Ðñïúüíôá ôïõ DJ, Á.Å.

Ç ôñéâÞ åìöáíßæåôáé üôáí ìðáßíïõíå óå äýï åðéöÜíåéåò ôçí åðáöÞ, üðùò üôáí óôçñßæåôáé ìéá ñüäá óå Ýíá ðÜôùìá. Ç ôñéâÞ åßíáé ç äýíáìç ðïõ áíôéóôÝêåôáé óôç ìåôáêßíçóç ìåôáîý ôùí áíôéêåéìÝíùí. Õðü ôïõò èåùñçôéêÜ ôÝëåéïõò üñïõò, ôï éäáíéêü ðåñéâÜëëïí ñïäþí èá Þôáí ìéá óêëçñÞ, ïìáëÞ ñüäá ðïõ êõëÜ ìéá óêëçñÞ, ïìáëÞ åðéöÜíåéá. Óôïõò ðñáãìáôéêïýò, ôÝëåéïõò üñïõò ìçí õðÜñîôå ðïôÝ. Óå Ýíá ÷áñáêôçñéóôéêü ðåñéâÜëëïí åñãáóßáò, ðïõ ÷ñçóéìïðïéåß ìéá óêëçñÞ ñüäá èá ïäçãÞóåé óõ÷íÜ óôçí õøçëüôåñç áíôßóôáóç êõëßóìáôïò, êáèþò åðßóçò êáé ôïí áõîáíüìåíïõò èüñõâï êáé ôç äüíçóç.

Êáé ïé óôáôéêÝò êáé äõíáìéêÝò äõíÜìåéò Ý÷ïõí åðéðôþóåéò óôçí ôñéâÞ. Ç áñ÷éêÞ äýíáìç þèçóçò áðáñáßôçôç íá ôïðïèåôÞóåé Ýíá áíôéêåßìåíï óôçí êßíçóç åßíáé ç óôáôéêÞ äýíáìç. Ç óôáôéêÞ äýíáìç åßíáé ãåíéêÜ ìåãáëýôåñç áðü ôç äõíáìéêÞ äýíáìç ðïõ åßíáé ç Üóêçóç áðáñáßôçôç íá êñáôÞóåé ôçí êßíçóç áíôéêåéìÝíïõ. Ôï ó÷Ýäéï ñïäþí ðñÝðåé íá èåùñÞóåé ôçí åíü÷ëçóç ôç óôáôéêÞ êáé äõíáìéêÞ äýíáìç.

Óå Ýíá óýóôçìá ñïäþí Þ ôñï÷ßóêùí, õðÜñ÷ïõí ôñåéò èÝóåéò üðïõ ç ôñéâÞ ìðïñåß íá Ý÷åé åðéðôþóåéò óôç äýíáìç:

• óôï óçìåßï üðïõ ï Üîïíáò êáé ç ñüäá äéáóõíäÝïõí
• åÜí Ýíáò ôñï÷ßóêïò óôñïöÝùí, óôçí êáôïéêßá óôñïöÝùí êáé
• óôç äéåðáöÞ åäÜöïõò/ñïäþí, éäéáßôåñá óå ïðïéáäÞðïôå óçìåßá üðïõ ç ñüäá èá ãëéóôñÞóåé Þ èá ðåñéóôñÝøåé óå ìéá åðéöÜíåéá.

Ç áðïäïôéêüôçôá ìéáò ñüäáò Þ åíüò ôñï÷ßóêïõ óôç ìåßùóç ôçò ôñéâÞò åîáñôÜôáé ü÷é ìüíï áðü ôï êáôÜëëçëï ó÷Ýäéï ç ßäéá ôçò ñüäáò, áëëÜ êáé áðü ôá õëéêÜ ðïõ ÷ñçóéìïðïéïýíôáé óôçí êáôáóêåõÞ ôçò êáé ôçí ôïðïèÝôçóç ôùí ñïäþí óôïí åîïðëéóìü ðïõ êéíåßôáé.

Ç áíýøùóç êáé ç ìåôáöïñÜ åßíáé ïé äýï õëéêïß äéá÷åéñéæüìåíïé óôü÷ïé ðïõ ïäçãïýí óôï ìÝãéóôï áñéèìü ôñáõìáôéóìþí åñãáæïìÝíùí êÜèå Ýôïò. (Äåßôå ôç èÝóç 14 ÌáÀïõ ìáò óôéò Üêñåò ãéá ôçí åñãïíïìéêÞ ìåôáöïñÜ.) ç åöáñìïãÞ ôçò åñãïíïìßáò óôïõò õëéêïýò äéá÷åéñéæüìåíïõò óôü÷ïõò ðïõ ðåñéëáìâÜíïõí ôçí áíýøùóç ìåéþíåé ôçí áíÜãêç ãéá êáé êáé ïé ôñáõìáôéóìüò-ðáñÜãïíôáò ðßåóçò ðïõ åêåßíåò ïé åíÝñãåéåò ìðïñïýí íá ôïðïèåôÞóïõí óôçí ðëÜôç êáé ôïõò þìïõò. Ç åñãïíïìßá ðñïóðáèåß åðßóçò íá ìåéþóåé ôï ðïóü ðñïóðÜèåéáò êáé äýíáìçò áðáñáßôçôùí íá åêôåëÝóïõí ôïõò óôü÷ïõò áíåëêõóôÞñùí.

Calculations of lift force involve both the amount of weight to be lifted and the time period over which the average worker can lift that weight without risk of developing lower back pain. Under ideal conditions, the maximum weight a typical healthy worker can lift with two hands over an 8-hour period is 51 pounds, according to the National Institute of Occupational Safety and Health (NIOSH). However, a number of variables can significantly reduce the maximum lift weight. 

To decrease the potential risk of injury from lift tasks, both overall work flow and individual work tasks should be evaluated to eliminate unnecessary lifting. Where lifting is necessary, ergonomically designed equipment can be used to facilitate many lift tasks. Workers can also be trained to use ergonomic principles in performing lift tasks to minimize potential injury.

To decrease injuries caused by lifting, follow these suggestions:

• Use ergonomic electric scissor lift tables and power hoists to lift and lower loads where possible to minimize manual lifting.
• Minimize the distance materials must be lifted or lowered.
• Use adjustable powered tugs that allow workers to position lift loads at the appropriate height for maximum lifting power.
• Tag unstable or heavy loads to alert workers. Promote team lifting of such loads to minimize potential worker injury.
• Test loads for weight and stability before lifting.
• Reduce load weights and balance loads to facilitate lifting without injury.
• Rotate workers between lifting and non-lifting tasks or have workers alternate lifting with non-lifting tasks to avoid over-straining muscles. 
• Reduce the frequency of lifting and amount of time workers perform lifting tasks.
• Provide clear access to materials to be lifted to prevent awkward reaching, bending and twisting during lifting.
• Provide secure grips on materials to be lifted.
• Provide sufficient foot traction with the floor to increase worker stability during lifting.

Improving the ergonomics of material handling decreases worker injuries, improves workplace efficiency and leads to a healthier bottom line. Medical costs, insurance premiums, workers¢ compensation payments and lost man-hours soar when ergonomics are ignored. Material handling is one of the most injury-intensive industries, according to the U.S. Department of Labor. Every effort you make to fit the demands of work tasks to the capabilities of your workers (i.e., ergonomics) will decrease costs and ultimately improve profit margins.

Material handling requires many actions that can result in serious and expensive musculoskeletal injuries. Repetitive motions, awkward postures and the application of force as workers lift, push, pull, carry and handle materials create daily opportunities for injury. Attention to ergonomics in designing tasks, workspaces and equipment can dramatically decrease the physical demands and injury potential of many material handling activities.

Carrying and lifting are the two actions that present the greatest potential for worker injury when handling materials. Today we¢ll address tips for ergonomic carrying; on Friday, we¢ll share tips for lifting ergonomically.

Carrying tasks place stress on the back and shoulders and create contact pressure on the shoulders and hands. When repeatedly strained or overstressed, the effort and force needed to carry materials can cause injury. To decrease injuries caused by carrying, follow these suggestions:

• Eliminate unnecessary carrying.
• Minimize the distances materials must be carried and use electric tuggers to carry materials over longer distances.
• Organize work tasks so that physical demands and work pace increase gradually as muscles warm up.
• Rotate workers or alternate carrying with non-carrying tasks to prevent overstraining the body and give muscles a chance to rest between efforts.
• Wear properly fitting gloves to improve grip stability.
• Reduce load weights and test loads for stability and balance before carrying.
• Slide, push or roll materials. These actions place less stress on the body than carrying.
• Use conveyors, slides or chutes to move materials.
• Use electric carts movers to transport heavy loads.