scholarly journals Assessment of Hand Function Through the Coordination of Contact Forces in Manipulation Tasks

2013 ◽  
Vol 36 (1) ◽  
pp. 5-160 ◽  
Author(s):  
Slobodan Jaric ◽  
Mehmet Uygur
Keyword(s):  
Hand Function ◽  
Safety Margin ◽  
Tangential Component ◽  
Contact Forces ◽  
Load Force ◽  
Dominant Hand ◽  
Factors Affecting ◽  
Relative Safety ◽  
Safety Margins ◽  
Mechanical Factors

Exploration of force coordination has been one of the most often used approaches in studies of hand function. When holding and manipulating a hand-held object healthy individuals are typically able to highly coordinate the perpendicular (grip force; GF) with the tangential component of the contact force (load force; LF). The purpose of this review is to present the findings of our recent studies of GF-LF coordination. Regarding the mechanical factors affecting GF-LF coordination, our data suggest that both different hand segments and their particular skin areas could have markedly different friction properties. It also appears that the absolute, rather than relative safety margin (i.e., how much the actual GF exceeds the minimum value that prevents slipping) should be a variable of choice when assessing the applied magnitude of GF. The safety margin could also be lower in static than in free holding tasks. Regarding the involved neural factors, the data suggest that the increased frequency, rather than an increased range of a cyclic LF could have a prominent detrimental effect on the GF-LF coordination. Finally, it appears that the given instructions (e.g., 'to hold' vs. 'to pull') can prominently alter GF-LF coordination in otherwise identical manipulation tasks. Conversely, the effects of handedness could be relatively week showing only slight lagging of GF in the non-dominant, but not in the dominant hand. The presented findings reveal important aspects of hand function as seen through GF-LF coordination. Specifically, the use of specific hand areas for grasping, calculation of particular safety margins, the role of LF frequency (but not of LF range) and the effects of given instructions should be all taken into account when conducting future studies of manipulation tasks, standardizing their procedures and designing routine clinical tests of hand function.

scholarly journals Factors affecting return to work after surgical treatment of trapeziometacarpal joint osteoarthritis

2020 ◽  
pp. 175319342097863
Author(s):  
Mark J. W. van der Oest ◽  
Joris S. Teunissen ◽  
Ralph Poelstra ◽  
Reinier Feitz ◽  
Alex Burdorf ◽  
...  
Keyword(s):  
Surgical Treatment ◽  
Return To Work ◽  
Hand Function ◽  
Population Level ◽  
Dominant Hand ◽  
Trapeziometacarpal Joint ◽  
Level Of Evidence ◽  
Factors Affecting ◽  
Lost Productivity ◽  
Trapeziometacarpal Joint Osteoarthritis

This study aimed to identify factors contributing to the timing of return to work after surgical treatment of trapeziometacarpal joint osteoarthritis and to calculate the costs of lost productivity. We included 627 patients with paid employment who underwent trapeziectomy and ligament reconstruction with tendon interposition. Time to return to work was measured through filling online questionnaires and analysed using survival analysis at 6 weeks and 3, 6 and 12 months after the surgery. Patients also filled in the Michigan Hand Outcomes Questionnaire. Costs of lost productivity were calculated using the human capital method. After 1 year, 78% of the patients returned to work. The median time to return to work was 12 weeks. Factors that significantly affected the time to return to work were occupational intensity (light, moderate or heavy physical labour), whether the dominant hand was treated and the Michigan Hand Outcomes Questionnaire work score and hand function score of the unoperated side at baseline. The costs of lost productivity were estimated at €11,000 on the patient level, resulting in €16.8 million on the Dutch population level per year. Level of evidence: II

Factors Affecting Overtaking Behaviour On Single Carriageway Road: Case Study at Jalan Kluang-Kulai

2014 ◽  
Vol 71 (3) ◽  
Author(s):  
Sitti Asmah Hassan ◽  
Othman Che Puan ◽  
Nordiana Mashros ◽  
Nur Sabahiah Abdul Sukor
Keyword(s):  
Traffic Accidents ◽  
Road Traffic ◽  
Safety Margin ◽  
Video Camera ◽  
Vehicle Speed ◽  
Factors Affecting ◽  
Sight Distance ◽  
Safety Margins ◽  
And Performance ◽  
Decision Times

Overtaking is one of many important behaviour considered in the analysis of road traffic accidents and performance of single carriageway road. This paper seeks to determine factors affecting the speed of an overtaking vehicle. The study was conducted for a single carriageway road section which is flat and straight so that there is no effect of sight distance on overtaking. Overtaking behaviour data were recorded using a video camera. The data extracted from the video recordings were the decision times, overtaking times, overtaking distances, safety margins, accepted and rejected gaps, headways at the start of the overtaking manoeuvres, headways at the end of the overtaking manoeuvres, speed of the overtaken vehicle, speed of the overtaking vehicle at the end of the overtaking and acceleration of the overtaking vehicle during the overtaking. The data were analysed statistically to establish relationships between the various overtaking parameters. This study found that the speed of overtaking vehicle was affected by the speed of overtaken vehicle, drivers’ decision times, safety margin, overtaking times and acceleration.

Clinical Update: Assessing Maximum Medical Improvement in Carpal Tunnel Syndrome

2003 ◽  
Vol 8 (4) ◽  
pp. 4-5
Author(s):  
Christopher R. Brigham ◽  
James B. Talmage
Keyword(s):  
Carpal Tunnel Syndrome ◽  
Carpal Tunnel ◽  
Proper Time ◽  
Carpal Tunnel Release ◽  
Hand Function ◽  
Factors Affecting ◽  
Early Results ◽  
Medical Evaluation ◽  
Nerve Recovery ◽  
Tunnel Syndrome

Abstract Permanent impairment cannot be assessed until the patient is at maximum medical improvement (MMI), but the proper time to test following carpal tunnel release often is not clear. The AMA Guides to the Evaluation of Permanent Impairment (AMA Guides) states: “Factors affecting nerve recovery in compression lesions include nerve fiber pathology, level of injury, duration of injury, and status of end organs,” but age is not prognostic. The AMA Guides clarifies: “High axonotmesis lesions may take 1 to 2 years for maximum recovery, whereas even lesions at the wrist may take 6 to 9 months for maximal recovery of nerve function.” The authors review 3 studies that followed patients’ long-term recovery of hand function after open carpal tunnel release surgery and found that estimates of MMI ranged from 25 weeks to 24 months (for “significant improvement”) to 18 to 24 months. The authors suggest that if the early results of surgery suggest a patient's improvement in the activities of daily living (ADL) and an examination shows few or no symptoms, the result can be assessed early. If major symptoms and ADL problems persist, the examiner should wait at least 6 to 12 months, until symptoms appear to stop improving. A patient with carpal tunnel syndrome who declines a release can be rated for impairment, and, as appropriate, the physician may wish to make a written note of this in the medical evaluation report.

scholarly journals Bootstrap and Order Statistics for Quantifying Thermal-Hydraulic Code Uncertainties in the Estimation of Safety Margins

2008 ◽  
Vol 2008 ◽  
pp. 1-9 ◽  
Author(s):  
Enrico Zio ◽  
Francesco Di Maio
Keyword(s):  
Confidence Interval ◽  
Order Statistics ◽  
Nuclear Reactor ◽  
Safety Margin ◽  
Fuel Cladding ◽  
Complete Group ◽  
Bootstrap Technique ◽  
Safety Margins ◽  
Group Distribution

In the present work, the uncertainties affecting the safety margins estimated from thermal-hydraulic code calculations are captured quantitatively by resorting to the order statistics and the bootstrap technique. The proposed framework of analysis is applied to the estimation of the safety margin, with its confidence interval, of the maximum fuel cladding temperature reached during a complete group distribution blockage scenario in a RBMK-1500 nuclear reactor.

SEISMIC ASSESSMENT OF CONTEMPORARY VERSUS OLD URBAN FRAME BUILDINGS

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
ABDELRAHMAN ASHRI ◽  
ANAS ISSA ◽  
Aman Mwafy
Keyword(s):  
Comparative Study ◽  
Lateral Force ◽  
Fragility Functions ◽  
Seismic Code ◽  
Earthquake Losses ◽  
Relative Safety ◽  
Safety Margins ◽  
Before And After ◽  
Benchmark Structures ◽  
The Comparative Study

This comparative study probabilistically assesses the relative safety margins of code-compliant and pre-seismic code RC buildings with different heights in a region of medium seismicity. Detailed structural design and fiber-based modeling of six benchmark structures, namely two code-compliant buildings and two pre-code structures before and after retrofit, are undertaken to develop fragility functions using several earthquake records representing the most critical seismic scenario in the study area. Several inelastic dynamic analyses are performed to assess the seismic response and derive a range of fragility functions for the six benchmark buildings. Compared with contemporary structures, the study highlights the vulnerability of pre-code buildings due to the insufficient stiffness, strength, and ductility provided by their lateral force resisting systems. A practical retrofit solution for pre-code structures is subsequently assessed using the methodology adopted for other modern and old buildings. The probabilistic assessment results confirmed the comparable seismic performance of the retrofitted and code-conforming buildings. The comparative study, which provided insights into the differences between code-compliant versus pre-seismic code buildings before and after retrofit, contributes to reducing earthquake losses and improving community seismic resilience in earthquake-prone regions.

scholarly journals Mechanical Factors Affecting the Evoked Pressures from a Simple Twitch Monitor

1972 ◽  
Vol 1 (2) ◽  
pp. 154-156 ◽  
Author(s):  
C. Shanks ◽  
G. A. Harrison
Keyword(s):  
Neuromuscular Blockade ◽  
Factors Affecting ◽  
Air Volume ◽  
Mechanical Factors

A syringe and aneroid manometer have been employed to quantitate neuromuscular blockade. The most important factors shown to vary its response were its air volume and the angulation of the syringe from the vertical. But even when these were held constant, the resultant pressures were not linearly related to the generative impulses. It is suggested that although this type of apparatus is not very accurate, the simple and inexpensive mechanism could benefit the practical anaesthetist monitoring nondepolarizing relaxants, providing its limitations are appreciated.

Some Physical and Mechanical Factors Affecting the Simple Shear Strength of Methylmethacrylate

1975 ◽  
Vol 108 ◽  
pp. 145-148 ◽  
Author(s):  
William J. Astleford ◽  
Marc A. Asher ◽  
Ulric S. Lindholm ◽  
Charles A. Rockwood
Keyword(s):  
Shear Strength ◽  
Simple Shear ◽  
Factors Affecting ◽  
Mechanical Factors

scholarly journals Age-related changes in multifinger synergies in accurate moment of force production tasks

2007 ◽  
Vol 102 (4) ◽  
pp. 1490-1501 ◽  
Author(s):  
Halla Olafsdottir ◽  
Wei Zhang ◽  
Vladimir M. Zatsiorsky ◽  
Mark L. Latash
Keyword(s):  
Hand Function ◽  
The Elderly ◽  
Time Profile ◽  
Uncontrolled Manifold ◽  
Elderly Subjects ◽  
Total Force ◽  
Dominant Hand ◽  
Total Moment ◽  
Age Related ◽  
Young Subjects

The purpose of this investigation was to document and quantify age-related differences in the coordination of fingers during a task that required production of an accurate time profile of the total moment of force by the four fingers of a hand. We hypothesized that elderly subjects would show a decreased ability to stabilize a time profile of the total moment of force, leading to larger indexes of moment variability compared with young subjects. The subjects followed a trapezoidal template on a computer screen by producing a time profile of the total moment of force while pressing down on force sensors with the four fingers of the right (dominant) hand. To quantify synergies, we used the framework of the uncontrolled manifold hypothesis. The elderly subjects produced larger total force, larger variance of both total force and total moment of force, and larger involvement of fingers that produced moment of force against the required moment direction (antagonist moment). This was particularly prominent during supination efforts. Young subjects showed covariation of commands to fingers across trials that stabilized the moment of total force (moment-stabilizing synergy), while elderly subjects failed to do so. Both subject groups showed similar indexes of covariation of commands to the fingers that stabilized the time profile of the total force. The lack of moment-stabilizing synergies may be causally related to the documented impairment of hand function with age.

Experimental Investigation of Vibratory Finishing Process

2014 ◽  
Author(s):  
Xiaozhong Song ◽  
Rahul Chaudhari ◽  
Fukuo Hashimoto
Keyword(s):  
Surface Roughness ◽  
Experimental Investigation ◽  
Metal Removal ◽  
Contact Forces ◽  
Chemical Solution ◽  
Impact Frequency ◽  
Vibratory Finishing ◽  
Factors Affecting ◽  
Finishing Process ◽  
Chemical Solutions

The vibratory finishing process is widely used for finishing metal components. An experimental investigation is reported on the factors affecting the metal removal and resultant surface roughness during vibratory finishing including the influence of chemical solutions. The effect of process parameters such as media size and impact frequency is studied by measuring the contact forces. A method to investigate the effect of chemical solution and to optimize the processing time to achieve desired resultant surface roughness is presented.

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