Transcript The Spine - Academics | Kansas State University

Chapter 9 The spine: Objectives
• Explain how anatomical structure affects
movement capabilities of the spine
• Identify factors influencing relative mobility and
stability of different regions of the spine
• Explain the ways in which spine is adapted to
carry out its biomechanical functions
• Explain the relationship between muscle location
and the nature and effectiveness of muscle action
in the trunk
• Describe the biomechanical contributions to
common injuries of the spine
The Spine: Outline
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Structure
Muscles and movements
Low Back Pain
Strengthening exercises
Lifting guidelines
Common low pack problems
WebSite for spine and spinal problems:
MMG - Patient Education back TOC
• Study questions for exam:
– Introductory problems, p 305: 1,6,7,9,10
– Additional problems, p 306: 1,5,8
Structure of the
Spine
Structure of Vertebrae
Note: orientation of facets largely
determines amount of movement possible
Facets and discs share load bearing
Question #5, p 306
Facet Orientation – related
To movement capability
Segmental Movements
Question #1,
P 305
The Spine: Muscles
• Spinal flexors – abdominal muscles
– Rectus abdominis
– External and internal obliques
• Spinal extensors
– Splenius cervicis and capitis (cervical)
– Erector spinae (lumbar and thoracic)
– Quadratus lumborum (lumbar)
Muscle force vectors
Flexion
Exercises
• Effect of
– Anchoring feet?
– Bending knees?
– Placement of hands and
arms?
– Inclined board?
Back Extension Exercises to Avoid:
Good morning exercise:
Hyperextended back:
Recommended Extension Exercise
Loads on the spine:
Line of gravity for upper body passes anterior to
vertebral column, creating a forward torque
It is important to keep pelvic
girdle balanced! (Question
# 6, 7 p 305)
Effect of posture on
lumbar compression
force:
Torque while lifting
Lifting recommendations
(1)bend knees , (2) keep weight close to hips
Lifting
recommendations
(3) Avoid lifting while
twisting and asymmetrical
frontal plane loading of
the trunk– it places 3
times more stress on the
spine (question #9, p 205)
(4) Avoid rapid, jerking
motion while lifting
Common Spinal Injuries
• Lumbar spinal injury is by far the most prevalent of all areas
of the spine
• Low back pain is most common and most expensive injury
in work place
• Low back pain is
usually related to
mechanical stress
• 60% of cases are
ideopathic
Stress Fractures
• Most common type of vertebral fracture is
in pars interarticularis
– Spondylolysis
– Spondylolisthesis
• Spondylolysis and spondylolisthesis don’t
tend to heal with time
– Common with sports involving repeated
hyperextension of the lumbar spine.
Common low back
problems
Spondylolisis – separation of vertebra
Spondylolisthesis – forward movement of
vertebral body
Disc degeneration
Disc Herniations
• Cause of 1-5% back pain cases
• Protrusion of part of nucleus pulposus from the
annulus.
• Traumatic or stress related.
• Common sites: between 5th-6th and 6th-7th cervical
vertebrae and 4th-5th lumbar and 5th lumbar and 1st
sacral.
• Sensory nerves supplying anterior and posterior
longitudinal ligaments generate pain signals.
Two common causes of low back pain
•Illustrations below are from: MMG - Patient Education back TOC
Compressive, or neurogenic:
Symptoms are referred due to
Spinal nerve compression
Mechanical - localized pain due to
Damage to facets, discs, and/or soft
tissue