1. Common Orthotics
Thomas Howard, MD
2010

2. Objectives Define Orthotics Discuss Common Orthotics
Focus on Foot Orthotics
Explain importance of Subtalar Joint
Review biomechanics of the foot- normal and pathologic
Review functional theories of foot orthotics
Assess foot orthotics role in the prevention and treatment of injury

3. What is an Orthotic??
Definition: An orthopedic appliance/device designed to correct, straighten or support a body part

4. How do they work?? Prevent abnormal motion or movement?
Change mechanics?
Proprioception?

5. Elbow
Tennis Elbow

6. Wrist
Cock-up splint
TSS
Carpal tunnel brace

7. Finger
Stax splint
Dorsal PIP splint

8. Back TLSO Milwaukee brace Lumbar Corset Hyperextension Brace
Cervical collar

9. Knee ACL/de-rotation brace MCL brace Knee sleeve Cho-pat strap
Single and dual strap

10. Ankle Stirrup brace Lace-up brace Tri-loc AFO Night splint
Short and long
Lace-up brace
?figure-eight strap
Tri-loc
AFO
Night splint

11. Foot
Met Pad
Bunion brace
Hammer toe brace
PSC
Arch Brace

12. Foot Orthotic Basics

13. What is a Foot Orthotic??
Device used to accommodate foot deformity or pressure lesions, cushion the foot, alter sensory input, or realign foot posture

14. Terminology Arch support Medial/lateral wedge Heel wedge
Insole
Heel wedge
Metatarsal pad

15. Terminology

16. Types of Orthotics Prefabricated OTC Advantage Disadvantage
Dr. Scholls, Spenco, Hapad
Advantage
Cheap
Convenient
Effective
Disadvantage
Mass produced
Nonspecific arch contour
Fails to address positional/structural deformities and compensations

17. Types of Orthotics Biomechanical or Custom Advantage Disadvantage
Address the source of compensation
Slow rate/extent of deformity
Disadvantage
Cost
Experience of provider
May not help

18. Accomodative Orthotics
Fit in shoe to stabilize foot deformity
Allows foot to compensate
Transfer weight from painful area
Improves shock absorption
Control ground reactive forces around a specific location
Example: Diabetic foot, Neuropathy, PVD, congenital malformations

19. Functional or Corrected Orthotic
Addresses patho-mechanical components of the lower extremity/foot/ankle condition
Resists abnormal compensation
Prevent pain during ambulation
Prevent pathologic ROM
Example: athletes, pes planus, pes cavus

20. Custom: Stiffness Rigid (pes planus) control foot function
provide stability
firm material
Semi-rigid (athletes)
dynamic balance of foot
layers of soft/rigid laterial
Soft (pes cavus)
absorb shock
improve balance
remove pressure
compressible material

22. Materials Thermoplastic/Polypropylene EVA (Ethyl vinyl acetate)
Carbon Fiber
Polyethylene Foam (“Plastazote”)
Cellular Urethane (“Poron”)
Graphite

23. Indications Support and correct intrinsic deformities
Decrease frequency of lower limb injuries
Control ROM
Improve sensory feedback / proprioception/neuromuscular responses
Dissipate pathologic ground reaction forces and improve shock absorption
Improve LE biomechanics

24. Evaluation Chief complaint Assess mobility (hypo, hyper)
Type of orthotic needed (dress, athletic, street)
Rigidity
Material

25. Evaluation Assess ROM, positioning Test lower quadrant muscle strength
Static stance position and toe rise
Leg length measurement
Gait analysis
Assess position & motion of spine hip/pelvis, knee, lesser metatarsals

26. How are they made??
Casting
Impressions
Gait/Balance Analysis

27. Modifications Metatarsal (MT) head cut-out Heel cushioning
MT cut-out
Modifications
Metatarsal (MT) head cut-out
Heel cushioning
Metatarsal pads
Morton’s extension
Rigid forefoot extension
Morton’s extension
Pad
Heel cushioning

28. How are they made?? No matter which method is done…..
Subtalar Joint must be in neutral position

29. Subtalar Joint
Anatomy:
-Talus
(superior)
-Calcaneus (inferior)

30. Subtalar Joint Oblique orientation Allows for pronation and supination
Motion is tri-planar
Affects motion/flexibility of midtarsal joint and tibia
Controls plantar surface pressure and contact with the ground during gait

31. SubTalar Joint Oblique axis: -23 degrees from long axis of foot
horizontal plane

32. Subtalar Joint Motion is tri-planar Pronation Supination
Eversion, abduction, dorsiflexion
Supination
Inversion, adduction, plantarflexion

33. Midtarsal Joint Calcaneocuboid Talonavicular Motion at STJ
Passes from talus/ calcaneus to navicular and cuboid
Affects flexibility or stiffness of foot

34. Tibial Rotation Torque developed by foot movement transmits proximally
1:1 relationship between degree of
Supination and tibial external rotation
Pronation and tibial internal rotation

35. Gait Biomechanics

36. Gait Cycle (walk) Heel Strike (0-15%):pronate
Stance/foot flat (15-30%): pronate to supinate
Push/toe off (30-45%): supinate
Swing (45-60%): supinate to pronate

37. Subtalar Joint Motion

38. Heel Strike Internal rotation of tibia Inversion of STJ
Eversion of calcaneus

39. Gait Biomechanics Heel Strike: Eversion of calcaneus
Alignment of mid-tarsal joints (parallel)
Allow increased motion/flexible foot
Absorb shock/accomodate

40. Heel Strike: Pronation

41. Stance Phase
Pronated position holds through 1st 15% of stance; then supination begins
External rotation of tibia
Eversion of STJ
Inversion of calcaneus

42. Gait Biomechanics Mid-Stance: Inversion of calcaneus
Midtarsal joint axis not parallel
Foot becomes more rigid
Increased stability

43. Stance toe-off: Supination

44. Abnormal Pronation Add 6° eversion to calcaneal ROM (nl=20°)
Increase ground reaction forces along medial chain
Excess internal rotation of tibia
Muscles work harder to keep balance
Decrease stability during propulsion

45. Abnormal Supination Add >12° of calcaneal inversion (nl=10°)
Increased forces along lateral chain
Hypomobility in subtalar joint
Decreased shock-absorbing capability
Decreased stability at heel strike

46. Subtalar Joint and Orthotics
Position of STJ affects position and function of entire foot
Neutral STJ is the point in the stance phase of gait where joint is not compensated

47. Subtalar Joint (STJ) and Orthotics
If capture pronated/supinated (compensated) foot for molding orthotic, get contour that reflects and facilitates compensated position
Want orthotic to control STJ motion before it compensates to allow optimal function of joints/muscles

48. Clinical significance???
Do abnormal properties of gait lead to clinical pathology??
Do orthotics change biomechanics of gait??
If so, have they been proven to prevent injuries??

49. Messier SP, Pittala KA. MSSE: Oct 1988;20(5):501-5
Retrospective study
Relationship between biomechanical variables and injury (ITB, shin splints, plantar fasciitis)
Results:
-Nonsignificant increase in
over-pronation and high arches in injury group

50. Willems TM, et al. Gait & Posture 23 (2006):91-98
Prospective study in freshmen athletes in Belgium
Risk factors for exercise-related lower leg pain (ERLLP)
Gait examined and injuries logged
Results
Overpronation associated with increased incidence of ERLLP

51. Kaufman KR, Brodine SK, et al. Am J Sports Med. 1999;27(5):585-93
Prospective study on Navy Seals
Biomechanics measured prior to training and injuries logged over 2 years
Results:
-Pes planus & cavus had 2X incidence of stress fracture compared to normal arch

52. Simkin A., et al. Foot Ankle. 1989;10(1):25
Prospective study of military recruits
Arches measured and incidence of stress fractures recorded
Femoral/tibial stress fractures higher with high arches
Metatarsal stress fractures higher in low arches

53. Increased risk of Stress Fracture/Overuse injury with Pes Cavus
Cowan, D., etal. MSSE 1989; 21: S60.
McKenzie, D., et al. Sports Med. 1985;2: 334.
Messier, S. P, et al. MSSE. 1988; 20: 501.
Warren, B. L, et al. MSSE. 1987; 19: 71.
Rodgers MM. Phys Ther. 1988; 68: 1822.
Chan CW. Mayo Clin Proc. 1994; 69: 448.

54. How do orthotics work??
Foot orthoses are generally believed to align the skeleton and to reduce the loading of biological structures in the lower extremities
…but is there evidence??

55. Mundermann, Nigg, et al. Clin Biomech. 2003; 18: 254
Effects of posting and custom-molding of foot orthotics on lower extremity kinematics
Results
Molding reduced maximum tibia rotation, foot inversion, and foot inversion velocity
Molding also reduced magnitude of vertical impact force
Results similar by adding medial post

56. Eng JJ, Pierrynowski MR. Phys Ther. 1994;74:836.
Effect of custom foot orthotics on subtalar joint and knee joint during walking and running
Adolescent females with PFPS and measured forefoot varus +/- calcaneal valgus >6°
Results
Subtalar joint rotation reduced 1 to 3 ° with orthotics
Knee motion reduced in frontal plane during walking, not running

57. Nester CJ, et al. Gait Posture. 2003; 17: 180.
Assess the effect of medially and laterally wedged foot orthotics on joint movements
Healthy subjects
Results
Medial wedge
Decreased rearfoot pronation
Increased lateral ground reaction force
Lateral wedge
Increased rearfoot pronation
Decreased lateral ground reaction force

58. MacLean C, et al. Clin Biomech. 2006 (in press).
Evaluate influence of custom foot orthotics on kinematics in runners
Healthy runners (normal eversion angles)
Results
Statistically significant reduction in rearfoot eversion angle in initial stance
No significant findings at knee joint

59. Stacoff A., et al. Clin Biomech. 2000; 15: 54.
Effects of medial foot orthotics on skeletal movements in running
Healthy male subjects (no overpronators)
Results:
-No change in eversion or tibial rotation with orthotics

60. Ferber R, et al. J Biomech. 2005; 38: 477.
Compare joint-coupling patterns (eversion/tibial internal rotation) with/without orthotics during running
11 overpronators measured
Results
No difference observed in treated group

61. Can orthotics help prevent and/or treat injury????

62. Rome K, et al. Cochrane Database Syst Rev. 2005; Issue 2.
Evaluated evidence from 10 randomized controlled trials of interventions for prevention of stress fractures
All trials involved military recruits and “shock-absorbing” inserts
Results
4 trials showed decrease in stress injuries
Evidence not consistent on particular design
Comfort very important

63. Gross ML et al. Am J Sports Med. 1991;19:409.
Questionnaire to runners wearing orthotics for various lower extremity complaints
Predominant insert type was flexible
Results
75.5% found improvement in their condition since wearing orthotic
90% continued to wear them after symptom resolution

64. Johnston LB, Gross MT. J Orthop Sports Phys Ther. 2004;34:440.
Effect of foot orthotics on quality of life in those with PFPS who demonstrate excessive pronation
3 month intervention with orthotics
Results
Significant decreases in pain/stiffness after only 2 weeks compared to pretreatment evaluation

65. COLLINS, ETAL. BJM :a1735
Compare PT, flat inserts or custom orthotics
52 wks all similar improvement

66. Others… James S., et al. Am J Sp Med. 1978; 6: 40.
78% with knee pain returned to running with orthotic use.
D’Ambrosia, et al. Clin Sports Med. 1985; 4: 611
Custom orthotics reduce frequency of running injuries.
Donatelli R., et al. J Orthop. Sports Phys. Ther. 1988; 10: 205
Survey showed 96% had pain relief from orthotics in treating tibial, knee, and ankle pain
70% able to return to activity

67. Take home points…
Foot orthotics come in all shapes/sizes and are used for a variety of conditions
When writing prescriptions:
-Know your foot type and activity level
-Identify trouble spots (for pads, wedges, etc…)
Subtalar joint is an important factor in understanding gait biomechanics and keeping in neutral controls compensation

68. Take home points…
Abnormal biomechanics are proven to increase risk for injury
Still debate over how orthotics actually work
Still work to be done on effectiveness…but comfort is key!!!