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by Alakananda Ma
In the famed twentieth chapter of the sutrasthanam of Charak Samhita, padashula or foot pain is listed second among the foot-to head list of the eighty diseases of vata. This important and quite common vata disorder presents its own diagnostic and therapeutic challenges. In this article we will look at the epidemiology, differential diagnosis and management of foot pain.
The Northwest Adelaide study, with over 4,000 participants, reported a 17.4 % prevalence of foot pain, with females, those over fifty and the obese particularly affected (1). Several studies indicate that foot pain may play a key role in disability (2, 3). Furthermore, by hampering walking and reducing walking speed, foot pain lowers overall wellbeing and longevity (2). Hence we can see that, now as in Charak's day, foot pain is a significant cause of discomfort, disability and increased mortality, especially among older women.
Foot pain can be differentiated into heel pain and metatarsal pain. Heel pain is described thus: Improper placing of the foot on the ground while walking or exhaustion due to exertion of walking makes for localization of vata in the region of the heels, causing severe pain. This is known as vatakantaka (4). The most common cause of heel pain is plantar fasciitis, which affects 10% of the US population (5). The plantar fascia or plantar aponeurosis consists of a fan-like array of connective tissue radiating from the calcaneal tuberosity (heel bone) to the toe bases. As indicated in Madhav Nidhan, excess walking, running or standing can lead to plantar fasciitis. Patients describe a throbbing or piercing pain, worse on first getting up in the morning and then worsening again after being on their feet or walking upstairs (5). On examination, there is usually tenderness around the calcaneal tuberosity where the plantar aponeurosis inserts.
Plantar fasciitis should be differentiated from other, less common causes of heel pain. Among neurological causes, nerve entrapment of the abductor digiti quinti nerve will cause burning in the heel pad (padadaha) (4). In disorders of the lumbar spine, pain may radiate down the leg to the heel. Knee and ankle jerk reflexes will show abnormality and there may be muscle weakness. Disorders of the medial calcaneal branch of the posterior tibial nerve will give rise to pain in the medial as well as posterior aspect of the heel. Diabetic or alcoholic peripheral neuropathy will cause more diffuse foot pain, which will occur chiefly at night rather than upon walking. Peripheral neuropathy may also give rise to symptoms of padaharsha: pins and needles and loss of sensation in the feet (4). Tarsal tunnel syndrome, entrapment of the posterior tibial nerve, will include combined symptoms of padashula, padadaha and padaharsha. A positive Tinel's sign can help confirm a clinical diagnosis. Tap over the affected nerve, the posterior tibial nerve, as it runs below the media malleolus of the ankle. A tingling electric shock sensation will confirm tarsal tunnel syndrome.
Among soft tissue causes, note that with Achilles tendonitis and retrocalcaneal bursitis, the pain will be behind the heel, and with posterior tibial tendonitis there will be pain on the inside of the foot and ankle. Other differential diagnoses include fat pad atrophy, heel contusion and ruptured plantar fascia. Among skeletal causes, Sever's Disease or plantar epiphysitis occurs in adolescents, before the epiphyses fuse. Calcaeneal stress fracture is an important differential diagnosis: look for the classic symptoms of inflammation: pain, swelling, heat and redness of the heel bone.
Treatment of plantar fasciitis is both local and systemic. Systemically, kaishore guggulu may be administered to relieve inflammation. Guggulu will of course also, by its lekhan action, help reduce weight, a causative factor in plantar fasciitis. As in all diseases of vata, castor oil is recommended internally (6). A teaspoon of castor oil may be taken in ginger tea twice weekly. Externally, the heel may be soaked in warm castor oil, or massaged with mahanarayan oil. After oiling, heat and cold may be applied alternately, dipping the heel in mustard seed tea, then ice water, then mustard seed tea, and so on. Yoga therapy should be used, since evidence-based medicine shows the efficacy of stretching the plantar fascia, while stretching of the calf muscles and Achilles tendon has also proved useful (7). With respect to ahara and vihara, (diet and lifestyle), emphasis should be placed on weight reduction in obese patients. Since padashula is a vata condition, vata reducing measures for diet and lifestyle are indicated.
With regard to metatarsal pain, causes are numerous and we will mention the more common. Traumatic causes include turf toe, a common football injury, from hyperextension at the first metatarsophalangeal (MTP) joint (8) and planter plate disruption at the second through fifth MTP joints as a result of wearing high-heeled shoes (9). March fracture, a metatarsal fracture famous in military recruits, is also common in runners, ballet dancers and gymnasts (10).
Metatarsal pain can also be caused by joint disorders. In diabetics, neuropathy can lead to reduced sensation of pain and proprioception, with resulting foot damage known as neuropathic osteoarthropathy, a condition of misalignment, disorganization and destruction of the metatarsal bones (11). The first MTP joint is a common site of osteoarthritis, which is often preceded by hallux valgus, a deformity where the great toe points laterally. Osteoarthritis of the first MTP joint can lead to hallux rigidus, a stiff condition of the great toe, rendering walking painful. Vatarakta or gout also occurs most commonly in the first MTP joint. Rheumatoid arthritis too, can affect the MTP joints. Bursitis in the forefoot may be related to gout, rheumatoid arthritis and affects the bursae between the metatarsals.
Most types of MTP joint pain can be managed or at least alleviated by rest, elevation, oiling with mahanaryana oil and alternate heat and cold therapy as described above. General vata soothing measures in diet and lifestyle are indicated and guggulu preparations, as well as boswellia, will help with joint inflammation (12). A tea containing tulsi, turmeric and ginger is a good anti-inflammatory home remedy. For systemic conditions such as gout and rheumatoid arthritis, local treatments should be accompanied by the full chikitsa protocol for that illness. For example, in gout, a low uric acid diet is recommended and treatments such as snehan, svedan, virechan (purgation) shita lepan (application of cooling pastes) and basti are indicated. Guduchi is a chief herb for management of vatarakta and kaishore guggulu is an important yoga (combination) (13). Precise diagnosis is important for hetu viparita chikitsa, treatment by reversing the cause. For example, a change in footwear, an adjustment in sport or dance training, or a course of yoga therapy to correct walking alignment may be necessary to remove the initial cause of the MTP pathology. The first MTP joint must bear the entire weight of the body when we walk and hence plays a crucial role in our mobility, wellbeing and longevity. Most of us take our feet for granted until they no longer serve us as they used to.
Foot pain, as we have seen, is a common cause of discomfort, disability and difficulty exercising. Foot pain may be classed into heel pain and forefoot or metatarsal pain and should be carefully diagnosed to allow for optimum treatment choices. Application of local and systemic Ayurvedic chikitsa and shodhan therapies may provide improved quality of life for individuals suffering from foot pain.
1. Hill CL, Gill TK et al Prevalence and correlates of foot pain in a population-based study: the North West Adelaide health study, Journal of Foot and Ankle Research 2008, 1:2
2. Leveille SG, Guralnik JM, Foot Pain and Disability in Older Women Am. J. Epidemiol. (1998) 148 (7): 657-665
4. Srikantha Murthy KR, (tr) Madhava Nidhanam Chaukambha Orientalia ,Varanasi p 87
5.Cole C, Seto C, Gazewood J, Plantar Fasciitis: Evidence-Based Review of Diagnosis and Therapy Am Fam Physician. 2005 Dec 1;72(11):2237-2242.
6. Bhavprakash Guduchyadi varga 64-66
7. DiGiovanni BF, Nawoczenski DA, Lintal ME, Moore EA, Murray JC, Wilding GE, et al. Tissue-specific plantar fasciastretching exercise enhances outcomes in patients with chronic heel pain. A prospective, randomized study. J Bone Joint Surg Am. 2003;85-A:1270-7.
8. Coughlin MJ. Conditions of the forefoot. In: Delee JC, Drez D, Jr, eds. Orthopaedic sports medicine: principles and practice. Philadelphia, Pa: Saunders, 1994; 1842-2034.
9. Yao L, Cracciolo A, Farahani K, Seeger LL. Magnetic resonance imaging of plantar plate rupture. Foot Ankle Int 1996; 17:33-36.
10. Weinfeld SB, Haddad SL, Myerson MS. Metatarsal stress fractures. Clin Sports Med 1997; 16:319-338.
11. Ashman CJ, Klecker RJ, Yu JS, Forefoot Pain Involving the Metatarsal Region: Differential Diagnosis with MR Imaging November 2001 RadioGraphics, 21, 1425-1440.
12. Roy S, Khanna S et al, Regulation of Vascular Responses to Inflammation: Inducible Matrix Metalloproteinase-3 Expression in Human Microvascular Endothelial Cells Is Sensitive to Antiinflammatory Boswellia Antioxidants & Redox Signaling. March/April 2006, 8(3-4): 653-660.
13. Shastry JNL, Lakshmana Prasad V, Madhava Chikitsa Sutramala, Chaukhambha Orientalia, Varanasi, 2007 p84.