The Vault

Our Dancing Motor Units

By Deborah Caplan


Teaching the Alexander Technique is a challenge, particularly since it is so unlike other disciplines. I have often said to a questioner, as I am sure you have too, “No, the Alexander Technique is not exercise,” (or manipulation, or massage, or hypnosis, or Yoga, or meditation, etc...). Because of this ‘unlikeness,’ it is indeed a challenge to teach such Alexander principles as ‘non-doing,’ ‘inhibition,’ and ‘non-endgaining.’ It can be quite difficult, particularly with over-zealous students, to get across the message that ‘allowing’ gets better results than a lot of hard work.

I have found help with this problem from one aspect of mind-body interaction that I refer to as ‘Our Dancing Motor Units.’ When I tell my students about our motor units, and how we can, with just a thought, influence their activity, the power of a thought becomes much more real.

What Is A Motor Unit?

When we decide to do, or not do, something with our skeletal muscles, this instructive thought must journey along many connecting pathways to reach its destination. A motor unit is the final segment of this journey. The motor unit starts in the spinal cord and goes out to the muscle fibers we want to influence. Each motor unit consists of a single motor nerve cell and some muscle fibers.

The main part of the motor nerve cell is its body, which lives in the spinal cord (see illustration opposite). Since this motor nerve cell must reach muscles that may be far away, it has a long tail. This tail is called the axon. The nerve cell body plus its axon is called a motor neuron. When the axon reaches a muscle, it attaches to some of the fibers in that muscle via a number of small branches, thus becoming what is called a motor unit. The motor unit, therefore, consists of a single nerve cell body, its axon, and the muscle fibers it activates.

Conscious Control Or Thinking To Our Motor Units

As a physical therapist I was occasionally required to refer to a textbook on electromyography titled Muscles Alive, by John V. Basmajian, (Williams & Wilkins). Electromyography (EMG) is the study of nerve-to-muscle activity. When I first looked through this weighty text, I was surprised to find a chapter bearing the title "Conscious Control and Training of Motor Units and Motor Neurons.” Having the soul of an Alexander teacher, the term ‘conscious control’ drew my interest, and I read the chapter. My efforts were rewarded with some fascinating information concerning our thoughts, our muscles, and our ability to make choices. Here is some of the information this chapter yielded:

[The researchers] demonstrated the existence of a very fine conscious control of pathways to single spinal motor neurons. Not only can human subjects fire single neurons with no overflow, or perhaps more correctly, with an active suppression or inhibition of neighbors, but also they can produce deliberate changes in the rate of firing.... Almost all subjects are able to produce well-isolated contractions of at least one motor unit, turning it off and on without any interference from neighboring units.1

I also read that some people could vary the activity of their motor units to such an extent that it was like making them dance (‘dance’ is my word, it does not appear in the textbook). Since EMG equipment includes a speaker to translate motor unit activity into sound, the researchers noted the following:

When the more able subjects are asked to produce special repetitive rhythms and imitations of drum beats, almost all are successful (some strikingly so) in producing subtle shades and coloring of internal rhythms. When tape-recorded and replayed, these rhythms provide striking proof of the fineness of the control.2

This research informs us that we can influence one motor unit at a time. This is indeed fancy thinking, because each muscle has many, often hundreds, of motor units. I also learned in this chapter that inhibition of motor unit activity can be as finely controlled as activation, and that “any skeletal muscle may be selected.”

These EMG studies demonstrate that we, as human beings, have evolved to the point where we have the potential for very sophisticated, selective conscious control over our skeletal muscles. I like to explain to my students that the Alexander Technique is a discipline that enables us to fulfil this potential. The elegant mind-body connections that are our evolutionary heritage give us the ability to make choices about our use. The Alexander Technique teaches us how to make the right choices.

As the Alexander Technique continues to grow as a profession, I see it enriching other disciplines and, in turn, being enriched by information from other fields of study. Knowing that we can make our motor units dance to a tune of our choice does not, in itself, enable us to function as well-integrated mind-body entities. But when we turn that dance into released necks, poised heads, lengthening and widening backs, free shoulders and legs, our dance becomes a dance of joy. ■


1. Basmajian J.V., De Luca C.J., Muscles Alive, 5th ed. (Baltimore, Williams and Wilkins, 1985) pp 170, 172.

2. Ibid., p 173.


Deborah Caplan received her Alexander certification in 1953 from Alma Frank, and her MA in Physical Therapy from New York University in 1956. She studied with F.M. Alexander, and is a founding member of The American Center for the Alexander Technique, Inc., where she is a senior faculty member of the Teacher Certification Program. Deborah was affiliated with New York University Medical Center for eight years, and lectures extensively to physical therapists on the Alexander Technique. She is the author of Back Trouble: A New Approach to Prevention and Recovery Based on the Alexander Technique (Triad, 1987). Deborah specializes in teaching the Alexander Technique to people with back problems.

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