health practices chapter 4

Chapter 4

The Spine

·      Spine=vertebral column

·      Central organizing structure of the skeleton

·      Most fundamental element of the axial skeleton

·      Vertebral column= head, trunk, and pelvis

Vertebrae

·      33 divided into 5 regions

·      7 cervical

·      12 thoracic

·      5 lumbar

·      5 fused form the sacrum

·      4 fused form the coccyx

·      Only the upper 24 are movable

Intervertebral discs

·      C2-sacrum in between each vertebrae

·      Allows for rotation and rocking

·      Absorption of compression forces

Specialized vertebral joints

·      Atlantoaxial joint

o   C1=atlas

o   C2=axis

o   45–50-degree rotation and “no”

·      Lumbosacral joint

o   L5 and S1

o   Ideal= 30-degree angle

Spinal movements

·      Lateral flexion- requires a co-contraction on posterior and anterior to retain alignment

·      Flexion and extension- in each the use of the abdominals is essential to avoid injury

o   Extension; think up, engage, and back to avoid excessive compression

·      Rotation

Core stability

·      Definition: the developments or restoration of neuromuscular aspects of lumbopelvic control vital for protecting the spine from injury or reinjury

·      2 components

o   Exercises to improve the muscular strength and endurance of key trunk muscles

o   Coordinated use of these key trunk muscles during functional movements

Centered movement

·      Core stability used is refined manner to meet aesthetic goals as well as biomechanical goals

o   Example- the ability to maintain the torso alignment during large movements and the extremities

·      More complex in modern dance when asked to work in various positions and move extremities

·      Requires strong trunk muscles appropriate timing and appropriate magnitude of activation

Abdominal Muscles

·      Rectus abdominis (6 pack area)

·      External obliques

·      Internal obliques

·      Transverse abdominis (deepest layer)

Lumbopelvic Muscles

·      Iliopsoas (iliacus and psoas)

·      Psoas major

·      Major hip flexor

Other back muscles

·      Erector Spinae

o   Major spine extensor

·      Quadratus lumborum

o   Keeping pelvis level, depressing the last ribs, stabilizing the spine

Spinal Misalignments

·      Lordosis- lumbar increased curvature

·      Kyphosis- upper back thoracic

·      Forward head- cervical spine

Partnering

·      Lifting from the legs with a vertical trunk

o   Keeping correct spinal and pelvic alignment

·      Partner is close to lifter

·      Engaging the abdominals and back extensors

o   Bracing

·      Directly facing your partner

·      Adequate muscular strength and flexibility

Guidelines for ab strengthening

·      Maintain rounded torso- using abs v psoas

·      Keep head and neck rounded

·      Keeping feet unrestrained- variations in the air

·      Pulling abdominal wall in/ hollowing- targeting transverse

o   Use of exhale can help engage

·      Posterior tilt of the pelvis uses more of the low abs

·      Pilates based and resistance training based

o   Transferability

Back Injuries in dancers

·      High incidence in athletes with

o   Weight loading and high compression forces

o   Forceful twist

o   Activities involving spinal extension

·      Back injuries may require longer recovery times

o   Weeks, months, sometimes years

·      May result in chronic or recurrent back pain

Prevention of back injuries

·      Adequate warm up prior to stressful movement

·      Focus on abdominal stabilization and spinal alignment

·      Develop biomechanically sound partnering techniques

Common back injuries

·      Lumbosacral strain/sprain- excessive stretching and injury to the spinal extensor muscles, ligaments or the spine or both

·      Disc herniation- the nucleus pulpous extruding out through the annulus fibrosis

·      Spondylolysis- stress fracture in vertebrae, typically L5-S1