Kinesiology of lumbar spine

Question 1

I. Osteokinematics

Answer 1

a. Primary motion: sagittal plane (12-20° at each segment)
b. Secondary motion: frontal plane (6° at each segment)
Tertiary motion: transverse plane (2° at each segment

Question 2

a. Facet orientation:

Answer 2

i. 45° to frontal plane dictates motion

Question 3

a. Lumbosacral joint

Answer 3

i. Oblique facet orientation allows rotation & flexion, limits lateral flexion
ii. Increased mobility = more problems

Question 4

a. Approximation (closing)

Answer 4

i. Facet surfaces move closer together

Question 5

a. Separation (gapping)

Answer 5

i. Facet surfaces move further apart

Mainly in rotation

Question 6

a. Sliding (gliding)

Answer 6

i. Linear translation of facet surfaces in the plane of facet joint

Question 7

a. Flexion

Answer 7

i. Inferior facets of superior vertebra slide upward on superior facets of inferior vertebra

Question 8

a. Extension

Answer 8

i. Inferior facets of superior vertebra slide downward on superior facets of inferior vertebra

Question 9

a. Right lateral flexion

Answer 9

i. Right inferior facet of superior vertebrae slides down, and left inferior facet of superior vertebrae slides up on corresponding superior facets of inferior vertebra

Question 10

a. Left lateral flexion

Answer 10

i. Left inferior facet of superior vertebra slides down, and right inferior facet of superior vertebra slides up on corresponding superior facets of inferior vertebra

Question 11

a. Right rotation

Answer 11

i. Separation of right facet and approximation of left facet joint

Question 12

a. Left rotation

Answer 12

i. Separation of left facet and approximation of right facet joint

Question 13

a. Coupled motion

Answer 13

i. Little agreement on coupled motions
ii. Other regions:
1. Upper cervical: contralateral
2. Mid-lower cervical: ipsilateral
3. Thoracic: no consistent pattern

Question 14

I. Posture

a. Static standing posture

Answer 14

i. Primary loads are:
1. Body weight
2. Mm activity
3. Pre-stress from ligaments (ligamentum flavum)
4. External loads

Question 15

Posture

Constant flexion moment

Answer 15

1. Anterior shear

2. Must be resisted by extensor mm (by adding posterior shear & compression)

Question 16

a. Ideal posture

Answer 16

i. Acromion lines up with ear, greater trochanter, lateral epicondyle, lateral malleolus
ii. Cervical & lumbar lordosis
iii. Thoracic kyphosis
iv. Symmetry

Question 17

a. Influence of Atypical Posture

i. Decreased lordosis (flat back)

Answer 17

1. Flexed lumbar spine (arthrokinematics = anterior superior slide)
2. Posterior pelvic tilt
3. Hip extension
4. Knee hyperextension/locking

Question 18

loading of decreased lordosis?

Answer 18

a. Anterior body & IVD compression (NP pushed posteriorly more likely to herniate), increased pressure on facets

Question 19

i. Increased lordosis (sway back)

Answer 19

1. Extended lumbar spine (arthrokinematics = downslide of facets)
2. Anterior pelvic tilt
3. Hip flexion
   Knee extension

Question 20

Loading in increased lordosis?

Answer 20

a. Anterior shear, posterior body & IVD compression, interpinous ligaments compressed, decreased pressure on facets
b. Reduced diameter of intervertebral foramina (nerve roots)

Question 21

i. Prolonged flexion (seated or standing)

Answer 21

1. Adaptive shortening of mm & connective tissue
2. Increased flexor moment on spine
3. Increased pressure on anterior IVD (may weaken posterior annulus fibrosis over time)
4. Impact on entire kinetic/kinematic chain

Question 22

i. Prolonged hyperextension (standing, pregnancy)

Answer 22

1. Compression of facets
2. Increased anterior shear @ lumbosacral joint
3. May lead to development of spondylolisthesis (one vertebra slips forward on the one below it)
4. Impact on entire kinetic/kinematic chain

Question 23

I. Aberrant Movement Patterns

a. Reversal of Lumbopelvic Rhythm

Answer 23

i. Patient asked to bed forward as far as they can (standing flexion) and return to upright posture
ii. Therapist observes relative timing & sequencing of trunk/pelvis motion
iii. Typical: trunk moves first in flexion, last in extension (pelvis moves last in flexion, first in extension)
iv. κ = .16 poor

Question 24

a. Gower Sign

Answer 24

i. ‘Thigh climbing’
ii. Patient asked to bend forward as far as they can (standing flexion) and return to upright
iii. Sign is positive if they must use hands on thighs to assist with return to standing
iv. 98% agreement between clincians

Question 25

a. Instability Catch Sign

Answer 25

i. Patient asked to bend forward as far as they can (standing flexion) and return to standing
ii. Sign is positive if they cannot return to erect posture due to sudden painful ‘catch’ in their low back
iii. κ = .25 poor-moderate?

Question 26

I. Supporting Structures

a. Longitudinal ligaments

Answer 26

i. Anterior longitudinal ligament
1. Vertebral body attachment (less to IVD)
2. Tight in extension
ii. Posterior longitudinal ligament
1. IVD attachment (less to body)
2. Tight in flexion

Question 27

a. Ligamentum Flavum

Answer 27

i. Connects adjacent vertebral arches
ii. High elastin content
iii. Contracts during extension, elongates during flexion
iv. Under constant tension
1. Pre-stresses the disc to create intradiscal pressure
2. Provides stability

Question 28

a. Intervertebral Discs

Answer 28

i. Components
1. Inferior/superior endplates
2. Annulus fibrosis
3. Nucleus proprius
ii. Functions
1. Weight bearing
2. Load distribution
3. Restrains excessive motion

Question 29

Acute overload exposure

Answer 29

i. primarily endplate fractures, no IVD injuries

Question 30

Cumulative exposures ?

Answer 30

i. more detrimental to IVD

Question 31

Herniation:

Answer 31

i. disc material worms its way thru annulus fibrosis