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Copyright of Giornale Italiano di Medicina del Lavoro ed Ergonomia is the property of Giornale Italiano di Medicina del Lavoro ed Ergonomia Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Giornale Italiano di Medicina del Lavoro ed Ergonomia is the property of Giornale Italiano di Medicina del Lavoro ed Ergonomia Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Gait of visually impaired subjects (VIS) is worse than that of sighted ones. VIS can use tactile ground surface indicators to optimize their walking efficiency. Aim of the study was to compare VIS walking efficiency on either trapezoidal and sinusoidal shape leading indicators. VIS walking on the sinusoidal leading indicators showed a worsening of the timedistance parameters (a longer stance phase, a shorter swing phase and shorter step and stride lengths), reduced lower limb joint excursions and increased center of mass oscillations. In conclusion sinusoidal tactile indicators induce a stiffening of joints and a loss of balance with an increased risk of fall. [ABSTRACT FROM AUTHOR]

Copyright of Giornale Italiano di Medicina del Lavoro ed Ergonomia is the property of Giornale Italiano di Medicina del Lavoro ed Ergonomia Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Giornale Italiano di Medicina del Lavoro ed Ergonomia is the property of Giornale Italiano di Medicina del Lavoro ed Ergonomia Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Giornale Italiano di Medicina del Lavoro ed Ergonomia is the property of Giornale Italiano di Medicina del Lavoro ed Ergonomia Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

One of the mechanisms adopted by the central nervous system to stabilize the joints or the spine is muscle co-activation. Nevertheless during lifting tasks muscle co-activation increases spinal load. For co-activation assessment during 3 lifting tasks at increasing load levels we utilized a time-varying co-activation algorithm proposed by Rudolph in 2000. We found that Rudolph co-activation index grew with lifting index. The time-varying co-activation index gave a continuous measure of low back compression. A time-varying co-activation index could be of great interest in all conditions in which NIOSH equation is not applicable.

As the airport traffic increases there is a continuous increase of passengers with different motor disabilities. Disabled passenger's assistance causes a biomechanical overload in airport workers. Some disabled passengers are classified by IATA as WCHC (wheel chair in cabin or Charlie). Our study, was performed in one of the most important Italian airport on Charlie passengers (about 10% of all assistances). We identified four critical points: 1) wheelchair and baggage moving (unstable load), 2) inclined ramps with worker's backwards steps and braked wheelchair to prevent passenger tipping or falling, 3) transfer from standard wheelchair to bicycle wheelchair, specifically designed for the aisle; 4.) transfer from bicycle wheelchair to aircraft seat. The last two points required sometimes to lift passengers over the armrest and positioning them on a window side seat, causing a serious increase of biomechanical load. For each critical point we have proposed technical and organizational measures to reduce airport worker's biomechanical risk.

Aim of this work is to assess, with an objective technique (i.e. surface electromyography), the upper limb biomechanical load in workers specialized in manufacturing of orthopedic prostheses. We considered two different working configurations (workstation height at 105 and 110 cm) and three different materials to be modeled (aluminum, steel and titanium). Our results showed significant differences between aluminum/steel and titanium bars. As regards the working configurations, we found differences in the muscle activation patterns between the two heights, with an increased exertion of the shoulder muscles at 110 cm with respect to 105.

Observational information on muscle activity is related to sEMG activity expressed as a percentage of the maximum voluntary contraction (MVC). This is the case for the Garg and Moore Strain Index and the Hand Activity Level (HAL) proposed by the ACGIH. This latter involves the assessor recording the levels of MVC in 10% intervals. This degree of sensitivity certainly calls for the use of surface electromyography (sEMG) rather than just observation. Furthermore sEMG signal can contribute to assess muscle fatigue and force with the modern instruments for signal frequency analysis; earlier limitations have been overcome and dynamic assessment can now be done.

Gait of visually impaired subjects (VIS) is worse than that of sighted ones. VIS can use tactile ground surface indicators to optimize their walking efficiency. Aim of the study was to compare VIS walking efficiency on either trapezoidal and sinusoidal shape leading indicators. VIS walking on the sinusoidal leading indicators showed a worsening of the time-distance parameters (a longer stance phase, a shorter swing phase and shorter step and stride lengths), reduced lower limb joint excursions and increased center of mass oscillations. In conclusion sinusoidal tactile indicators induce a stiffening of joints and a loss of balance with an increased risk of fall.

We analyzed the coordination patterns between elbow, shoulder and trunk in a motor task consisting of reaching out, picking up a cylinder, and transporting it back by using the Dynamical Systems Theory and calculating the continuous relative phase (CRP), a continuous measure of the coupling between two interacting joints. We used an optoelectronic motion analysis system consisting of eight infra-red ray cameras to detect the movements of nine skin-mounted markers. We calculated the root square of the adjusted coefficient of determination, the coefficient of multiple correlation (CMC), in order to investigate the repeatability of the joints coordination. The data confirm that the CNS establishes both synergic (i.e. coupling between shoulder and trunk on the frontal plane) and hierarchical (i.e. coupling between elbow-shoulder-trunk on the horizontal plane) relationships among the available degrees of freedom to overcome the complexity due to motor redundancy. The present study describes a method to investigate the organization of the kinematic degrees of freedom during upper limb multi-joint motor tasks that can be useful to assess upper limb repetitive movements.