Thoracic and ribs Flashcards
Inferior angle of scapula =
T7/T8
T-spine Rule of 3’s
- T1-T3 are at same level as TPs
- T4-T6 are 1/2 vertebral level blow the TPs
- T7-T9 - full vertebral level blow
T10-T12 are at same vertebral level
Thoracic facet joint angles
Superior articulations oriented 60* from horizontal, 20* from frontal
Inferior articulations match the superior articulations and face anterior, inferior, slightly medial
Superior facet originate from superior vertebrae of t-spine
Thoracic disks
thinner compared to cervical and lumbar
Disc height ratios - cervical, thoracic, lumbar
Cervical: 2 to 5
Thoracic: 1 to 5
Lumbar 1 to 3
Ribs 1-7
True ribs because they attach to sternum
Heads to ribs 3-9 have 2 facets for attachment to corresponding demifacets on vertebral bodies
Superior facets to superior vertebral body, inferior attaches to numerically corresponding vertebral body
Ribs 8-12
False ribs because they attach distally to costochondral cartilage of superior rib
Rib 11 and 12 have no anterior atachment
1st, 10th, 11th, 12th rib
attach to only 1 facet on corresponding vertebral body
Ribs 11 and 12 do not attach to TP and do not have a costotransverse process
Upper thoracic rib joint style
Upper t/spine to T5/6 -rib portion is concave and transverse process is convex - more rotation and torsional movement
Lower t-spine - the costotransverse joints are planar. - more planar movement
Inspiration in upper vs. lower ribs
Upper rib cage flexes (rises) and lower ribs widen (abduct).
Trapezius
Oirigin: all thoracic SPs, external occipital protuberance, ligamentum nuchae, SP of C7
Action: assists with force coupling allowing for normal scapular upward rotation and posterior tipping during elvation of humerus.
Iliocostal thoracis
Origin: angel of ribs 7-12
Insertion: ascends to angles of ribs 1-6 and TP of C7
Iliocostalis lumborum
Originates: posterior aspect of sacrum and thoracolumbar fascia
Inserts: ascends to angles of ribs 6-12.
Erector spinae
Important role in health and function of spine
In t/s they maintain an upright, neutral thoracic curve
Spinal extensor weakness
Along with reduced muscle density has been associated with thoracic hyperkyphosis, osteoporosis, decreased quality of life, increased risk fo falling in older adults
Serratus anterior muscle
Orign: muscle arises from outer surface and superior border of upper 8th-10th ribs and fascia of associated external intercostal muscles
Insertion: Anterior surface of vertebral border of scapula
Action: protract scapula, assist in force couple for normal scapular upward rotation and posterior tipping
If scapula is fixed, SA will result in posterior directed force on ribs
Pec Major
3 proximal attachments: clavicle, sternum, costal cartilages of ribs 1-6
Distal: lateral lip of bicipital groove
Action: adduct and IR humerus
- Clavicular portion can assist the coracobrachilais and anterior delt with GH flexion
- When distal attachment is fixe with humerus flexed, pec will result in anterior, superior, and lateral force on rib cage
Pec Minor
Origin: anterior and superior surfaces of ribs 3-5
Insertion: medial superior coracoid process of scapula
Shortening and hypertonicity of this muscle can lead to protraction and anterior tipping of scapula, which can affect normal scapular motion during elevation of arm
Diaphragm
Primary muscle of inspiration
Broad MSK attachments to ribs and spine
3 parts:
- sternal
* origin: xiphoid process - costal
* internal surfaces of rib costal cartilages and adjacent parts of lower 6 ribs - lumbar
* first 2 or 3 lumbar vertebrae
Diaphragm and spine disorders
Lack of relaxed, diaphragmatic breathing is an impairment that often accompanies both acute and chronic spinal disorders and contributes to thoracic spinal mobility restrictions
Thoracic spinal nerves
- 12
- Divided into anterior and posterior rami - posterior rami are divided into medial and lateral branches
- exits below respective intervertebral disk
Thoracic dermatomes
*run in circumferential pattern inferior to corresponding thoracic vertebrae from posterior midline to anterior midline
Medial branch of upper 6 segments
supplies semispinalis and multifidus
Medial branch of lower 6 segments
Supplies transversospinalis and longissimus
Lateral branch
supplies longissimus, iliocastalis, costotransverse joints