thoracic biomechanics Flashcards
What is the main source of support in the thoracic area
Ligamentous support
What type of joint is the zygapophyseal joint?
gliding synovial joints
What directions do the superior facets face?
posteriorly, superiorly and laterally
What directions do the interior facets face?
anteriorly, inferiorly, and medially
What is the intervertebral joint?
articulation between each vertebra with an intervertebral disc
Which capsule is tighter between the cervical and thoracic spine?
thoracic spine
Is a disc herniation common in the thoracic spine?
no, they are rare
What joints make up the thoracic spine (other than the ones that are the same as all others)?
- costovertebral
- costotransverse
- costochondral
- interchondral
- chondrosternal
- xiphisternal
- manubriosternal
What articulations make up the costovertebral joint?
- head of rib articulates with 2 adjacent vertebral bodies and the IVD
- vertebral bodies of T2-T9
How is the costovertebral joint reinforced?
intra-articular ligament
absent in atypical joints
how is the costovertebral capsule supported?
radiate ligament
What articulations make up the costotransverse joint?
- articulation of the transverse process and the rib
- TP of T1-T10
How is the costotransverse joint and joint capsule reinforced?
- lateral costotransverse ligament
- costotransverse ligament
- superior costotransverse ligament
What articulations make up the costochondral joint?
- articulation of the 1st-10th ribs anterolaterally with the costal cartilages
- direct attachment of the rib
What ligaments support the costochondral joint?
none-lacks true ligamentous support
What articulations make up the interchondral joint?
- synovial articulation between corresponding ribs
- costal cartilages of ribs 7-10 articulate with cartilage immediately above
What is the only connection between the sternum and ribs 8-10?
interchondral joint
How is the interchondral joint supported?
- a capsule and interchondral ligament
What articulations make up the chondrosternal joint?
- articulation of costal cartilages of ribs 1-7 anteriorly with the sternum
- continues with sternum
What articulations make up the xiphisternal joint?
-articulation between the main body of the sternum ad xiphoid process
Is the xiphisternal always cartilaginous?
no, it is cartilaginous during childhood but ossifies in adulthood
What ligaments support the xiphisternal joint?
none-no direct ligamentous support
What articulations make up the manubriosternal joint?
articulations between the most superior portion of the sternum (manubrium) and the largest portion of the sternum (sternal body)
What ligaments support the manubriosternal joint?
none-no direct ligamentous support
What structures in the thoracic spine reduce thoracic mobility?
- decreased IVD height
- rib articulation with thoracic spine
- facet joint orientation
How many degrees of freedom does the thoracic spine have? And what are they?
Sagittal: flexion/extension
Transverse: Axial rotation
Frontal: side bending
Arthokinematics: flexion at thoracic spine and ribcage
T-spine: anterior and superior translation-anterior rotation
Ribcage: rolls superiorly on the transverse process
Arthokinematics: extension at thoracic spine and ribcage
T-spine: posterior rotation and posterior translation
Ribcage: posterior roll
Arthokinematics: rotation at thoracic spine and ribcage
BOTH: -ipsilateral posterior medial glide
-contralateral anterior lateral glide
Arthokinematics: side bending at thoracic spine and ribcage
BOTH:
- ipsilateral superior facet inferior glide and approximation
- contralateral facet superior glide and gapping
What are vertical changes in the interthoracic volume with inspiration and expiration?
- Diaphragm contracts and lowers increasing negative pressure for inspiration
- diaphragm relaxes and raises for quiet expiration
How does elevation of the ribs affect inter thoracic volume?
Elevation of ribs produces an increase in anterioposterior and mediolateral distances increasing interthoracic volume during inspiration
-bucket handle/pump handle motion
How does depression affect interthoracic volume
Depression of ribs produces a decrease anterioposterior and mediolateral distances decreasing interthoracic volume during expiration
-bucket handle/pump handle motion
Arthrokinematics: respiration at ribs 1-6
Inspiration and expiration
Primary movement is rotation
Inspiration: anterior portion moves superior, posterior portion moves inferior
Expiration: posterior portion moves superior, anterior portion moves inferior
Pump handle
Arthrokinematics: Respiration ribs 7-10
Inspiration and expiration
Inspiration: superior, anterior, and lateral
Expiration: inferior, posterior, and medial
Bucket handle
Explain “bucket-handle” in simple terms for inspiration and expiration
Inspiration : ribs rotate upward and outward
Expiration: ribs rotate down and in
What occurs during forced inspiration?
The movement of the ribs is combined with slight thoracic extension
Thoracic muscles
Last Erector spinal Traps Rhomboid minor and major External oblique Rectus abdominis Pec major and minor
Primary muscles of respiration
Diaphragm
Sternocostal
Intercostal
All act on the rib cage to promote inspiration
Diaphragm
-Most important muscle of inspiration: increases intrathoracic volume
-Dome shaped
-separates thoracic cavity from abdominal cavity
-connected by the central tendon
-innervated by the phrenic nerve
Drops during inspiration; elevates during expiration
What are the three intercostal muscles and what part of respiration are they active during
External intercostals: pull the lower rib toward the upper rib in inspiration
Internal intercostals: pulls the upper rib down during expiration
Sternocostals: active during inspiration
Secondary muscles of respiration
Anterior and middle scalenes Serratus posterior Pec maj and min Last Traps SCM
Assist with inspiration and expiration during activity, stress, or illness
Clinical implications: posture
Changes in posture affect muscle length
Affects respiration
Important to monitor progression during therapeutic exercise
Clinical implication: rib dysfunction
A rib that does not coordinate its movements with the other ribs
-pain, muscle spasms, difficulty breathing
Wide variety of causes
- posture, trauma, rotational strains, forceful compression, coughing attack
Clinical implications: scoliosis
Frontal and transverse plane deviation of the normal alignment of the spinal curve
Named by the shape, spine location, and the side of convexity
Functional or structural
Rib hump is always present in structural scoliosis
Varying degrees of severity: Cobb angle
Open, closed and Capsular pattern in thoracic
Open:midway between flex and extended
Closed:full extension
Capsular pattern:extension, side bending, rotation>flexion
