In today’s blog we are going to continue with our foot related topics and discuss Morton’s neuroma’s, a common pain felt underneath the ball of the foot.
Morton’s neuroma involves the plantar nerves, the metatarsals, and the metatarsal ligaments.
The pain is caused by the entrapment of one of the plantar (interdigital) nerves between the metatarsals. This typically occurs between the 3rd and 4th metatarsals but can also occur between the 2nd and 3rd.
A Morton’s neuroma arises due to swelling of an interdigital nerve and scar tissue development caused by compression of the nerve between two metatarsals.
This entrapment usually occurs under the transverse ligament, which causes the nerve to become inflamed. When healing occurs tough scar tissue is then formed around the nerve, making it appear as a bulb-like growth (non-cancerous) which gets trapped between the metatarsals during weightbearing, causing pain.
A Morton’s neuroma is generally the result of complex biomechanical changes that occur in the feet. There are several theories as to the exact cause of the scarring and thickening, but it basically boils down to an overload of the tissue structure during weightbearing.
This overload causes inflammation (the bodies way of healing damaged tissue) which as it heals creates scar tissue. With repetitive loading, more inflammation is created, and hence more scar tissue formed leading to a progressive increase in the size of the neuroma.
Tight-fitting shoes can also exacerbate a Morton’s neuroma as they squeeze the metatarals together putting pressure on the neuroma. Other types of shoes such as high heels and those with tight toe boxes (eg women's fashion shoes and cowboy boots) can also be particularly damaging to the toes. These shoes have a sloping foot bed and narrow toe box, which causes the front of the foot to bear the weight of the body and the angle of the toe box to squeeze the metatarsals together.
Footwear is not the only cause of a Morton’s Neuroma. Injuries to the foot can also be a factor in developing the condition, by changing the posture of the foot and biomechanics of the leg. Poor foot posture and subsequent arch control can lead to flat, or over-pronated, feet, which increases the pressure on the metatarsals making them more susceptible to Neuroma development.
Symptoms of a Morton’s Neuroma include:
· Pain through the forefoot and toes on weight bearing, frequently after only a short time.
· Sharp shooting pain into the inside of the two toes the neuroma sits between.
· Stone like sensation in the front of the foot.
· Sensation of walking on razor blades.
· Burning, numbness, and paresthesia into the toes can also be experienced.
· Presence of a palpable lump or clicking through the metatarsal heads.
Clinical diagnosis can be up to 99% accurate with typical complaints of plantar web-space pain, paresthesias and/or numbness aggravated by weight-bearing activities and eased by rest and massage the key signs.
There is often no obvious deformity, signs of inflammation, or limitation of movement. Direct pressure between the metatarsal heads will replicate the symptoms, as will compression of the forefoot between the finger and thumb to compress the transverse arch of the foot and put pressure on the neuroma.
The main focus of treatment is aimed at controlling the pain associated with the neuroma and unloading it to reduce inflammation and subsequent pain.
In the initial stages ice, anti-inflammatory medication and unloading taping are very useful in reducing symptoms. However, unless the root-cause is addressed it’s highly likely to return.
In most cases, Morton’s neuromas arise due to poor or altered lower limb and foot biomechanics. As such, long term resolution relies on correcting these issues by addressing foot posture with alternate footwear or orthotics.
If conservative methods are ineffective, then cortisol injections, Sclerosing alcohol injections and surgery may be recommended. These techniques have high success rates, but again the long-term improvement relies on correction of the underlying biomechanical abnormality.
Some good preventative methods include:
1. Always ensure you wear good, supportive footwear, with adequate arch support and toe box space.
2. Ensure you maintain adequate strength and muscular control around the hips, knees and ankles.
3. Seek help early. If you experience the above symptoms consult with your healthcare practitioner ASAP so that unloading techniques can be applied early to minimise the risk of developing a substantial neuroma.
So that’s an overview of what a Mortons neuroma is and how it occurs. If you have any questions or comments, please email us at firstname.lastname@example.org and we will be happy to answer them for you.
If you suffer with pain through the top of the foot, feel free to call us on (08) 9486 8653 and our therapists will be happy to chat with you about the best management plan.