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   giorgiana1976 Teacher
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   Biomechanical calculations were made,after serious injuries had happened during heavy loads lifting  activities.

   First of all, it's important the fact that a force from a lifted load is felt in the spine with a 10 times more intensity. During lifting activity, vertebrae fractures are not the specific injuries, but discs between each pairs of vertebrae damages, mainly at the discs between L4/L5 and L5/S1.

   Before biomechanical calculation, some calculating hypothesis are made: it is considered an individual with an weigh of 75 Kg. Between the moment arm of erector muscle and the disc , there is a distance of 6cm. With the aid of these values there are written the equilibrium equations for:

   - moment around L5/S1;

   -add forces perpendicular to spine direction;

   -add forces parallel with the spine direction;

   Models concerning lifting techniques:

   1. Lifting with straight arm, in this way, the tensions felt in the upper arm and the shoulder muscle are reduced;

   2. The squat position (straight back and bent knees) should be adopted, while lifting;

   3.The opposite of squat position, bent back and straight knees.

    

    

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   Posted by giorgiana1976 on Wednesday November 11, 2009 at 10:14 AM