, Marc

    2014-04-01

    During a grasping movement, the maximum grip aperture (MGA) is almost linearly scaled to the dimension of the target along which it is grasped. There is still a surprising uncertainty concerning the influence of the other target dimensions on the MGA. We asked healthy participants to grasp cuboids always along the object's width with their thumb and index finger. Independent from variations of object width, we systematically varied height and depth of these target objects. We found that taller objects were generally grasped with a larger MGA. At the same time, the slope of the regression of MGA on object width decreased with increasing target height. In contrast, we found no effect of varying target depth on the MGA. Simulating these movements with a grasping model in which the objective to avoid contact of the digits with the target object at positions other than the goal positions was implemented yielded larger effects of target height than of target depth on MGA. We concluded that MGA does not only depend on the dimension of the target object along which it is grasped. Furthermore, the effects of the other 2 dimensions are considerably different. This pattern of results can partially be explained by the aim to avoid contacting the target object at positions other than the goal positions. PMID:24417290

  18. Effects of material properties and object orientation on precision grip kinematics.

    PubMed

    Paulun, Vivian C; Gegenfurtner, Karl R; Goodale, Melvyn A; Fleming, Roland W

    2016-08-01

    Successfully picking up and handling objects requires taking into account their physical properties (e.g., material) and position relative to the body. Such features are often inferred by sight, but it remains unclear to what extent observers vary their actions depending on the perceived properties. To investigate this, we asked participants to grasp, lift and carry cylinders to a goal location with a precision grip. The cylinders were made of four different materials (Styrofoam, wood, brass and an additional brass cylinder covered with Vaseline) and were presented at six different orientations with respect to the participant (0°, 30°, 60°, 90°, 120°, 150°). Analysis of their grasping kinematics revealed differences in timing and spatial modulation at all stages of the movement that depended on both material and orientation. Object orientation affected the spatial configuration of index finger and thumb during the grasp, but also the timing of handling and transport duration. Material affected the choice of local grasp points and the duration of the movement from the first visual input until release of the object. We find that conditions that make grasping more difficult (orientation with the base pointing toward the participant, high weight and low surface friction) lead to longer durations of individual movement segments and a more careful placement of the fingers on the object. PMID:27016090

  19. A method to study precision grip control in viscoelastic force fields using a robotic gripper.

    PubMed

    Lambercy, Olivier; Metzger, Jean-Claude; Santello, Marco; Gassert, Roger

    2015-01-01

    Instrumented objects and multipurpose haptic displays have commonly been used to investigate sensorimotor control of grasping and manipulation. A major limitation of these devices, however, is the extent to which the experimenter can vary the interaction dynamics to fully probe sensorimotor control mechanisms. We propose a novel method to study precision grip control using a grounded robotic gripper with two moving, mechanically coupled finger pads instrumented with force sensors. The device is capable of stably rendering virtual mechanical properties with a wide dynamic range of achievable impedances. Eight viscoelastic force fields with different combinations of stiffness and damping parameters were implemented, and tested on eight healthy subjects performing 30 consecutive repetitions of a grasp, hold, and release task with time and position constraints. Rates of thumb and finger force were found to be highly correlated (r>0.9) during grasping, revealing that, despite the mechanical coupling of the two finger pads, subjects performed grasping movements in a physiological fashion. Subjects quickly adapted to the virtual dynamics (within seven trials), but, depending on the presented force field condition, used different control strategies to correctly perform the task. The proof of principle presented in this paper underscores the potential of such a one-degree-of-freedom robotic gripper to study neural control of grasping, and to provide novel insights on sensorimotor control mechanisms. PMID:25014953

  20. The effectiveness of combined gripping method in tensile testing of UHMWPE single yarn

    NASA Astrophysics Data System (ADS)

    Wang, H. X.; Hazell, P. J.; Shankar, K.; Morozov, E. V.; Escobedo, J. P.

    2015-07-01

    This paper presents the experimental study on the effectiveness of combined gripping method employed in the tensile testing of UHMWPE (Dyneema® SK75) single yarn. Seven different solutions including epoxy, acrylic, and ethyl cyanoacrylate adhesives were tested under quasi-static loadings in order to determine the most effective adhesive for bonding UHMWPE single yarn to aluminium sheets. The ethyl cyanoacrylate adhesive combined with polyolefin surface primer was found to be the best choice which could prevent yarn slippage and ensure the failure of yarn occurs in the gauge section. The single yarns were then tested at three strain rates of 3.3×10-5, 3.3×10-3, and 0.33 s-1. The tensile strength, maximum strain, and Young's modulus were determined from the measured stress-strain curves and compared with the values from literature; the results showed these tensile properties of single yarn depend on strain rate over the range tested.

  1. Operability evaluation using an simulation system for gripping motion in robotic tele-surgery.

    PubMed

    Kawamura, Kazuya; Kobayashi, Yo; Fujie, Masakatsu G

    2009-01-01

    Tele-surgery enables medical care even in remote regions and has been accomplished in clinical cases by means of special communication lines. To make tele-surgery a more common method of medical care, the surgical environment must be made available using public lines of communication, such as the Internet. Moreover, a support system during operation is required as the use of surgical tools occurs in a delayed environment. In our research, we focus on the operability of certain tasks conducted by surgeons during a medical procedure, and aim to clarify the optimum environment for robotic tele-surgery using a simulation. In the present study, we conducted an experiment to evaluate this operability using a simulation system consisting of a virtual slave manipulator, network simulator and an organ deformation calculator. The operability of a task to grip soft tissue was evaluated using a subjective workload assessment tool, NASA Task Load Index (NASA-TLX). Results indicate that operability changed over a delay of 200 ms in the environment during the experiment. Future studies will focus on clarifying a comfortable tele-surgical environment using the present evaluation of operability. In addition, an intra-operative assistance system will be constructed using a simulation. PMID:19963881

  2. Hand grips strength effect on motor function in human brain using fMRI: a pilot study

    NASA Astrophysics Data System (ADS)

    Ismail, S. S.; Mohamad, M.; Syazarina, S. O.; Nafisah, W. Y.

    2014-11-01

    Several methods of motor tasks for fMRI scanning have been evolving from simple to more complex tasks. Motor tasks on upper extremity were applied in order to excite the increscent of motor activation on contralesional and ipsilateral hemispheres in brain. The main objective of this study is to study the different conditions for motor tasks on upper extremity that affected the brain activation. Ten healthy right handed with normal vision (3 male and 7 female, age range=20-30 years, mean=24.6 years, SD=2.21) participated in this study. Prior to the scanning, participants were trained on hand grip tasks using rubber ball and pressure gauge tool outside the scanner. During fMRI session, a block design with 30-s task blocks and alternating 30-s rest periods was employed while participants viewed a computer screen via a back projection-mirror system and instructed to follow the instruction by gripping their hand with normal and strong grips using a rubber ball. Statistical Parametric mapping (SPM8) software was used to determine the brain activation. Both tasks activated the primary motor (M1), supplementary motor area (SMA), dorsal and ventral of premotor cortex area (PMA) in left hemisphere while in right hemisphere the area of primary motor (M1) somatosensory was activated. However, the comparison between both tasks revealed that the strong hand grip showed the higher activation at M1, PMA and SMA on left hemisphere and also the area of SMA on right hemisphere. Both conditions of motor tasks could provide insights the functional organization on human brain.

  3. LXRα represses LPS-induced inflammatory responses by competing with IRF3 for GRIP1 in Kupffer cells.

    PubMed

    Miao, Chun-Mu; He, Kun; Li, Pei-Zhi; Liu, Zuo-Jin; Zhu, Xi-Wen; Ou, Zhi-Bing; Ruan, Xiong-Zhong; Gong, Jian-Ping; Liu, Chang-An

    2016-06-01

    Liver X receptors (LXRs) in the nucleus play important roles in lipid metabolism and inflammation. The mechanism of LXR regulation of the LPS-induced Toll-like receptor 4 (TLR4) inflammatory signaling pathway remains to be elucidated. C57/BL6 mice were randomly divided into four groups: control, T0901317 (a LXRs agonist), LPS and T0901317+LPS. Additionally, Kupffer cells isolated from male C57/BL6 mice were divided into the same four groups. A decreased amount of inflammatory cells infiltrated the portal areas and the hepatic sinusoids in the livers of mice in the T0901317+LPS group than in those of mice in the LPS group. In the T0901317+LPS group, the serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and tumor necrosis factor alpha (TNF-α) were lower, while the serum level of interleukin-10 (IL-10) was higher. In vitro, Kupffer cells pretreated with T0901317 for 24h presented reduced TNF-α, interferon-beta (IFN-β) and interleukin-1 beta (IL-1β) levels, while the IL-10 level increased; however, the mRNA and protein expression levels of interferon regulatory factor 3 (IRF3) and glucocorticoid receptor-interacting protein 1 (GRIP1) were not significantly reduced. The co-IP data illustrated that LXRα bound to GRIP1 specifically in the T0901317+LPS group, while less IRF3 was bound to GRIP1 in the T0901317+LPS group than in the LPS group. Furthermore, the DNA-binding activity of NF-κB was decreased by pretreating Kupffer cells with T0901317 for 24h. These results suggest that activated LXRα competes with IRF3 for GRIP1 binding, thus repressing IRF3 and NF-κB transcriptional activity and inhibiting the inflammatory response initiated by LPS in Kupffer cells. PMID:27085678

  4. Using Goal- and Grip-Related Information for Understanding the Correctness of Other’s Actions: An ERP Study

    PubMed Central

    van Elk, Michiel; Bousardt, Roel; Bekkering, Harold; van Schie, Hein T.

    2012-01-01

    Detecting errors in other’s actions is of pivotal importance for joint action, competitive behavior and observational learning. Although many studies have focused on the neural mechanisms involved in detecting low-level errors, relatively little is known about error-detection in everyday situations. The present study aimed to identify the functional and neural mechanisms whereby we understand the correctness of other’s actions involving well-known objects (e.g. pouring coffee in a cup). Participants observed action sequences in which the correctness of the object grasped and the grip applied to a pair of objects were independently manipulated. Observation of object violations (e.g. grasping the empty cup instead of the coffee pot) resulted in a stronger P3-effect than observation of grip errors (e.g. grasping the coffee pot at the upper part instead of the handle), likely reflecting a reorienting response, directing attention to the relevant location. Following the P3-effect, a parietal slow wave positivity was observed that persisted for grip-errors, likely reflecting the detection of an incorrect hand-object interaction. These findings provide new insight in the functional significance of the neurophysiological markers associated with the observation of incorrect actions and suggest that the P3-effect and the subsequent parietal slow wave positivity may reflect the detection of errors at different levels in the action hierarchy. Thereby this study elucidates the cognitive processes that support the detection of action violations in the selection of objects and grips. PMID:22606261

  5. Interaction of Arl1 GTPase with the GRIP domain of Golgin-245 as assessed by GST (glutathione-S-transferase) pull-down experiments.

    PubMed

    Lu, Lei; Tai, Guihua; Hong, Wanjin

    2005-01-01

    Arl1 is a member of the Arf/Arl family of Ras-like GTPase superfamily. Arl1 is enriched in the trans-Golgi network (TGN). We have recently shown that Arl1 regulates TGN recruitment of GRIP domain-containing Golgin-97 and Golgin-245 by interacting with the conserved GRIP domain present in their carboxyl (C)-termini. We describe here methods for the analysis of the interaction between Arl1(GTP) and the GRIP domain of Golgin-245 using in vitro GST pull-down experiments. GST-Arl1(GTP) can recover endogenous Golgin-245 from HeLa cell cytosol. Furthermore, GST-GRIP domain of Golgin-245 can efficiently retain endogenous active Arl1. A pull-down assay is developed to quantify the relative level of active Arl1. PMID:16413289

  6. The Change of Grip Strength in a Patient with Congenital Myotonic Dystrophy Over a 4-year Period

    PubMed Central

    Kozuka, Naoki; Uchida, Eiji; Ninomiya, Takafumi; Tatsumi, Haruyuki; Takeda, Hidekatsu; Tachi, Nobutada

    2008-01-01

    Myotonic dystrophy (MyD) is a neuromuscular disease that is autosomal dominant and the most common form of muscular dystrophy affecting adults. The clinical features of MyD include a multisystemic disorder characterized by myotonia, progressive muscle weakness and wasting, cataracts, premature balding and mental retardation. The most severe type of MyD is classified as congenital MyD (CMyD). The muscle weakness in CMyD is very severe, but muscle development can be observed in the period of growth. However, no clinical case of this type has been reported yet. Therefore, we report on a girl with CMyD who had an increase in muscle strength over a four-year period. The girl with CMyD participated in this study from the age of 9 to the age of 12. The measurement of muscle strength was recorded as the maximum score of grip strength with the use of dynamometers. Grip strength was assessed once a year by the same two physical therapists. Grip strength of CMyD for each year was markedly weak when compared with the normal controls, but muscle strength changed within some specific growth areas. The muscle weakness in CMyD was remarkable, but the result showed that specific muscle strength of CMyD in childhood was actually increased. PMID:25792886

  7. GRiP - A flexible approach for calculating risk as a function of consequence, vulnerability, and threat.

    SciTech Connect

    Whitfield, R. G.; Buehring, W. A.; Bassett, G. W.

    2011-04-08

    Get a GRiP (Gravitational Risk Procedure) on risk by using an approach inspired by the physics of gravitational forces between body masses! In April 2010, U.S. Department of Homeland Security Special Events staff (Protective Security Advisors [PSAs]) expressed concern about how to calculate risk given measures of consequence, vulnerability, and threat. The PSAs believed that it is not 'right' to assign zero risk, as a multiplicative formula would imply, to cases in which the threat is reported to be extremely small, and perhaps could even be assigned a value of zero, but for which consequences and vulnerability are potentially high. They needed a different way to aggregate the components into an overall measure of risk. To address these concerns, GRiP was proposed and developed. The inspiration for GRiP is Sir Isaac Newton's Universal Law of Gravitation: the attractive force between two bodies is directly proportional to the product of their masses and inversely proportional to the squares of the distance between them. The total force on one body is the sum of the forces from 'other bodies' that influence that body. In the case of risk, the 'other bodies' are the components of risk (R): consequence, vulnerability, and threat (which we denote as C, V, and T, respectively). GRiP treats risk as if it were a body within a cube. Each vertex (corner) of the cube represents one of the eight combinations of minimum and maximum 'values' for consequence, vulnerability, and threat. The risk at each of the vertices is a variable that can be set. Naturally, maximum risk occurs when consequence, vulnerability, and threat are at their maximum values; minimum risk occurs when they are at their minimum values. Analogous to gravitational forces among body masses, the GRiP formula for risk states that the risk at any interior point of the box depends on the squares of the distances from that point to each of the eight vertices. The risk value at an interior (movable) point will be

  8. Rapamycin increases grip strength and attenuates age-related decline in maximal running distance in old low capacity runner rats

    PubMed Central

    Xue, Qian-Li; Yang, Huanle; Li, Hui-Fen; Abadir, Peter M.; Burks, Tyesha N.; Koch, Lauren G.; Britton, Steven L.; Carlson, Joshua; Chen, Laura; Walston, Jeremy D.; Leng, Sean X.

    2016-01-01

    Rapamycin is known to extend lifespan. We conducted a randomized placebo-controlled study of enteric rapamycin-treatment to evaluate its effect on physical function in old low capacity runner (LCR) rats, a rat model selected from diverse genetic background for low intrinsic aerobic exercise capacity without genomic manipulation and characterized by increased complex disease risks and aging phenotypes. The study was performed in 12 male and 16 female LCR rats aged 16-22 months at baseline. The treatment group was fed with rapamycin-containing diet pellets at approximately 2.24mg/kg body weight per day and the placebo group with the same diet without rapamycin for six months. Observation was extended for additional 2 months. Physical function measurements include grip strength measured as maximum tensile force using a rat grip strength meter and maximum running distance (MRD) using rat physical treadmill test. The results showed that rapamycin improved grip strength by 13% (p=.036) and 60% (p<.001) from its baseline in female and male rats, respectively. Rapamycin attenuated MRD decline by 66% (p<.001) and 46% (p=.319) in females and males, respectively. These findings provide initial evidence for beneficial effect of rapamycin on physical functioning in an aging rat model of high disease risks with significant implication in humans. PMID:26997106

  9. Telomere length is associated with decline in grip strength in older persons aged 65 years and over.

    PubMed

    Woo, Jean; Yu, Ruby; Tang, Nelson; Leung, Jason

    2014-01-01

    Telomere length (TL) attrition is associated with chronic diseases characterized by chronic inflammatory states. Inflammatory cytokines may play a role in sarcopenia. This study examines the association between TL and the diagnosis of sarcopenia based on appendicular skeletal mass index (ASMI), grip strength, walking speed, and chair stand in a prospective study over 5 years of 976 men and 1,030 women aged 65 years and over living in the community. TL in leukocytes was measured using the quantitative PCR method. TL was divided into quartiles, and analysis of covariance (ANCOVA) was adopted to examine its association with components of sarcopenia, adjusting for age, education, body mass index, smoking, physical activity, and probable dementia. In both men and women, the percentage decline in grip strength over the 5-year period of follow-up was slower in those in the highest quartile of TL than those in the lower quartiles (multivariate-adjusted p < 0.05). No association between TL and the diagnosis of sarcopenia, ASMI, walking speed, or chair stand was observed. In conclusion, longer TL was associated with slower decline in grip strength in Chinese older persons. PMID:25182538

  10. Observations During GRIP from HIRAD: Images of C-Band Brightness Temperatures and Ocean Surface Wind Speed and Rain Rate

    NASA Technical Reports Server (NTRS)

    Miller, Timothy L.; James, M. W.; Jones, W. L.; Ruf, C. S.; Uhlhorn, E. W.; Biswas, S.; May, C.; Shah, G.; Black, P.; Buckley, C. D.

    2012-01-01

    HIRAD (Hurricane Imaging Radiometer) flew on the WB-57 during NASA s GRIP (Genesis and Rapid Intensification Processes) campaign in August - September of 2010. HIRAD is a new C-band radiometer using a synthetic thinned array radiometer (STAR) technology to obtain cross-track resolution of approximately 3 degrees, out to approximately 60 degrees to each side of nadir. By obtaining measurements of emissions at 4, 5, 6, and 6.6 GHz, observations of ocean surface wind speed and rain rate can be inferred. This technique has been used for many years by precursor instruments, including the Stepped Frequency Microwave Radiometer (SFMR), which has been flying on the NOAA and USAF hurricane reconnaissance aircraft for several years. The advantage of HIRAD over SFMR is that HIRAD can observe a +/- 60-degree swath, rather than a single footprint at nadir angle. Results from the flights during the GRIP campaign will be shown, including images of brightness temperatures, wind speed, and rain rate. To the extent possible, comparisons will be made with observations from other instruments on the GRIP campaign, for which HIRAD observations are either directly comparable or are complementary. Features such as storm eye and eyewall, location of vortex wind and rain maxima, and indications of dynamical features such as the merging of a weaker outer wind/rain maximum with the main vortex may be seen in the data. Potential impacts on operational ocean surface wind analyses and on numerical weather forecasts will also be discussed.

  11. Tyre-road grip coefficient assessment - Part II: online estimation using instrumented vehicle, extended Kalman filter, and neural network

    NASA Astrophysics Data System (ADS)

    Luque, Pablo; Mántaras, Daniel A.; Fidalgo, Eloy; Álvarez, Javier; Riva, Paolo; Girón, Pablo; Compadre, Diego; Ferran, Jordi

    2013-12-01

    The main objective of this work is to determine the limit of safe driving conditions by identifying the maximal friction coefficient in a real vehicle. The study will focus on finding a method to determine this limit before reaching the skid, which is valuable information in the context of traffic safety. Since it is not possible to measure the friction coefficient directly, it will be estimated using the appropriate tools in order to get the most accurate information. A real vehicle is instrumented to collect information of general kinematics and steering tie-rod forces. A real-time algorithm is developed to estimate forces and aligning torque in the tyres using an extended Kalman filter and neural networks techniques. The methodology is based on determining the aligning torque; this variable allows evaluation of the behaviour of the tyre. It transmits interesting information from the tyre-road contact and can be used to predict the maximal tyre grip and safety margin. The maximal grip coefficient is estimated according to a knowledge base, extracted from computer simulation of a high detailed three-dimensional model, using Adams® software. The proposed methodology is validated and applied to real driving conditions, in which maximal grip and safety margin are properly estimated.

  12. The effects of ball impact location and grip tightness on the arm, racquet and ball for one-handed tennis backhand groundstrokes.

    PubMed

    King, Mark A; Kentel, Behzat B; Mitchell, Sean R

    2012-04-01

    A torque-driven, 3D computer simulation model of an arm-racquet system was used to investigate the effects of ball impact location and grip tightness on the arm, racquet and ball during one-handed tennis backhand groundstrokes. The stringbed was represented by nine point masses connected to each other and the racquet frame with elastic springs and three torsional spring-dampers between the hand and the racquet were used to represent grip tightness. For each perturbation of nine impact locations and grip tightness, simulations were run for a 50 ms period starting with ball-racquet impact. Simulations showed that during off-centre impacts below the longitudinal axis of the racquet, the wrist was forced to flex up to 16° more with up to six times more wrist extension torque when compared to a centre impact simulation. Perturbing grip tightness had no substantial effect on centre impact simulations. However, for off-centre impacts (below the longitudinal axis of the racquet) a tight grip condition resulted in a substantial decrease in racquet rotation within the hand (less than 2°) and an increase of 6° in wrist flexion angle when compared to the equivalent simulation with a normal grip. In addition there was approximately 20% more wrist extension torque when compared with equivalent off-centre impact simulation with a normal grip. Consequently off-centre impacts below the longitudinal axis of the racquet may be a substantial contributing factor for tennis elbow injuries with a tight grip aggravating the effect due to high eccentric wrist extension torques and forced wrist flexion. PMID:22325977

  13. Status of Middle Atmosphere-Climate Models: Results SPARC-GRIPS

    NASA Technical Reports Server (NTRS)

    Pawson, Steven; Kodera, Kunihiko

    2003-01-01

    The middle atmosphere is an important component of the climate system, primarily because of the radiative forcing of ozone. Middle atmospheric ozone can change, over long times, because of changes in the abundance of anthropogenic pollutants which catalytically destroy it, and because of the temperature sensitivity of kinetic reaction rates. There is thus a complex interaction between ozone, involving chemical and climatic mechanisms. One question of interest is how ozone will change over the next decades , as the "greenhouse-gas cooling" of the middle atmosphere increases but the concentrations of chlorine species decreases (because of policy changes). concerns the climate biases in current middle atmosphere-climate models, especially their ability to simulate the correct seasonal cycle at high latitudes, and the existence of temperature biases in the global mean. A major obstacle when addressing this question This paper will present a summary of recent results from the "GCM-Reality Intercomparison Project for SPARC" (GRIPS) initiative. A set of middle atmosphere-climate models has been compared, identifying common biases. Mechanisms for these biases are being studied in some detail, including off-line assessments of the radiation transfer codes and coordinated studies of the impacts of gravity wave drag due to sub-grid-scale processes. ensemble of models will be presented, along with numerical experiments undertaken with one or more models, designed to investigate the mechanisms at work in the atmosphere. The discussion will focus on dynamical and radiative mechanisms in the current climate, but implications for coupled ozone chemistry and the future climate will be assessed.

  14. Individuals with autism spectrum disorder show abnormalities during initial and subsequent phases of precision gripping.

    PubMed

    Wang, Zheng; Magnon, Grant C; White, Stormi P; Greene, Rachel K; Vaillancourt, David E; Mosconi, Matthew W

    2015-04-01

    Sensorimotor impairments are common in autism spectrum disorder (ASD), but they are not well understood. Here we examined force control during initial pulses and the subsequent rise, sustained, and relaxation phases of precision gripping in 34 individuals with ASD and 25 healthy control subjects. Participants pressed on opposing load cells with their thumb and index finger while receiving visual feedback regarding their performance. They completed 2- and 8-s trials during which they pressed at 15%, 45%, or 85% of their maximum force. Initial pulses guided by feedforward control mechanisms, sustained force output controlled by visual feedback processes, and force relaxation rates all were examined. Control subjects favored an initial pulse strategy characterized by a rapid increase in and then relaxation of force when the target force was low (Type 1). When the target force level or duration of trials was increased, control subjects transitioned to a strategy in which they more gradually increased their force, paused, and then increased their force again. Individuals with ASD showed a more persistent bias toward the Type 1 strategy at higher force levels and during longer trials, and their initial force output was less accurate than that of control subjects. Patients showed increased force variability compared with control subjects when attempting to sustain a constant force level. During the relaxation phase, they showed reduced rates of force decrease. These findings suggest that both feedforward and feedback motor control mechanisms are compromised in ASD and these deficits may contribute to the dyspraxia and sensorimotor abnormalities often seen in this disorder. PMID:25552638

  15. Individuals with autism spectrum disorder show abnormalities during initial and subsequent phases of precision gripping

    PubMed Central

    Magnon, Grant C.; White, Stormi P.; Greene, Rachel K.; Vaillancourt, David E.

    2014-01-01

    Sensorimotor impairments are common in autism spectrum disorder (ASD), but they are not well understood. Here we examined force control during initial pulses and the subsequent rise, sustained, and relaxation phases of precision gripping in 34 individuals with ASD and 25 healthy control subjects. Participants pressed on opposing load cells with their thumb and index finger while receiving visual feedback regarding their performance. They completed 2- and 8-s trials during which they pressed at 15%, 45%, or 85% of their maximum force. Initial pulses guided by feedforward control mechanisms, sustained force output controlled by visual feedback processes, and force relaxation rates all were examined. Control subjects favored an initial pulse strategy characterized by a rapid increase in and then relaxation of force when the target force was low (Type 1). When the target force level or duration of trials was increased, control subjects transitioned to a strategy in which they more gradually increased their force, paused, and then increased their force again. Individuals with ASD showed a more persistent bias toward the Type 1 strategy at higher force levels and during longer trials, and their initial force output was less accurate than that of control subjects. Patients showed increased force variability compared with control subjects when attempting to sustain a constant force level. During the relaxation phase, they showed reduced rates of force decrease. These findings suggest that both feedforward and feedback motor control mechanisms are compromised in ASD and these deficits may contribute to the dyspraxia and sensorimotor abnormalities often seen in this disorder. PMID:25552638

  16. Self-organization, free energy minimization, and optimal grip on a field of affordances

    PubMed Central

    Bruineberg, Jelle; Rietveld, Erik

    2014-01-01

    In this paper, we set out to develop a theoretical and conceptual framework for the new field of Radical Embodied Cognitive Neuroscience. This framework should be able to integrate insights from several relevant disciplines: theory on embodied cognition, ecological psychology, phenomenology, dynamical systems theory, and neurodynamics. We suggest that the main task of Radical Embodied Cognitive Neuroscience is to investigate the phenomenon of skilled intentionality from the perspective of the self-organization of the brain-body-environment system, while doing justice to the phenomenology of skilled action. In previous work, we have characterized skilled intentionality as the organism's tendency toward an optimal grip on multiple relevant affordances simultaneously. Affordances are possibilities for action provided by the environment. In the first part of this paper, we introduce the notion of skilled intentionality and the phenomenon of responsiveness to a field of relevant affordances. Second, we use Friston's work on neurodynamics, but embed a very minimal version of his Free Energy Principle in the ecological niche of the animal. Thus amended, this principle is helpful for understanding the embeddedness of neurodynamics within the dynamics of the system “brain-body-landscape of affordances.” Next, we show how we can use this adjusted principle to understand the neurodynamics of selective openness to the environment: interacting action-readiness patterns at multiple timescales contribute to the organism's selective openness to relevant affordances. In the final part of the paper, we emphasize the important role of metastable dynamics in both the brain and the brain-body-environment system for adequate affordance-responsiveness. We exemplify our integrative approach by presenting research on the impact of Deep Brain Stimulation on affordance responsiveness of OCD patients. PMID:25161615

  17. Birth weight, intrauterine growth restriction and nutritional status in childhood in relation to grip strength in adults: from the 1982 Pelotas (Brazil) birth cohort

    PubMed Central

    Bielemann, Renata Moraes; Gigante, Denise Petrucci; Horta, Bernardo Lessa

    2016-01-01

    Objective The aim of this study was to evaluate the association among birth weight, intrauterine growth, and nutritional status in childhood with grip strength in young adults from the 1982 Pelotas (Brazil) birth cohort. Methods In 1982, the hospital live births of Pelotas were followed. In 2012, grip strength was evaluated using a hand dynamometer and the best of the six measurements was used. Birth weight was analyzed as z-score for gestational age according to Williams (1982) curve. Weight-for-age, weight-for-length/height, and length/height-for-age at 2 and 4 y were analyzed in z-scores according to 2006 World Health Organization Child Growth Standards. Lean mass at 30 y was included as possible mediator using the g-computation formula. Results In 2012, 3701 (68.1%) individuals were interviewed and 3470 were included in the present analyses. An increase of 1 z-score in birth weight was associated with an increase of 1.5 kg in grip strength in males (95% confidence interval, 1.1–1.9). Positive effect of birth weight on grip strength was found in females. Grip strength was greater in individuals who were born with appropriate size for gestational age and positively associated with weight- and length/height-for-age z-score at 2 and 4 y of age. A positive association between birth weight and grip strength was only partially mediated by adult lean mass (50% and 33% of total effect in males and females), whereas direct effect of weight at 2 y was found only in males. Conclusions It is suggested that good nutrition in prenatal and early postnatal life has a positive influence on adult muscle strength. The results from birth weight were suggestive of fetal programming on grip strength measurement. PMID:26678603

  18. Vitamin D status predicts hand-grip strength in young adult women living in Auckland, New Zealand.

    PubMed

    von Hurst, P R; Conlon, C; Foskett, A

    2013-07-01

    The identification of the vitamin D receptor (VDR) in skeletal muscle tissue and research in muscle strength and development in VDR-null mice confirms a role for vitamin D in muscle function. The relationship between muscle strength and vitamin D status has been explored to some degree in older populations with regard to fall prevention, but there has been very little research in younger adults. This cross-sectional study considered the predictors of muscle strength in 137 young women (19-29 years) living in New Zealand. The following measurements were taken in the latter months of winter: plasma 25OHD, dominant (HGD) and non-dominant hand-grip (HGND) strength (hand-grip dynamometer), counter measure jump, and recreational physical activity (RPA) assessed from a recent physical activity questionnaire (RPAQ). Dietary intake was measured with a four-day food diary, and body composition using air displacement plethysmography. This was a relatively inactive group of women; total RPA ranged from 0 to 3.93h per week, mean (SD) 0.86(0.74) h, approximately 50% comprised outdoor activities. Mean 25OHD was 54(28)nmol/l, HGD and HGND were significantly different (t=6.049, p<0.001) at 27.3(5.8) and 25.6(5.7)kg respectively. Total RPA and 25OHD were entered into a linear regression model with handgrip strength as the dependent variable (Model R(2)=0.11, p=0.001 non-dominant, R(2)=0.13, p<0.001 dominant). Serum 25OHD was significantly associated with HGD (B(SE)=0.05(0.02), p=0.016) and HGND (B(SE)=0.04(0.02), p=0.019), independent of recreational physical activity. Recreational activity had an association with both hand-grip strength and serum 25OHD, and when each were adjusted to remove this association, 25OHD accounted for 4.3% of HGND and 4.5% of HGD. These results suggest that vitamin D status does have a small but significant association with hand-grip strength in this group of young women. Further investigation in this age group with a randomised controlled trial is

  19. [Gait speed, grip strength and self-rated health among the elderly: data from the FIBRA Campinas network, São Paulo, Brazil].

    PubMed

    Bez, Joelita Pessoa de Oliveira; Neri, Anita Liberalesso

    2014-08-01

    The article seeks to investigate patterns of performance and relationships between grip strength, gait speed and self-rated health, and investigate the relationships between them, considering the variables of gender, age and family income. This was conducted in a probabilistic sample of community-dwelling elderly aged 65 and over, members of a population study on frailty. A total of 689 elderly people without cognitive deficit suggestive of dementia underwent tests of gait speed and grip strength. Comparisons between groups were based on low, medium and high speed and strength. Self-related health was assessed using a 5-point scale. The males and the younger elderly individuals scored significantly higher on grip strength and gait speed than the female and oldest did; the richest scored higher than the poorest on grip strength and gait speed; females and men aged over 80 had weaker grip strength and lower gait speed; slow gait speed and low income arose as risk factors for a worse health evaluation. Lower muscular strength affects the self-rated assessment of health because it results in a reduction in functional capacity, especially in the presence of poverty and a lack of compensatory factors. PMID:25119074

  20. Strength and muscle activities during the toe-gripping action: comparison of ankle angle in the horizontal plane between the sitting upright and standing positions

    PubMed Central

    Soma, Masayuki; Murata, Shin; Kai, Yoshihiro; Nakae, Hideyuki; Satou, Yousuke

    2016-01-01

    [Purpose] The aim of this study was to investigate whether toe grip strength and muscle activities are affected by the ankle angle in the horizontal plane in the sitting upright and standing positions. [Subjects] The subjects were 16 healthy young women. [Methods] We measured toe grip strength and the maximum voluntary contraction activities of the rectus femoris, biceps femoris, anterior tibialis, and medial head of the gastrocnemius. In addition, we calculated the percent integrated electromyography during foot gripping in 3 different ankle joint positions between the long axis of the foot and the line of progression on the horizontal plane, namely 10° of internal rotation, 0°, and 10° of external rotation. [Results] Two-way analysis of variance revealed significant differences. A significant main effect was observed in the measurement conditions for the percent integrated electromyography of the rectus femoris muscle and long head of the biceps femoris. However, two-way analysis of variance did not reveal any significant difference, and a significant main effect was not observed in toe grip strength. [Conclusion] These findings suggest that exerted toe grip strength is only slightly affected by the ankle angle in the horizontal plane in the sitting upright and standing positions. Therefore, the current measurement positions were shown to be optimal for measurement. PMID:27134399

  1. Factor recruitment and TIF2/GRIP1 corepressor activity at a collagenase-3 response element that mediates regulation by phorbol esters and hormones

    PubMed Central

    Rogatsky, Inez; Zarember, Kol A.; Yamamoto, Keith R.

    2001-01-01

    To investigate determinants of specific transcriptional regulation, we measured factor occupancy and function at a response element, col3A, associated with the collagenase-3 gene in human U2OS osteosarcoma cells; col3A confers activation by phorbol esters, and repression by glucocorticoid and thyroid hormones. The subunit composition and activity of AP-1, which binds col3A, paralleled the intracellular level of cFos, which is modulated by phorbol esters and glucocorticoids. In contrast, a similar AP-1 site at the collagenase-1 gene, not inducible in U2OS cells, was not bound by AP-1. The glucocorticoid receptor (GR) associated with col3A through protein–protein interactions with AP-1, regardless of AP-1 subunit composition, and repressed transcription. TIF2/GRIP1, reportedly a coactivator for GR and the thyroid hormone receptor (TR), was recruited to col3A and potentiated GR-mediated repression in the presence of a GR agonist but not antagonist. GRIP1 mutants deficient in GR binding and coactivator functions were also defective for corepression, and a GRIP1 fragment containing the GR-interacting region functioned as a dominant-negative for repression. In contrast, repression by TR was unaffected by GRIP1. Thus, the composition of regulatory complexes, and the biological activities of the bound factors, are dynamic and dependent on cell and response element contexts. Cofactors such as GRIP1 probably contain distinct surfaces for activation and repression that function in a context-dependent manner. PMID:11689447

  2. Factor recruitment and TIF2/GRIP1 corepressor activity at a collagenase-3 response element that mediates regulation by phorbol esters and hormones.

    PubMed

    Rogatsky, I; Zarember, K A; Yamamoto, K R

    2001-11-01

    To investigate determinants of specific transcriptional regulation, we measured factor occupancy and function at a response element, col3A, associated with the collagenase-3 gene in human U2OS osteosarcoma cells; col3A confers activation by phorbol esters, and repression by glucocorticoid and thyroid hormones. The subunit composition and activity of AP-1, which binds col3A, paralleled the intracellular level of cFos, which is modulated by phorbol esters and glucocorticoids. In contrast, a similar AP-1 site at the collagenase-1 gene, not inducible in U2OS cells, was not bound by AP-1. The glucocorticoid receptor (GR) associated with col3A through protein-protein interactions with AP-1, regardless of AP-1 subunit composition, and repressed transcription. TIF2/GRIP1, reportedly a coactivator for GR and the thyroid hormone receptor (TR), was recruited to col3A and potentiated GR-mediated repression in the presence of a GR agonist but not antagonist. GRIP1 mutants deficient in GR binding and coactivator functions were also defective for corepression, and a GRIP1 fragment containing the GR-interacting region functioned as a dominant-negative for repression. In contrast, repression by TR was unaffected by GRIP1. Thus, the composition of regulatory complexes, and the biological activities of the bound factors, are dynamic and dependent on cell and response element contexts. Cofactors such as GRIP1 probably contain distinct surfaces for activation and repression that function in a context-dependent manner. PMID:11689447

  3. Prognostic value of physical function tests: hand grip strength and six-minute walking test in elderly hospitalized patients

    PubMed Central

    Martín-Ponce, Esther; Hernández-Betancor, Iván; González-Reimers, Emilio; Hernández-Luis, Rubén; Martínez-Riera, Antonio; Santolaria, Francisco

    2014-01-01

    To discern if physical function test are better mortality predictors than muscle mass in elderly hospitalized patients, we analyzed the prognostic value of muscle mass malnutrition and compared it with physical muscle function tests, including the six-minute walking test (6MWT) and hand grip strength. We included the ankle brachial index (ABI) to assess arterial disease, related to muscle atrophy due to hypoperfusion. We also analyzed the relationship of ABI with malnutrition, physical function tests and survival. We studied 310 hospitalized patients older than 60 years. To assess nutritional status, we determined BMI, triceps skinfold and mid-arm muscle area; we performed a subjective nutritional assessment; and evaluated the degree of inflammatory stress. We assessed physical function by hand grip strength and 6MWT. We evaluated arterial disease by ABI. Forty-one patients died during hospitalization; 269 were discharged and followed for a mean 808 days, reaching a mortality of 49%. Muscle malnutrition was frequent and was related to mortality, but the best predictors were physical function tests: inability to perform the 6MWT and low handgrip strength. Function tests were closely related to each other and correlated with nutritional data. Reduced ABI was related to impaired nutritional status, physical function tests and mortality. PMID:25531922

  4. Wonders From a new 3085m Deep ice Core From NorthGRIP on the Greenland ice Sheet.

    NASA Astrophysics Data System (ADS)

    Dahl-Jensen, D.; Johnsen, S. J.; Jouzel, J.; Miller, H.; Schwander, J.; Steffensen, J. P.; White, J.

    2004-05-01

    A new 3085m deep ice core has been retrieved from (75.1N, 42.3W), the northern part of the Greenland Ice Sheet. The North GReenland Ice core Project was initiated in 1996 by an international team of researchers from Denmark, Belgium, France, Germany, Iceland, Japan, Sweden, Switzerland and USA and after 7 field seasons bedrock was reached on 17 July 2003. The purpose of the NorthGRIP program was to obtain an undisturbed climatic record of ice older than 105 ka, especially to recover a record of the last interglacial period, the Eemian, 115-130 ka before present. This period was not recovered in chronological order from the two central Greenland ice cores GRIP and GISP2 because the deep ice was disturbed by flow over mountainous bedrock. The NorthGRIP drill site was chosen 325 km down the gently NNW sloping ice ridge originating from the top point of the Ice Sheet, where the European GRIP core was drilled. The site is located at a position where the bedrock is very smooth and the annual accumulation rate is 0.195 m/a, the mean annual surface temperature is -32 deg C Approaching bedrock it became clear from measurements of temperatures in the borehole that the basal ice would be on the melting point. High resolution measurements on the ice cores confirmed that basal melting must occur. Drilling in the warm ice near the bedrock turned out to be difficult and new drilling techniques were developed before bedrock was reached in July 2003. The ice core has been measured in high resolution for stable oxygen isotopes, soluble and unsoluble impurities, optical line scan, electrical and dielectrical properties and crystal rheology. Gas, tephra and beryllium measurements are ongoing. The results from the ice core show that the basal melt rate is 0.7 +-0.2 cm ice/a and the ice at the base is 123 +-4 ka old. The continuous impurity measurements and the optical line scan on the ice core are so highly resolved that annual layers can be detected though the whole ice core with

  5. The relationship of birthweight, muscle size at birth and postnatal growth to grip strength in 9 year-old Indian children: findings from the Mysore Parthenon Study

    PubMed Central

    Barr, James G; Veena, Sargoor R; Kiran, K N; Wills, Andrew K; Winder, Nicola R; Kehoe, Sarah; Fall, Caroline HD; Sayer, Avan A; Krishnaveni, Ghattu V

    2012-01-01

    Fetal development may permanently affect muscle function. Indian newborns have a low mean birthweight, predominantly due to low lean tissue and muscle mass. We aimed to examine the relationship of birthweight, and arm muscle area (AMA) at birth and post-natal growth to hand-grip strength in Indian children. Grip strength was measured in 574 children aged 9 years, who had detailed anthropometry at birth and every 6-12 months post-natally. Mean (standard deviation (SD)) birthweight was 2863 (446) g. At 9 years, the children were short (mean height SD −0.6) and light (mean weight SD −1.1) compared with the World Health Organization growth reference. Mean (SD) grip strength was 12.7 (2.2) kg (boys) and 11.0 (2.0) kg (girls). Weight, length and AMA at birth, but not skinfold measurements at birth, were positively related to 9-year grip strength (β=0.40 kg per standard deviation increase in birthweight, p<0.001; and β=0.41 kg per standard deviation increase in AMA, p<0.001). Grip strength was positively related to 9-year height, body mass index and AMA and to gains in these measurements from birth to 2 years, 2-5 years and 5-9 years (p<0.001 for all). The associations between birth size and grip strength were attenuated but remained statistically significant for AMA after adjusting for 9-year size. We conclude that larger overall size and muscle mass at birth are associated with greater muscle strength in childhood, and that this is mediated mainly through greater post-natal size. Poorer muscle development in utero is associated with reduced childhood muscle strength. PMID:23750316

  6. High risk of fall, poor physical function, and low grip strength in men with fracture—the STRAMBO study

    PubMed Central

    Feyt, Clément; Chapurlat, Roland

    2015-01-01

    Abstract Background Several studies assessed the association of prevalent fractures with muscle mass, strength, and physical capacity in men. Clinical impact of these associations is not clear, and they could be influenced by confounders. Our aim was to assess the association of the prevalent fractures with muscle strength, physical function, and the risk of subsequent falls in older men after adjustment for muscle mass and potential confounders. Methods In a cohort of 890 men aged 50 and older, we assessed appendicular skeletal muscle mass (ASM) by DXA, grip strength, physical function (chair stands, static, and dynamic balance). Relative ASM (RASM) was calculated as ASM / (height)2. Then, 813 men aged 60 and over were followed up prospectively for 5 years and 144 sustained >1 incident falls. All the analyses were adjusted for lifestyle factors, co‐morbidities, and hormones known to influence muscle and physical function. Results Low leisure physical activity, very high occupational physical activity, Parkinson's disease, diabetes mellitus, low apparent free testosterone concentration (AFTC), as well as Grade 2 and 3 vertebral fractures and multiple fractures were associated with lower grip strength when adjusted for confounders including upper limb RASM. Low leisure physical activity, very high occupational physical activity, diabetes mellitus, prior stroke, low AFTC and 25‐hydroxycholecalciferol, high C‐reactive protein, vertebral fractures, and non‐vertebral fractures were associated with poor physical function (lowest quintile of the score of tests) when adjusted for confounders including lower limb RASM. Grade 2 and 3 and multiple vertebral fractures were associated with twofold higher risk of multiple falls after adjustment for confounders. Men having multiple fractures had a twofold higher risk of multiple falls after adjusting for confounders. In multivariable models, risk of falls increased proportionally to the increasing severity and

  7. Cross-Talk in Mechanomyographic Signals from the Forearm Muscles during Sub-Maximal to Maximal Isometric Grip Force

    PubMed Central

    Islam, Md. Anamul; Sundaraj, Kenneth; Ahmad, R. Badlishah; Sundaraj, Sebastian; Ahamed, Nizam Uddin; Ali, Md. Asraf

    2014-01-01

    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, R2x, 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. PMID:24802858

  8. Reduction of chronic post-herniotomy pain and recurrence rate. Use of the anatomical self-gripping ProGrip laparoscopic mesh in TAPP hernia repair. Preliminary results of a prospective study

    PubMed Central

    Hoskovec, David

    2015-01-01

    Introduction The role of fixation of the mesh is especially important in the endoscopic technique. The fixation of mesh through penetrating techniques using staples, clips or screws is associated with a significantly increased risk of developing a post-herniotomy pain syndrome. Aim To demonstrate the safety and efficacy of the self-fixating anatomical Parietex ProGrip laparoscopic mesh (Sofradim Production, Trévoux France) used with laparoscopic transabdominal preperitoneal hernia repair. The incidence of chronic post-herniotomy pain and recurrence rate in the follow-up after 12 months were evaluated. Material and methods Data analysis included all patients who underwent inguinal hernia surgery at our Surgical Department within the period from 1.05.2013 to 31.12.2014, who fulfilled the inclusion criteria. Standard surgical technique was used. Data were prospectively entered and subsequently analyzed on the Herniamed platform. Herniamed is an internet-based register in German and English language and includes all data of patients who underwent surgery for some types of hernia. Results There were 95 patients enrolled in the group and there were in total 156 inguinal hernias repaired. The mean follow-up was 15.52 months. At the assessment at 1 year mild discomfort in the groin was reported in 2 patients (3.51%) (1–3 VAS). No recurrence or chronic postoperative pain was reported. Conclusions Laparoscopic inguinal hernia repair using the transabdominal preperitoneal technique with implantation of the ProGrip laparoscopic mesh is a fast, effective and reliable method in experienced hands, which according to our results reduces the occurrence of chronic post-operative inguinal pain with simultaneously a low recurrence rate. PMID:26649083

  9. Golf players exhibit changes to grip speed parameters during club release in response to changes in club stiffness.

    PubMed

    Osis, Sean T; Stefanyshyn, Darren J

    2012-02-01

    The influence of golf club stiffness on driving performance is currently unclear, and it is possible that this ambiguity is due in part to golfer adaptation to equipment. The purpose of the current study was to elucidate mechanisms of adaptation to club stiffness, during the golf swing, by employing tendon vibration to distort proprioceptive feedback. Vibration (∼50 Hz, ∼1 mm amplitude) was applied to the upper extremities of 24 golfers using DC motors with eccentric weights. Golfers hit golf balls in a laboratory setting using three clubs of varying shaft stiffness, and club kinematics were recorded using high speed (180 Hz) digital cameras. The results demonstrated significant slowing of the club grip during club release for a high-stiffness shaft with vibration. This suggests that, when proprioceptive feedback is available, players adapt to changes in club stiffness by modifying the release dynamics of the club late in the downswing. PMID:21820748

  10. Maximal dynamic grip force and wrist torque: the effects of gender, exertion direction, angular velocity, and wrist angle.

    PubMed

    Morse, Jonathan L; Jung, Myung-Chul; Bashford, Gregory R; Hallbeck, M Susan

    2006-11-01

    The objective of this study was to examine the effects of gender, exertion direction, angular velocity and wrist angle on simultaneous grip force and wrist torque under the isokinetic condition. The study used 20 participants (10 males and 10 females) and included 6 angular velocities (15, 30, 45, 60, 75, and 90 degrees /s) and 2 wrist exertion directions (flexion and extension) over the wrist range of motion of 70 degrees flexion to 60 degrees extension in 5 degrees increments. Similar to other studies, males and flexion exertion produced larger forces than females and extension exertion, respectively. However, the largest forces were generated at near extreme flexion of the wrist and the dependent variable of angular velocity was not practically significant. These results can contribute to the evaluation of cumulative trauma syndromes, but there is a need for more research on the dynamic measures of the hand and wrist complex and for standard development for dynamic force measurement. PMID:16442072