If you're here, you probably know what a metatarsal dome is and why you want one, but in case you're not clear, I'll give a summary.
What is a metatarsal dome?
A metatarsal dome is a dome shaped object that sits just behind the ball of your foot (under the heads of the metatarsal bones). The idea is that as the foot supports your body's weight, the dome supports your foot by spreading your metatarsal bones apart slightly around it, relieving pressure on the soft tissue around the metatarsals.
Metatarsal domes can be useful in managing certain types of pain in the forefoot, for example a Morton's neuroma. In the case of a neuroma, which is usually caused by nerve compression between the metatarsals, the dome helps by spreading the metatarsals and giving the nerve just a bit more space.
When I say 'dome', I am not referring to things often marketed as 'pads'. The terminology is inexact, but pads tend to be cushioned flat pads that are designed to be worn somehow underneath the ball of your foot. These do not support the metatarsals. Instead they just add a bit more cushioning, which may or may not be useful (or desirable, as they will cause your foot to point upwards slightly).
How to create your own metatarsal dome
I make my own metatarsal domes, and it's really easy.
Insoles with in-built metatarsal domes are an option, as are individual metatarsal domes, but I tend to dislike these because:
- Insoles often come with other things like cushioning or arch support, which my shoe is already giving me
- Insoles can make the shoe fit tighter, and tight shoes can aggravate neuromas
- They often don't wear very well
- Metatarsal domes seem to be a poorly defined thing. Some domes are huge, flat and wide and aren't really giving support in the right area. Others are too tiny to do anything.
Overall I find it easier to do it myself.
It's actually really easy. All you need is a shoe, ideally with a removable insole (which most if not all running shoes have), some podiatric felt and some tape (I use microporous tape because it's fairly easy to remove, but it's really not important).
The felt I use is this stuff, but you can use whatever you can find. This one is 7mm thick and has adhesive on one side.
What I do is I cut out a teardrop shape from the felt, and right in the middle of it, I add another little square (maybe 1cm square) of felt, so it's doubled up at that one point. It's not exact, the idea is just to create a dome shape, so that it's not all one height.
I stick the smaller one onto the bigger one using the adhesive on the felt, then I tape it underneath the insole.
You will need to play around with placement, which is why it helps to use tape rather than the adhesive on the felt, but basically you're aiming for the fleshy part slightly behind the ball of your foot.
The felt dome will flatten a bit under your weight when you wear it regularly, and the insole will mould itself slightly around it.
Summary and thoughts
I prefer to use tape instead of adhesive on the felt because it makes it easier to move around if needed.
I prefer to put it underneath the insole instead of on top because 1) you can tape it more easily (see previous point), 2) it protects from the mechanical friction and moisture from your foot, and 3) I suspect that the way the insole moulds itself around the felt helps create more of a 'dome' shape than having the felt above the insole.
The felt tends to come in 7mm or 5mm thickness. As it's doubled up, I have a 14mm tall dome digging into my foot, which sounds quite big. In reality, it gets squashed down pretty quickly so it's not really that big, however, if you have small feet you might prefer the 5mm.