Neuromas And Metatarsalgia: Is Treatment the Same From A Biomechanical Perspective?

I want to diverge this month and talk about neuromas and metatarsalgia. Yes, metatarsalgia is a garbage can term for any forefoot pain but, in this instance, it will refer to pain under a metatarsal head. Metatarsalgia pain can be caused by a hammertoe or a plantar plate tear in general. Neuroma pain usually relates to nerve pain between the metatarsal heads. The cause for neuroma pain is usually tight shoes but there can be other mechanically-related issues as well.

From my biomechanical perspective, which I have been discussing this last year, I really see little, if any, difference between these two entities. Yes, the pain is usually mechanical in the case of metatarsalgia and neurogenic with respect to neuromas. However, the mechanics of how to treat them both are essentially identical from a biomechanical and orthotic perspective.

One of the primary things I usually see with these issues are hypermobility or lack of dorsiflexion stiffness of the first ray. This will keep the center of pressure more in the midfoot as without a stable or stiff first ray, we cannot effectively have propulsive gait. There is also often hypermobility or lack of dorsiflexion stiffness of the fifth ray as well in these patients. This usually causes the pain and center of pressure to stay in the central rays, usually the second and third rays, or the second through the fourth rays because the medial and lateral rays are not stable.

Secondarily, we will often see long second and third metatarsals with these conditions. This can cause increased pressures under the metatarsal heads, which can overload the plantar plate structures, and/or in the case of a neuroma cause the metatarsals to spread and lead to some sort of traumatic event on the nerve(s) between those metatarsals.

Again, I will mention how the decreased stiffness or hypermobility of the medial and lateral columns works with the long metatarsals to exacerbate these issues.

In clinic, I will often have patients stand on the affected foot, flex their knee slightly and then lift their heel so they are balancing on the ball of only one foot. You will see most of them sway from the first through fifth rays, trying to find a stable “sweet spot” for stable balance. I find this to be exaggerated more in patients with neuroma than in patients with metatarsalgia but not always. Either way, their area of stability tends to be focused in the area of their forefoot pain.

Finally, I almost always see a significant amount of ankle equinus or limited ankle joint dorsiflexion range of motion in these patients. I have discussed this previously in my blog posts.

For treatment, the goal here, from my perspective, is to bring stability to the foot so the patients do not have to overload the central rays where the discomfort lies. To do this, you have to stabilize the lateral column and the medial column, account for any ankle joint equinus, and usually accommodate the area of pain of either the neuroma or the metatarsalgia.

In regard to my usual orthotic prescription, I will use an appropriate length first ray cutout to allow the first MPJ to plantarflex and a digital wedge under the hallux to assist the first MPJ. I will also use a valgus forefoot wedge as necessary under the lateral column if the excursion or hypermobility of the fifth ray is high, which is usually the case. Finally, we will then use a reverse Morton’s extension with an accommodation under the area of the metatarsal or neuroma pain.

Often, I will use a digital pad under the toes to engage the plantar fascia for added foot stability. If you do this, keep in mind that you should grind down the material under the toe(s) that are associated with the metatarsal or neuroma pain. Extending the MPJ is not good for alleviating pain in these conditions.

Finally, I will use a heel lift from 3 to 6 mm as necessary to combat any limitation in ankle joint dorsiflexion range of motion. This will prevent the patient from having prolonged forefoot pressures and help stabilize the timing and transfer of forces from the rearfoot to the forefoot.

Cheers until next month!