Back Muscles (lab)

Spasm

A sudden involuntary contraction of one or more muscles groups. Result in: cramps, pain, and interference with function, producing involuntary movement and distortion of the vertebral column.

The splenius muscles acting alone do what? Acting together?

Acting alone they laterally flex the neck and rotate head to the side of active muscles Acting together they extend the head and neck.

Adipose tissue

Adipocytes predominate Connective tissue

Back sprain

An injury in which only ligamentous tissue, or the attachment of ligament to bone, is involved without dislocation or fx.

Obliquus capitis inferior

Arises from the spinous process of C2 and inserts into the transverse process of the C1 vertebra. The only capitis muscle that has no attachment to the cranium. Innervation by suboccipital nerve (C1) Rotates head to same side.

Rotatores

Brevis and longus. Best developed in the thoracic region -- deepest of the 3 layers of transversospinales muscles. May function as organs of proprioception; possibly stabilize vertebrae and assist with local extension and rotatory movements of vertebral column.

CAT scan

Computed (axial) tomography: CAT scans that use x-rays in multiple views (so a high level of radiation exposure) to offer additional visualization of tissues (and bone). Can be performed rapidly.

Cartilage

Connective tissue -- chondrocytes in lacunae, avascular ECM; variations such as hyaline cartilage (articular surface) and fibrocartilage (intervertebral disc)

Bone

Connective tissue -- osteocytes in lacunae, heavily mineralized

Loose connective tissue

Connective tissue with fewer fibers and more cells

Connective tissue

Connective tissue: cells in an extracellular matrix of fibers (e.g., collagen) and ground substance (e.g., glycosaminoglycans such as chondroitin sulfate) Blood, adipose tissue, cartilage, bone, fibrous connective tissue, loose connective tissue

Multifidus

Consists of short, triangular muscular bundles that are thickest in the lumbar region (and therefore implicated in low back pain LBP) Helps to stabilize the lumbar spine during local movements. Innervated by dorsal rami of respective spinal nerves.

Erector spinae m., & clinical significance:

Consists of: Iliocostalis m. Longissimus m. Spinalis m. Large block of epaxial muscle -- major spine extensor and a lateral flexor. Note: epaxial mm. names refer more to patterns of attachment than to individual muscles. Clinical significance: Trigger points in the erector can give you pain all over your entire back and may even send pain to you upper leg and lower abdominal region.

What is the clinical significance of the suboccipital triangle?

Contents include vertebral artery, suboccipital nerve (first cervical nerve), RCPMajor and Minor, OCSup./Inf. -- May be involved in Whiplash, or may be trigger points to be addressed by massage therapy. Presumably, these small muscles are offering proprioceptive information regarding head and neck movements.

Muscle tissue

Contractile via actin and myosin interactions; skeletal and cardiac based on sarcomeres and so striated; smooth not striated.

Suboccipital triangle

Deep to the semispinalis capitis (and trapezius), including a number of muscles innervated by C1 (suboccipital n.). Includes: rectus capitis posterior major and minor m., obliquus capitis superior and inferior m. **May be involved in Whiplash injury, or trigger points to be addressed by massage therapy. Presumably, these small muscles offer proprioceptive info regarding head/neck movements.

Interspinales (interspinal) and intertransversarii (intertransverse) m.:

Deepest back muscles, dorsal rami of spinal nerves, either between spinous process to extend or transverse processes to flex, respectively. Stabilize adjoining vertebrae allowing more effective action from other muscle groups.

Semispinalis

Divided into semispinalis capitis, semispinalis cervicis, and semispinalsis thoracis. Innervation: Respective spinal nerves of each region* *Dorsal rami of spinal nerves. Extends head, neck, and thorax, and rotates them to opposite side.

Trapezius

Elevates, retracts, and rotates scapula; lower fibers depress scapula. CN XI = spinal accessory nerve

Simple squamous epithelium:

Endothelium or serosa

Epithelial tissue

Epithelial tissue: lining, covering, avascular as resting on a basement membrane

Intermediate layer of intrinsic back muscles:

Erector spinae muscles: iliocostalis, longissimus, and spinalis.

Blood

Erythrocytes predominate Connective tissue

Splenius capitis & clinical significance

Extend head/neck or if singly, can rotate to one side. The splenius capitis and cervicis muscles can give you pain in the head/skull, on top of the head - also called vertex pain - and neck pain if they are too tight or contain trigger points.

What are the main action(s) of semispinalis?

Extends head, neck, and thorax. Rotates head, neck, and thorax to the opposite side.

Thoracolumbar fascia

Fascia surrounding deep muscle, esp. in lumbar region, blends in with other fascia, e.g. that of quadratus lumborum m.

How does a back sprain result?

From excessively strong contractions related to movements of the vertebral column, such as excessive extension or rotation.

Where do the transversospinales mm. originate?

From the transverse processes of vertebrae, and pass to spinous processes of more superior vertebrae.

Intrinsic back muscles

Includes: splenius capitis, splenius cervicis, erector spinae, semispinalis, multifidi, rotatores Innervated by the posterior (dorsal) rami of spinal cord, and act to maintain posture and control movements of the vertebral column.

What innervates the muscles of the suboccipital triangle? What type of injury could these muscles be involved in?

Innervated by the suboccipital nerve, posterior ramus of C1 Whiplash injury, or trigger points

Serratus posterior superior

Innervation : Intercostal nerves Action : Elevates ribs and so assists inspiration.

Obliquus capitis superior

Innervation by suboccipital nerve (C1) Extends head and bends it laterally.

Rectus capitis posterior major

Innervation by suboccipital nerve (C1) Extends head and rotates to same side.

Rectus capitis posterior minor

Innervation by suboccipital nerve (C1) Extends the head

Serratus posterior inferior

Innervation: Intercostal nerves Action: Depresses ribs and so assists expiration

Latissimus dorsi

Innervation: Thoracodorsal nerve (C6-C8) Extends, adducts, and medially rotates humerus. Inferior back -- makes up posterior axillary wall, thoracodorsal n., antagonistic to pectoralis muscles, useful for butterfly swimmers. Pain in the shoulder, upper arm, lower abdominal area, hand, and difficulty breathing can signal latissimus dorsi muscle dysfunction.

What are the 3 muscles which are the smallest of the deep back muscles?

Interspinales, intertransversarii, and levatores costarum. Interspinales and intertransversarii connect spinous and transverse processes, respectively.

Back strain

Involves some degree of stretching or microscopic tearing of muscle fibers.

Stratified columnar epithelium

Keratinized (epidermis) vs. non-keratinized (e.g. esophagus)

Fibrous connective tissue

Large bands of collagen fibers; variations such as dense regular connective tissue (e.g. tendons) and dense irregular connective tissue (e.g. joint capsules)

Pseudostratified epithelium

Lining airways

Columnar epithelium

Lining the GI mucosa, GB, uterus/oviducts -- absorption, secretion of enzymes

Transitional epithelium

Lining urinary tracts

Cuboidal epithelium

Location: thyroid gland follicles, kidney tubules, ducts of glands, surface of ovary function: absorption and secretion Characteristics: single layer of cube/square shaped cells with a central spherical nucleus Found on the free surface of the ovary, in the retina, and lining the kidney tubules.

Semispinalsis capitis is responsible for the:

Longitudinal bulge on each side in the back of the neck near the median plane. Ascends from the cervical and thoracic transverse processes to the occipital bone.

MRI

Magnetic resonance imaging: MRI depends on a strong magnetic field for high soft tissue resolution (vs. bone).

Motor units of muscle:

Motor units as controlled by motor neurons extending from the ventral horn of the spinal cord and ventral root of spinal nerves. Skeletal muscle is striated given its sarcomere functional unit basis, such that the striations can indicate the direction of action of the muscle contraction.

Common trigger points:

Neck: levator scapulae, splenius capitis, trapezius, SCM. Shoulder: infraspinatus, supraspinatus, rhomboid Lower back: quadratus lumborum, gluteus medius, tensor fasciae latae Thigh: biceps femoris, vastus lateralis, adductor longus Leg: gastrocnemius, soleus

Levatores costarum

Origin: Transverse processes of C7-T11 Insertion: Posterior surface of ribs Innervation: Dorsal rami of corresponding spinal nerves Action: Elevate ribs (assisting in respiration, lateral flexion of vertebral column)

Myofascial pain

Pain a/w a muscle or its adjacent fascia that may be felt at a single point or at multiple active "trigger" points, sending a signal to the CNS. Trauma, muscle overuse, poor posture, and disease may precipitate the pain. The trigger site may be tender to palpation and may initiate a muscle spasm-pain-spasm cycle

Using the back as a lever when lifting:

Puts an enormous strain on the vertebral column and its ligaments and muscles. These strains can be minimized if the lifter crouches, holds the back as straight as possible, and uses the muscles of the buttocks and lower limbs to assist with the lifting.

What are the transversospinales mm. from superficial to deep?

Semispinalis (spans 4-6 segments), multifidus (spans 2-4 segments), and rotatores (the deepest, spanning 1-2 segments).

Intermediate extrinsic back muscles

Serratus posterior superior and inferior -- thin muscles that are commonly designated superficial respiratory muscles, but are more likely proprioceptive rather than motor in function.

Superficial layer of intrinsic back muscles:

Splenius capitis and splenius cervicis

Rule of Nines

The rule of nines for body surface area for typical adults (head and arms 9% each, legs 18%, torso 18% in front and 18% in back, genitalia 1%) can offer a quick guide to the extensiveness of the burn.

Actions of erector spinae mm.

These muscles act bilaterally to extend the vertebral column and head. They act unilaterally to laterally flex the vertebral column.

What do the back muscles do as a protective mechanism?

They go into spasm after an injury or in response to inflammation (e.g. of ligaments).

Splenius muscle

Thick and flat, and lie on the lateral and posterior aspects of the neck, covering the vertical muscles somewhat like a bandage. Arise from the midline and extend superolaterally to the cervical vertebrae (splenius cervicis) and cranium (splenius capitis) These muscles cover the neck muscles.

What is the clinical significance of thoracolumbar fascia?

Thoracolumbar fascia injury resulting in thoracolumbar fascia pain: Tightness of the lumbar spine and paraspinal region along with spasticity and increased tone. Increased lumbar lordosis can cause thoracolumbar fascia pain. Persistent lumbar spine pain.

Which muscles are usually involved in back strains?

Those producing movements of the lumbar IV joints, especially the erector spinae. If the weight is not properly balanced on the vertebral column, strain is exerted on the muscles.

Deep layer of intrinsic back muscles

Transversospinales muscle group -- composed of: semispinalis, multifidus, and rotatores.

Superficial extrinsic back muscles:

Trapezius, latissimus dorsi, levator scapulae, and rhomboids -- connect the upper limbs to the trunk. Receive their nerve supply from the anterior rami of cervical nerves.

Ultrasound

U/S with a transducer generating high frequency sound waves; safe, portable, useful for real-time imaging solid/fluid interfaces (not good for gas or bone).

What are the main action(s) of multifidus?

Unilateral contraction rotates to contralateral side; stabilizes vertebrae during local movements of vertebral column

What are the contents of the suboccipital triangle?

Vertebral artery and suboccipital nerve (C1)

What is the most common cause of low back pain?

Weight is not properly balanced on the vertebral column and strain is exerted on the muscles.