Mechanical Vibration
M. L. H. Arnold Snow, M.D.

Chapter 5

General Physiological Effects of Mechanical Vibration

    MASSAGE AND MECHANO-EXERCISE have been investigated for many years, and of late vibration, manual and mechanical, has received attention.  As certain facts and principles have been considered by Ling, Maggiora, Colombo, Mezger, Sargent, Kellgren, Cyriax, Savage, Taylor, Graham, Kellogg, Fleisch, v. Marxow, Buchheim, Saquet, Meltzer, Lagrange, Bechterew and Tschigajew, Langendorff, Axenfeld, Lange, Mesnard, Lavalette, Hasebroek, Winternitz, Kumpf, Ewer, Bjorksten, Zander, Abrams, Ledermann, Nebel, Granville, Charcot, and others, it is fitting to recognize their efforts.  Beginning with the work heretofore accomplished, it will be possible to approach a more complete system.  For a full appreciation of the subject it is necessary to recall certain anatomical and physiological data.

    MECHANICAL -VIBRATION when applied in accordance with varying rapidity of speed, length of stroke, degree of pressure - light, moderate or heavy - is capable of affecting every tissue and organ in the body, with varying degrees of intensity.  The EFFECTS may be classified as follows:

1. MECHANICAL - It induces the removal of extravasations, lymph, exudations and transudations, breaks up adhesions and stimulates the circulatory and lymphatic systems.  It improves respiration, stimulates excretion and secretion, relaxes over contracted parts, and contracts relaxed parts.

2. CHEMICAL - It assists in the interchange of oxygen and CO2 and in the increase of certain waste products such as sarcolactic acid.

3. THERMAL - It causes the generation of heat; vibratory friction increases heat elimination, and deep interrupted vibration-with moderate or heavy pressure by acting on muscles increases heat production.  Cutaneous and vaso-motor stimulation affect the storage of heat, for contraction of the skin and its blood-vessels diminishes the heat evolved.  If they dilate it is increased.  If stimulation [Landois and Stirling.  Text Book of Human Physiology, 4th edition, page 410] of sensory nerves causes the circulation to, be accelerated, the respiration to be increased, the skeletal muscles to be relaxed, "the temperature of the interior of the body and rectum is increased."  If stimulation of sensory nerves causes the circulation to be retarded, respiration to be decreased, and the skeletal muscles to be contracted reflexly, "the temperature of the interior of the body and rectum is diminished."  "External parts [Landois and Stirling.  Text Book of Human Physiology, 4th edition, page 411] give off more heat than they produce, so that they become cooler the more slowly new blood flows into them, and warmer the greater the rapidity of the blood stream through them."  The temperature of internal parts falls" when the blood stream through them is accelerated and it is raised when the blood stream is retarded."  An increased temperature means an increase in the number of heart beats, according to Liebermeister [Landois and Stirling.  Text Book of Human Physiology, 4th edition, page 419].

"Pulse beats per minute....... 78.6     91.2     99.8     108.5     110     137.5

Temperature in C.............    370       380       390       400        410      420."

4. PHYSICAL - It assists endosmosis of the lymphatics and the physical action of respiration.

5. METABOLIC - It induces anabolic or katabolic changes affecting the functional activity of a part as in the removal of stasis and an increase in the nutrition of a poorly nourished muscle.

6. REFLEX - It induces activities and changes in related parts through the nerve stimulation of the central and peripheral parts of the cerebro-spinal and sympathetic systems, as in its action as a sedative.

    The following, by Taylor [Massage], is of interest: "The analysis of transmitted motion into its factors, and the discrimination of the separate, distinct effects of these, is of direct consequence for estimating the influence of different rates of rhythm or length of motion-waves transmitted.

    "We may presume that the heat evolved must pretty closely correspond with the rectilinear extent of the motion and the accompanying pressure whatsoever the length of the waves.  On the other hand, the chemical products are in proportion to the number of changes of direction into which this imaginary direct line of motion is broken up, for every concussion which accompanies change of direction throws off energy in the chemical form, doubtless increasing the oxidation and other chemical changes to which all constituents of the organism are by nature destined, and the promotion of which all curative processes must include.

    "But the evidences derived from chemical analogies and chemical facts are by no means the conclusion of the array available.  Those ordinarily satisfactory are abundant.  These are clinical tests.  The peculiarity of this class of evidence of chemical effects consists in removing obstinate local and general manifestations of disease, for which the most potent chemical remedies are commonly employed with far less conclusive success.  This effect of rapid wave or vibratory motion shows that profound chemical changes are superinduced by the means used, which in this case can only be liberation of chemical energy in contact with material having unstable equilibrium - the non-vital suboxides."


1. Cardiac activity is regulated.  Blood pressure may be lowered reflexly.  It may be raised also.

2. Contracts arterial blood vessels. If prolonged, dilatation results.  Pulse rate may be lowered.

3. It induces many reflex effects as well as motor, sensory, secretary and vaso-motor effects.  It lessens and removes hyperactivity of nerves.  It diminishes pain and relieves congestion not due to organic conditions.

4. Diminishes and relieves muscular pain and stiffness.  It can relax tense muscles and cause relaxed and atrophied muscles to become firm and increase in size.  It tones up cardiac muscles.

5. Reflexly induces contraction of the lungs.  Relieves pain and dyspnoea.  Improves respiration.

6. Diminishes size of glands, directly and reflexly.

7. Contracts or dilates the liver, stomach and spleen.

8. Diminishes irritability of the bladder when not due to organic conditions.

9. Induces peristalsis.

10. Increases or diminishes lymphatic circulation according to the vibratory friction given, centripetal or centrifugal.

11. Assists in diminishing intraocular tension.

12. Lessens nasal hyperemia.

13. Suction vibrations are valuable in removing pus from a boil, etc.

    Vibration, having a marked effect on respiration, digestion, absorption, heat, secretion, excretion, the nervous system, the muscular system and all physiological processes which are affected by active change, it is necessary that the anatomical relations, the physiological function, the blood, nerve and lymph supply of each organ or part of the human body be thoroughly understood in order to more fully appreciate faulty technique, for too often vibratory work is misdirected, energy is misspent, and mechano-vibration or the particular vibrator used, is condemned.

    THE PHYSIOLOGICAL EFFECT OF VIBRATION, according to Reich, is to increase "the excitability as well in the motor as in the sensory nerves if the excitation continues for a short period, but to lessen the excitability if the time given for the vibration or concussion is prolonged.  Therefore we have reason to believe that small excitations of long duration have the same effect upon the nerves as strong applications which only work once, according to Pfluger-Arndt's law.

    The skin will be pale after a short application of vibration (high frequency), but will redden after a longer application.  Therefore a contraction will be at the beginning sometimes even contraction of muscles of the skin, while vaso-dilatation will ensue in the further application." He believes that general vibration increases the blood pressure, accelerates the circulation, increases absorption and the secretory power of glands.  Mechanically it can favor the expulsion of gall and kidney stones.  Reflexly when vibration is applied "in the region of the roots of the spinal cord, especially of the neck a general sense of cold results." The writer has noted this when the vibratode is applied over the exit of the second cervical nerve.  If applied to the spinal cord in the interscapular region a decrease in heart rhythm ensues.  "Manipulations of short duration will have a stimulating and tonic effect while prolonged vibration will have a quieting, analgesic, sedative effect; therefore use short but often repeated vibrations in cases of paresis, cutaneous anesthesia and when used as an analgesic.

    "In relaxations of contractile tissue, in weakness of the heart, in floating kidney, in relaxations of the uterus, in hemorrhoids and prostatic hypertrophy, for the sensations of lassitude of neurasthenic patients - in all these conditions use short but often repeated vibration.

    "The prolonged vibration should be used in neuralgia, hyperaesthesia, spasms, tremor, paralysis agitans, insomnia and all conditions of general excitability.  Also use prolonged vibration for the mechanical effect; for instance, for the expulsion of kidney and gall stones.  Sometimes the treatment may be given for as long a period as one-half hour.  (Reich.)

    Throughout this work the word "vibration" is used to include vibration of all frequencies.  Some writers prefer to call vibration of low frequency concussion."

    THE FOLLOWING DEDUCTIONS WHEN SPINAL CONCUSSION or vibration was employed, have been noted by Abrams [Spondylotherapy] and the author.

1. Contraction of the myocardium associated with the heart reflex of contraction.  It increases pulse volume and diminishes frequency.

2. If the heart is weak and blood-pressure is high, a strengthening of the heart will cause fall of pressure by vibration of 7th cervical spine.  Concussion properly applied can cause fall of blood pressure.  Vaso-dilators in drugs reduce blood-pressure by "paralyzing the vaso-constrictor mechanism."

3. If the heart is weak and vaso-motors do not compensate the failing heart, a strengthening of the heart causes rise of blood pressure by vibration of 7th cervical spine.  Concussion selectively applied can raise blood pressure.

4. Heart reflex of dilatation increases area of cardiac dullness associated with no increase in diameters of heart as "heart muscle can increase the size of its cavities without any corresponding augmentation of tension of its walls."

5. The aortic reflex of contraction is associated with stimulation "of the vaso-constrictor nerves or their centers in the cord.  They emerge with the anterior roots as preganglionic sympathetic fibres."

6. The aortic reflex of dilatation is associated with stimulation of the vaso-dilator nerves or their centers in the cord.  They emerge with the posterior spinal nerves.

7. Stimulation of the longitudinal muscular fibres of intestine occurs in intestinal reflex of dilatation.

8. Induction of contraction of circular fibres occurs in intestinal reflex of contraction.

9. The excretion of indican is promoted after 15 minutes' concussion of first three lumbar vertebrae or corresponding intervertebral vibration between the 1st and 2nd and 2nd and 3rd lumbar vertebrae.

10. An increase in volume of liver occurs in liver reflex of dilatation by concussion of llth dorsal vertebra.

11. Depletion of liver induced by liver reflex of contraction.

12. It augments the tone of the splanchnic vasomotor mechanism by expressing the blood from the abdominal vessels to the right heart, by concussion of the spines of 2nd, 3rd, 4th, 5th, 6th, 7th and 8th dorsal vertebrae which correspond to splanchnic nerves from the 5th, 6th, 7th, 8th, 9th, 10th, 11th and 12th dorsal nerves or by corresponding intervertebral vibration.

13. It has a mechanical effect on the spleen by concussion of first three lumbar spines or corresponding intervertebral vibration causing a reflex contraction of the spleen.

14. It induces dilatation as well as contraction of kidney thus varying its volume which depends on structural distension and amount of lymph, and blood in its vessels.

15. Concussion or vibration "stimulates the motor component of a spinal segment and subdues its sensory constituent."

    The effect of vibration has been appreciated for a long time, as noted by Snow in his work, "Static Electricity and the Uses of the Roentgen Ray," as follows:

    "The action upon metabolism of vibratory influences has long been recognized by physiologists such as that attributed to the heart's impulse.  Dubois-Reymond taught 'That the nutritional effects depend not on the quantity of the electricity but upon the variations in the quantity, and the suddenness of these variations,'" which is true as applied to vibration, but requires qualification in various features of administration.

1. The vibration should possess the necessary rapidity and length of stroke.  Exerted pressure should be painless or according to tolerance.

2. The rapidity, stroke, pressure or non-pressure should be governed by the indications and the patient's reactionary resistance.

3. The interruptions when using interrupted vibration should be limited in number to avoid exhaustion in nerve power.

4. The intervals of rest should be as long or twice as long as the period of impulse contact to assist in the perpetuity and fixedness of the effect.

5. The stroke should be adapted to the density of the part treated, and the speed to the condition.

6. Vibratory effects should be applied to aid or promote functional activity of a part without altering the integrity or unfavorably affecting, the normal activity of the part.

7. The effect directly or indirectly will vary with the duration, speed, direction and pressure used in the treatment.

    Cyriax ["Vibrations and Their Effects." Lecture given before the Ling Association, London, on Jan. 5, 1900, by Edgar F. Ciriax, M. D., G. D.] summarized an exhaustive study of the effect of vibration in which he considered both manual and mechanical vibration.  The following is a brief summary of his observations.

    "The great majority of the conclusions quoted are obtained from experiments with machine vibrations."

1. "EFFECT ON THE CELLS of the human body.  Fleisch V. Marxow set up the theory that the (vibrations) minute shocks imparted to the cells of the lungs by the heart beat were necessary for the gaseous interchange, that these were in fact a sine qua non for actual existence.  Other observers have concurred in this.

2. "EFFECT ON BACILLI.  Saquet found no change in the growth and characteristics of bacilli after eight days' continued vibration, whereas Meltzer found destructive effect with shorter time of vibration.

3. "EFFECT ON THE TEMPERATURE. Taylor, Lagrange, Saquet found a rise of temperature after using vibrating machines.  Bechterew and Tschigajew, using vibration of the whole body, found a rise in the internal temperature and a fall in the skin and axillary temperatures.

4. "RELATION BETWEEN SPEED AND EFFECT.  Langendorff, using a tuning fork on a nerve, found the maximum result with 4800 oscillations per minute.  Axenfeld with the same kind of apparatus considered that up to a certain point the slower the rate the better, as the amplitude of the movements of the tuning fork was then greater.  Lange concluded that a rate of 1100 to 1200 per minute produced the greatest effect."  Mesnard caused muscular tetanus with 15,000 vibrations per minute.

5. ON THE MUSCLES.  Muscular contraction was induced. (Rood, Lavalette.) Mesnard used "very rapid vibrations" to cause contractions.  Ewer "states that vibrations can sometimes cause contraction in muscles which will not react to electrical stimuli."

6. ON THE HEART.  It diminishes excited cardiac action (Winternitz, Levin, Hasebroek, Nebel, Ziegelroth).  "Achert and Siegfried found very little effect, and Bechterew and Tschigajew a varying one.  Heitler found that vibration of the heart set up by the so called hacking over it raised the tone of the cardiac muscle and diminished the size of the organ.  A strong manual vibration on the heart is one of the best methods of causing it to beat again" when the heart ceases to beat (Strassmann, Korte and Kurnpf).  Some consider that heart vibration acts reflexly and others that it acts directly.  On the blood vessels it causes contraction and rise of blood-pressure according to Bjorksten, Zander, Bechterew, and Colombo, which according to some is followed by a dilatation and fall of blood pressure.  The writer finds that it may raise or lower blood-pressure.

7. EFFECTS ON NERVES.  Bechterew and Tschigajew by vibrating the whole body induced sleepiness in about a quarter of an hour.  The vibrating casque of Charcot has been extensively used in France to promote sleep.  Vibration diminishes pain.  "Buchheim obtained stimulatory effects on the sympathetic and vagus in the neck according to the site of application."


9. GLANDULAR CONSTITUENTS, solid and liquid, of liver, stomach, etc., are increased by "a combination of petrissage, friction and vibration."  (Colombo.)

10. IT PROBABLY INCREASES OR DIMINISHES THE FLOW OF LYMPH according to the direction of the running vibrations used, - centripetal or centrifugal.



    Cyriax has probably compiled the most exhaustive summary extant on the effects of the Kellgren method of manual vibration.  The same effects have been verified in many instances by the writer with mechanical vibration.