Study page ~ ‘The Weber-Fechner-Henneman Movement Optimization Cycle’  (Russell 2017)

“Roger Russell, M.A., PT, trained with Moshé Feldenkrais in San Francisco, Amherst, and Israel (1975 – 1982). A movement scientist, physical therapist, and Feldenkrais trainer, he is co-director of the Feldenkrais-Zentrum in Heidelberg, Germany. Since 1975, he has been intrigued by the network of ideas, including neuroscience, which stands behind the practical methods that Feldenkrais developed. He is one of the initiators of the Feldenkrais Science Network and a leading participant in the FGNA/FEFNA symposia Movement and the Development of Sense of Self (2004) and Embodying Neuroscience (2012). ”

‘The Weber-Fechner-Henneman Movement Optimization Cycle’
by Roger Russell 2017 in The Feldenkrais® Journal!


Know-how and know-what

Muscle fibers and the Henneman size principle

Sensory feedback and the Weber-Fechner principle

The Coordination Cascade
1 The brain initiates and plans movements based on our self-image, and directs
2 the coordination cascade through the nervous system leading to
3 the spinal cord, where the Henneman size principle results in
4 specific (size-dependent) recruitment of muscle fibers which
5 enables optimal biomechanical organization of the ongoing
6 including force optimization, smooth movements, and
reversibility of the movement pattern
7 which by way of the Weber-Fechner principle increases
the sensitivity of the proprioceptive feedback networks
8 clarifying the body image, and resulting in more efficient
plans for the next coordination cycle. Movement coordination improves as the Feldenkrais lesson unfolds.



© Copyright Roger Russell 2017 for all images. Art: Bettina Beiderwellen, Speyer, Germany. Coordination Cascade: Susanne Mertner, Nördlingen, Germany and Stefanie Ho , Saarland, Germany.

1 ER Kandel, JH Schwartz, TM Jessell, Principles
of Neural Science, 4th ed. (New York: McGraw- Hill, 2000), 419-428. The most comprehensive English-language source on Fechner is Michael Heidelberger, Nature from Within: Gustav Theodor Fechner and His Psychophysical Worldview, Cynthia Klohr, trans. (Pittsburgh: University of Pittsburgh Press, 2004). Heidelberger’s book also serves as an excellent introduction to Weber’s work.

2 Elwood Henneman, “Relation between size of neurons and their susceptibility to discharge,” Science 126 (1957), 1345-1347

3 Simon Blackburn, Oxford Dictionary of Philosophy (Oxford: Oxford University Press), 123.

4 RS Reber, “Implicit Learning and Tacit Knowledge,” Journal of Experimental Psychology: General 118, no. 3 (1989), 219-235
5 LR Squire, D Berg, FE Bloom, S du Lac, A Ghosh, NC Spitzer, Fundamental Neuroscience, 4th ed. (Amsterdam: Academic Press–Elsevier, 2013), 616–651.

6 Moshe Feldenkrais, Body and Mature Behavior (Tel Aviv: Alef Publishers 1947/1988).

7 Kandel et al., 683–687.

Fig 1 Schematic diagram of a transected muscle showing the three muscle fiber types

Fig 2 Force and contraction time of:
T) Tonic slow fibers;
F-R) Fast-fatigue-resistant fibers;
F-F) Fast-fatigable fibers

Fig 3 Spinal alpha motor neurons and the three muscle fiber types—the size of spinal motor neuron cell bodies (triangles) matches the muscle fibers they enervate

Fig 4 Brain recruitment of spinal alpha motor neurons and muscle fibers—Elwood Henneman discovered that the size of the neuron cell body determines the order in which motor nerves and their muscle fibers are recruited

8 NA Bernstein, “On Dexterity and Its Development,” in ML Latash and MT Turvey, eds., Dexterity and Its Development (Mahwah, NJ: Lawrence Erlbaum, 1996); DA Winter, Biomechanics and motor control of human movement, 2nd ed. (New York: Wiley-Interscience, 1990).
9 Elwood Henneman, EG Somjen, DO Carpenter, “Functional significance of cell size in spinal motoneurons,” Journal of Neurophysiology 28 (1965), 560-580; Elwood Henneman, EG Somjen, DO Carpenter, “Excitability and inhibitability of motoneurons of di erent size,” Journal of Neurophysiology 28 (1965), 599-620.

10 KV Kardong, Vertebrates: Comparative anatomy, function, evolution, 3rd ed. (Boston: McGraw Hill, 2002), 375.

11 FW Nutter, “Weber-Fechner Law,” Plant Pathology and Microbiology Publications 71 (2010), accessed online July 27, 2017, plantpath_pubs/7

Fig 5 Subjective experience and absolute stimulus value in the cases of pain, light, and weight

Fig 6 Relationship between force/ weight and just noticeable difference thresholds in different activities—the just noticeable difference (jnd) for muscle effort varies for strength training, endurance, and coordination exercises— using low force in Feldenkrais lessons allows us to sense smaller differences in our movements

Fig 7 Relationship between force/weight and information impact in different activities—turning the curve in Fig. 6 around shows that when force is reduced, the impact of feedback information for our coordination is higher than it is in strength and conditioning exercises done with more effort

Fig 8 The Coordination Cascade illustrates how Feldenkrais lessons refine the functioning of our nervous system—at every level

12 “Gregory Bateson,” bateson/ (accessed July 27, 2017).

13 Roger Russell,Poster: The Coordination Cascade and the Feldenkrais Method, 2014, Feldenkraiszentrum- Heidelberg. This image is a top-down schematic representation of how movement experiments can be directed by the prefrontal system for exploratory fast learning. Multiple sources in neuroscience literature have served as background knowing what for this poster, which is available through the FGNA bookstore.

14 Squire et al., 616–651

Fig 9 The Weber-Fechner- Henneman Movement Optimization Cycle

15 Kandel et al., 661-663 and 726-730.

Pen and ink drawings of “Book on Foot” and “Dead Bird” Feldenkrais Awareness Through Movement lessons by Andrew Dawson, 2016′



Below are links to informal recorded readings of Roger’s article and the references. (our usual password)
The Weber-Fechner-Henneman Movement Optimization Cycle by Roger Russell 2017 (K reading text)
The Weber-Fechner-Henneman Movement Optimization Cycle by Roger Russell 2017 (K reading REFERENCES)