Effect of Tool Handle Design Parameters on Upper Extremity Muscle Performance in Periodontology

Author(s):  
Vibha Bhatia ◽  
Jagiit Singh Randhawa ◽  
Parveen Kalra ◽  
Ashish Jain ◽  
Vishakha Grover
Author(s):  
Charles Pontonnier ◽  
Georges Dumont ◽  
Mark de Zee ◽  
Afshin Samani ◽  
Pascal Madeleine

Repetitive arm movement and force exertion are common in meat cutting tasks and often lead to musculosketal disorders. In this study, the effects of the workbench height and the cutting direction on the levels of muscular activation of the upper extremity during meat cutting tasks were investigated. Seven subjects performed 4 trials of 20s each at the 4 different heights (0 cm, −10 cm, −20 cm and −30 cm below the elbow height), alternating two cutting directions. Activation levels of upper extremity muscles (biceps brachii, triceps long head, deltoideus anterior, deltoideus medialis and upper trapezius) and cutting forces were recorded synchronously. Then the trends of the normalized activations with regard to the workplace design parameters (table height and cutting direction) were computed. Results showed that the optimal configuration is a partially related to the task, whereas motor control strategies have also an influence on it. The present results provide new key information about the effects of workbench heights during a repetitive meat cutting task and a complete assessment protocol to analyse workstation design parameters influence on muscles activation levels.


Author(s):  
Yi Xu ◽  
Qing-hua Hou ◽  
Xiu-lan Han ◽  
Chu-huai Wang ◽  
Dong-feng Huang

Author(s):  
C J R Sheppard

The confocal microscope is now widely used in both biomedical and industrial applications for imaging, in three dimensions, objects with appreciable depth. There are now a range of different microscopes on the market, which have adopted a variety of different designs. The aim of this paper is to explore the effects on imaging performance of design parameters including the method of scanning, the type of detector, and the size and shape of the confocal aperture.It is becoming apparent that there is no such thing as an ideal confocal microscope: all systems have limitations and the best compromise depends on what the microscope is used for and how it is used. The most important compromise at present is between image quality and speed of scanning, which is particularly apparent when imaging with very weak signals. If great speed is not of importance, then the fundamental limitation for fluorescence imaging is the detection of sufficient numbers of photons before the fluorochrome bleaches.


2002 ◽  
Vol 7 (2) ◽  
pp. 1-4, 12 ◽  
Author(s):  
Christopher R. Brigham

Abstract To account for the effects of multiple impairments, evaluating physicians must provide a summary value that combines multiple impairments so the whole person impairment is equal to or less than the sum of all the individual impairment values. A common error is to add values that should be combined and typically results in an inflated rating. The Combined Values Chart in the AMA Guides to the Evaluation of Permanent Impairment, Fifth Edition, includes instructions that guide physicians about combining impairment ratings. For example, impairment values within a region generally are combined and converted to a whole person permanent impairment before combination with the results from other regions (exceptions include certain impairments of the spine and extremities). When they combine three or more values, physicians should select and combine the two lowest values; this value is combined with the third value to yield the total value. Upper extremity impairment ratings are combined based on the principle that a second and each succeeding impairment applies not to the whole unit (eg, whole finger) but only to the part that remains (eg, proximal phalanx). Physicians who combine lower extremity impairments usually use only one evaluation method, but, if more than one method is used, the physician should use the Combined Values Chart.


2003 ◽  
Vol 8 (5) ◽  
pp. 4-12
Author(s):  
Lorne Direnfeld ◽  
James Talmage ◽  
Christopher Brigham

Abstract This article was prompted by the submission of two challenging cases that exemplify the decision processes involved in using the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides). In both cases, the physical examinations were normal with no evidence of illness behavior, but, based on their histories and clinical presentations, the patients reported credible symptoms attributable to specific significant injuries. The dilemma for evaluators was whether to adhere to the AMA Guides, as written, or to attempt to rate impairment in these rare cases. In the first case, the evaluating neurologist used alternative approaches to define impairment based on the presence of thoracic outlet syndrome and upper extremity pain, as if there were a nerve injury. An orthopedic surgeon who evaluated the case did not base impairment on pain and used the upper extremity chapters in the AMA Guides. The impairment ratings determined using either the nervous system or upper extremity chapters of the AMA Guides resulted in almost the same rating (9% vs 8% upper extremity impairment), and either value converted to 5% whole person permanent impairment. In the second case, the neurologist evaluated the individual for neuropathic pain (9% WPI), and the orthopedic surgeon rated the patient as Diagnosis-related estimates Cervical Category II for nonverifiable radicular pain (5% to 8% WPI).


2001 ◽  
Vol 6 (1) ◽  
pp. 1-3
Author(s):  
Robert H. Haralson

Abstract The AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fifth Edition, was published in November 2000 and contains major changes from its predecessor. In the Fourth Edition, all musculoskeletal evaluation and rating was described in a single chapter. In the Fifth Edition, this information has been divided into three separate chapters: Upper Extremity (13), Lower Extremity (14), and Spine (15). This article discusses changes in the spine chapter. The Models for rating spinal impairment now are called Methods. The AMA Guides, Fifth Edition, has reverted to standard terminology for spinal regions in the Diagnosis-related estimates (DRE) Method, and both it and the Range of Motion (ROM) Method now reference cervical, thoracic, and lumbar. Also, the language requiring the use of the DRE, rather than the ROM Method has been strengthened. The biggest change in the DRE Method is that evaluation should include the treatment results. Unfortunately, the Fourth Edition's philosophy regarding when and how to rate impairment using the DRE Model led to a number of problems, including the same rating of all patients with radiculopathy despite some true differences in outcomes. The term differentiator was abandoned and replaced with clinical findings. Significant changes were made in evaluation of patients with spinal cord injuries, and evaluators should become familiar with these and other changes in the Fifth Edition.


1998 ◽  
Vol 3 (5) ◽  
pp. 1-3
Author(s):  
Richard T. Katz ◽  
Sankar Perraraju

Abstract The AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fourth Edition, offers several categories to describe impairment in the shoulder, including shoulder amputation, abnormal shoulder motion, peripheral nerve disorders, subluxation/dislocation, and joint arthroplasty. This article clarifies appropriate methods for rating shoulder impairment in a specific patient, particularly with reference to the AMA Guides, Section 3.1j, Shoulder, Section 3.1k, Impairment of the Upper Extremity Due to Peripheral Nerve Disorders, and Section 3.1m, Impairment Due to Other Disorders of the Upper Extremity. A table shows shoulder motions and associated degrees of motion and can be used in assessing abnormal range of motion. Assessments of shoulder impairment due to peripheral nerve lesion also requires assessment of sensory loss (or presence of nerve pain) or motor deficits, and these may be categorized to the level of the spinal nerves (C5 to T1). Table 23 is useful regarding impairment from persistent joint subluxation or dislocation, and Table 27 can be helpful in assessing impairment of the upper extremity after arthroplasty of specific bones of joints. Although inter-rater reliability has been reasonably good, the validity of the upper extremity impairment rating has been questioned, and further research in industrial medicine and physical disability is required.


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