Thoracic Flashcards
What are the main bony structures of the thoracic region?
Vertebrae, sternum, ribs
How many thoracic vertebrae are there?
12
What are the key features of thoracic vertebrae?
Heart-shaped body, costal facets for rib articulation, long downward-sloping spinous processes
What are the three parts of the sternum?
Manubrium, body, xiphoid process
What joint connects the sternum to the clavicle?
Sternoclavicular joint
How many pairs of ribs are there?
12
Which ribs are considered true ribs?
Ribs 1-7 (directly attach to the sternum via costal cartilage)
Which ribs are considered false ribs?
Ribs 8-10 (attach indirectly to the sternum via shared costal cartilage)
Which ribs are considered floating ribs?
Ribs 11-12 (do not attach to the sternum)
What is the function of the thoracic cage?
Protects vital organs, supports respiration, provides attachment for muscles
What structural feature of thoracic vertebrae contributes to kyphotic posture?
Anterior wedging
What feature of thoracic vertebrae allows articulation with ribs?
Demifacets
How does the size of the thoracic vertebral canal compare to other regions?
Round and smaller than in the cervical and lumbar regions
What is the structure of the posterior elements of thoracic vertebrae?
Short pedicles that emerge into broad and thick laminae
How do the spinous processes change from T5 to T8?
Long and progressively angle more downward
How do the spinous processes of T11 and T12 differ from mid-thoracic vertebrae?
Triangular and project horizontally
What are the characteristics of thoracic transverse processes?
Long, round, club-like, angling posterolaterally and slightly superior
Which thoracic transverse processes lack facets for rib articulation?
T11 and T12
What is the function of the anterior facets on thoracic transverse processes?
Articulation with the tubercles of the corresponding ribs (except T11 and T12)
What is the Rule of 3’s for thoracic vertebrae?
Classification of spinous process positioning relative to transverse processes
What is the spinous process position relative to the transverse process for T1-T3?
Same level
What is the spinous process position relative to the transverse process for T4-T6?
Half a vertebral level lower
What is the spinous process position relative to the transverse process for T7-T9?
One vertebral level lower
What is the spinous process position relative to the transverse process for T10-T12?
Same level
What are the three parts of the sternum?
Manubrium (head), body (gladiolus), xiphoid process (tail)
What is the function of the sternum?
Anterior connection point for ribs and anchor point for the upper extremity
At what vertebral level is the sternal notch located?
T2/T3
At what vertebral level is the xiphoid process located?
T9/T10
What are the structural characteristics of ribs?
Long, elastic, curved bones with highly vascular trabecular bone within a thin layer of cortical bone
What is the difference between true ribs and false ribs?
True ribs (1-7) attach directly to the sternum; false ribs (8-10) attach indirectly via shared costal cartilage
What is unique about ribs 11 and 12?
They are floating ribs and do not attach to the sternum
How do rib facets articulate with vertebral bodies?
Superior rib facets attach to the superior vertebral body; inferior facets attach to the corresponding vertebral body
Which ribs are considered atypical?
1st, 10th, 11th, and 12th ribs (attach to only one facet on the corresponding vertebral body)
Why is the second rib considered atypical?
It attaches posteriorly to T1 and T2 but connects anteriorly at the manubriosternal junction
What is the function of thoracic interbody joints?
Flat vertebral surfaces allow for translations to occur
What type of joints are facet joints?
Synovial joints that are planar in structure
What is the orientation of superior thoracic facet articulations?
60° from the transverse plane and 20° from the frontal plane
How do inferior thoracic facet articulations align?
Match superior articulations; face anterior, inferior, and slightly medial
What are costovertebral joints?
Synovial plane joints between rib heads and vertebral bodies
What is the function of costovertebral joints?
Allow gliding or sliding costal motions
What structures form the costotransverse joint?
Tubercle of the rib and the facet at the tip of the transverse process of its corresponding vertebra
What type of joint is the costotransverse joint?
Synovial joint with a thin articular capsule
What motions are allowed at the costotransverse joint?
Gliding and slight rotational motions
How do upper thoracic costotransverse joints differ from lower thoracic ones?
Upper thoracic: Convex transverse process with concave rib; Lower thoracic: Planar joints
What type of movement changes the anterior-posterior diameter of the thorax?
Main motion of the upper ribs
What is the common axis of motion for upper rib movement?
Almost all in the frontal plane
In what plane does thoracic motion occur for upper rib movement?
Sagittal plane
What happens to the upper ribs during inspiration?
They elevate
How does the motion of the upper ribs affect the sternum?
Pushes the sternum ventrally and superiorly
What is the overall effect of upper rib and sternum movement?
Increases the anterior-posterior diameter of the thorax
Which muscles primarily contribute to upper rib movement?
Muscles laterally placed in the ribcage
What is the name of the movement pattern of the upper ribs and sternum?
Pump handle movement
What type of movement changes the transverse diameter of the thorax?
Main motion of the lower ribs
What is the common axis of motion for lower rib movement?
The lower ribs move around an axis that is almost aligned with the sagittal plane, meaning their movement occurs mostly forward and backward.
In what plane does thoracic motion occur for lower rib movement?
Frontal plane
What happens to the lower ribs during inspiration?
They elevate
How does the shape and attachment of lower ribs influence their motion?
Motion is more in the lateral part due to angled shape and indirect attachment
What is the overall effect of lower rib movement?
Increases the transverse diameter of the thorax
Which muscles primarily contribute to lower rib movement?
Muscles anteriorly and posteriorly placed in the ribcage
What is the name of the movement pattern of the lower ribs?
Bucket handle movement
What is the normal thoracic kyphosis angle?
40°
What causes normal thoracic kyphosis?
Slight wedging of the vertebrae (anterior aspect of vertebral body is slightly smaller than the posterior aspect)
What is the normal infrasternal angle?
90-100°
Which ribs form the infrasternal angle?
Costal margin of ribs 7-10
What is kyphosis in terms of thoracic alignment?
Increase in the flexion curve
What are the effects of increased kyphosis?
Leads to increased force on the vertebral body and disc
What is flat back in terms of thoracic alignment?
Decrease in the flexion curve
What are the features of flat back posture?
Scapular winging appearance, posterior trunk sway, upper back shifted back, hips swayed forward (shoulders posterior to hips)
How can you differentiate between structural vs functional kyphosis or flat back?
Structural (fixed) vs functional (posture or weakness/tightness)
What overly tight muscle can cause kyphosis?
Tight rectus abdominus
What is the effect of flat back on ribcage expansion?
Decreases expansion of the posterior ribcage, especially the upper 6 ribs
What is the muscular impact of flat back posture?
Postural muscles have increased resting tension
What causes posterior trunk sway in impaired thoracic alignment?
Decreased posterior trunk extensors and increased tension in rectus abdominus
(The back extensor muscles are too weak to keep the body upright, while the abdominal muscles (rectus abdominis) are too tight, pulling the torso forward. To compensate for weak back muscles and tight abdominals, the person may extend their trunk excessively. This can create a posterior trunk sway, where the upper body leans backward to maintain balance.)
What is the characteristic feature of impaired thoracic alignment in terms of rotation?
Asymmetry of the ribcage, with the contralateral side being more prominent
(i.e. Uneven rib cage, opposite side sticks out more)
What condition is associated with asymmetrical ribcage contour?
Scoliosis
What type of rotational pattern is most commonly associated with impaired thoracic alignment?
Functional rotation, usually from repeated movements in one direction
What are common causes of functional rotation?
Unilateral sports, desk sitting, working towards one side
What is a wide infrasternal angle (ISA)?
ISA greater than 100°
Which muscles are typically tight in individuals with a wide infrasternal angle (ISA)?
The internal obliques are tight, while the external obliques tend to be elongated.
What posture is commonly associated with a wide ISA?
A supine position (lying on the back) is often associated with a wide ISA because it allows for greater posterior ribcage expansion, making the ribcage flare outward more.
- (i.e seen when someone is in supine but corrected with exercises like wall-supported downward reach)
What is a narrow infrasternal angle (ISA)?
ISA less than 90°
What muscles are tight with a narrow ISA?
Tight external oblique from a descended diaphragm and long internal oblique
What postures can help correct a narrow ISA?
Prone or quadruped, allowing more anterior expansion
What is the rib cage appearance in someone with a wide ISA (lifter)?
Squished front to back, sides are flared, likely a belly breather
What movements are associated with a wide ISA posture?
Sacral nutation, innominate extension, adduction, and internal rotation
What postural pattern is common with a wide ISA?
Lumbar lordosis, thoracic kyphosis (upper crossed syndrome)
What treatment is recommended for someone with a wide ISA?
Wall-supported downward reach and sidelying
What is the rib cage appearance in someone with a narrow ISA (marathon runner)?
Squished side to side, difficulty with front to back or pump handle motion
What movements are associated with a narrow ISA posture?
Sacral counter-nutation, innominate flexion, abduction, and external rotation
What causes the narrow ISA appearance?
Overly descended diaphragm
What postural pattern is common with a narrow ISA?
Flatback posture
What treatment is recommended for someone with a narrow ISA?
Quadruped breathing or hooklying
Where is the apex of the infrasternal angle (ISA) measurement?
Xiphoid process
Where do you measure the infrasternal angle (ISA) from?
The side of the ribs, typically 7-10 rib cartilage side
How much should the rib cage expand with max inhalation?
5-10 cm
What happens to rib expansion when arms are elevated?
It should be on the lower end of the 5-10 cm range
What is considered impaired rib expansion?
Less than 3 cm change
What does less than 3 cm of rib expansion indicate?
Possible shortness in the abdominal obliques
What muscle group is implicated if the subcostal margin does not expand with arms-raised inhalation?
Shortness of the external obliques
What coupled motion occurs with bilateral shoulder elevation?
Thoracic extension
What coupled motion occurs with unilateral shoulder elevation?
Ipsilateral rotation and lateral flexion
What is the coupling pattern in the upper thoracic spine due to the frontal plane facet orientation?
Ipsilateral coupling of rotation and side-bending
What is the coupling pattern in the lower thoracic spine due to the sagittal plane facet orientation?
Contralateral coupling pattern
What muscles are likely short in a patient with thoracic pain, sway back posture, and forward head?
Tight hip flexors, hamstrings, lumbar extensors, upper trapezius, and pectorals
What muscles are likely long and weak in a patient with thoracic pain, sway back posture, and forward head?
Weak deep neck flexors, lower trapezius, rhomboids, and abdominal muscles
What are two priority stretch exercises for a patient with sway back posture and forward head?
Chest/pectoralis stretch and hip flexor stretch
What are two priority strengthening exercises for a patient with sway back posture and forward head?
Chin tucks (for deep neck flexors) and scapular retraction exercises (for lower trapezius and rhomboids)
What are key postural instructions for a patient with sway back posture and forward head?
Engage core, avoid forward head posture, keep shoulders back, and maintain neutral spine
What breathing exercises are helpful for a patient with sway back posture and forward head?
Diaphragmatic breathing (to engage the lower ribcage) and ribcage expansion exercises
What posture is most likely for a patient with an ISA of 70°?
Narrow ISA posture
What position would you place a patient with an ISA of 70° for intervention?
Prone or quadruped position
What are two priority interventions for a patient with an ISA of 70°?
Quadruped breathing exercises and hooklying position breathing exercises
