This pathology affects the metatarsal bones (bones in the foot), which have the burden of carrying the entire weight of the body. Therefore, these bones support tremendous pressure of continuous tension, if they become overloaded, a wide variety of diseases or disorders can develop, including metatarsalgia. Calluses can also form and even deform your feet.
“The metatarsal bones are miniature long bones, with each of the five having a proximal flat or slightly concave base and a distal rounded head. The tarsometatarsal joints consist of the articulations of the medial cuneiform with the first metatarsal, all three cuneiforms forming stable contact around the second ray, the lateral cuneiform with the third ray, the lateral cuneiform and cuboid contacting the fourth ray, and the cuboid with the fifth ray. The greater bony stability of the second ray is important in the late stance phase of gait, when increased load is transmitted from the ground through the second metatarsal. The tarsometatarsal joints are capable of gliding motion as are the intermetatarsal joints, which consist of articulations between adjacent metatarsal bases. The biconvex metatarsal heads and biconcave proximal phalangeal bases form the MTP joints, which allow plantar flexion and dorsiflexion, abduction and adduction, and the combination of these four motions, circumduction.”1
Metatarsalgia is a medical condition in which there is intense pain and swelling located in the regions occupied by the metatarsal bones. Usually, there is no mention of a serious disorder and it is effectively treated in most clinical cases. However, there are certain conditions in which the problem can become complicated, causing various symptoms.
“Metatarsalgia is a commonly presenting concern of patients seeking podiatric medical care. The typical patient with mechanically induced lesser metatarsalgia relates to a relatively longstanding period of gradually worsening, aching pain in the ball of the foot. This is most often plantar to the second, third, or fourth metatarsal heads or associated metalarsophalangeal joints, and is aggravated by weight-bearing activity. Usually there is no specific event related to the onset of the pain, however patients will occasionally relate the onset of symptoms to a new job or activity which requires prolonged standing or walking, usually on a hard surface. A history of a specific traumatic event in which the metatarsal region was injured is less common. The onset of symptoms is usually insidious, and pain is often well-established before treatment is sought. Moreover, associated conditions such as a plantar hyperkeratotic lesion, hammertoe or other form of digital contracture, and dorsal metatarsophalangeal joint swelling and pain may be evident at the time of initial presentation.”2
“Metatarsalgia is defined as pain in the forefoot under one or more metatarsal heads. Treatment strategies are guided by the multifactorial nature of metatarsalgia, which results from variable combinations of congenital, acquired, and/or iatrogenic factors. Surgery as a treatment for metatarsalgia remains controversial. The many available procedures range from extensive surgery to local intervention dictated by the symptoms and findings from the physical and radiographic evaluations. A thorough understanding of the biomechanical and anatomical causes of metatarsalgia is crucial to ensure selection of the optimal treatment.
The forces applied to the forefoot can cause metatarsalgia of varying severity. Their distribution varies with physical activities, age, footwear, posterior muscle chain flexibility, and forefoot morphology. Biomechanical factors explain 90% of all cases of metatarsalgia.”3
“Metatarsalgia is pain and tenderness of the plantar heads of the metatarsal bones. This occurs when the transverse arch becomes depressed and the middle metatarsal head bears a disproportionate amount of weight. Metatarsalgia can occur in athletes or runners wearing inappropriate footgear. The athlete’s sports shoes should be examined for abnormal wear patterns. Typically, the foot pronates and the transverse arch becomes depressed. There will be excessive wear on the medial aspect of the heel and under the metatarsal arch. Osteopathic manipulative treatment helps to restore structure and function of the foot. Elevating the middle portion of the arch avoids pressure on the painful metatarsal heads. The pronated foot is treated by exercises to strengthen the intrinsic muscles, Achilles’ tendon stretching, improvement of gait mechanics, and the use of orthotics such as an inner heel wedge, and various metatarsal pads placed behind the metatarsal heads. Localized injection of anesthetic to abort the pain cycle may be necessary in athletes with severe pain.”4
Signs of Metatarsalgia
Patients who suffer from metatarsalgia usually present a series of signs that can be associated with this disease. These alterations usually appear only in one foot but can present themselves in both extremities.
For example, among the frequent symptoms, we can include:
- Sensation of tingling or numbness of the toes, usually accompanied by discomfort.
- A feeling of having a stone in the shoe due to the intense pain in the plantar region. As a general rule, this condition is accentuated when walking and can cause the person in question to walk incorrectly. However, the alteration usually remits if the patient is sitting, lying down or in any other resting position.
- Hip or back pain when limping
- Formation of calluses.
“The symptoms in Morton’s metatarsalgia include a burning pain or ache between a pair of metatarsal heads with radiation into the corresponding toes. The pain is aggravated by walking or standing, while rest and removal of shoes brings relief. Clinically there may be tenderness and a dorsal bulging lump may be found. The tumor may cause deviation of adjacent toes. When pressure is applied axially to the intermetarsal space acute pain is induced. This may be associated with a painful and palpable clicking sensation (Mulder’s sign). Magnetic resonance imaging and ultrasonography may be used to confirm the diagnosis in equivocal cases. Both are equally effective in demonstrating the enlargement of the nerve. However, small lesions, which can be just as painful as larger lesions, may be missed. Ultrasonography however is the most convenient and the least expensive method to determine the shape and size of Morton’s neuroma under investigation.”5
Causes of Metatarsalgia
We can differentiate the triggers that can lead to the formation of metatarsalgia. Among the most common, we can mention:
- The use of inadequate shoes. Heels are a typical example, although we can also point to shoes that are too tight and / or poorly padded. “Inadequate footwear precipitates trauma via a number of different mechanisms, including: footwear lacking a protective enclosed upper allows acute external trauma; ill-fitting or non-fastening footwear facilitates chronic repetitive shear stresses and footwear unable to redistribute high plantar pressure areas facilitates chronic repetitive plantar pressures. These mechanisms are particularly problematic for people with diabetes or neuropathy, due to the inability to detect chronic or acute trauma to the foot and high plantar pressures associated with these diseases [9,10]. Unfortunately, once a foot ulcer develops, intensive ongoing health care provision is required to facilitate healing and prevent the cascade of infection, hospitalization, amputation and potentially death”6
- Being overweight. Obesity increases the body mass of the patient, causing the bones of the feet to becomes overloaded and altered more easily. “The maintenance of functional mobility should be one of the highest priorities in the management of an obese individual, with or without comorbid conditions. High levels of body fat plus increased loads on the major joints has the potential to lead to pain and discomfort, inefficient body mechanics and further reductions in mobility. Efficiency of movement may be improved with an appropriate prescription of aerobic activity and resistance weight training, and interventions to improve gait, posture and balance. An understanding of locomotor characteristics and biomechanical efficiency concurrent with metabolic efficiency during the performance of daily living tasks would greatly assist the clearer understanding of movement-related difficulties of the obese.”7
- Certain types of deformations of the feet. Anatomical changes cause more pressure to the metatarsal area. For example, ‘cavus foot’, a painful arching of the feet. “The exact cause in the cavus foot is a longstanding issue, and both intrinsic and extrinsic muscle imbalance may play a role in the final deformity.6 An imbalance between the antagonistic muscles, in particular the peroneus longus and tibialis anterior, is often listed as a cause.”8
- Other diseases that can alter the functioning of our lower extremities. For instance, the presence of diabetes, bunions, fluid retention, etc.
“Nearly 80% of the normal population present some form of pain in the metatarsal region over their lifetime. The main etiological factors are biomechanical alterations, which make up 92% of the total. These can be classified as primary, secondary and iatrogenic. Primary metatarsalgia alterations are related to the anatomy of the metatarsals and their relationships, which can lead to mechanical overload on the affected metatarsus and may evolve with pain and plantar callosities. In some cases, these consequences may become incapacitating. The presence of a short first metatarsus, known as Morton’s toe, is considered by many authors to be a contributing factor for the development of primary metatarsalgia. The relationship among the lengths of the metatarsals is defined as the metatarsal formula. Although this tool is used both for diagnostic investigation and for guidance toward treatment, the choice of the measurement method and their results are matters of controversy in the literature. The methods most cited are Morton’s transverse line (MTL) and Hardy and Clapham’s arc method (AM).”9
Your doctor or specialist usually performs several types of tests in order to identify metatarsalgia and differentiate it from other conditions with similar characteristics. They might suggest physical exam to evaluate the symptoms that the patient has developed. The clinical history of the subject, the antecedents that he may have and the lifestyle he has adopted are also studied in depth. They can also suggest X-rays, ultrasound and the use of a baropodometer, which is a test where the distribution of body weight between the two feet are analyzed.
“The baropodometer is an advanced force platform, used for the analysis of plantar pressure areas applied by the body in both motion and static position. It uses appropriate software to produce images similar to a podoscope. This technique provides data with a high diagnostic value, which are printed in graphs. It provides direct and indirect information about the position of the patient in the standing position, dynamic gait analysis, distribution of loads during walking, peak pressure and contact time with the ground, and detection of areas in risk on foot and helps in the production of orthotic insoles, on the detection of biomechanical abnormalities of the foot, pelvis, and spine. With baropodometry, different authors suggest the treatment of different postural problems using appropriate stretching and/or use of different shoe insoles.
Several scientific evidences suggests that the contracture of the posterior tendons and calf muscle bellies increases the load transfer from the hindfoot to the forefoot, changing the load distribution on the plantar surface, which could influence on the emergence of calluses, metatarsalgia, lesser toes deformities, and skin ulcers. In a randomized study with patients with diabetic forefoot ulcers, surgical lengthening of the Achilles tendon decreased the number of reulceration, due to decreased pressure on the forefoot.”10
Specialists will also recommend a series of guidelines
- Rest, in order to avoid overloading the feet and exacerbating discomfort
- Taking analgesic medications (to relieve pain) such as Ibuprofen
- The use of comfortable shoes that are adapted to the needs of the patient
- Application of ice on problem areas several for a few minutes, several times a day. It is important to remember not to use ice directly on the skin (the skin could become damaged), but to wrap it in a thin cloth.
“Surgical treatment of metatarsalgia is indicated when conservative measures have failed to improve the patient’s symptoms. Surgical planning requires a sound knowledge of what biomechanical parameters need to be corrected and what associated conditions need to be addressed. The overall aim of surgical intervention is to restore a normal pressure distribution to the forefoot while minimizing complications. Sometimes this may be achieved by procedures away from the forefoot itself such as gastrocnemius recession to reduce plantar pressure in patients with an isolated gastrocnemius contracture, which remains refractory to a stretching program. This procedure has been shown to produce an enhanced range of ankle motion and self-reported function while not inducing any detrimental effects to plantarﬂexion strength. In other cases, where the metatarsalgia and abnormal plantar loading of the lesser metatarsal heads is due to shortening or instability of the ﬁrst ray, addressing the ﬁrst ray abnormality may be all that is required.”11
(1) Riegger, C. L. (1988). Anatomy of the ankle and foot. Physical therapy, 68(12), 1802-1814. Available online at https://pdfs.semanticscholar.org/bf66/bfdd5f2ae6319bff2a3ab6ef070622c9b1fe.pdf
(2) Malay, D. S. (1996). Mechanically induced metatarsalgia. Gait Posture, 4, 198-199. Available online at https://www.podiatryinstitute.com/pdfs/Update_1994/1994_13.pdf
(3) Besse, J. L. (2017). Metatarsalgia. Orthopaedics & Traumatology: Surgery & Research, 103(1), S29-S39. Available online at https://www.sciencedirect.com/science/article/pii/S187705681630189X
(4) Carreiro, J. E. (2003). An osteopathic approach to children. Edinburgh: Churchill Livingstone. Available online at https://www.sciencedirect.com/topics/medicine-and-dentistry/metatarsalgia
(5) Pace, A., Scammell, B., & Dhar, S. (2010). The outcome of Morton’s neurectomy in the treatment of metatarsalgia. International orthopaedics, 34(4), 511-515. Available online at https://link.springer.com/article/10.1007/s00264-009-0812-3
(6) Barwick, A. L., Hurn, S. E., van Netten, J. J., Reed, L. F., & Lazzarini, P. A. (2019). Factors associated with wearing inadequate outdoor footwear in populations at risk of foot ulceration: A cross-sectional study. PloS one, 14(2), e0211140. Available online at https://www.researchgate.net/publication/331267791_Factors_associated_with_wearing_inadequate_outdoor_footwear_in_populations_at_risk_of_foot_ulceration_A_cross-sectional_study
(7) Hills, A. P., Hennig, E. M., Byrne, N. M., & Steele, J. R. (2002). The biomechanics of adiposity–structural and functional limitations of obesity and implications for movement. Obesity reviews, 3(1), 35-43. Available online at http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.476.4531&rep=rep1&type=pdf
(8) Maynou, C., Szymanski, C., & Thiounn, A. (2017). The adult cavus foot. EFORT open reviews, 2(5), 221-229. Available online at https://www.researchgate.net/publication/316891908_The_adult_cavus_foot
(9) Arie, E. K., Moreira, N. S. A., Freire, G. S., dos Santos, B. S., & Yi, L. C. (2015). Study of the metatarsal formula in patient with primary metatarsalgia. Revista Brasileira de Ortopedia (English Edition), 50(4), 438-444. Available online at https://core.ac.uk/download/pdf/82248012.pdf
(10) Baumfeld, D., Baumfeld, T., da Rocha, R. L., Macedo, B., Raduan, F., Zambelli, R., … & Nery, C. (2017). Reliability of baropodometry on the evaluation of plantar load distribution: a transversal study. BioMed research international, 2017. Available online at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5352867/
(11) Pearce, C. J., & Calder, J. D. (2011). Metatarsalgia: proximal metatarsal osteotomies. Foot and ankle clinics, 16(4), 597-608. Available online at https://www.academia.edu/29964626/Metatarsalgia_proximal_metatarsal_osteotomies