View Full Version : summary - finger pulp compress.

Tim Meserth-etm015
10-21-1996, 12:20 AM
A couple of weeks ago I requested information on modeling finger pulp
compression when light forces ( < 3 lb.) are applied to the padded underside
of digits one and two. At this time I haven't been able to evaluate all of
the papers. Here is a summary of the responses. Thank you to everyone that
responded to my question. Tim

The UCSF / UCBerkeley Ergonomics Lab has a home page @ http://www.me.
berkeley.edu/ergo/ that includes a list of references regarding computer
keyboard and mouse studies. Here are the papers that appear to be the most

Martin BJ, Armstrong TJ, Foulke JA, Natarajan S, Klinenberg E, Serina E,
Rempel D. Finger force during computer keyboard work. Part I: Relation of
keyboard reaction force to finger flexor muscles surface EMG. Human Factors,
1994 (submitted).

Rempel D, Serina E, Klinenberg E, Martin BJ, Armstrong TJ, Foulke JA,
Natarajan S. Finger force during computer keyboard work. Part II: Relation
of keyswitch make force to applied force and surface EMG. Human Factors,
1994 (submitted). .

David Rempel, Jack Dennerlein, C.D. Mote, Jr and Thomas Armstrong, A METHOD
1101-1104, 1994.

Peter Johnson, Ron Tal, Paul Smutz and David Rempel, Computer mouse designed
to measure finger forces during operation, Proc. of IEEE EMGS, San Diego,

Serina ER, Mote CD Jr, Rempel DM. Mechanical Properties of the Fingertip
Pulp Under Repeated, Dynamic, Compressive Loading. American Society of
Mechanical Engineers Winter Annual Meeting, November 1995, San Francisco,

A comparison of fingertip forces applied to a mouse with and without drag
lock. Peter Johnson, Steven Lehman, Jack Lu, Ron Tal, David Rempel;

Force transmission of the fingertip pulp during keyboard-like work. Elaine
Serina, Jack Dennerlein, David Rempel; California

Dr. Elaine Serina (author of some of the papers above) returned my message
with a note about a paper currently submitted to the Journal of Biomechanics.
It appears she research the topic of finger pulp compression extensively
and would be a great source of information.

Serina, E.R., Mote, C.D., and Rempel, D. (1997) Force Response of the
Fingertip Pulp to Repeated Compression: Effects of Loading Rate, Loading
Angle, and Anthropometry. J. Biomech., in press.

She also mentioned the following papers.

Phillips, J.R. and Johnson, K.O. (1981) Tactile spatial resolution - III. A
continuum mechanics model of skin predicting mechanoreceptor responses to
bars, edges, and gratings. J. Neurophysiol. 46, 1204-1225.

Srinivasan, M.A. (1989) Surface deflection of primate fingertip under line
load. J. Biomech. 4, 343-349.

Srinivasan, M.A. and Dandekar, K. (1996) An investigation of the mechanics
of tactile sense using two-dimensional models of the primate fingertip. J.
Biomech. Eng. 118, 48-55.

Dr. Andy Hoffer responded with the following interesting related
information from a cat hind-foot pad model. The article is:

Haugland, M., Hoffer, J.A. and Sinkjaer, T. Skin contact force information
in sensory nerve signals recorded by implanted cuff electrodes. IEEE Trans.
Rehab. Engng. 2:18-28, 1994.

Data in their Fig. 9 show that 1 Hz sinusoidal forces in the range 0-9 N
(just about 0-2 lb.), produced up to 7 mm of indentation of the glabrous
skin and pad of the cat hindfoot. The relationship is quite nonlinear: 2.5
N is needed to achieve half of the max indentation during increasing force
(just 1 N is needed during decreasing force). I.e., the pad becomes
relatively less compressible for higher forces, and there is hysteresis
(greater forces are needed to reach a given indentation when force is
increasing than when it is decreasing). There is also considerable settling
using dynamic forces: after the first couple of cycles, when the
sinusoidal force is zero the pad is still compressed about 1.5 mm. The pad
normally requires several seconds after the end of force application to
regain its normal uncompressed shape, presumably because it takes time for
fluids to fully reperfuse the pad.

These references were also sent to me. Something may have been lost during

Sakata K, G Parfitt, KL Pinder: Compressive Behavior of a
Physiological Tissue, {\em Biorheology}, {\bf 9}:173-184, l972.

Thompson, DE and HMG Hussein: Characterization of Orthotic
Materials by Mechanical Impedance Method, Proc. 30th ACEMB, Los Angeles,

Thompson, DE, HMG Hussein,and R.Q. Perritt: Point Impedance
Characterization of Soft Tissues, {\it in vivo}, Proc. Second International
Symposium for Bioengineering and the Skin, Cardiff, Wales, 1979.

Dr. Takashi Maeno, Assistant Professor, Department of Mechanical
Engineering, Keio University, sent me the following note: "I've been
working on Finite Element modeling of the human skin. Results of the study
were presented in the following:"

K. Kobayashi, T. Maeno, N. Yamazaki, Relationship between Structure of
Finger Tissue and Tactile Receptors, Proc. 73rd JSME Spring Annual Meeting,
pp. 478-479 (1996) (in Japanese)

T. Maeno, K. Kobayashi, N. Yamazaki, Effect of Geometry and Property of the
Finger Tissue on Stress/Strain Distribution Near the Tactile Receptors, Proc.
10th Conf. of the European Society of Biomechanics, pp. 312 (1996)

He also made a post to the BIOMCH-L last year on a related topic. To keep
this summary fairly brief I will only include the original post and the
references to papers.

I am interested in the contact problem between skin and object. For example,
contact between finger skin and flat surface. I am also interested in the
dynamic deformation of the skin near cutaneous receptors. I'd like to know
if there are some good references on research being performed in this area.
Especially, I'd like to know if there are research on human skin by using
Finite element analysis. Any help would be greatly appreciated. Thanks in

Haugland, M. and Hoffer, J.A. Slip information provided by nerve cuff
signals: application in closed-loop control of functional electrical
stimulation. IEEE Trans. Rehab. Engng. 2:29-36, 1994.

3. Haugland, M. and Hoffer, J.A. Artifact-free sensory nerve signals
obtained from cuff electrodes during functional electrical stimulation of
nearby muscles. IEEE Trans. Rehab. Engng. 2:37-40, 1994.

Buchholz, B., Armstrong, T. J., and Goldstein, S. A., Anthropometric data
for describing the kinematics of the human hand, Ergonomics, Vol. 35, No. 3,
261-273, 1992

Johansson, R. S., and Vallbo, A. B., Tactile sensory coding in the glabrous
skin of the human hand, Trends in Neuroscience, 6, pp.27-32, 1983

Lanir, Y., Dikstein, S., Hartzshtark, A., and Manny, V., In-vivo indentation
of human skin, ASME Journal of Biomechanical Engineering, Vol. 112, No. 1,
pp. 63-69, 1990

Yuan-cheng Fung, Biomechanics---Motion, Flow, Stress, and Grouth,
Springer-verlag, 1990

Y. C. Fung$B!'(BBiomechanics: Mechanical Properties of Living Tissues,
Springer-Verlag (1981)

Srinivasan, 'Surface deflection of primate finger tip under lineload', J.
Biomechanics, 22:343-349., 1989

Oomens et al, 'A mixture approach to the mechanics of skin', J. Biomechanics,
20:877-885, 1987

Anani AB, Ikeda K, Korner ER. Human ability to discriminate various
parameters in afferent electrical nerve stimulation with particular
reference to prostheses sensory feedback. Med. & Bio. Eng. and Comp. 1977;
15:363 to 373.

Jebsen R. An objective and standardized test of hand function. Arch. Phys.
Med. Rehab. 1969; 311 - 319.

Johansson S, Westling G. Roles of Glabrous Skin Receptors and Sensorimotor
Memory in Automatic Control of Precision Grip when Lifting Rougher or More
Slippery Objects. Exp. Brain Res. 1984; 56:550 - 564.

Johansson S, Westling G. Programmed and Triggered Actions to Rapid Load
Changes During Precision Grip. Exp. Brain Res. 1988; 71:72 - 86.

Johansson S, Westling G. Signals in tactile afferents from the fingers
eliciting adaptive motor responses during the precision grip. Exp. Brain
Res. 1988; 66:141 - 154.

Ruzena B. What can we learn from one finger experiments? In: M. Brady and
R. P. Paul, ed. Robotics Research: The First International Symposium.
Cambridge: MIT Press., 1984: 509 - 528.