Spine muscles (wk10)

Question 1

Global movers v Local stabilisers

Answer 1

Global movers v Local stabilisers:
-Global movers:
* Global movers are involved in generation of torque and range of movement
* Function: In a phasic manner, i.e. on/off, and their movement is dependent on direction
* Dysfunction: Spasm, pain and restricted range of movement
-Local stabilisers:
* Local stabilisers are the deeper muscles that control segmental movements of the spine
* Function: Activity is tonic and low for long periods of time
* Dysfunction: Inhibition of function, delayed timing or recruitment deficiencies and loss of segmental control and posture

Question 2

-Key muscles for cervical flexion -> Superficial neck flexors: sternocleidomastoid and anterior scalene, Deep neck flexors: Longus colli and Longus capitis

Answer 2

• Sternocleidomastoid -> O: Sternum and clavicle, I: Mastoid process, I: Accessory nerve, F: Bilaterally; neck flexion, Unilaterally; ipsilateral flexion and contralateral rotation
• Anterior scalenes -> O: Transverse processes of C3-C6, I: 1st rib, I: C5-C6, F: Elevation of the 1st rub, ipsilateral flexion and contralateral rotation
• Longus colli and Longus capitis -> O: Transverse processes of C3-T5, I: Transverse processes of C1-6, I: Longus capitus; C1-3 and Longus colli – C2-6, F: Maintain cervical lordosis and provide segmental control. Cranio-cervical flexion.

Question 3

Key muscles for cervical extension
-Layer 1, 2, 3 and 4

Answer 3

Layer 1: Upper trapezius, Levator scapulae, Cervical extension.
Layer 2: Splenius capitus and cervicis, Cervical extension and rotation, Levator scapulae.
Layer 3: Semispinalis capitus, Cervical extension and lateral rotation.
Layer 4: Semispinalis cervicis, Posterior support of cervical lordosis in synergy with the deep neck flexors and prevent a forward head position.

Question 4

-Key muscles for trunk flexion -> Superficial trunk flexors: Rectus abdominus, External oblique and Internal oblique, Deep abdominal muscles: Transverse abdominus

Answer 4

• External oblique -> O: 5th- 12th ribs on each side of the rib cage, I: Iliac crest and pubic regions, I: T8-L1, F: Flexion, ipsilateral lateral flexion and contralateral rotation
• Internal oblique -> O: Iliac crest, I: The costal cartilages of the 8th-12th ribs and the linear alba, I: T8-L1, F: Flexion, ipsilateral lateral flexion, ipsilateral rotation. Support and compress abdomen, and raise intra-abdominal pressure.
• Rectus abdominus -> O: Crets of pubis, I: Cartilage of 5-7th ribs and xiphoid process, I: T7-T12, F: Flexion, sit-up, crunch, Intersections: The level of the umbilicus, the level of the xiphoid process and midway between these 2 points
• Transverse abdominus -> O: Iliac crest, lower 6 costal cartilage, I: Xiphoid process, the linear alba and the pubic symphysis, I: T8-L1, F: Support spine and abdominal wall, aid forced expiration, raise intra-abdominal pressure

Question 5

Key muscles for trunk extension -> Superficial: Erector spinae (cervical to lumbar regions), Deep layer (core muscles): Semispinalis (cervical and thoracic regions), Multifidus (cervical, thoracic and lumbar regions), Quadratus lumborum

Answer 5

• Erector spinae (Iliocostalis – lateral layer, Longissimus – middle layer, Spinalis – medial layer) -> O: Iliac crest sacral regions, I: Posterior ribs, cervical transverse/spinous process, occipital bone, I: Posterior branches of the spinal nerves, F: Extension, lateral flexion, ipsilateral rotation of the spine and head
• Semispinalis -> O + I: Transverse process of C4-6 to spinous process of C7-T7, I: Spinal nerves, F: Trunk criticism (bilaterally), ipsilateral lateral flexion and contralateral rotation (unilaterally)
• Multifidus cervical, thoracic and lumbar regions -> It lies lateral to the spinous processes and cover the laminae of the underlying vertebrae, but at lumbosacral levels it expands to cover the posterior surface of the sacrum. It functions to extend the vertebrae, stabilise spinal columns
• Quadratus lumborum -> O +I: Posterior inner lip of the iliac crest to the 12th rib and transverse process of L1-4, I: T12 and L1 spinal nerves, F: Ipsilateral flexion, stabiliser of pelvis and lumbar spine, pelvic rotation

Question 6

Relate dysfunction of spinal muscles to movement disorders:
-Includes: Amyotrophic lateral sclerosis and Spinal muscular atrophy

Answer 6

-A substantial number of low back problems are caused by improper use of the back over time. These improper mechanisms often result in acute strains and muscle spasm of the lumbar extensors and chronic mechanical changes leading to disk hernation.
-Our lifestyles chronically place us in lumbar flexion, which over time leads to gradual loss of lumbar lordosis. This flat-back syndrome results in increased pressure on the lumbar disk and intermittent or chronic low back pain.
-Amyotrophic lateral sclerosis (ALS) -> This condition leads to the loss of nerve cells in the brain and spinal cord. Weakness in the muscles causes trouble with movements and speech. ALS may also eventually lead to issues with swallowing and breathing.
-Spinal muscular atrophy (SMA) -> This group of genetically inherited disorders causes symptoms such as hypotonia (decreased muscle tone) in the arms/legs, feeding issues, and breathing issues. Many forms start in infancy/ childhood, but some begin in adulthood as well.