[Quantifying the biomechanical forces applied on the vertebral column during praying]

ABSTRACT

Vertebral column or spine is the main part of the upper torso of human skeleton. The vertebral enables body to bend and turn in all directions, and supports the body and vital structures such as nerves and spinal cord. The aim of this research is to quantify and measure the moment and force on the L4 and L5 vertebrae in different races and genders, during praying. The necessity of performing this type of research on the spine is to show the effects of religious activity on physical health of people with different anthropometry. In this study, for biomechanical analysis of vertebral column, two methods were used modeling and analysis in CATIA [Computer Aided Three-dimensional Interactive Application] V5R20 software and torque calculations based on inverse dynamics. The amount of torque and force which are applied on the spine during praying among different races were evaluated and compared by using these methods. In addition, by application of occupational health and safety standards in software, the motor position of manikin limbs was judged. Comparison between the compressive force exerted on the L4 and L5 vertebrae and standards in software indicated the amount of force on the L4 and L5 is less than NIOSH AL, which is 3433 N. In addition, in all nationalities, compressive force and moment about L4 and L5 in woman were lower than men. Also, results showed that the relative error of the torque calculated by inverse dynamics and CATIA software was 4.6 to 20.9 percent and the maximum percentage of population who were unable to perform bowing wasbelow 1% for all nationalities. The results of this study compared with international standards such as NIOSH, indicate that applying forces on the spine during daily praying task, contrary to the statements of some articles, does not create any problems for prayer