554 Unit 5: Lumbar Spine

describe Connective tissue balance: the functional coupling of the deep abs and paraspinal muscles

* Vleeming (2014) "There exists a point of equal tension between the paraspinal muscles and the transverse abdominis and internal oblique muscles acting through the common tendon producing force closure and self-bracing of the spine" Tesh (1987) -increasing either intra-abdominal or intra-compartmental pressure increased lumbar spine stiffness in sagittal plane. -But intra-articular pressure was more diffuse and intra-compartmental pressure was more local to the spinous level -Only increasing intra-abdominal pressure increased stiffness in frontal plane

describe what happens to the sacroiliac joint throughout life by decade

-1st decade: flat; stability via interosseous lig. -3rd decade: articular convex ridge and cartilage erosion on the ilium and concave sacral surface, capsular tightening -4th and 5th: arthrosis on the iliac side, clinical gliding tests suggest that intra-articular movement is available -6th and 7th: irregular surface, subchondral bone exposed, limited mobility -8th: intra-articular fibrous connections, periarticular osteophytes

a functional spinal unit (FSU) is defined as ...?

2 neighboring vertebrae, including disc and ligament, void of muscles

Provide a definition of a functional spinal unit.

A Functional Spinal Unit (FSU) consists of two neighboring vertebra, the intervertebral disc and the ligaments. The musculature is not included.

How much weight can a cadaveric lumbar spine support? a. Body weight b. About 1 Newton c. About 10% body weight d. The weight of the head, arms, and trunk

About 10% body weight

what are the ligaments supporting the sacroilias joint posteriorly?

Dorsal - fibers that run transversely, obliquely, and vertically Sacrotuberous: receives some fibers from biceps fem, vital to dynamics of the pelvic girdle Sacrospinous: lower lateral sacrum and coccyz to ischial spine of innominate

Deep fibers of the multifidus are thought to contribute to stability by all of the following EXCEPT a. Being deep contralateral rotators of the spine b. Counteracting shear forces c. Preventing intervertebral motion

a. Being deep contralateral rotators of the spine

Choose the correct statement. a. One theory of back injury discussed here states that tissue failure is a result of injury in high-demand activities. b. One theory of back injury discussed here states that instability is a result of injury in high-demand activities.

a. One theory of back injury discussed here states that tissue failure is a result of injury in high-demand activities.

The ground reaction force during weight acceptance of gait is transferred to the hip joint. As a result of this force, the innominate rotates a. Posteriorly b. Anteriorly c. Medially in reference to the sacrum d. Laterally in reference to the sacrum

a. Posteriorly

Which SI ligament received fibers from the biceps femoris? a. Sacrotuberous ligament b. Interosseous ligament c. Sacrospinal ligament d. Iliolumbar ligament

a. Sacrotuberous ligament

axial rotation is defined by the _______________ vertebral body and in reference to the __________________ vertebrae

anterior; caudal

Which of the following is the strongest ligament that stabilizes the sacroiliac joint? a. Sacrospinous ligament b. Interosseous ligament c. Sacrotuberous ligament

b. Interosseous ligament

What is the direction of rotation at the L4-L5 functional spinal unit (FSU) when L5 is rotated right? a. Right b. Left

b. Left

Which anterior muscle is responsible for working with the multifidi to contribute to deep lumbar stabilization? a. Rectus abdominis b. Transversus abdominis c. External oblique

b. Transversus abdominis

Which of the following is not a con of the stoop lift? a. Creates larger external moment arm b. Creates large force on lumbar spine c. Creates greater demand on quadriceps

c. Creates greater demand on quadriceps

Which is not a piece of evidence supporting the role of the lumbar multifidus as a stabilizer? a. Large physiological cross-sectional area b. Small moment arm at the lumbar spine c. Majority Type II (fast-twitch, fatiguable) muscle fibers d. Preactivates before voluntary limb movement

c. Majority Type II (fast-twitch, fatiguable) muscle fibers

From superficial to deep, what are the layers of the abdominal muscles? a. External oblique, rectus abdominis, transverse abdominus, internal oblique b. Rectus abdominus, transverse abdominus, external oblique, internal oblique c. Rectus abdominis, external oblique, internal oblique, transversus abdominus

c. Rectus abdominis, external oblique, internal oblique, transversus abdominus

Which of the listed muscles does not contribute to stabilization of the SI joint of the stance leg during walking? a. Rectus abdominis b. Piriformis c. Vastus lateralis

c. Vastus lateralis

Facilitated contraction of which muscle will result in rotation of the sacrum to the left? a. Left piriformis b. Rectus abdominis c. Bilateral multifidus d. Right piriformis

d. Right piriformis

T/F IV disc is not a part of an FSU

false

Match the following terms with their corresponding definitions according to Panjabi's research. flexibility testing stiffness testing a. When a set joint displacement is achieved and the amount of force required to attain the displacement is measured b. When a set amount of torque is applied to a joint and the joint displacement is measured

flexibility testing - b. stiffness testing - a.

_______________________ ligament is the strongest, completely fills the sacral crest and iliac tuberosity, dorsal to the cavity of the joint

interosseous

With age the surface of the SI joint becomes smoother. Yes or no?

no

What type of combined motion (coupled or noncoupled) occurred when L4-L5 was side-bent right and rotated right in extension?

non coupled

Weight acceptance during stance phase of gait results in nutation or counternutation of the sacrum?

nutation

When the base of the sacrum moves anteriorly, the motion of the sacrum is called what?

nutation

what does nutation and counternutation mean?

nutation = sacrum flexing in space counternutation= scrum extending in space

FSU exhibits motion around an axis (________________) and linear motion at the discal joint (_____________)

osteokinematic; arthrokinematic

an aging disc loses the capacity to imbibe water, resulting in what?

resulting in decreased disc height and, consequently, in diminished kinematics and decreased IV foramen

a healthy disc has the capacity to imbibe water, resulting in what?

resulting in increased disc height and adaptable mechanical properties

what is the IV discs mechanical role?

shock absorber

what is the clinical relevance of coupled motion observed at the axial skeleton?

since coupled motion happens automatically, we need to be cognizant of it when assessing active and passive motion -as PTs we can enhance or control the secondary motion Coupled motion is used to treat zygapophyseal joint dysfunction -it allows us to limit motion at the treated joint and impart slow or fast joint mobilization -its also used to limit motion in the neighboring joints

motion of the SI joint

small movement -0.2-2 degrees of rotation and 1-2mm of translation actively Passive motion -7-8 degrees

why does coupled motion occur?

structure (bony morphology of the zygapophyseal joints) and posture (extended or flexed lumbar spine)

automatically, muscle action is described as a point of insertion moving toward the origin. if we were to stabilize the point of insertion and contract the muscle, what would happen?

the origin would move toward the insertion. think about how the muscle action would change.

due to highly congruent facet joints, inducing motion in the frontal plane facilitates secondary motion in the ___________________ plane. this is called __________ motion

transverse; coupled

T/F IV disc allows slight movement of the vertebrae?

true

T/F intervertebral discs form a symphysis - a fibrocartilaginous joint

true

what happens when we apply a pure moment into right side bending initiated cranially?

we would expect to see side bending to the Right We would also see coupled motion of -Left rotation -small amount of flexion -small amount of right translation *according to the panjabi study

can the automatic coupling be modified?

yes: this automatic coupled motion can be actively or passively increased or limited