biomechanics of lumber spin.pdf

BIOMECHANICS OF THE LUMBER SPINE D R ALI YA AS AK D PT OMPT  33 vertebrae 23 intervertebral disks Primary curves Secondary curves  STRUCTURE OF THE LUMBAR REGION The first four lumbar L-1 L-4 vertebrae are similar in structure. The fifth L5 vertebrae has structural...

BIOMECHANICS OF THE LUMBER SPINE D R ALI YA AS AK D PT OMPT  33 vertebrae 23 intervertebral disks Primary curves Secondary curves  STRUCTURE OF THE LUMBAR REGION The first four lumbar L-1 L-4 vertebrae are similar in structure. The fifth L5 vertebrae has structural adaptation for articulation with sacrum.  FIFTH LUMBAR VERTEBRA L5 has the largest body and transverse processes of all vertebrae. The anterior aspect of the body has a greater height then posterior. This creates the lumbosacral angle between the lumbar region of the vertebrae and the sacrum KINETICS  FORCES ACTING ON THE SPINE Forces Acting On The Spine Include: Body Weight Tension In The Spinal Ligaments Tension In The Surrounding Muscles Intraabdominal Pressure The Major Form Of Loading On The Spine Is: Axial  UPRIGHT POSITION Spinal Compression Resulting From: Body Weight + Weight Held by Arms and Hands When Standing Upright Total Body Center of Gravity Is Anterior to the Spinal Column. Spine Is Placed Under Constant Forward Bending Moment.  TORQUE Defined: The Rotary Effect of a Force About An Axis of Rotation, Measured as the Producer of the Force and the Perpendicular Distance Between the Force’s Line of Action And The Axis To Maintain An Upright Position Torque Is Counteracted by Tension in the Back Extensor Muscles.  LOW BACK PAIN 75%-80% of Americans Experience Low Back Pain Sometime During Life. Second Only to the Common Cold In Causing Absence In The Workplace. Mechanical Stress & Psychosocial. THANK YOU