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Bobcat -> Re: Transverse Myelitis and Genu Recuvatum (April 22, 2000 3:26:00 PM)
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Well, DP, your description was well-rendered. Your follow-through, however, was non-existent.
This is a part of the solution:
Presumptions:
1. The child was motorically normal prior to the transverse myelitis, and was accustomed to a normal gait cycle and speed.
2. There are no cognitive impairments.
3. The transverse myelitis has impaired the child's control in a manner similar to a partial/incomplete spinal cord transection.
4. Left LE lacks consistent antigravity support capability; extensors and flexors are approximately equally affected, proximal and distal segments are approximately equally affected.
5. "Strength" impairment in the affected limbs are due to motor recruitment reduction and reduced conduction rate of voluntary fibers, as well as decreased sensory feedback during a volitionally executed task, which will decrease motor output per specific task, especially automatic responses modulated by conscious control.
Comments:
Positional states of knee hyperextension and excessive lumbar lordosis are components of a mechanically stable configuration that typically establish stable columnar support for erect stance. The other evident components include hip extension and pelvic anterior tilt.
The configuration can be maintained passively by aligning body segments relative to an assigned neutral line of gravitation such that influence of gravity is effected counter to existing passive soft tissue constraints.
Though statically stable, the configuration can be used to provide brief yet reliable, stable support for transitions to dynamic postures, as during mid and terminal stance.
As a result, the position may be energetically favorable and no motor activity or effort and delay of recruitment is necessary to sustain the position within a certain range of deflection of the so-called "thrust line". In turn, it may also be behaviorally favorable from the child's perspective, because the static stability is known to be more reliable than attempting active antigravity control, and it also feels "locked in" and safe.
In this particular case, the child locks into knee hyperextension upon L sided loading to establish a stable support column on the left side before pushing off to support on the right. If one tries to decrease the child's reliance on the stable knee hyperextension position, it must first be well established that there is effective active control at the knee, and that the control is sufficiently rapid and forceful, and finally, that it is responsive enough in terms of sensorimotor communication to catch the trunk should the unsteady knee begin to buckle. If one does not establish this capability, though one can brace the ankle to force relative flexion at the knee with one result being collapse of the knee extensor mechanism, and a fall, or, a compensatory extremely short stance time on the impaired side. In transverse myelitis, it is not only the sensory delay but also the motor delay of transmission, so that even though the child can generate a contraction of sufficient strength, the event may not happen quickly enough.
Therapies to address knee control are PNF contract-relax and rhythmic stabilization methods. Motor level electrical stimulation is effective if the child can tolerate it.
Some specific things that can work:
Stand the kid up against the wall. Nudge her onto the weak side and give firm manual support and assurance. Weak knee should go into hyperextension, otherwise there may be a loss of static position. Manually move the knee out of hyperextension into neutral and then flexion. Observe for attempted compensatory movements above the leg, and also knee extensor and flexor activity, as well as ankle stabilizing activity (in terms of motor reaction). Observe for sufficient motor activity and speed to sustain a flexed knee position using the wall for some friction. You can modify this by using a tilt platform (table) to decrease the load due to gravitation and then modulate the influence of the load vector. To coax the child into moving the knee into flexion -- try a teletubby on a string -- you know -- bump the teletubby with your knee, etc.
You can also do more traditional PNF contract relax methods but I doubt the child will pay any attention.
Another thing to try is to sit the child and have her do either:
a) cycling
or
b) rolling a ball with the foot.
If you have her cycle, you can apply force through those phases of the cycle where you would expect knee extensor recruitment and activation and encourage it with tapping or timed E-stim. Or bribery with candy and toys. If you use the ball, you must apply greater manual constraint of lateral deviation off the ball, but the ball is usually more fun, and because it allows more degrees of freedom at the terminal end of the closed chain, much more positional sensory feedback is afforded, as compared to the cycle, where more joint compression though sagittal directions are provided (assuming there are receptors available to pick up the movement).
If there is a sensory deficit impairing motor output, strap on a cuff weight, usually distally, to increase sensory feedback due to sheer load and also inertia, or, if you are brave, firmly tape theraband along the lateral and anterior aspects of the leg - directly to the skin. This acts as a contractile external circuit, so to speak, in which tension occurs during certain movements and can provide both cutaneous and out of the ordinary motor resistive effects against desired movement which can effectively bombard a sensory impaired motor behavior with information that it needs. Tapping doesn't hurt either.
You can also translate some of these methods to the giant foam hotdogs.
There are some things you can do with theraband in standing, but these methods are usually not effective with children.
Other obvious measures are knee extensor control exercises gravity reduced in water, and via sling support in a sling-pulley setup. I can elaborate on this if anyone's interested.
That partial weight bearing gait device Drew promotes would probably be very useful also.
[This message has been edited by Bobcat (edited April 22, 2000).]
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