What kind of shoe do you put this foot in?
Look carefully at these dogs. Notice anything peculiar? Look at the forefoot to rearfoot relationship. What do you see?
Normally, we should be able to draw a line from the center of the heel and it should pass between the 2nd and 3rd metatarsal heads. If the line passes through or outside the 3rd metatarsal heads, you have a condition called metatarsus adductus. It occurs from fetal positioning in utero. In children (18 mos to 4 years) it can often be corrected by wearing the shoes on the opposite feet (yes, you read that correctly)
We usually try and distinguish whether the adductus is occurring at the tarsal/ metatrsal articulation or the transverse tarsal joint.
OK, so now what?
Think of the unique biomechanics that happen here. Adduction (along with plantar flexion and inversion) are components of supination. So, the adduction component makes for a more rigid foot (notice the arch structure in the pedograph). We are not saying this foot does not pronate, only that it pronates less.
Total amount of pronation will be determined by several factors,
- including body weight
- available rear foot motion
- available forefoot motion
- knee angulation (ie genu valgus or varus)
- available internal rotation of the hips (how much ante or retroversion/torsion is present)
- strength of abdominals, particularly the external obliques
- tibial torsion
This individual had
· markedly increased valgus angle (14 degrees)
· moderate external tibial torsion
· femoral antetorsion
this, along with their body weight, explains the rear foot pronation seen on the pedograph.
So, what type of shoe? You should pick a shoe that:
· does not exaggerate the deformity (ie. a shoe that does not have an excessively curved last)
· a shoe that does not work (too much) against the deformity (ie. an extremely straight lasted shoe)
· In this case, a shoe with some motion control features (to assist in controlling some of the increased rear foot motion. This may be something as simple as a dual density midsole
· a shoe that, upon gait analysis, works to provide the best biomechanics for the circumstances.
As you can see, when it comes to shoe fit and prescription, there are no had and fast rules. You need to examine the individual and have all the facts.
If you are a little lost, or want to know more, you should take our National Shoe Fit Program. Maybe you even should consider getting Level 1 certified by taking the International Foot and Gait Education Council exam. Need more details? Email us at: firstname.lastname@example.org