Help in unusual case please

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Patient

Female, early 60’s
Generally healthy and been active in sport and ballet and dance all her life.
Walking was normal and brisk pre incident.

Incident

History of sciatica resulting from significant disc bulge
Had laminectomy 2 years ago to L5/S1
Since then has had numbness to the plantar foot and around the heel and slightly up into the Achilles - bilateral


Main concern:

Is in her current walking ability. Walking post surgery is problematical in that she is unable to initiate unilateral heel lift in gait.

Observations

1. In bilateral stance, she can initiate a slight jump (swinging her arms upwards) that allows her then to go up onto her toes. This involves a slight forward lean and use of the arms to generate power. Once there she can maintain it a while but does exhibit weakness by starting to go over laterally at the ankles.

This cannot be done unilateral

2. Once on her toes bilaterally, unilateral toe walking is possible but at huge energy expenditure, instability and use of the whole upper body in a manner resembling someone with marked co-ordination problems.

Conversely, heel walking gives her a sense of normal walking without the need for the exaggerated pelvic and hip function and marked torso and arm rotation


3. When walking she has to exaggeratedly rotate the pelvis and torso, slightly hitch the pelvis to generate unilateral forward propulsion as she cannot generate heel lift.

4. Slightly heeled foot wear makes no difference in ability to initiate unilateral stance.

5. Standing with knees slightly flexed, bilateral or unilateral, does not help in initiating heel raise

6. NWB dorsiflexion and plantar flexion power against resistance is normal but there is poor eversion and inversion power against resistance.

7. Has reduced calf bulk bilateral, especially soleus

8. She has been informed by a neurological consultant that nerve conduction tests show irrevocable degeneration of the nerves to the low leg, Achilles reflex is very poor to none existent bilateral.

Current considerastions

Am considering footwear adaptations that may allow some roll onto the ball of the foot to see if that helps. I feel something like the MBT with its negative heel is not appropriate for gait because postural stability is already compromised, however, at the back of my mind I do wonder if they might serve as an exercise function in stance only to see if anything could get the triceps waking up (badly put but been a long day!!).

Equally, I wondered if there is any material that could be used in the heel that would give adequate energy return that may help in unilateral heel raise. Trouble is I don’t know if it is unilateral carrying of body weight that inhibits further the initiation of heel lift or if it is just a neurological issue that cannot be overcome no matter what we do.

Thoughts and suggestions would be valued even if it is just a case of saying we can’t do anything.

Thanks
Ian

 

Hi Ian
Heres my 2 cents...

Maybe as an experiement you could get EVA heel lifts that finish just behind the metatarsal heads of various heights.

ie 2mm - 4mm - 6mm - 8mm - 10mm -12mm etc

Spend some time with her put in the lifts get her to walk around maybe film gait after a few minutes and then with her option and what you detect workout if a various size heel make any difference with gait.

You may also want to try a foot and ankle device - There are devices with are called toe-off. which help in creating a plantarflexion moment at the ankle joint.This is created through the tibia moving forward with knee flexion, as the knee flexes increased load is placed on a graphite plate under the foot, which flexes and this aids in heel lift. This may give the patient some feeling of greater support due to the greater surface area contact. A P & O maybe able to help here.

Hope that helps some.

 

No. 6 doesn't fit with the other observations. How's inversion/ eversion strength?

Going back to the Hicks paper, you need ankle plantar flexion power to get weigth on to the ball of the foot. A rocker bottom shoe will shorten the lever arm of ground reaction force to create a dorsiflexion moment at the ankle. (= less resistance to plantar flexion moment from Achilles.) However, if the Triceps Surae can't develop enough force, you will never get the center of pressure far enough forward to make the shoe rock. (Imagine putting your finger inside of a rocker shoe and pushing downward. Your finger is the cente of pressure. The shoe will not rock until your finger is distal to the rocker point. Everyting points to a very weak Triceps surae, except the NWB exam. Especially the decreased calf circumference. If the nerves aren't there, you're not going to get much of an excercise effect to increase strength. However, you need to figure out why you are seeing plantar flexion power non weight bearing. Are you resisting with anything near her body weight. The peroneals and post tib and FDL are very weak ankle plantar flexors because they have such a small lever arm at the ankle. Is she starting to get a hallux hammertoe from using FHL as an ankle plantar flexor?

The problem with "springs" in the heel is the timing of heel off. If you watch a "normal" gait, the heel contacts the ground and then stays on the ground while the body pivots over the ankle. Then the heel raises. You have to get the springs to wait before they can push the heel upward. How long they have to wait is going to vary on the speed of the gait.

A different approach is to store energy in a spring at the ankle. There was an interview on the Colbert Report with a woman athelete who had a BK amputation and talked about using different prostheses for different activities. This is probably related to the timing of the energy return from the flexible "feet". If you had a research facility, and plenty of time, you might be able to create an AFO that could act like those prosthetic feet for that amputee.

Good luck to you and her,

Eric

 

A SACH might help with absorbing the impact and a very small return of energy, that depends on the compound used in the SACH.

But l think for footwear l would consider a simple rocker heel first, although that will depend on the length of the clients stride.

From heel strike as the weight moves forward of the fulcrum you are getting the heel lifting off the ground from its initial strike point, but its the follow through that you want to see and the rocker toe may give that to you?

Also consider the clients balance, she is a past dancer, but as you present a rocker bottom to the soles you are making the base of the shoe smaller.

l think you are wise staying clear of the MBT type footwear with this client, not because of the negative heel, but because the overall structure of the shoe creates instability through out gait and during stance

 

Hi Mike and David

Thanks for the input and I will look into the things you mention. I have an O&P friend who I may refer her to but I'll play some more with the lifts before I refer on.

Eric
You wrote: No. 6 doesn't fit with the other observations. How's inversion/ eversion strength?

Which you correctly pointed out does not seem right. At the end of the day it is what's there unfortunately. Inversion and eversion strength is quite poor.

Your comments on centre of pressure were helpful and I'll give more thought to it along these lines as well.

I'll feed back when I have seen her next time.

Than ks
Ian