Total Pageviews



Tuesday, March 15, 2011

Inverted Orthotic Technique: Arch Changes 35 to 50 Degrees

The photo below is of 2 left foot orthotic devices. The blue is set at 35 degrees Inverted. The green is set at 50 degrees Inverted with Medial Column Correction and Kirby Skive. Charles has left foot posterior tibial dysfunction and is trying to avoid further collapse of his foot and surgery (at least postpone the need for surgery). Besides these corrective orthotic devices, Charles is doing foot strengthening exercises daily, kinesio tapes his arch daily, wears supportive motion control shoes or light weight boots, and power laces his shoes.
Charles relaxed heel position is 11 degrees everted on the left and 4 degrees everted on the right side. My initial correction was 35 degrees (a 7 degree varus cant) on the left and 20 degrees on the right (a 4 degree varus cant. 35 degrees is my standard highest correction to get patients used to such a change. His previous orthotic devices had changed his heel position to 9 degrees everted and 2 degrees everted, and they were hard and uncomfortable. My initial correction using a soft plastic of 5/32" polypropylene changed his heel position to 10 degrees everted on the left and vertical on the right. So I am brillant half the time!! The correction was just not enough to control his foot.
The photo below again shows the difference in the two left orthotic devices, but I have put the medial arches side by side. The blue again is a 35 degree Inverted cant and the green is 50 degree Inverted Cant with higher than normal medial arch and Kirby Skive. In my twisted mind, pre dementia, the 50 degree Inverted position should give a 10 degree change normally, the medial arch correction 2 more degrees of change, and the Kirby Skive another 2 degrees of varus change. So what happened?

When I measured Charles in his 50 degree Inverted left and 20 degree Inverted right, his resting heel position was 4 degrees everted left, and vertical right. So something positive is happening. I will give him 3 to 4 months to get used to, and then crank up the left again. Why? This is a big question. Even with the original left of 35 degrees, Charles felt very good. But, I can not lose sight of what we are trying to prevent. Surgery. With that at stake, I tend to go for perfect support more aggressively.
The photo below of the left is the same as above. It is hard to see the exact 4 degree angle in this photo, but you can probably note the heel still pronating on the device and moving to the outside (lateral) part of the heel cup. See how the better corrected right foot sits down well in the heel cup in the photo above. My heel cups for most Inverted Technique patients range from 21 mm to 27 mm, so they are deep adding to the control of the heel motion.

Below is a photo of Charles' left heel in his original orthotic device. Goniometer readings had this at 9 degrees everted.
Here a goniometer with one arm along the floor and the other arm along the heel bisection is measuring that initial 9 degrees everted position. What you can not see is that orthotic was reinforced in the medial arch by the well meaning podiatrist to get more support. Any time you don't really control the everted position, and you remove the flexibility of the arch by arch fills for reinforcement, you run the risk of making a very uncomfortable orthosis. As was this one.

In conclusion, the inverted technique is used very successfully in these severe pronators. But, because of the posterior tibial weakness and the length of time the foot has been flat and the soft tissues have had time to contract, the exact degree changes can be unpredictable yet logical. I present Charles since his challenge comes to my office routinely and I will be working on his third left orthotic device in the near future. And I feel really proud of what I can do for him!!

No comments:

Post a Comment

Thank you very much for leaving a comment. Due to my time restraints, some comments may not be answered.I will answer questions that I feel will help the community as a whole.. I can only answer medical questions in a general form. No specific answers can be given. Please consult a podiatrist, therapist, orthopedist, or sports medicine physician in your area for specific questions.