Plantar Fasciitis - Evidence for practice

By Bodhi Haraldsson, RMT
Originally published in Massage Matters Winter 2007
(http://www.massagetherapy.bc.ca/general/links/magazine_subscription)


Anatomy

The plantar fascia is comprised primarily of a substantial central longitudinal
component, the plantar aponeurosis, as well as medial and lateral components.[1]
The central aponeurotic band is considered the most significant, both structurally and functionally.[2]

The thick central portion is narrowest at its origin at the anteromedial process of the calcaneal tuberosity. The fascia broadens and thins as it traverses the arch of the foot and, distally, divides near the metatarsal heads into five digital slips, one for each toe. [1]

The fascia assists in the maintenance of the foot arch and keeps the foot in relative supination through the push-off phase of ambulation. This is illustrated by the ‘‘windlass’’ mechanism; during static stance, plantarflexion of the metatarsals is resisted by ground reaction force and elevation of the arch is achieved by the complex movement of supination and external rotation of the foot and lower limb.[2,3]


Epidemiology

Plantar fasciitis is the most common cause of chronic plantar heel pain (CPHP), these terms are used interchangeably in the literature [4]
Chronic plantar heel pain is a common condition which is estimated to affect 10% of runners, and to occur in a similar proportion of the general population over 40. It accounts for 15% of reported foot complaints. CPHP does not seem to be gender specific [5,4]
Plantar fasciitis is one of the most commonly diagnosed running soft-tissue injuries. These injuries tend to have a peak period in the first two weeks or with change in volume of training [6]

Pathology

Little is known of the underlying disease process or the clinical course of the condition.
Although often eventually self-limiting in untreated individuals, it can be a source of morbidity over several months and occasionally, in the worst instances, years. [5]

Individuals with pes cavus frequently report foot pain, complaints reported in the literature include forefoot metatarsal pain and plantar heel pain [7]

There is a general consensus within the literature that mechanical overload and excessive strain produce microscopic tears within the fascia. The mechanism underlying the development of plantar fasciitis may be related to advanced fascial degeneration (collagen degeneration), and more akin to that of tendinosis (tendon degeneration) than that of tendinitis or inflammation. Alternative mechanisms including ‘stress-shielding’, vascular and metabolic disturbances, the formation of free radicals, hyperthermia and genetic factors have also been linked to degenerative change in connective tissues. [2]
Plantar, or inferior, heel pain may have traumatic, vascular, neurologic, arthritic, infectious, autoimmune, or mechanical causes. The term plantar fasciitis is often used interchangeably with these various causes of heel pain. [1]



Risk Factors
Irving et al in their systematic review of factors associated with CPHP noted that: Increased body mass index is strongly associated with CPHP in a non-athletic population, Calcaneal spur is associated with CPHP but is likely to be part of the spectrum of pathology rather than risk factor, 45% of patients with plantar fasciitis and 20% of non affected population have calcaneal spurs in radiographic studies.
Limited ankle dorsiflexion; leg length discrepancy; pes planus; limited toe range of motion; foot wear all have limited or absent evidence for association to CPHP risk factors due to low quality of evidence. [4]


Diagnosis

The clinical features are pain and tenderness under the medial heel on weight bearing, with associated limitation of activity. CPHP can be bilateral in up to third of cases. Typically, this pain is worst first thing in the morning and upon initiation of ambulation. [1,5,4,8] The potential role, if any, of imaging studies in guiding treatment, monitoring the course of the disorder, or both has yet to be clarified; currently, imaging techniques have little role in routine clinical practice. [8]


Differential Diagnosis
Heel pain can also be associated with other conditions such as: Rheumatoid arthritis, ankylosing spondylitis, Reiter syndrome, and other seronegative arthropathies. These diagnoses must be entertained in the appropriate age group and gender, especially when the pain is bilateral.
Nerve entrapment syndromes, the diagnosis of isolated nerve entrapment is made on clinical characteristics. Heel spurs, calcaneal bursitis, inappropriate shoe wear, and fat pad atrophy are other potential causes of heel pain. [1]


Treatment
The effectiveness of frequently employed treatments in altering the clinical course of plantar heel pain has not been established in randomised controlled trials.
At the moment there is limited evidence upon which to base clinical practice. Treatments that are used to reduce heel pain seem to bring only marginal gains over no treatment and control therapies such as stretching exercises.
Steroid injections are a popular method of treating the condition but only seem to be useful in the short term and only to a small degree.
Orthoses should be cautiously prescribed for those patients who stand for long periods; there is limited evidence that general stretching exercises and heel pads are associated with better outcomes than custom made orthosis in people who stand for more than eight hours per day. [5]

The effectiveness of general stretching exercises and of insoles and footwear modification in the prevention of lower extremity soft tissue injuries associated with running is unknown.
Controlling the intensity of running (distance, frequency and duration) may be effective in the prevention of lower extremity soft tissue injuries associated with running. [6]


Al-though there is some anecdotal evidence for widely proposed massage therapy treatments [Rattray F] and they have reputedly provided some level of relief, the final outcome, as well as the financial and personal burden imposed by each treatment, must be considered when choosing treatment modality and length of treatment.

Since there is limited evidence about the value of treatments for plantar fasciitis, a reasonable approach to intervention is to start with patient-directed, low-risk, minimal-cost interventions, such as regularly stretching the calf muscles and the plantar fascia, avoiding flat shoes and walking barefoot, using over-the-counter arch supports and heel cushions, and limiting extended physical activities. [8]

DiGiovanni et al reported in their clinical trial that a program of non-weight-bearing stretching exercises specific to the plantar fascia is superior to standard program of weight bearing Achilles tendon stretching exercises for the treatment of symptoms of proximal plantar fasciitis. [9]

Injured patients should receive instructions regarding the nature of their condition, risk factors, preventative measures and goals of therapy. Recommended therapy length is 6 visits over 4 weeks [10]



References

1. S.K. Williams, M. Brage. Heel pain—plantar fasciitis and Achilles enthesopathy. Clin Sports Med 23 (2004) 123–144
2. Wearing SC, Smeathers JE, Urry SR et al. The Pathomechanics of Plantar Fasciitis. Sports Med 2006; 36 (7): 585-611
3. Hicks JH. The mechanics of the foot. II. The plantar aponeurosis and the arch. J Anat 1954;88:25.
4. DB Irving, JL Cook, HB Menz. Factors associated with Chronic Plantar Heel Pain: a systematic review. Journal os Science and Medicine in Sports (2006) 9, 11-22
5. F Crawford, C Thomson. Interventions for treating plantar heel pain. Cochrane Database of Systematic Reviews 2003, Issue 3. Art. No.: CD000416. DOI: 10.1002/14651858.CD000416.
6. EW Yeung, SS Yeung. Interventions for preventing lower limb soft-tissue injuries in runners. Cochrane Database of Systematic Reviews 2001, Issue 3. Art. No.: CD001256. DOI: 10.1002/14651858.CD001256
7. J Burns, KB Landorf, MM Ryan, J Crosbie, RA Ouvrier.
Interventions for the prevention and treatment of pes cavus. Cochrane Database of Systematic Reviews 2006, Issue 3. Art. No.: CD006154. DOI: 10.1002/14651858.CD006154.
8. R Buchbinder, Plantar Fasciitis, N Engl J Med 2004;350:2159-66.
9. BF DIGIOVANNI, DA NAWOCZENSKI, DP MALAY. ,PLANTAR FASCIA-SPECIFIC STRETCHING EXERCISE IMPROVES OUTCOMES IN PATIENTS WITH CHRONIC PLANTAR FASCIITIS. THE JOURNAL OF BONE & JOINT SURGERY VOL 88-A · NUMBER 8 · AUGUST 2006
10. Work loss data institute, Official Disability Guidelines 11th edition 2006, integrated treatment/disability duration guidelines, Ankle and Foot (acute and chronic)