Engineers are interested in skin

For years I've been talking and promoting skin stretch as a not just a good avenue for kinesthetically influencing another human nervous system, but as probably one of the best ways:

1. the easiest, because skin is already out there, the first thing one "touches", and is already set up neurologically, connecting that person's brain with/for contact with environment

2. most practical, because it is the most highly innervated and therefore sensitive, and doesn't require much physical strength or special leverage from a practitioner

3. strongest neurologically, in terms of response elicited for effort made, and results gained for time spent.

It's the easiest way to stimulate physiologic nonconscious movement for the person's own brain to then harness into pain relief of ordinary uncomplicated mechanical pain or stiffness. I've worked this way for a couple decades now. (Elsewhere I've referred to this as "dermoneuromodulation", and to dermoneuromodulation as a major feature of "human primate social grooming.")

Earlier today I found a paper by some mechanical engineering students at Stanford who seem awfully interested in skin stretch. I think they are investigating haptic capacity - maybe they want to build better robots which can carry tea in expensive china without either
a) spilling tea, or;
b) dropping and breaking the china.

It's by Bark et al., and called Comparison of Skin Stretch and Vibrotactile Stimulation for Feedback of Proprioceptive Information; it can be found online (here's an html version I found).

I very much admire the way in which engineers simply read, absorb, accept things that are obvious at face value, and move on to develop cool applications based on research. My profession is so determined to seem scientific on the one hand, yet is so mired in "traditional" ways of applying manual therapy that it won't let go of visualizing everything backwards, from the joints out. See the attached Shaffer paper. (At least it does actually mention cutaneous receptors as maybe being somewhat important for balance and equilibrium...)

But generally, trying to get my own profession interested in the sensitivity and handling of skin is very difficult. It would rather contemplate bones, joints, muscles, and in general, innervation of mesoderm, rather than realize that the brain of a patient is always going to register skin contact first, at multiple levels which will react accordingly.

The Bark paper is loaded with excellent references to do with skin stretch and how it might apply to haptic possibilities for mechanical devices. See at bottom.


Additional Reading:

Shaffer SW, Harrison AL; Aging of the Somatosensory System: A Translational Perspective. (15-page pdf) Physical Therapy Vol 87 No 2 Feb 2007
.

From the Bark paper:
[1] K. Bark.Preliminary results from skin stretch perception tests,http://bdml.stanford.edu/twiki/bin/v...ontesting,2007.

[2] K. Bark, J. Savall, and R. Holop. Measuring skin stretch strain, http://bdml.stanford.edu/twiki/bin/v...roperties,2007.

[3] J. Biggs and M. Srinivasan. Tangential versus normal displacements of skin: Relative effectiveness for producing tactile sensations. In 10th International Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems, pages 121–128. IEEE ComputerSociety, 2002.

[4] D. Caldwell, N. Tsagarakis, and C. Giesler. An integrated tactile/shear feedback array for stimulation of finger mechanoreceptor. International Conference on Robotics and Automation, pages 287–292, 1999.

[5] D. F. Collins, K. M. Refshauge, G. Todd, and S. C. Gandevia. Cutaneous receptors contribute to kinesthesia at the index finger, elbow,and knee. Journal of Neurophysiology, 94:1699–1706, May 2005.

[6] B. Edin and N. Johansson. Skin strain patterns provide kinaestheticinformation to the human central nervous system. Journal of Physiology, (487):243–251, 1995.

[7] B. B. Edin. Cutaneous afferents provide information about knee joint movements in humans. The Journal of Physiology, (531.1):289–297,2001.

[8] B. B. Edin. Quantitative analyses of dynamic strain sensitivity in human skin mechanoreceptors. Journal of Neurophysiology, 92:3233–3243, 2004.

[9] F. Freybergery, M. Kuschel, B. Farber, M. Buss, and R. Klatzky. Tilt perception by constant tactile and constant proprioceptive feedback through a human system interface. In Second Joint EuroHaptics Conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems, March 2007.

[10] M. Fritschi. Design of a tactile shear force prototype display. Inhttp://www.touch-hapsys.org, page Work package 6, 2003.

[11] E. Gardner and J. Martin. Coding of Sensory Information, chapter 21,pages 411–429. Principles of Neural Science. McGraw-Hill, fourth edition, 2000.

[12] E. Gardner, J. Martin, and T. Jessell. The Bodily Senses, chapter 22,pages 431–450. Principles Of Neural Science. McGraw Hill, fourth edition, 2000.

[13] G. D. Garson. Univariate glm,anova,and ancova”from statnotes:Topics in multivariable analysis. In http://www2.chass.ncsu.edu/garson/pa...htm,volume2007, page 1, 2007.

[14] G. M. Goodwin, D. I. McCloskey, and P. B. C. Matthews. The contribution of muscle afferents to kinesthesia shown by vibration induced illusions of movement and by the effects of paralysing joint afferents. Brain, 95(4):705748, 1972.

[15] V. Hayward and M. Cruz-Hernandez. Tactile display device using distributed lateral skin stretch. In Proceedings of the Haptic Interfaces for Virtual Environment and Teleoperator Systems Symposium, volume ASME DSC-69-2, pages 1309–1314. ASME IMECE2000.

[16] R. Johannson. Skin Mechanoreceptors in the Human Hand: Receptive Field Characteristics, pages 159–170. Sensory Functions of the Skin in Primates, with special reference to Man. Pergamon Press Ltd.,Oxford,, 1976.

[17] L. Jones, M. Nakamura, and B. Lockyer. Development of a tactile vest. In Proceedings of the 12th International Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems. IEEE,March 2004.

[18] K. J. Kuchenbecker, N. Gurari, and A. M. Okamura. Effects of visual and proprioceptive motion feedback on human control of targeted movement. In IEEE International Conference on Rehabilitation Robotics, pages 513–524, June 2007.

[19] R. H. LaMotte, M. A. Srinivasan, C. Lu, P. S. Khalsa, and R. M. Friedman. Raised object on a planar surface stroked across the fingerpad: Responses of cutaneous mechanoreceptors to shape and orientation. Journal of Neurophysiology, 80:2446–2466, 1998.

[20] V. Levesque and V. Hayward. Experimental evidence of lateral skin strain during tactile exploration. In Proc. Eurohaptics, July 2003.

[21] J. Luk, J. Pasquero, S. Little, K. E. MacLean, V. Levesque, and V. Hayward. A role for haptics in mobile interaction: Initial design using a handheld tactile display prototype. In Proc. of the ACM 2006 Con-ference on Human Factors in Computing Systems, CHI 2006, pages171–180, 2006.

[22] D. Mahns, N. Perkins, V. Sahai, L. Robinson, and M. Rowe. Vi-brotactile frequency discrimination in human hairy skin. Journal of Neurophysiology, 95:1442–1450, March 2006.

[23] Y. Makino and H. Shinoda.Selective stimulation to superficial mechanoreceptors by temporal control of suction pressure. In Haptic Interfaces for Virtual Environment and Teleoperator Systems, WorldHaptics Conference, pages 229–234, March 18-20, 2005.

[24] G. Moy and R. Fearing. Effects of shear stress in teletaction and human perception. In Proceedings of the 1998 ASME Dynamic Systems and Control Division, ASME International Mechanical Engineering Congress and Exposition, volume DSC-Vol. 64, pages 265–272, November 1998.

[25] A. Murray, R. Klatzky, and P. Khosla. Psychophysical characterization and testbed validation of a wearable vibrotactile glove for telemanipulation. Presence: Teleoperators and Virtual Environments, 12(2):156– 182, April 2003.

[26] M. Pare, H. Carnahan, and A. Smith. Magnitude estimation of tangential force applied to the fingerpad. Experimental Brain Research,142:342–348, 2002.

[27] I. Summers, P. Dixon, P. Cooper, D. Gratton, B. Brown, and J. Stevens. Vibrotactile and electrotactile perception of time-varying pulse trains.Journal of Accoustical Society of America, 95(3):1548–1558, March1994.

[28] H. Tan, R. Gray, J. J. Young, and R. Traylor. A haptic back display for attentional and directional cueing. Haptics-e, 3(1), June 2003.

[29] H. Tan, A. Lim, and R. Traylor. A psychophysical study of sensory saltation with an open response paradigm. In In Proceedings of the Ninth (9th) International Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems, American Society of Mechanical Engineers Dynamic Systems and Control Division, volume 69-2,pages 1109–1115, 2000.

[30] Q. Wang, V. Hayward, and A. M. Smith. A new technique for the controlled stimulation of the skin. In Proceedings of the Canadian Medical and Biological Engineering Society Conference, CMBEC, September 9-11, 2004.