Forefoot Changes

My name is Amy and I’m a podiatrist at Waikato Podiatry Clinic.

You may have noticed this doesn’t look like a podiatry clinic today because we’re in lockdown level four. But rest assured podiatrists are still talking feet.

Today I thought I’d do a little video on forefoot anomalies. We see a lot of complications in the clinic surrounding the foot. Lots is around heel pain, but today I thought I’d do a little blurb on the forefoot.

A lot of you may know already things such as bunions and phrases around that, but I thought we’ll give a little more detail on those today. So interestingly, the forefoot is made up of the metatarsal bones, the long bones of the foot, going across to the metatarsal arch and from the metatarsal arch are the digits of the foot.

Interestingly, the metatarsal arch should sit up in a rainbow shape like this, but with age and time, often the metatarsal arch will collapse and drop. So we have more of a C shaped curvature of the bottom of the foot and the collapsing of the forefoot. Where we have a collapsed metatarsal arch, we often get this retraction of the lesser digits, and people often refer to that as hammer toes. Interestingly, a hammer toe is the retraction of the proximal phalanx, a mallet toe is the flexion of the distal phalanx. We see that normally in the lesser digits of the foot.

Another forefoot anomaly that we see in the clinic is bunions. And bunions, the technical name for that is hallux valgus. Hallux means the name of the big toe joint valgus refers to the deviation of the big toe, swinging towards the lesser toes. So it’s the big toe deviating towards the second toe.

We often refer to hallux abducto valgus which describes the rotation that happens with the big toe and on some feet the rotation can be so advanced that the nail is actually touching the bottom of the shoe, because of the angle that the bunion is on.

Now, bunions or as we refer to them as hallux abducto valgus is a technical change that’s happening back at the level of the first metatarsophalangeal joint. And there are several reasons why it happens: There’s a link to family history – parents or grandparents have had the similar problem; There’s often a mechanical cause – footwear complications. But interestingly, because I don’t have a foot model to show you, I’ve grabbed an image out of an old textbook, you’ll be able to see the angulation that happens here between the first and the second and as the Bunyan advances, the the gap between the first and second gets bigger as the metatarsal bone moves towards the midline and the first toe swings back on this angle.

Interestingly, when a bunion advances or a hallux abducto valgus advances because of the pressure that the first digit puts on the second toe with advanced changes, we often see the second toe then crawling back.

Another interesting point to make is that as the hallux abducto valgus increases in angulation because of the change with the bunion moving out, and the big toe swinging back, the whole first column shortens rendering the medial side of the foot unstable and we see lots of complications in the clinic as well.

Interestingly, when there are changes and there’s pressure over the big toe joint, the first metatarsophalangeal joint, because of footwear constraints, often this area will become quite weird and swollen.

People will present to the clinic and say my bunion is swollen. We know that the bunion itself the bone does not swell, but there is an acquired soft tissue bursa that develops underneath the skin. And a bursa is technically a sack of fluid that sits between the bone and the skin and that tends to swell at different times based on the amount of pressure applied.

Another fun fact is that we talk about bunions around the first metatarsophalangeal joint, but they can also happen on the side of the little toe as well.

This is often referred to as a bunionette and another word is a tailor’s bunion, and it’s referred to a tailor’s bunion because dress makers back in the day used to sit cross legged on the floor and there would be this constant pressure on the side of the fifth metatarsophalangeal joint.

There’s lots more to come. But hopefully that’s a start for everyone today.

Thanks – Amy

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