Dirty Half Dozen

Question 1

LBP - What do physicians look for?

Answer 1

Reflex loss
Sensory loss
Motor Weakness

Question 2

The Dirty Half Dozen Study

Answer 2

Looking for mechanical reasons and interventions for persistent LBP

183 patients with “Failed low back syndrome” (79 male, 104 female)

Avg. age 40.8

Disabled avg. 30.7 mo

Found 6 somatic dysfunction present in most patients

• 2.7% had none of the DHD
• 55% had three or more of the DHD
• 75% of the patients returned to full employment and ADL’s following treatment plan and home exercise/stretch regimen despite and average of 2.5 years disability!!!

Question 3

The Dirty Half Dozen

Answer 3

Non-neutral dysfunction within the lumbar spine
Pubic symphysis dysfunctions
Posterior extensions or torsions of the sacrum
Innominate shears
Short-leg, pelvic-tilt syndrome
Muscle imbalance of the trunk and LE

Question 4

Pubic symphysis

Answer 4

Pubic rami must be able to move superiorly and inferiorly during the gait cycle
Aids in distribution of forces from the femur into the pelvis and across the SIJ’s

Question 5

Pubic symphysis somatic dysfunction

Answer 5

75% of patients in the DHD study had pubic symphysis unleveling
Somatic dysfunction causes distortion of the pelvic brim
Increases the force load across the SIJ’s

Most commonly right inferior (32%), left superior (25%)

• Hypertonic adductors
• Weak lower abdominals

Question 6

Innominate dysfunctions

Answer 6

24% of DHD patients showed the presence of innominate shears

• 19% superior
• 4% inferior

Shears, while not common, are most troublesome
- SIJ dysfunction reflexly inhibits gluteus maximus firing destabilizing pelvis and lumbar spine

Question 7

Short-leg, pelvic-tilt

Answer 7

63% of DHD study patient had this present

Short leg on one side creates a constellation of structural dysfunctions
- LE somatic dysfunction
- Innominate rotations
- Pelvic unleveling 
- Spinal asymmetry
---- Coronal plane (sidebending)
----- Chronic Type I dysfunctions
----- Muscular imbalance
Shoulder asymmetry

Question 8

Innominate rotations

Answer 8

NOT part of the DHD, but may be indicative of the short leg, pelvic tilt syndrome
Axis of innominate rotation posterior to the acetabulum, influencing the rotational motion
May also be indicative of muscular imbalance

Question 9

Checking for short leg/pelvic tilt

Answer 9

Standing flexion test
Foot arches
Greater trochanter height
Iliac crest height
Pelvic side shift
Presence of persistent Type I dysfunctions
Shoulder unleveling
CCJ unleveling

Question 10

Sacral dysfunctions

Answer 10

48.8% of DHD study patients had a restriction to anterior nutation of the sacrum

• Backward torsion
• — L on R = 17.5%
• — R on L = 15.8%

Bilaterally extended= 15.3%

Question 11

Posterior sacral dysfunctions are painful! - form closure

Answer 11

Form closure
Flat surfaces of the SIJ are susceptible to shear forces
Wedge shape of the sacrum in the AP as well as the vertical planes protects against this

Question 12

Force closure

Answer 12

Begins in the LE through force coupling
Heel strike: peroneus longus and biceps femoris into the sacrotuberous ligament and across the ipsilateral SIJ
Midstance: downward force of Biceps femoris contraction countered by upward contraction of ipsilateral gluteus maximus and contralateral latissimus dorsi through thoracolumbar fascia

Creates a muscle-tendon-fascial sling that is temporally precise: any delay in firing of these mm decreases the stability of the entire mechanism

Question 13

Counternutation dysfunctions

Answer 13

by definition, decrease the ability of the sacrum to nutate
Leads to loss of form closure
Leads to arthrokinematic inhibition of Gluteus Maximus diminishing force closure and destabilizing the muscle-tendon-fascia sling

Question 14

Anterior sacral torsions

Answer 14

Not part of the Dirty Half Dozen

Recurrent presence may be indicative of short leg/pelvic tilt syndrome

Question 15

Unilateral sacral dysfunctions

Answer 15

Present in chronic recurrent LBP with minimal radiation to the LE below the buttocks
Standing for longer periods of time increases pain; walking sitting decreases pain
Usually one legged standers (creates postural imbalance)
Most common pattern:
- Left superior pubic symphysis
- Left unilateral sacral flexion
- Left posterior innominate
- L5 ERS left
- Hypertonic erector spinae, weak abdominals, weak pelvic stabilizers (Glut med/min)

Tx:

• Correct somatic dysfunctions present
• Postural retraining

Question 16

Lumbar dysfunctions

Answer 16

84% of DHD patients had Type II dysfunctions of the lumbar spine
ERS = 34.9%
FRS = 83.6%

Most had multiple dysfunctions and were clustered at L4 & L5

Question 17

Type II dysfunctions

Answer 17

inhibit transversospinal function
These work synergistically with transversus abdominus and internal obliques, thoracolumbar fascia, iliopsoas and quadratus lumborum
Inhibition of transversospinal mm leads to decoupling of entire core mechanism

–> Loss of core control

Question 18

Muscle imbalance

Answer 18

Greater than 95 % of population had significant muscle imbalance between trunk and lower extremities.
Primarily tight hip flexors, tight piriformis, tight adductors, weak abdominals, weak gluteus maximus and medius.
Poor proprioceptive balance and trunk rotator control.

Question 19

Core control is key

Answer 19

Abdominal muscles notoriously weak

• Transversus abdominus essential for core control
• TA fires first with all upper and lower extremity motion
• In patients with persistent or recurrent LBP TA shows delayed firing
• Leads to decreased core control and increased instability

Question 20

Treatment sequence

Answer 20

Pubic symphysis dysfunctions
Innominate shears
Sacral dysfunctions
Lumbar Type II’s
Correct short leg if present
Correct muscle imbalance with home exercise and retraining program