Plantar Fasciitis

              Plantar fasciitis is the most common cause of inferior heel pain. The majority of those who are inflicted by it are middle-aged women and young male runners (1). Those diagnosed with plantar fasciitis range in age from as young as 8 years to as late as 80 years old. In the United States, over 2 million people are treated for plantar fasciitis annually (2). Although many patients have experienced plantar fasciitis, its etiology is still not fully understood. The suffix “-itis” implies inflammation, however “…various lines of evidence indicate that this disorder is better classified as ‘fasciosis’ or ‘fasciopathy’ (2).

              The plantar fascia is a long thin sheet of dense connective tissue on the underside of the foot that runs from the heel to the ball of the foot. Their most important functions are maintaining the longitudinal arch in the foot and absorbing shock from the forces placed on the foot. The anatomical design of the plantar fascia allows the foot to adjust on irregular walking surfaces. If the plantar fascia is completely severed, the arch is forced to flatten.

              There are certain factors which contribute to plantar fasciitis. Tightness of the Achilles tendon, or limited dorsiflexion of the affected foot by more than 5 degrees, is found in 78 percent of patients (2). Other common causes are sudden weight gain, pes planus (flat foot), pes cavus (high arches), and extended periods of bearing heavy weight.

              Diagnosing plantar fasciitis is relatively easy, however other possibilities that cause heel pain should be ruled out. Other causes of heel pain are heel spurs, heel bruising, bursitis, fat pad atrophy, stress fractures, and nerve damage. Be aware that it is not uncommon to suffer from plantar fasciitis and another cause of heel pain at the same time. Half of patients with plantar fasciitis have heel spurs (2). When the plantar fascia is slightly damaged, pain will normally originate under the heel on the medial side. The localized damage done to the plantar fascia is sensitive and can be easily palpated with a firm finger. Swelling is common and most evident in the morning when getting out of bed however the pain decreases after several minutes of walking around. The first steps are difficult because when we sleep, our feet tend to remain plantar flexed, allowing the plantar fascia to contract. After remaining in that position for several hours, stretching out the plantar fascia can take some time and cause discomfort. However as time passes and the plantar fascia relaxes, pain subsides and is barely noticeable during normal activity. In the case of nerve damage or a fracture, pain would increase with more walking. Aggravating the plantar fascia is possible during intense exercise or running. This level of activity should be avoided until the plantar fascia has completely recuperated. Plantar fasciitis usually occurs in only one of the two feet, however there are studies that show it can be bilateral in up to 15 percent of patients (2).

              Stretching is very, if not the most important, rehabilitative exercise for plantar fasciitis. The plantar flexor muscles of the foot, specifically the gastrocnemius and soleus, need to be stretched out because those two muscles attach to the heel through the Achilles tendon. “Tightness of the Achilles tendon will predispose to plantar fasciitis because limited dorsiflexion of the foot strains the plantar fascia” (2). A 2012 study by Bolívar, Martínez, and Padillo found that a statistically significant correlation exists between patients with plantar fasciitis and tightness of the posterior lower limb muscles (3). Stretches should be performed several times a day, every day. The first stretch is designed to target the gastrocnemius. With the back knee extended, lean against a wall and bend at the ankle until a good stretch is felt in the proximal region of the lower leg. The front leg should be bent at the knee and used to support and stabilize one’s self. The second stretch is performed with similar body position as the first, but instead of keeping the back leg straight, bend slightly at the knee and lean slightly forward; this stretch targets the soleus muscle.

              In addition to a strict stretching regiment, there are several other methods to curing plantar fasciitis and hopefully never having a flare up. First off, walking on hard, flat surfaces for an extended period of time should be avoided. Worn-down shoes may aggravate plantar fasciitis because of either poor cushioning or poor arch support. A seemingly effective inhibitor of continued stress on the plantar fascia is a set of orthotics placed in the sole of the shoe. The orthotics maintain the longitudinal arch of the foot and add cushioning. It is imperative to buy orthotics with cushioning rather than solid plastic ones. Rigid orthoses rarely alleviate the symptoms and often aggravate the heel pain (2). Oral anti-inflammatory drugs provide temporary pain relief and are useful in decreasing inflammation. Night splints are a great solution to the morning tightness of the plantar fascia and reduce pain considerably. They function by strapping one end above the calf and the other end around the ball of the foot. The length can be adjusted and should be set so that the foot cannot plantar flex. The ideal position of the foot should be fixed 5 degrees dorsiflexed. Rolling the foot over a frozen water bottle or tennis ball helps lightly stretch the plantar fascia. There are a couple of exercises which help strengthen the deeper muscles in the lower leg that flex the toes. Such exercises are picking up marbles with the toes and towel curls. The latter exercise involves resting a towel on the ground under your foot and pulling it towards your body with only your toes. Surgery is an option, but should only be considered in the most extreme cases when all treatment efforts have not helped for 12 consecutive months (2).

              A relatively new treatment for connective tissue damage that has had considerably effective results in recent studies is shock wave therapy (SWT). The treatment functions by pounding the tissue with high-pressure sound waves, ultimately reducing pain. It is still not fully understood how this treatment actually affects the body. A 2010 study performed by Ibrahim et al. showed very promising results for SWT in terms of reducing pain for subjects who suffer from plantar fasciitis (1). The study tested the hypothesis that plantar fasciitis can be successfully treated with only 2 treatments of SWT one week apart. A total of 50 patients were randomly assigned to a placebo group and a SWT group. All 50 patients had been suffering from plantar fasciitis for over 6 months. The patients’ level of pain and quality of life were measured in the Visual Analog Scale (VAS), which is a horizontal scale from 0 to 10, 0 being no pain, 10 being as bad as it could be. Each score was taken the first day before treatment, 4 weeks after treatment, and 12 weeks after treatment. The mean VAS scores for the group treated with SWT were reduced from 8.5 before treatment to .5 24 weeks after treatment. The placebo group had a mean VAS score of 8.9 before treatment and 7.4 24 weeks after treatment. The results show a statistically significant difference between the SWT group and the placebo group. The long-term treatment success of those in SWT group was 100 percent compared to only 16 percent in the placebo group. Overall, it was a safe and easy treatment for the involved patients. The fact that treatment success for chronic plantar fasciitis (PF) can be achieved with just two SWT sessions could increase its attractiveness for both patients suffering from chronic PF and health care providers treating their condition (1).

              Although RSWT shows promise, there have been reports of adverse side effects such as pain during treatment, soft-tissue damage, nausea, and high costs. Another possible option is platelet-rich plasma (PRP) injections; a relatively new treatment that has been used to treat muscle and tendon injuries. Martinelli et al. studied the safety and efficacy of PRP for treating chronic plantar fasciitis (4). The purpose of their study was to assess the safety of PRP injections for and to evaluate its effectiveness. Martinelli et al. received statistically significant results in terms of the PRP injections’ effectiveness at reducing pain. Out the 14 patients that experienced chronic plantar fasciitis for over 6 months, 11 felt much better after 12 weeks and were able to return to normal functioning. Only 1 experienced no improvement. There are many limitations to this study, for instance the sample size, but it could inspire larger randomized clinical trials in the near future.

              There are many factors physicians and physical therapists take into account when treating and curing plantar fasciitis. An informed and educated patient can work together with their team to determine the best treatment options so they can return to normal function as soon as possible.

Written by Bradley Vogel Castellanos and Eric Sternlicht, Ph.D. Occidental College, Los Angeles, CA.

References

1.  Singh, D., Angel, J., Bentley, G., & Trevino, S. (1997). Plantar fasciitis. BMJ, 315(7101), 172-175.

2.  Ibrahim, M., Donatelli, R., Schmitz, C., Hellman, M., & Buxbaum, F. (2010). Chronic plantar fasciitis treated with two sessions of radial extracorporeal shock wave therapy. Foot & Ankle International,31(5), 391-397.

3.  Bolivar, Y. A., Martinez, P. V. M., & Padillo, J. P. (2013). Relationship between tightness of the posterior muscles of the lower limb and plantar fasciits. Foot & Ankle International, 34(1), 42-48.

4.  Martinelli, N., Marinozzi, A., Carni, S., Trovato, U., Bianchi, A., & Denaro, V. (2012). Platelet-rich plasma injections for chronic plantar fasciitis. International Orthopaedics, 1-4.

5.  Roxas, M. (2005). Plantar fasciitis: Diagnosis and therapeutic considerations. Alternative Medicine Review, 10(2), 83-93.