Stacks Image 382
Stacks Image 219

THE RESEARCH
Research indicates orthotic insoles produce only small, unpredictable, and subject specific changes in foot posture and joint motion [1,2], and that the height of the medial longitudinal arch is a poor indicator of how the foot functions, i.e. how it reacts to vertical ground reaction forces (GRF) and is probably a pathomechanically insignificant metric. [3-7]
A number of recent studies suggest the symptom-relieving benefits of orthotic insoles may be primarily due to kinetic rather than kinematic changes in lower-limb function [8-10], i.e., orthotic insoles alter the magnitude, direction, and temporal patterns of GRF (external moments) on the plantar surface of the foot, which in turn alters the tensile and compressive forces acting upon the osseous and soft-tissue structures of the musculoskeletal system [8-10], and modulates the temporal activity of major muscle groups.

GROUND REACTION FORCE (GRF)
GRF is a vector composed of vertical force, anterior-posterior shear, and medial and lateral shear. It has been postulated that only three orthotic design variables can alter the components of GRF:

1 The top-surface geometry,
2 The load-deformation or stiffness of the shell, and
2 The frictional characteristics of the top surface of the device. [12]
Stacks Image 211

THE SPENCO MEDICS™ PARADIGM
While all orthotic insoles with a heel cup and a degree of arch support will produce small and unpredictable kinematic changes in some wearers some of the time, they are likely to produce a greater kinetic effect in all wearers all of the time. When prescribing orthotic insoles as part of a comprehensive treatment program for lower-limb pathology, perhaps more than motion control, clinicians should consider how changing the magnitude and direction of GRF at the foot-orthosis interface may modulate the tensile and/or compressive forces acting upon the injured structure. For example, if an excessive pronation force is causing the tibialis posterior tendon to function outside its zone of optimal stress (ZOOS) as the etiology of tendinitis, and orthotic insole designed to increase the supination moments (reduce the pronation moments) should be dispensed without too much emphasis being placed on achieving a change in foot posture. This orthotic prescription method has been called the Tissue Stress Theory or Paradigm. [13]

“Orthoses do not need to change kinematics to reduce pain.” [14]

Stacks Image 319
• Spenco's tried and tested-for-comfort TOTAL SUPPORT® top surface contour incorporates a deep heel cup, medial arch support, lateral arch support, metatarsal dome and a first metatarsal head cut-out with a soft-spot; in a choice of stiffness and style, based on the patient's body weight and activity level.

• A low-friction top cover helps reduce the magnitude of the Fx and Fz components of GRF. Silpure Antimicrobial helps reduce odor.

• 3-Pod™ GRF Technology with hook-and-loop replaceable pods of different densities to modulate GRF based on the clinician's appreciation of the kinetic aetiology (the excessive forces) responsible for the chief complaint.
Stacks Image 333
Stacks Image 325
Stacks Image 335
Stacks Image 339
Spenco Medics™ Preformed Professional Orthotics are available in four configurations: "Sport" with a blue, high-performance technical top cover and "Dress" with a leather-style brown top cover to complement most dress shoes. Both Sport and Dress are available in Full-Length and 3/4-Length for low-volume or tighter-fitting shoes. Spenco Medics™ Diabetic + Insoles come in Full-length only with non-replaceable heel and forefoot cushioning zones. Spenco Medics™ Diabetic+ Insole features a Plastazote® top cover to reduce friction an cushion the sensitive diabetic foot.
Stacks Image 366

Remove pods completely to increase the GRF modulation prescription options.
3-Pod™ GRF Technology puts Spenco Medics™ Orthotic Insoles miles ahead of every other professional preformed orthotic device—well ahead of the paradigm curve.

Think force as well as motion, and then choose Spenco Medics™ Orthotic Insoles with 3-Pod™ GRF Technology for your patients.

For more information contact Spenco at 1-800-877-3626 or visit spencodirect.com to order

Stacks Image 380
References
1. Nigg BM, Khan A, Fisher V, Stefanyshyn D:
Effect of shoe insert construction on foot and leg movement. Sci Sports Med Exerc. 1998 Apr;30(4):550-5).
2. Stacoff A, Reinschmidt C, Nigg BM, van den Bogert AJ, Lundberg A, Denoth J, Stüssi E.:
Effect of foot orthoses on skeletal motion during running, Clin Biomech (Bristol, Avon), 2000 Jan;15(1):54-64 .
3. Nigg BM, Cole GK, Nachbauer, W:
Effects of arch height of the foot on angular motion of the lower extremities in running,. J. Biomechanics, 1993, Aug;26(8):909-16.
4. Cashmere T, Smith R, Hunt R:
Medial longitudinal arch of the foot: stationary versus walking measures. Foot Ankle Int. 1999 Feb:20(2):112-8.
5. Hededus EJ, Cook C, Fiander C, Wright A:
Measures of arch height and their relationship to pain and dysfunction in people with lower limb impairments. Physiother Res Int. 2010 Sep;15(3):160-6. doi: 10.1002/pri.459.
6. Nakhaee Z, Rahimi A, Abaee M, Rezasoltani A, Kalantari:
The relationship between the height of the medial longitudinal arch (MLA) and the ankle and knee injuries in professional runners. Foot (Edinb) 2008 Jun; 18(2): 84-90. doi: 10.1016/j.foot 2008.01.04. Epub 2008 Mar 18.
7. LLahi, OA, Hohl, HW 3rd:
Lower extremity morphology and alignment and risk of overuse injury. Clin. J Sports Med. 1998 Jan:(8)1: 38-42.
8. Williams DS, McClay DI, Baitch SP:
Effect of inverted orthoses on lower-extremity mechanics in runners. Med Sci Sports Exerc. 2003, Dec;35(12):2060-8.
9. Kirby KA, Green DR:
Evaluation and Nonoperative Management of Pes Valgus, pp. 295–327. In DeValentine S.(ed.), Foot and Ankle Disorders in Children. Churchill-Livingstone,New York, 1992.
10. Kirby KA:
Foot and Lower Extremity Biomechanics II: Precision Intricast Newsletters, 1997–2002. Precision Intricast, Inc., Payson, AZ, 2002.
11. Dedieu P, Drigeard C, Gjini L, Dal Maso, F, Zanone PG:
Effects of foot orthoses on the temporal pattern of muscular activity during walking. Clin Biomech (Bristol, Avon) 2013 Aug;28(7):820-4.
12. Anthony, RJ:
Spenco Total Support Insoles: A Step Ahead of the Paradigm Shift. Spenco Spotlight, Newsletter, October, 2013. http://www.multibriefs.com/briefs/cb-spenco/paradigm2.pdf.
1.  Fuller EA, Kirby KA.:
Subtalar joint equilibrium and tissue stress approach to biomechanical therapy of the foot and lower extremity. In Albert SF, Curran SA (ed.): Biomechanics of the Lower Extremity: Theory and Practice, Volume 1.  Bipedmed, LLC, Denver, 2013, pp. 205-264.
2. Anthony, RJ:
Should "arch support" be the primary objective in the treatment of pronated feet? Spenco Spotlight, Newsletter, March 2014. https://www.spenco.com/article.aspx?rid=181&ProdId=0&CatId=186&cid=
3. Spooner SK, Smith DK, Kirby KA:
In-shoe pressure measurement and foot orthosis research: a giant leap forward or a step too far? J Am Podiatr med Assoc. 2010 Nov-Dec;100(6):518-29
4. Griffiths I:
The myths of foot orthoses The Sports Physio, 2013, Sept 29. https://thesportsphysio.wordpress.com/2013/09/29/the-myths-of-foot-orthoses-a-guest-article-by-ian-griffiths/
® Registered and ™ Trademark of Spenco Medical Corporation © Copyright 2015. All Rights Reserved. Silpure is a Registered Trademark of Thomson Research Associates, Inc. Plastazote is a registered trademark of Zotefoams, Inc.