Thoracic biomechanics

Question 1

rotation is more available in…

Answer 1

The upper and mid thoracic region
As compared to flexion extension and lateral flexion

Question 2

flexion and extension motion availability increases in

Answer 2

Lower thoracic spine

Due to facet orientation more approximating lumbar vertebra

Question 3

thoracic movement ranges

Answer 3

flexion 30-40
extension 20-25
rotation 30-35
lateral flexion- 25-30

Question 4

thoracic flexion

Answer 4

occurs during forward bending and exhalation

anterior rotation and translation of superior vertebrae on inferior vertebrae

Inferior facet slide up and forward on superior facets

Question 5

thoracic flexion coupled rib motion

Answer 5

superior vertebral body motion causes anterior rotation of the rib head (inferior demifacet attachment)

Anterior portion of the rib moves inferiorly

in lower ribs… they elevate

Question 6

thoracic extension

Answer 6

Occurs during backward, bending and inhalation

Posterior rotation and translation of the superior vertebrae on the inferior vertebrae

Inferior facet slides down and backwards on superior facet

Question 7

thoracic extension, coupled rib motion

Answer 7

Superior vertebral body motion causes posterior rotation of the rib head (inferior Demi facet attachment)

Anterior portion of the rib moves superiorly

lower ribs… depression

Question 8

Thoracic lateral flexion R

Answer 8

lateral flexion in frontal plane, sagittal axis

Type one mechanics
Ipsilateral compression on the closing facets; downward glide
Contralateral distraction, opening facets; upward glide
Rotation to the opposite direction

L ribs- move away from each other (posterior rotating) depressing lower ribs
R ribs- move towards each other (anterior rotating) elevating lower ribs

Question 9

thoracic rotation R

Answer 9

rotation occurs in a transverse plane around the vertical axis

Type two mechanics
Causes same side sidebending

The rotate to right, sidebend the right
shifting of the vertebral body to the left-hand side
Ribs on the left are flexed
Ribs on the right extending

Question 10

Primary muscles of respiration

Answer 10

diaphragm
Scalenes
Intercostals

Question 11

muscles of forced inspiration

Answer 11

Serratus posterior Superior and inferior
Levator costarum
Sternocleidomastoid
Latissimus dorsi
Iliocostalis cervicis and thoracis
Pectoralis minor and major
Quadratus lumborum

Question 12

Muscles of forced expiration

Answer 12

abdominals
Transverses thoracis
Internal intercostals

Question 13

upper ribs mechanics

Answer 13

Pump handle movement
Changes AP diameter

Posteriorly means they elevate
Anteriorly means they depress

Question 14

middle ribs mechanics

Answer 14

Bucket handle movement
Changes AP and transverse diameter

Question 15

lower ribs mechanics

Answer 15

caliper like movement

changes transverse diameter
Elevation And depression

Question 16

Three distinct regions of the T spine

Answer 16

Upper- T1-T3 ( functions as part of the lower C spine); more flexion/extension (treated more efficiently with rotational and lateral flexion techniques)

lower- T10-T12 (functions as part of the upper L spine) (favorably treated with rotational or sidebending techniques)

functional T4- T9 ( true T-spine)
The greatest amount of motion tends to be rotational movements
More limitation with flexion extension
Flexion extension techniques tend to work better in a true thoracic spine

Question 17

two common patterns of clinical present

Answer 17

Pain from loading- load attenuation

Symptoms related to movement restrictions

Question 18

load attenuation

Answer 18

Compressive loads on thoracic spine, increase caudally from 9% bodyweight at T1 to 47% bodyweight at T12

design is to handle increasing low demand by progressive increase in
Vertebral body height
end plate cross-sectional area
Bone content higher in lower than upper

Question 19

upper t spine load

Answer 19

76% compressive load transferred through vertebral body disc complex

Question 20

lower t spine load

Answer 20

greater load transferred through posterior column via the interlocking lamina and facet joints

Question 21

IVD load

Answer 21

thinner than the C spine and L spine discs

Annulus Fibrosis is stronger
greater ability to resist rotational stress

Disc lesions are more evident
73% of asymptomatic population had some form of disc lesion

Question 22

upper and mid thoracic discs

Answer 22

Undergo greater deformation and creep

More viscous, mechanical behavior due to structural arrangements of the annular lamellae

Question 23

L spine load

Answer 23

Compressive loading evenly distributed across surface of the end plate independent of position of the motion segment

Question 24

t spine load

Answer 24

load distribution across the end plate becomes asymmetric when loaded outside the neutral position

Can explain pain associated with sustained loading postures like on computers, driving

Question 25

t spine flexion and extension motion accompanied by very little movement in other planes is due to

Answer 25

Symmetrical anterior rotation of the upper ribs constraints couple movements

Question 26

Rotation and lateral flexion are more complex due to

Answer 26

asymmetrical movement patterns in the spinal motion segments and the ribs

Question 27

Lateral flexion

Answer 27

ipsilateral anterior rotation and Contralateral posterior rotation of the upper ribs

Question 28

upper T spine rotation to the right

Answer 28

posterior rotation of right ribs Anterior rotation of left ribs

Question 29

Normal mechanics and motion of the cervical spine and shoulder should be dependent

Answer 29

upon normal mobility of the upper T spine

Question 30

habitually flexed upper T spine

Answer 30

reduce capacity of muscles to provide cervical thoracic retraction Anteriorly rotated upper ribs, restrict the range of the C spine extension and rotation due to requirement for movement out of the neutral spinal alignment

Question 31

Restricted upper rib mobility has signs and symptoms consistent with

Answer 31

Subacromial impingement or thoracic outlet syndrome

Question 32

in the mid thoracic spine, the anterior elements are subject to high compressive loads because

Answer 32

Of apex of kyphosis

Question 33

Progressive wedge deformity of vertebral bodies and disc space narrowing are

Answer 33

Quite common Can lead to hypomobility of mid thoracic motion segments, and ribs Particularly in rotation and extension

Question 34

Anatomical variations are common at

Answer 34

The TL junction and need to be considered Can be gradual or abrupt

Question 35

PA stiffness of the thoracic spine increases from

Answer 35

Upper to lower

Question 36

PA applied perpendicular to the spinal curvature causes

Answer 36

anterior translation And extension

Question 37

directed towards body eliminates

Answer 37

Extension but induces a longitudinal force of up to half the applied load