Thursday's Orthotic Discussion of the Week: First Toe Stability aid with Budin Splints

I love Budin Splints to stabilize the 2nd metatarsal phalangeal joint. In this images, I am failing at my goal. I need to get the 2nd metatarsal down more, so that when the patient stands, the second acts as a stabilizing force against the first. If the second can be brought down with a tighter fit, or my changing to a double Budin Splint, I will have achieved a more stable first ray. The more stable this medial column, the more stability and comfort there will be in the body.

First Metatarsal Position: Important to Know with Metatarsal Problems

One important measurement that bio mechanic specialists evaluate is the relationship of the first metatarsal to the second metatarsal head. The foot should be centered under the ankle joint (therefore not pronated or supinated). One thumb on bottom and index finger on top grab the second metatarsal head and stabilize it. This will be the reference point. With the other hand, grab the first metatarsal head also from top and bottom. See where the first metatarsal head lies in relation to the second metatarsal head when the thumb fingernails are parallel. Then move the first metatarsal head up and down noting the overall motion and position. The motion is ideally 5 mm up and 5 mm down. In this patient, the left first metatarsal moved only 2 mm total (4 mm down and -2 mm up). This is called a stable plantar flexed first ray. Ideally the first and fifth metatarsal heads are lower than their adjacent metatarsals.

On this patient's right foot, the first metatarsal rested 3 mm above the second metatarsal. The overall motion with 6 mm (6 mm up and 0 mm down). This is called an elevated first ray or metatarsus primus elevatus (I love to talk like I am smart!!) This is an unstable first metatarsal that will not hold up the arch, and causes instability in the foot. It can be the cause of bunions or produced by the formation of a bunion. When recognized, orthotic modifications like the Cluffy Wedge or Morton's Extension  can be used, and if surgery is being done, corrections for the elevated bone can be done. With an elevated first metatarsal, the weight goes more to the second and sometimes third metatarsals leading to pain syndromes like metatarsalgia, capsulitis, neuromas, and hammertoes. 

Importance of the Positioning of the First Metatarsal

It is extremely important to know where the first metatarsal lies in relationship to the other metatarsals, especially the second. These photos to follow show the classic Root evaluation of the first metatarsal in relationship to the second metatarsal. Normally, the first metatarsal lies mainly plantar to the second metatarsal. In the first photo below see how the first metatarsal lies 3 mm above the first metatarsal, even though I have pushed it down as far as it can go!! This is called an elevated first metatarsal, producing a hypermobile first ray which does not bear weight well, allowing for more pronation to occur. 

The above photo shows the same observation of the first metatarsal in its most elevated position. When you see the 2 positions, maximally up and maximally down, you can tell this is elevated from the second--also called metatarsus primus elevatus (elevated first ray). 

The photo above shows the more normal right foot where the first metatarsal is 5 mm below the second when pushed down. It is so crucial to keep your thumbs parallel when doing this maneuver.