Biomechanics Exam 2 (Chapter 9)

List and describe the 3 abnormal deviations in the spinal curvature.

Lordosis: exaggeration of the lumbar curve Often associated with weakened abdominal muscles and anterior pelvic tilt. The causes include a congenital spinal deformity, weakness of abdominal muscles, poor postural habits, and over training in sports requiring repeated lumbar hyperextensions such as gymnastics, figure skating, and swimming Kyphosis: extreme thoracic curvature this can result from a congenital abnormality, from a pathology such as osetoporosis or scheuermann's disease for adolescents who heavily train in the butterfly stroke Scholiosis: Lateral spinal curvature Results from congenital abnormality and selected cancers nonstructural scholiosis can occur secondary to a local inflammation. Small lateral deviations in spinal curvature relatively common from carrying books or a heavy purse on one side

Explain proper spinal position while lifting. Also, explain why twisting should be avoided when lifting.

Proper spinal position lift would be to minimize trunk flexion, which minimizes the torque generated on the spine by body weight, though this is impractical. It's more important to maintain normal lumbar curve rather than increasing lumbar lordosis. Twisting should be avoided because of the asymmetrical frontal plane loading of the trunk.

List and discuss the primary abdominal muscles, explaining how they perform motion in all 3 planes.

The main abdominal muscles are rectus abdominis, external and internal obliques. Functioning bilaterally, these muscles muscles are the major spinal flexors & reduce anterior pelvic tilt. Tension development in the internal obliques causes rotation of the spine toward the same side. Tension development by the external obliques results in rotation toward the opposite side. If the spine is fixed the internal obliques produce pelvic rotation toward the opposite side, w/ the external obliques producing rotation of the pelvis toward the same side.

How can we properly breathe (and brace) while lifting?

We should brace our core while lifting so that there is enough tension so that your core does not fold under loads. You should fill your trunk with pressure while bracing, and you should also tighten your stomach and then breathe into your stomach using your diaphragm.

How do we help to prevent lower back pain?

Diet and exercise seemed to play an important role in reducing lower back pain since obesity is significantly associated w/ low back pain in men and women. Avoiding repetitive handling of heavy materials, sitting for long periods of time, cigarettes, and certain exercises that put a lot of pressure on the back (sit-ups, certain curl-ups)