A Clinical View

David G. Wedemeyer DC, C.Ped.
Contributing Author

Plantar Fasciitis is the most common cause of heel and medial arch pain. It affects approximately 10% of the population over their lifetime and appears to affect men and women equally.

Studies show that the single greatest risk factor for development of plantar fasciitis is limited ankle dorsiflexion range of motion¹.

Other factors in the onset of plantar fasciitis include obesity and sudden weight gain, work-related weight-bearing activity, sudden increase in activity levels or specific activities (especially those that place a great deal of stress on the Achilles tendon), improper footwear and faulty foot biomechanics. In this article I will focus on the latter, bearing in mind that all of the above factors should be addressed in your history, examination and treatment program.

Acute plantar fasciitis is typically an overuse injury that produces microtrauma resulting in pain and inflammation. Current studies provide a conflict though as to whether or not this is a purely inflammatory condition noting degenerative changes in chronic cases². Chronic plantar fasciitis is now being more appropriately referred to as plantar fasciosis, which exhibits degeneration of the fascia on imaging and ultrasonography studies.

We will focus on the acute patient with plantar fasciitis, which I believe is inflammatory early and that commonly accepted interventions are very beneficial. Plantar fasciitis is often a self-limiting condition where early recognition and conservative care typically produces excellent outcomes.

Anatomy: The plantar fascia originates at the medial calcaneal tubercle and inserts into the plantar plates of the metatarsophalangeal joints and bases of the proximal phalanges. It can be divided into three parts; a medial, middle and lateral band

Function: The plantar fascia serves to support the foot and provide an energy return vehicle to produce propulsion via the windlass mechanism

History: First-step morning heel pain is pathognomonic for plantar fasciitis. The pain is typically felt at the anterior border of the calcaneus and can often be reproduced by applying digital pressure into the origin at the medial calcaneal tubercle. Often medial longitudinal arch tenderness will also be present.

Examination: The first consideration should be palpation to attempt to reproduce the presenting complaint, location of symptoms and correlation with the patient history.

Visual inspection of the foot structures should follow, observing any patterns of callus formation, digital alignment and clawing or hammering of the toes. A short first metatarsal (Morton’s Toe) is often implicated. Genu and tibial varum and valgum should be evaluated and noted as well. The relative arch height off weight-bearing should be compared to single limb stance in full weight-bearing.

Passive ankle dorsiflexion should be 10 degrees with the knee extended if it is not, equinus is probably contributory. First metatarsophalangeal dorsiflexion should be 40 degrees passively and if it is not Funcitonal Hallux Limitus and disruption of the windlass mechanism is a consideration in treatment. http://www.wheelessonline.com/ortho/windlass_mechanism

An appropriate biomechanical examination will always include gait analysis and can be very telling when patients present with plantar fasciitis due to biomechanical deficit. Because the etiology of plantar fasciitis is multi-factorial, expansive exploration of all biomechanical possibilities is beyond the scope of this article. We will go into more detail in training modules but specifically excessive pronation; a diminution of the medial longitudinal arch due to inherent midfoot flexibility and true acquired flatfoot (pes planus) should be considered as causative. Disruptions in the windlass mechanism become more apparent with practice and observation; supinatory rock, rapid heel abduction at toe-off, early heel lift-off etc. are all features of pathologic gait that contribute to the biomechanical deficits that cause tissue stress and ultimately lead to plantar fasciitis.

Both low arched and high arched feet have been implicated in the onset of plantar fasciitis so it is equally important to evaluate both the rigid, high-arched foot (cavus) as well as the flexible high-arched (the latter is uniquely problematic due to forefoot compensation of heel varus (the Coleman Block test is confirmatory).

Differential Diagnoses: The differential diagnoses of plantar fasciitis are myriad and include:

1. Neurologic: Lumbar radiculopathy, medical calcaneal and plantar nerve entrapment and tarsal tunnel syndrome.

2. Soft Tissue: Subcalcaneal bursitis, Achilles tendinopathy and fat pad atrophy.

3. Skeletal: Calcaneal stress fracture and apophysitis, Haglund’s deformity and bone bruising.

4. Systemic: Less frequently reactive spondyloarthropathy should be ruled out; Reiter’s syndrome, Ankylosing Spondylitis, and psoriatic arthritis, rheumatic conditions such as rheumatoid arthritis and Lyme disease (especially in atypical plantar fasciitis).

Imaging Studies:

Often there is a visible heel spur found on the calcaneus at the site of the origin of the plantar fascia on plain. This is a finding of a traction spur that develops in response to constant tensioning of the fascia. It is not the cause of the patient’s pain however, in fact it is very rarely causative nor does it require treatment.

As previously noted, in refractory heel pain an MRI may elicit thickening of the fascia consistent with a degenerative process.

Treatment:

1. Inflammation: Due to the inflammatory component of acute plantar fasciitis (chronic plantar fasciitis is thought to be a non-inflammatory, degenerative process termed fasciosis), one of the primary goals of treatment should be to reduce inflammation: A natural anti-inflammatory supplement and/or a NSAID’s and icing should be enacted immediately. A local steroid injection should also be considered when the condition is severe or more conservative anti-inflammatory methods are not effective. I realize that as Doctors of Chiropractic, many within our ranks will be averse to referring a patient for steroid injection. I urge you to consider that in many cases it will produce immediate benefit and its limited use is appropriate for this condition.

2. Orthotic support: There is solid research to support the role of both pre-molded and custom foot orthoses (CFO’s) being beneficial in treating plantar fasciitis. One study reports success as high as a 75% reduction in disability rating and a 66% reduction in pain rating with the use of foot orthoses³. There are studies however that report that specifically in relation to acute plantar fasciitis that quality pre-molded orthotics may provide equal benefit to CFO’s (custom foot orthoses)⁴. The point is that orthotic support does benefit greatly a total program of care for the treatment of acute plantar fasciitis and knowing which is more appropriate will set you apart from your colleagues. CFO’s provide a level of function specific change that no pre-molded device can, obviously. Often once a patient’s plantar fasciitis has resolved with a pre-molded orthotic and ancillary care, the rationale to prevent recurrence with a CFO becomes very apparent, especially to the patient.

3. Passive stretching: A home care stretching program should immediately be initiated off weight-bearing, especially in those with ankle equinus. Short foot exercises have recently shown in studies to be beneficial.

4. Footwear modification: Appropriate and supportive footwear is very helpful in treating plantar fasciitis. Shoes of the correct size, fit and flex point at the ball of the foot and those that possess a supportive shank in the midfoot. This is also paramount to success with pre-molded and custom foot orthoses.

5. Low-dye taping: Low-dye taping can prove very beneficial by and supporting the plantar arch and therefore significantly reducing microtrauma. If a patient feels immediate improvement in their condition weight-bearing with low-dye taping, this provides a rationale for orthotic intervention in my office. They can also continue to use this method during waking hours when they are shod, typically performing activities of daily living.

6. Weight modification: Any patient with a BMI > 30 should be afforded a weight management program. Reducing weight reduces the magnitude of forces on the feet.

7. Manipulation: Chiropractic manipulation can be an effective part of the total treatment of the acute plantar fasciitis patient. It’s efficacy in the literature is sparse but clinically I have witnessed dramatic results in pain reduction post-manipulation.

8. Manual Therapy: Cross-friction massage of the medial plantar fascia and origin at the calcaneus is highly beneficial in aiding new collagen formation and reducing pain. Manual soft-tissue techniques such as ART and instrument assisted techniques such as Graston and IASTM are beneficial as adjuncts.

9. Modalities: I have found subaqueous ultrasound with common Epsom salts very beneficial in symptom reduction of plantar fasciitis. Additionally phonophoresis of NSAID’s and dexamethasone (prescription) provide benefit, as does Interferential current.

Specific orthotic shell modifications which reduce medial plantar fascial load are beyond the scope of this article and will be discussed in future training modules. Solelutions Orthotic Lab clients enjoy direct access to Dr. Wedemeyer in discussing cases and receive individualized support..

Hopefully this article has given you some insight into a very common foot malady, plantar fasciitis. This condition is highly manageable within your office and our orthotic devices, along with simple home care and physiologic therapeutics, will aid you in helping your patients with condition specific reduction in pain and disability and resolution of their symptoms.

References:

1. Risk factors for Plantar fasciitis: a matched case-control study. Riddle DL, Pulisic M, Pidcoe P, Johnson RE. J Bone Joint Surg Am. 2003 May;85-A(5):872-7.

2. The Pathomechanics of Plantar Fasciitis. Wearing, Scott; Smeathers, James; Urry, Stephen; Hennig, Ewald; Hills, Andrew P. Sports Medicine, Volume 36, Number 7, 2006 , pp. 585-611(27)

3. The impact of custom semi-rigid foot orthotics on pain and disability for individuals with plantar fasciitis. Gross MT, Byers JM, Krafft JL, Lackey EJ, Melton KM: J Ortho Sp Phys Ther, 32:149-157, 2002.

4. Effectiveness of Different Types of Foot Orthoses for the Treatment of Plantar Fasciitis. Landorf KB, Keenan A, Herbert RD. J Am Podiatr Med Assoc 94(6): 542–549, 2004.