LOW INTENSITY THERAPEUTIC ELECTRICAL STIMULATION

Thanks to a therapist friend, Karen Karmel-Ross in Cleveland, I became interested in the use of electrical muscle stimulation in the late 1980's. Though her published work focused on improved quadriceps strength and gait in children with Spina Bifida, my interest was focused more on possibilities to assist other postural groups to activate more readily and simultaneously. Karen's shared knowledge about flexible low impedance electrodes allowing much better tolerance of the sensation of ES in younger children, was very helpful. Through a small grant, 2 Statodyn EMS2 units and enough 1 1/2 X 3 inch Encore electrodes were purchased to allow each of 6 therapists a trial each with single child during therapy sessions. The results of up to 4 site simultaneous stimulation, using bifurcation lines, were fascinating.

Messing with electrodes and wires soon took it's toll on the interest level of several of my colleagues, but the very positive results with one 2 year old boy with spastic diplegia, a 10 year old girl post selective dorsal rhisotomy and a rather cantankerous 12 year old body with hemiplegia and severe left side neglect spurred my continued exploration of this therapeutic medium. Travis, the 2 year old with moderate spasticity and movement control deficits, was just beginning to attain free standing balance in therapy. Firm manual input to abdominals, gluteals and quads seemed to help him find and activate the muscle groups simultaneously, but he was unable to sustain this for longer that a few seconds on his own. Low intensity(2-2.5 on a scale of 10) ES to quads and gluteals, increased his ability to activate and sustain activity in these muscle groups to support balance, single and dual support stance many fold. Interestingly adductor spasticity faded from high moderate range to mild when the ES was turned on and I was able to challenge Travis to work his legs in much more difficult ways. Though he also needed verbal cueing, independent controlled non-propulsive steps emerged in therapy with the ES on. Over the next 2 years, Travis moved through marginal free ambulation to secure free ambulation and running. His function was so dramatically improved with the ES that I felt obligated to let him borrow a EMS2 unit for home use. Soon, thereafter, as parents were preparing to purchase more expensive EMS2 unit, we discovered that an inexpensive TENS unit worked equally well and the family purchased this for 1/10 the cost.

Deep sensory information provided by low pulse rate (30-60pps) low intensity TES supports improved muscle activation and active control, not only in the groups stimulated, but in adjacent posturally connected muscle groups. Travis described it once, "I can feel my muscles. It goes bam, bam, bam, bam!" Another older boy with moderate diplegia remarked that it made his "muscles fizz." Still others could feel nothing , but active loading over legs, balance and postural stability in upright was significantly improved with the TES.

In addition to improved deep sensation, there may also be a direct subcontractile effect which improves the readiness state of the muscle and supports continuation of active contraction for postural synergies. Persons with neuromotor control deficits appear to have more difficulties controlling eccentric (stabilizing and decelerating) muscle contractions which are common components of postural loading strategies. Concentric (movement generating) contractions appear easier, perhaps because they provide inherently more proprioceptive feedback.

More recent availability of the Octostim Unit which was designed by a man with cerebral palsy specifically for this TES function. The unit allows individual adjustment of stimulation to 8 site and is a much more flexible TES for this use.

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