Sesamoiditis and the Sesamoid Bones
The Sesamoid Bones
The sesamoid bones may only be small, but they can cause a considerable amount of pain. These small bones are located within tendons; at the point where a tendon passes over a joint. They can be found in numerous locations throughout the body, including the knees, hands and wrists; however the sesamoid bones most prone to injury are located in the feet.
The function of these small bones - which are actually very hard cartilage - is to help the tendons function more efficiently. The bones act as a fulcrum, and keep tendons away from the bones giving them some room to move freely. The sesamoid bones also help to protect the tendons by keeping them away from the bones and ensure a more uniform pull.
In the foot these bones are located at the base of the big toe where the toe joins the ball of the foot; or underneath the metatarsal head to be more anatomically correct. Such a location means that these small bones have to wear some of the body weight, especially during the push off phase of the stride when walking or running.
When these bones are damaged or fractured pain is most commonly experienced when the body weight is transferred to the toes.
Sesamoiditis and Sesamoid Bone Injuries
Due to their location just behind the big toe, the sesamoid bones are weight bearing structures, and as such are prone to injuries. As with any weight bearing bones, they are prone to fractures from trauma. A sudden onset of pain at the base of the big toe could indicate a stress fracture to these tiny bones.
A far more common problem is a condition called sesamoiditis, which is the inflammation of the bones themselves and the surrounding tissues. Sesamoiditis can trigger the sudden onset of pain, but it is far more common that pain builds slowly over time. Sufferers of sesamoiditis complain about intensifying pain during exercise, which is felt particularly at the toe off phase of the gait cycle, as the weight is transferred to the ball of the foot. The pain usually subsides rapidly when the foot is rested.
Sesamoiditis causes are varied; however most frequently in younger adults the condition is caused by excessive forces applied to the bones over a period of time. Sufferers are frequently those people who exercise frequently such as runners, joggers, and those who participate in sports where the ball of the foot is subjected to increased pressure and strain, such as occurs when jumping. People who have to crouch a lot, raise up onto the balls of the feet, or carry heavy loads as part of their job are also more likely to suffer from the condition.
Sesamoiditis in the older age groups is usually the result of osteoarthirtis of the sesamoid bones, with the condition also more likely with sufferers of osteoporosis. Osteoporosis can also be one of the causes of sesamoiditis in younger women, especially those who suffer from poor nutrition, are afflicted by anorexia, or who have infrequent periods.
There is also a genetic component often at work, not for the condition itself, but from foot deformities such as enlarged sesamoid bones. The larger the bones, the more weight they are made to endure, and the more likely they are to get injured. Runners and joggers are frequent sufferers of sesamoiditis, with it being linked to overpronation, or excessive rolling in of the foot when running. Runners who overpronate, roll their feet inwards to a greater degree, which increases the forces acting on the sesamoid bones, and thus the chance of injury and the onset of sesamoiditis.
The condition is treatable at home in most cases and rarely requires surgical intervention, unless the condition has deteriorated significantly, and bone spurs have formed on the sesamoid bones, which can add to the irritation of the tendons and muscles and increase inflammation.
Inflammation, and the associated pain can be treated with ice, which will also help to reduce any local swelling, with NSAID (Non-steroid Anti inflammatory drugs) also useful. However the best course of action is to rest the affected foot to allow it time to heal. Since for most people a long period off the feet is not possible, there are many orthotic devices which can ease the pressure on the Sesamoid bones when walking, and are highly effective at treating sesamoiditis.
Sesamoiditis Risk Factors
Sesamoiditis can be caused by the following conditions, which place an increased force on the sesamoid bones and the ball of the foot:
- High arches
- Low arches and flat feet
- Gait irregularities which cause increased pressure on the forefoot
- Other foot conditions which cause a transfer of the weight onto the inside of the foot
- Heavy lifting, crouching and raising onto the balls of the feet
- Large sesamoid bones
Sesamoiditis Treatment | Metatarsal Bars and Metatarsal Pads
When you think about injuries to the sesamoid bones, which hurt when pressure is applied, many would think that the best way to cushion and ease the pain is to treat sesamoiditis is to use cushioning directly under the bones themselves. However the support devices best suited to easing the pressure and pain, actually sit under the lesser toes, and not the sesamoid bones, which are left unsupported.
Metatarsal pads and metatarsal bars, including Lynco insoles with metatarsal pads are particularly beneficial.They raise the metatarsals, wth padding under the lesser metatarsals, with the sesamoid bones are allowed to "float". When pressure is transferred to the ball of the foot and the toes, the pressure on the sesamoid bones is greatly reduced, and so is the pain.
Metatarsal pads and metatarsal bars can be inserted into most shoes, and feature an adhesive backing to hold them in place, and are frequently prescribed by doctors and podiatrists to ease the pain from sesamoiditis.
If you are on a really tight budget, and already have standard insoles, you can gain some relief by cutting out an aperture underneath the base of the big toe, which will help to ease the pressure when walking, although its best to purchase metatarsal pads, which are available for under $10. Lynco insoles with metatarsal pads will set you back around $60.
Insoles with metatarsal pads are usually worth the extra cost, especially if you suffer from flat feet, low arches or high arches. In addition to easing the strain on the metatarsals, they offer increased arch support, which in most cases is the root cause of sesamoiditis in the first place. They will not only help to treat the condition, but will go some way to ensuring that the problem does not flare up again.
Running Shoes for Supinators
Supination and Pronation Control Running Shoes and Insoles
Runners who overpronate are prone to develop sesamoiditis, due to an increased force being applied to the sesamoid bones when jogging and running. As the foot rolls inwards, the sesamoid bones have to take an increased force which can lead to damage to the bones and surrounding tendons.
The best way to prevent sesamoiditis caused by pronation and supination is to use orthotic insoles which correct the gait and guide the foot through a more healthy heel to toe roll. For runners and joggers the best bet is to purchase running shoes which offer a degree of pronation control. All of the major running shoe manufacturers such as Mizuno, Brooks, and Asics have a large range of footwear which offers pronation control for mild pronators and for those who havesevere overpronating feet.
Whilst pronation is a problem, so too is supination, which is an inflexibility of the foot often the result of high arches. High arches are less effective at dealing with the shock waves from running and can lead to the development of sesamoiditis. Orthotic insoles and footwear is also available to provide superior arch support for those with high foot arches.
Suppinating runners, and those with high arches usually benefit most from shoes which offer and increased amount of cushioning. The increased cushioning makes up for the lack of natural cushioning which would otherwise come from the foot arches. Choosing running shoes such as the Mizuno Wave, Adidas Supernova or the Asics Gel Numbus range are all excellent choices, with the latter getting some of the best reviews.
Arch supports are also highly beneficial and ensure that the foot arches are well supported, which can help reduce the likelihood of developing sesamoiditis and suffering from sesamoid bone injuries.