1. Scoliosis and Short Leg – An Osteopathic Manipulative Medicine Approach
Jonathon R. Kirsch, D.O., C-NMM/OMM
Associate Physician
Neuromusculoskeletal Medicine/OMM
Marshfield Clinic Stevens Point Center
4100 N. Hwy 66
Stevens Point, Wisconsin, 54482
Presenting at WAOPS Fall Seminar, Sept , 2015

2. Learning Objectives
Describe postural strain, its effects on the body, its diagnosis and treatment.
Classify and Differentiate various types of scoliosis, and discuss its clinical significance.
Discuss management and OMT for scoliosis.
Describe diagnosis, implications, and appropriate heel lift protocol for anatomical short leg.
Discuss gait, postural mechanics, and related clinical presentations for the sacrum and pelvis regions.

3. Learning Objectives
Describe the use of radiographic studies in postural diagnosis and management.
Discuss and interpret the “Cobb Angle” measurement from an AP radiograph of the thoracolumbar spine.
Discuss and interpret sacral base unleveling measurement from an AP radiograph of the pelvis.
Discuss and interpret lumbosacral angle and pelvic index measurements from a lateral postural x-ray.

4. Learning Objectives
Discuss strategies for osteopathic manipulative treatment in functional scoliosis.
Perform structural exam of spine, noting asymmetry and lateral curvature.
Observe and document changes in asymmetries with the use of a heel lift before and after OMT.
Diagnose and treat somatic dysfunction in the pelvis, sacral, lumbar, and thoracic regions.

5. Materials Needed for This Lab
12 pieces of 20lb copy paper
Your hands

6. Construct a Heel Lift
Start with 12 pieces of standard copy paper (20lb)
Take 3 pages and stack them together.
Fold in half
Fold in half again
Fold in half a third time
Tape the open edges closed with scotch tape.
You now have a 1/8 inch heel lift for this lab!
Stack 2 of these together for ¼ inch lift.
Stack 4 together for ½ inch lift (total of 12 pages)

7. The Consequences of Unlevel Foundations…

8. Postural Homeostasis
Postural changes take place in order to coordinate visual, vestibular, and kinesthetic input
Each person responds to asymmetric postural stress uniquely
Changes occur in a more predictable pattern in the lumbopelvic region
due to unique biomechanics.
like the righting reflex
due to proximity to center of gravity

9. Effects of Postural Strain - Bone and Joint
Wolff’s law
Wedging of vertebral body and exostoses (spurs).
Can result in modified function and increased calcium deposition
Increased functional demand + asymmetry  joint degeneration
Long term radiographic postural studies: progressive postural decline
Lateral curves more likely to evolve if leg-length difference > 10 mm.
Wolff’s law: under chronic stress (like exaggerated postural curves), bone will remodel itself over time to become more resilient to the stressor.
Degenerative arthritis targets of hip joint of long leg; accompanied by tenderness over that side’s greater trochanter.

10. Postural Observation Asymmetry Rotoscoliosis screening
Body position and alignment
Spaces or gaps from one side to the other
Key landmarks
Rotoscoliosis screening
Levelness of key landmarks
In static position
In dynamic position (when patient bends forward)
Compare gaps between arms & trunk.

11. Ideal Posture: Sagittal Plane
Center of gravity should pass through following points:
Just anterior to lateral malleolus
Just posterior to mid-knee
Femoral head
Anterior third of sacral base
Middle of body of L3
Humoral head
External auditory meatus
Failure to maintain this perfection shifts burden of weightbearing to soft tissues and joint facets  dysfxn.

12. Iliolumbar Ligament Strain
Anterior Sacral Rotation
Strains portions labeled “1”.
Posterior Innominate Rotation
Strains portions labeled “2”

13. Iliolumbar Ligament – Postural Effects
One of the first structures involved in postural decompensation
Exhibits tenderness, edema, pain
Groin pain
Hip pain

14. Scoliosis-defined as a pathological or functional lateral curve; an appreciable lateral deviation in the normally straight vertical line of the spine. (Dorland).
Scoliosis

15. Demographics 10 in 200 children by age 10-15 are diagnosed
1 in 200 children have clinical symptoms
Curves progress during rapid growth
Boys and girls are affected equally initially, but in girls is 3-5 times more likely to progress
It usually stabilizes after the child stops growing.
If the child stops growing with less than a 40 degree Cobb angle, adult progression is rare.

16. Naming by Side
Named according to the Convexity Dextroscoliosis-curve that is sidebent left, scoliosis/convexity is to the right. Levoscoliosis-curve that is sidebent right, scoliosis/convexity is to the left.

17. Classification By Cause
Idiopathic (70-90% scoliotic curves)
Unlevel sacral/cranial base
Sagittal plane biomechanics
Other unknown causes
Congenital
75% are progressive
Acquired
Short leg syndrome, Psoas syndrome, Osteomalacia, Inflammation, Irradiation, Sciatic irritibility, Healed leg fracture, Following hip fracture

18. Double Major Scoliosis (most common)
Classify by LOCATION:
Double Major Scoliosis (most common)
Balanced curve
Subject to Degeneration at Cross Over Areas of Curve

19. Single Thoracic Scoliosis
Cosmetically noticable
Heart and Lungs in jeopardy with progression of scoliosis

20. Single Lumbar Scoliosis
Associated with
Arthritic change

21. Junctional thoracolumbar scoliosis
Less Common
Associated with Arthritis often (due to long length of curve)

22. Classification By Reversibility
Functional vs. Structural
Functional curves go away with side bending, rotation, or forward bending
Structural curves are fixed and do not reduce with side bending, rotation, or lift therapy

23. Classification By Severity
Mild Scoliosis (less than 20 degrees).
Moderate Scoliosis (between 20 and 45 degrees).
Severe Scoliosis (between 45 and 70 degrees).
Very Severe Scoliosis (Over 100 degrees).

24. Cobb Angle
Angle of Lines across the top of the superior vertebral segment, and
Across the bottom of the inferior vertebral segment of a spinal scoliotic curve
The perpendicular lines intersect to form an angle (“Cobb angle”)
FOM fig 43.11
FOM

25. Management in Mild Scoliosis
Periodic Monitoring
OMT
Physical Therapy
Orthotics / Lift Therapy
Education

26. OMT for Scoliosis - Overview
Treat lumbar and pelvic somatic dysfunction.
Assess for anatomic leg length difference.
Long restrictor muscle stretch for side of concavity (Hypertonic m. stretching)
Postural exercises for retraining
Possible heel lift for anatomical short leg.

27. Management in Moderate Scoliosis (between 20 and 45 degrees)
Bracing – consider in curves 20 to 50 degrees
OMT, Exercise, Physical Therapy
Orthotics
Education
Electrical stimulation (debatable efficacy)

28. Management in Severe Scoliosis (between 45 and 70 degrees).
OMT
Exercise, Education
Orthotics
Bracing
Electrical stimulation (debatable efficacy)
Surgery as possible last resort (1 in 1000 cases)
Curves greater than 45 degrees
Prevents heart and lung complications
At >75 degrees the distortions may also cause dangerous changes in the heart or lungs

29. SpondyloListhesis

30. DEFINITION Forward displacement of one vertebra over another
usually L5 over S1
Clinical Presentation:
Back pain plus or minus leg pain and tight hamstrings
Radicular pain more common in adult
Painful extension
L5 nerve deficits
Classifications
Type I – Dysplastic
congenital deficiency of neural arch of L5 (most commonly) or uppersacrum
insufficiency of superior sacral facets
2 girsl: 1 boy ratio
Type II – Isthmic
II-A: lytic fatigue fracture of pars articularis; most common < 50 y/o
II-B: elongated but intact parts; probably due to repeated microfractures
II-C: acutely fractured pars; Hx of severe trauma
Type III – Degenerative
at apophyseal joints due to long-standing intersegmental instability
4 female: 1 male
3 black: 1 white
common at L4
not seen before age 40, rare b/w 40-50
Type IV – Traumatic
due to Fx in other areas of the bony hook than the parts
heals w/ immobilization
Type V – Pathologic
generalized or localized bone disease
neoplasm, osteogenesis imperfecta, Paget’s, etc.
Hereditary Factors
Observations that argue against direct inheritance of spondylolisthesis:
1. there is an increased incidence w/in family groups, but individuals exhibit different types of spondylolisthesis
2. infants rarely reported to have spondylolysis (pre-spondylolisthesis)
incidence increases after they become upright and continues up to age 20
Hereditary factors are those that predispose the region to instability
e.g spina bifida  lack of posterior support  may concentrate postural weightbearing forces in the area  subluxation of L5
Genetics can also predispose pts to stress fracture of pars interarticularis  L5 slides forward (isthmic spondylolisthesis)
Type III: Degenerative spondylolisthesis (aka: pseudo-spondylolistheis) is 2-3x more common in African Americans
greater L5-S1 stability
Low pelvic index for age 60
higher incidenc of sacralization of L5 and/or block-shaped L5 vertebrae
lower incidence of posterior defects than the general population
increased instability at L5  instability higher in the lumbar spine

31. Classification Types Type I: Dysplastic Type II: Isthmic
Insufficiency of articulatory process
Type II: Isthmic
Defect in Pars Interarticularis
Or Fracture
Type III: Degenerative
Changes in apophyseal joints
Type IV: Traumatic
Fracture other than in pars interarticularis
Type V: Pathologic
Secondary to Disease

32. Meyerding Grading System
For each one quarter that the upper vertebra is displaced forward on the vertebra below
I (1-25%)
II (25-50%)
III (50-75%)
IV (more than 75%)
Progression
Fastest ages 9-15
Rare progression over age of 20
System is commonly used, quick, and clinically relevant
Progression over age 20 rare - Especially in pts with a sclerotic buttress on the anterior lip of the sacrum

33. Risk of Cauda Equina
Can occur in isthmic spondylolisthesis above grade II (50% anterior movement)
Can occur in dysplastic spondylolisthesis above grade I (25% anterior movement)

34. Postural Etiology
Hyperlordosis transfers weightbearing from the vertebral bodies onto the articular facets
Higher incidence is seen in gymnasts due to increase in backward bending.

35. Microtrauma Etiology Repetitive lumbosacral motion
Ex. Weight lifters, soldiers carrying backpacks, and college football linemen
Frequent postural stress, especially during growth spurt, contributes to the syndrome

36. Diagnosis Diagnostic Testing Radiography (Ferguson’s Angle)
History (½ of patients asymptomatic)
Physical examination
Spinal palpation
Neurologic testing
Preventative care depends on early and accurate diagnosis

37. Palpatory Findings Anteriorly located spinous process
Sacral base motion exhibits laxity in anterior motion
Paraspinal tissues – tissue texture changes and tenderness
Iliolumbar ligament = bilateral tension and subjective tenderness
Patient may present with lateral thigh and/or groin pain

38. Radiographic Findings
Lumbolumbar or lumbosacral lordotic angles are objective measurements of lumbar lordosis
Hyperlordosis is significant in patients with sagittal plane postural problems

39. Lumbosacral Angle (AKA Feguson’s Angle or Sacral Base Angle)
Is a measure of lumbosacral lordosis
Angle between the top of the sacral base, and the horizontal plane.
Normal is degrees.
Reference line
Line A
Line B

40. Conservative Management
Treatment addressing the underlying instability, spinal mechanics, and patient homeostasis.
Stretch hamstrings, improve lumbar and abdominal strength, and flexibility
Promote anti-lordotic posture
Boston Brace for antilordosis (9-12 mo.)
OMT, orthotics, patient education
Exercise - stabilize the lumbosacral region, diminish the lumbar lordosis, flexion-type only

41. Goals of OMM in Spondylolisthesis
Reduce Lumbar Lordosis and somatic dysfunction
Help promote lympathic drainage
Promote optimal stability of weightbearing posture
Directed at support structures, eg. Pelvis
Correct Sacral Base Unleveling with heel lift orthotic
Thoracic spine and thoracolumbar junction
Quadratus lumborum and the iliolumbar ligament
Avoid HVLA**

42. Short Leg Syndrome and Lift therapy

43. Anatomic versus Functional
Anatomic Short Leg- One leg is anatomically shorter than the other.
Functional Short Leg- one leg appears shorter than the other but is secondary to pelvic dysfunction or other structural imbalance or scoliotic curve.

44. Effects of Short Leg Pelvis side shifts and rotates toward long leg
Innominate rotates anterior on side of short leg or posterior on side of long leg
Foot of long leg pronates, internally rotating lower leg
Lumbosacral angle increases by 2 to 3 degrees
Lumbar spine has convexity on short leg side (sidebending away from short leg)
Compensatory curves are generally type 1 neutral.

45. Lateral Curves over Time
Sacral base unlevels in coronal plane
Curve forms in one spinal region - C-shaped curve
Over time, other spinal curvatures develop
S-shaped curve
Thoracic curve may develop with convexity opposite the lumbar spine
Lumbar spine side bends away from and rotates toward the low sacral base (explain pic)
C-shaped curve – single long scoliotic curve in the lumbar or lumbothoracic spine
S-shaped curve – The shoulders and the greater trochanteric planes are typically depressed on the same side as the depressed sacral base

46. Sacral Mechanics with Short Leg
In short leg there will be lumbar sidebending, affecting sacral mechanics through the L5-Sacrum mechanical relationship.
Lumbar sidebending to the left (see figure) if chronic, will be associated with a left oblique axis sacral somatic dysfunction
Lumbar sidebending convexity is usually on the side of the short leg (DiGiovanna)

47. Sacral Motion in Gait Left rotation on a left oblique axis
Left oblique axis is engaged
L5 RR
Right rotation on a right oblique axis
Right oblique axis is engaged
L5 RL
Example: When the left leg is weight bearing, then the left axis of the sacrum is engaged.
Spinal column sidebends to the left (the weight bearing side)
The weight pins the upper pole of the sacrum on the weight bearing side.
As free lower extremity swings forward, it carries the free pole of the sacrum anteriorly, creating rotation of the sacrum about the Oblique Axis.
We call this a left rotation on a left oblique axis. This is normal.

48. Sacral Base Unleveling – Associated Findings
If sacral base is inferior on one side in the coronal plane, and
If this is due to leg length inequality,
Then the following are typically inferior on the side of inferior sacral base:
Greater trochanter of femur
PSIS
iliac crest

49. Innominate Dysfunction in Short Leg
Innominate rotation dysfunction can give rise to functional short leg, as acetabulum is anterior to mid-line of bone.
Anterior rotation  contralateral short leg
Posterior rotation  ipsilateral short leg
Anterior Innominate
ASIS inferior
PSIS superior
Anatomic short leg can give rise to compensatory innominate rotation dysfunction.
Short right leg  Right anterior innominate
Short left leg  Left anterior innominate

50. Short Leg Diagnosis Check for sacral and innominate shear.
OMT should be directed to all related somatic dysfunctions prior to diagnosis
Observe iliac crest height, femoral head height, sacral base leveling, degree of scoliotic compensatory curvatures, angle of the scapula, etc…
Obtain standing postural x-ray

51. AP Postural Xray Interpretation
Vertical lines are drawn from femoral heads
A sacral base line is constructed across the top of the sacrum, to femoral head lines
Intersection of sacral base line and femoral head lines gives femoral head height differential (C and C’ in diagram)
The sacral base unleveling is reported as the height differential between the
measurements taken at the line intersecting the vertical transecting the femoral heads.
Measurements using this protocol report accuracy to within ± 0.75mm, when other methods report errors of ± 2mm.

52. Treatment Short leg Syndrome
OMT directed to the spine, pelvis, LE’s, all associated musculature, ligaments and fascia.
If leg length discrepancy is apparent after somatic dysfunction addressed, order standing postural x-ray series.
If the Standing Postural Series reveals a femoral head discrepancy of >5mm., consider heel lift therapy.

53. Lift Therapy
Initiated to help body return to better structural alignment and function
The patient’s postural mechanisms are reeducated toward ideal posture
Paraspinal muscle tension and other spinal physiologic parameters become more symmetrically normalized
Level foundation of vertebral column

54. “Flexible Spine” Mild to Moderate Strain
Spine is flexible
No more than mild to moderate strain is noted in the myofascial system
Begin with 1/8-inch lift and lift at a rate no faster than 1/16 of an inch per week, or 1/8 of an inch every 2 weeks.

55. “Fragile Patient”
Arthritic, osteoporotic, aged, having significant acute pain, etc.
Begin with 1/16-inch lift and lift no faster than 1/16 of an inch every 2 weeks.

56. Sudden Loss of Length
Recent sudden loss of leg length on one side, (eg. following fracture or a recent hip or knee replacement surgery)
Patient had a level sacral base before the fracture or surgery
Lift the full amount that was lost.

57. Lift Therapy in Children
Monitor children with lifts closely
Wolf’s Law may cause longer leg to grow faster
Check bone length on X-ray if possible and monitor leg lengths
Fryette found that in his pediatric patients the short leg would grow to equal the long leg with lift therapy, over time.

58. Heel Lift Therapy
Final lift is ½- ¾ amount of total discrepancy, unless is immediately after a surgery where height was lost, and full amount of change can be corrected.
A maximum of ¼ inch should be lifted inside of shoe, if greater, lift outside of shoe.
If need to lift > ½ inch, should also lift sole of shoe to prevent compensatory inominate rotation.

59. Standing postural asymmetry examination Seated postural examination
Perform a structural exam with attention to coronal plane asymmetry and lateral curves
Gait evaluation
Standing postural asymmetry examination
Seated postural examination
did anything change?
Have your instructors check your findings

60. Standing Sidebending Test
Slide hand down thigh toward knee
Look at curve in thoracolumbar spine
Smooth curve?
Abrupt changes in curve?

61. Gross Spinal Flexion Test
With standing forward flexion, observe thoracic spine for any rotational humping on one side.
This indicates a lateral curve
For eg., a hump on the left signifies a lateral group curve in the spine, which is sidebending right, with rotation left.
Rotoscoliosis

62. STANDING FLEXION TEST The patient stands - feet are hip’s width apart
- knees extended
The physicians's
- fingers on the iliac crest
- thumbs thumbs rest on the posterior
superior iliac spines (PSIS).
Ask the patient, “Bend forward slowly without flexing the knees”
Physician feels and observes the superior movement of the PSIS
(The side which moves first and furthest indicates restriction of the iliosacral joint on the same side.)

63. Sidebending: Mid-Thoracic Region (T4 to T8)
The hands of the examiner are placed on the shoulders over the acromion process.
A downward and medial pressure is exerted, depressing the shoulder on one side and then on the other.
Check for asymmetry in ease of shoulder movement in the inferior direction, on each side.

64. Rotation - (T8 to T11) Place hands are on the shoulders
Rotate the trunk to both sides.
Check for symmetry or asymmetry.
Note: The lower thoracic spine has greater rotation than the upper due to rib attachments that restrict the upper region.

66. Hip flop Patient supine
Knees up, feet on table, lift buttocks off table, then down again, and straighten legs

67. Medial malleolus position
Grasp ankles bilaterally, with thumbs Inferior to medial malleolus on each side
Make sure lower extremities are lying straight
Assess relative levelness of medial malleolus (superior/inferior)
Record position of Side of Lateralization

68. ASIS Levelness

69. Pubic Tubercle Levelness

70. ASIS Compression Test
Have the patient lie supine. The patient is then asked to raise his/her bottom up off the table and then set it back down again.
Doctor Stands with head and shoulders centered over the patient.
Contact the ASIS
Stabilize one ASIS while applying pressure at a 45 degree angle to the other ASIS
Positive test - restricted movement of the Sacroiliac joint -> rock like motion
Negative test - a sense of give or resilience => bounce or spring like motion
*This is done to help them center their weight on the table.
**(this is to help eliminate the effects of eye and hand dominance)

71. SLR (hamstring tension)

72. Setting the Pelvis (Prone)

73. Quad tension and Psoas tension

74. PSIS

75. Ischial Tuberosity Gluteal curve- where thigh joins gluteus muscle.
Palms approximately 4” apart.
Push superiorly, slightly laterally until you run into a very firm bone (ischial tuberosity).
Is the ischial tuberosity superior or inferior on the lateralized side?

76. Lumbosacral Spring Test
Patient Prone
Physician at Side of Table
Place Heel of Hand over Lumbosacral Junction (L5-S1)
Keep arms straight, and lean with body
Spring Several Times –
Negative Test is a Mobility to Springing (motion is felt at joint)
Positive Test is Restriction to Anterior Springing

77. Decreased Sacral Base Asymmetry indicates a Negative Test
SPHINX TEST
Decreased Sacral Base Asymmetry indicates a Negative Test
Increased Sacral Base Asymmetry indicates a Positive Test

78. Sacral Motion Testing Motion testing over the 4 Corners of the Sacrum
Place thumb on the right sacral base. Keep arms extended. Spring anteriorly
Place thumb on the left sacral base. Keep arms extended. Spring anteriorly
Place thumb on the right ILA. Keep arms extended. Spring anteriorly
Place thumb on the left ILA. Keep arms extended. Spring anteriorly
Record (+), (-), or (+/-).
+ means a sense of resiliency, springs back
- means little to no motion, bricklike
+/- means some motion
Record your findings on your Sacral Motion Testing Worksheet.

79. Make Your Diagnosis of Somatic Dysfunction
Psoas/Hamstring
Femoroacetabular
Innominate
Sacrum
Lumbar
Thoracic
Short Leg Syndrome?
Functional
Anatomic

80. Effects of Short Leg Pelvis side shifts and rotates toward long leg
Innominate rotates anterior on side of short leg or posterior on side of long leg
Foot of long leg pronates, internally rotating lower leg
Lumbosacral angle increases by 2 to 3 degrees
Compensatory curves are generally type 1 neutral.

81. Scoliosis and Lateral Curves
Treatment Section

82. OMT for Scoliosis - Overview
Treat sacral and innominate dysfunction.
Assess for anatomic leg length difference.
Thoracic and lumbar type 2 dysfunctions
Thoracic and Lumbar treatment of type 1 group curves.
Long restrictor muscle stretch for side of concavity (Hypertonic m. stretching)
Postural exercises for retraining
Possible heel lift for anatomical short leg.

83. Application of Heel Lifts
Pre-OMT
Application of Heel Lifts

84. Exaggerate the lateral curves
Add 1/8 inch lift under the heel of the side with the high iliac crest
Observe what happened
Did the asymmetry increase ?
Did the compensatory curves change ?
Add ¼ inch lift and repeat observations.

85. Use lifts to level the iliac crests and sacral base
Place lifts under the heel of the side with the low iliac crest, place enough lift to level iliac crest.
Observe what happened
Did the asymmetry increase ?
Did the compensatory curves change ?
Observe what happened to the primary and secondary curves

86. OMT Part One: Innominate / Hip

87. Hamstring Stretch – For Shortened Hip Extensors, 4613.11A

88. Iliopsoas Stretch

93. Muscle energy for posterior innominate technique

94. Muscle energy technique for anterior innominate technique

95. OMT Part Two: Lumbo-Sacral

99. For Non-Neutral Dys.

101. Lumbar HVLA – for Neutral Dys.
11. A high velocity, low amplitude thrust is applied antero-superiorly to the pelvis while providing counterforce through the patient's shoulder
12. Recheck
Dx: L3-5NSlRr

106. KIM 213A

107. TX: Unilateral Sacral Flexion (Sacral Shear) DX: Left unilateral sacral flexion
KIM 213A

108. KIM 216A

109. Recheck Symmetry

110. Repeat the standing postural examination on your partner
Did your findings change?
What changed
Is your partner a candidate to be evaluated for possible lift therapy?

111. Use lifts to level the iliac crests and sacral base
Place lifts under the heel of the side with the low iliac crest. Place enough lift to level the iliac crests.
Observe what happened
Did the asymmetry decrease?
Did the compensatory curves change?

112. What is next?
Does your partner still have a low iliac crest on standing, after OMT?
Did you successfully treat all the somatic dysfunctions that could be contributing to the high/low iliac crest/sacral base?
Is it an acute or chronic problem? (recent lower extremity surgery, or long term?)
Is further work-up for short leg indicated?

113. Sources
Steinberg, Akins, Baran, Orthopaedics in Primary Care, 3rd ed., LWW, Philadelphia, 1998, Pg
Kuchera and Kuchera, Osteopathic Principles in Practice, 2nd ed., revised. Greyden Press, Columbus, Ohio, 1994.
Ward, editor, Foundations for Osteopathic Medicine., 2nd ed., LWW, Philadelphia, PA 2003
Chila, Foundations for Osteopathic Medicine, 3rd Ed., 3rd ed., LWW, Philadelphia, PA 2010, pg
The Muscle Energy Manual, Mitchell, Fred L., Volume 3, pg
An Osteopathic Approach to Diagnosis and Treatment, DiGiovanna, pp
Kimberly, P., Outline of Osteopathic Manipulative Procedures, “The Kimberly Manual”, 2006 ed., (2008 update), Walsworth Pub Co, Marceline, MO., 2008.