Pelvis Flashcards
Name the movements of the vertebral column?
- Flexion and extension
- Lateral flexion
- Rotation
Name the joints that allow movement?
- Anterior joints = intervertebral discs in between vertebrae.
- Posterior joint = facet joints between each vertebrae.
Name the 4 major muscle groups in the vertebral column?
- Semispinalis - deep layer
- Erector spinae - surface layer
- Spinal flexors
- Abdominal muscles
Describe the action of erector spinae?
- Extension of the column = bilateral isotonic, concentric muscle work.
- Flexion of the column = bilateral isotonic, eccentric muscle work.
- Lateral flexion = unilateral isotonic concentric muscle work.
Describe the muscles within the spinal flexors?
- Longus capitis = flexion and rotation of the neck.
- Longus colli = flex and rotates neck.
- Quadratus lumborum = lateral flexion.
Describe the abdominal muscles?
- Transversus abdominis = deepest muscle.
- Internal oblique
- Rectus abdominis
- External oblique = most superficial layer.
Describe the action of the abdominals?
- Flexion of the column; rectus abdominis deresses ribs and flexes VC. External oblique, internal oblique and transversus abdominis; compress abdomen and spine.
- Lateral flexion = unilateral muscle work of internal and external oblique.
- Rotation of column = rotation and unilateral muscle work.
What is the pelvis girdle formed of?
- Sacrum
- Coccyx
- Innominate bones; including ilium, ischium + pelvis.
Describe how the bones are fused?
- Joined by sacrum + symphysis.
- 3 bones fused to form acetabulum (bony socket of joint).
How does the pelvis bear weight?
- Absorbs the locomotive forces from lower limbs and weight of body.
- Weight bearing arch.
Name the joints of the pelvic girdle?
- Sacroiliac joints (movement is small)
- Symphysis pubis
- Girdle moves as a whole unit.
Describe the functional movements of the pelvis?
- Forward / anterior tilt caused by the iliac crest forward and coccyx back.
- Backward / posterior caused by iliac back and coccyx forward.
Describe how an upright posture is maintained?
- Bones and ligaments of VC form a stable support maintenance.
- Minimal muscle activity.
- Tension in deep muscles.
How is anterior tilt prevented during standing?
- Rectus abdominis = pulling pubis in direction of the ribs.
- Gluteus maximus = pulling on posterior surface of sacrum in opposite direction.
How is a lateral tilt prevented in standing?
- When one leg is lifted, pelvic girdle would tend to drop and so lateral tilt.
- Lift right leg, the pelvis would drop down, centre of gravity moves out of base of support.
- Abductors on weight bearing side need to work together to correct the tilt.
