Thoracic Biomechanics Flashcards
What are the three principles of Fryette model?
- One = opposite
- Two = together
- Alter motion in one place, affects motion in all planes
What are some biomechanic properties unique only to thoracics?
Dysfunctions can occur in only one plane
Usually flexed for extended
Little sidebending or rotations
What is a sign for thoracic somatic dysfunction?
Tenderness
Where would you be likely to feel tenderness in thoracic somatic dysfunction?
Lateral to the tips of the transverse processes
On the tip of the spinous process
Which way to do the thoracic facets face and what movement does this allow for?
Coronal, rotation
What is the limiter of rotation?
Ribs
Name the ribs types which promotes the greatest movement from greatest to least.
Floating ribs
False ribs
True ribs
What are the degrees of the flexion and extension (sagittal pane) for thoracic vertebrae?
T1-5: 4 degrees
T6-10: 6 degrees
T11-L1: 12 degrees
What are the degrees of sidebending (coronal plane) of motion for thoracics?
T1-10: 6 degrees
T11-12: 8-9 degrees
What are the degrees of rotation (horizontal plane) of motion for thoracics?
T1-T9: 8-9 degrees
T10: 10 degrees
T11: 12 degrees
T12: 14 degrees
How was thoracic motion measured?
Gregerson & Lucas inserted Steinman pins into the spinous processes of the thoracic vertebrae of six medical students, left them protruding through the skin and measured the available motion
What is the main effect of the ribs and sternum on the thoracic spine?
Stiffen the spine
What are the motions stiffened by the ribs?
Flexion – stiffened by 27%
Extension – stiffened by 132%
Sidebending – stiffened by 45%
Rotation – stiffened by 31%
Why is T12 more susceptible to mechanical influences or trauma?
Upper facet joints coronally oriented
Lower facet joints sagittally oriented
What are the rule of threes?
T1-3: TP at the same level as SP T4-6: TP one half level above the SP T7-9: TP one full level above the SP T10: Like T7-9 T11: Like T4-6 T12: Like T1-3
What do the costal ligaments do?
Stiffen the thoracic spine
What is the superficial layer of muscle in the thoracic area?
Trapezius
Latissimus dorsi
Rhomboideus major and minor
Trapezius: attachment
Spinous process of T1-T12
Trapezius: actions
Scapular retraction and depression
Trapezius: innervation
Spinal accessory (C1-C6), ascends though the foramen magnum and exits via jugular foramen in petrosquam suture
Trapezius: motion loss
Hypertonicity causes loss of scapular protrusion and elevation
Trapezius: symptoms
Interscapular pain, shoulder pain, pectoral region pain, lateral rib cage pain
Latissimus dorsi: attachments
Lower 6 thoracic spinous processes lumbar and sacral spinous processes, supraspinous ligament and iliac crest via lumbodoral fascia
Latissimus dorsi: action
Humeral adduction, medial rotation, extension
Latissimus dorsi: innervation
C6, C7, C8
Latissimus dorsi: thoracic dysfunction
T7, T8
Results in limited humeral external rotation, flexion (reaching)
Latissimus dorsi: symptoms
Infrascapular mid-thoracic backache
Rhomboid major and minor: Attachment
Major-T2 to T5 and supraspinous lig
Minor - C7 & T1
Rhomboid major and minor: Action
Scapular retraction, elevation
Rhomboid major and minor: Innervation
C4, C5
Rhomboid major and minor: Thoracic dysfunction
Scapular protrusion is limited and painful
Rhomboid major and minor: Symptoms
Pain along vertebral border of the scapula extending into the supraspinous fossa of scapula
Muscle tends to ache at rest (postural pain)
Look for tense shortened pectoralis muscles
What is the intermediate layer of muscle in the thoracic area?
Erector spinae
Erector spinae: attachments: Longissimus thoracis
Lumbar transverse processes to all of the thoracic thransverse processes and lower 9-10 ribs just lateral to costotransverse articulation
Erector spinae: attachments: Longissimus cervicis
T1-T5 transverse processes to C2-C6
Erector spinae: attachments: Longissimus capitis
Transverse processes of C4 to T5, extends up to mastoid process
Erector spinae: action: longissimus thoracic and cervicis
Backbend and sidebend the vertebral column
Erector spinae: action: Longissimus capitis
Extends the neck and rotates the head to the same side
Erector spinae: innervation
Dorsal rami of thoracic and upper lumbar and lower cervical nerve roots
Erector spinae: Segmental dysfunction
Longissimus hypertonicity locally with restricted flexion and sidebending
Neck motion would be limited in contralateral rotation
Erector spinae: symptoms: longissimus thoracis
Local muscle tenderness and pain, extends over approx. 4 thoracic segments
T10-T12 range can refer pain down to the lower portion of the buttock
What is the deep layer of muscle in the thoracic area?
Rotatores
Levator Costae
What is the action of the rotatores?
They function mostly in sidebending and extension of the thoracic segments, contrary to their name
Their attachment is too close to the base of the spinous process to effect much rotation
What would cause a type II segmental dysfunction of the rotatores?
Spasm or hypertonicity
What muscle can cause sidebending if anchored to a rib?
Levator costae
