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1989;39;1542Neurology
Douglas J. Lanska
The history of reflex hammers
October 31, 2011This information is current as of
http://www.neurology.org/content/39/11/1542
located on the World Wide Web at:
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Enterprises, Inc. All rights reserved. Print ISSN: 0028-3878. Online ISSN: 1526-632X.
continuously since 1951, it is now a weekly with 48 issues per year. Copyright © 1989 by AAN
® is the official journal of the American Academy of Neurology. PublishedNeurology
by DOUGLAS LANSKA on October 31, 2011www.neurology.orgDownloaded from
historical
neurology
The history
of
reflex hammers
Douglas
J.
Lanska, MD
Article
abstract-Following the simultaneous description of muscle stretch reflexes by Heinrich Erb and Carl Westphal in
1875, neurologists used direct finger taps or chest percussion hammers
to
elicit these phenomena. Because of inadequacies of chest
percussion hammers for eliciting muscle stretch reflexes, a variety of hammers were developed specifically for this purpose. In
1888,
J.
Madison Taylor, working for
S.
Weir Mitchell at the Philadelphia Orthopedic Hospital, designed the
first
such “reflex
hammer.” Taylor’s hammer had
a
triangular rubber head and a short, flattened metal handle. Krauss (1894), Berliner (1910),
Troemner (1910), Babinski (1912). and Wintle (1925) also designed popular reflex hammers. Many of these hammers and several
others are still
in
use. NEUROLOGY 1989;39:1542-1549
After Erb and Westphal described the clinical
usefulness of muscle stretch reflexes in
1875,
chest per-
cussion hammers became popular for eliciting these
reflexes, coincident with a decline in their use for per-
cussion. Subsequently, neurologists developed ham-
mers specifically for eliciting reflexes; these “reflex
hammers” are now critical tools in the neurologic exam-
ination.
Percussion
hammers.
Inspired by the practice of
thumping a wine cask
to
determine the level of fluid,
Viennese physician Leopold Auenbrugger
(1722-1809)
first described the use of percussion as an aid
to
medical
diagnosis in
1761.1-3
In his monograph entitled
New
Invention to Detect Diseases Hidden Deep Within the
Chest,
Auenbrugger noted that by tapping or percussing
with the fingers directly on the chest, back, and ab-
domen, and listening to the resultant sounds, the con-
dition of the underlying organs could
be
determined.4
In
1826,
Pierre Adolphe Piorry
(1794-1879),
of Paris,
described the technique of percussion using a plex-
imeter3v5.6; the pleximeter was a resonator in the form of
a small ivory, metal, cedar, or rubber disk that was
placed on the chest and struck with a finger. Shortly
thereafter
(ca
1828),
Scottish physician Sir David Barry
(1781-1836)
fashioned a small percussion hammer for
striking the pleximeter.6~~ Barry was apparently
prompted
to
develop the hammer by the Swiss veterin-
ary practice of skull percussion for hydatid cysts re-
ported in van Swieten’s
The
Commentaries Upon the
Aphorisms
of
Dr. Herman Boerhaave7:
There have also been..
.
serous tumours found in
the cavity of the cranium, containing a collection of
lymph under a thin membrane; and these likewise
are capable of producing an apoplexy, when they are
increased in their bulk
. .
. .
Wepfer several times ob-
served
tumours of the same kind, in brutes; nay he
relates, that a vertigo frequently happens
to
black
cattle in the district of Underwold in Switzerland,
which the heardsmen cure in the following manner:
They strike upon the skull, behind the horns, with a
small hammer, and from the sound they discover
whether there is any preternatural cavity under the
skull; which when they suspect, they immediately
bore through the part which they beat upon, and by
means
of
a reed, which they introduce through the
hole, they suck out such small bladders as
are
above
mentioned; which if they are situated on the surface
of the brain, the cure succeeds; but if they are deeper
lodged in the substance of the brain, they have no
hopes; wherefore, the butcher who is present, when
that is the case immediately kills them.*
Unfortunately, Piorry considered Barry’s hammer a
superfluous invention and it
was
not widely adopted.sJ
In
1841,
German clinician Max
A.
Wintrich
(1812-1882)
created the first popular percussion ham-
mer, which was adopted throughout Europe and went
through several modifications (figure
1)
.6*9-11
Despite its
popularity, Wintrich’s hammer was not without critics,
including many of those who were advocating their
own
hammers. Vernon, for example, claimed
that
there were
several “defects of Dr. Winterich’s
[sic]
percussor”12:
It is inconvenient
to
hold, it is rigid, and it will not
produce a note of the same value at each stroke
unless the direction in which the axis of the hammer-
head strikes the body is the same each time; it re-
quires education
to
use it, and even then it does not
fulfill its purposes.
A
wide variety of percussion hammer styles were sub-
sequently developed. Some were T-shaped or L-shaped;
others resembled battle-axes, tomahawks, or even
magic
wand~.~J3J~
The handles were made variously from
~~ ~~~ ~ ~
From
the Department of Neurology, and the Division
of
Geriatric Medicine, University Hospitala
of
Cleveland, and Caae Western Reserve University, Cleveland, OH.
Presented in part at the forty-first annual meeting
of
the American Academy
of
Neurology, Chicago,
IL.
April 1989.
Received May 11,1989. Accepted
for
publication in
final
form May
12,1989.
Address correspondence and reprint requests
to
Dr. Lanska, Department of Neurology, Albert
B.
Chandler Medical Center, University
of
Kentucky, Lexington. KY
40536.
1542
NEUROLOGY 39
November
1989
by DOUGLAS LANSKA on October 31, 2011www.neurology.orgDownloaded from
Figure
1.
Several versions of the Wintrich hammer, the first
popular percussion hammer. (Left) The original version
(1841); (center) a later modification by Wintrich (1854); and
(right) Ebstein’s modification, the “repex and sensibility
tester”
(1912).9
wood, ebony, whalebone, brass, and other metals, while
the heads were of
materials
such
as
velvet-covered wor-
sted,
wood, rubber, lead, and bra~9.l~ In addition
to
the
hammer developed by Wintrich, Flint,15 Niemeyer?
Skoda? Traube? Seit~,~ Vernon,12 and othersg devel-
oped popular percussion hammers. There were
so
many
hammers that Wintrich complained in 1873, “Presently
there are probably as many percussion hammers with
so
many names attached to them
as
there are obstetric
forcep~.”~ (There were over
400
varieties of forceps at
the time [J.M. Edmonson, personal communication]).
Muscle stretch reflexes.
Almost parallel with the
development of percussion, the concept of reflex action
was developed in the latter part of the 18th century by
Robert Whytt, John Augustus Unzer, and G. Pro-
chaska.l6 In the 18309, Marshall Hall (1790-1857) ex-
tended the domain of reflexes
to
include blinking, swal-
lowing, sneezing, vomiting, and reflexes mediated by
the autonomic nervous system. Hall’s experimental
work, and his formulation of the concept of
a
“reflex
arc,” established reflex action as “one of the cor-
nerstones of neurophysiological doctrine.”16
Forty years later, in 1875, Erb and Westphal
first
reported the diagnostic utility of the patellar or knee-
jerk reflex. Heinrich Erb (1840-1921) was the leading
German neurologist of his day,17 and the first neu-
rologist
to
emphasize detailed and systematic examina-
tion of the nervous system.18 Erb
was
one of the
first
to
recognize the clinical utility of muscle stretch reflexes,
and
was
the
first
neurologist
to
use
a percussion ham-
mer
to
elicit them,7J7.19.20 a practice he initiated around
1870.20 After Erb submitted his original paper on the
knee jerkI9
to
the German
Archives
of
Psychiatry and
Nervous Diseases,
he discovered that the editor-Carl
Friedrich Otto Westphal(1833-1890)-was preparing a
similar paper, and the
2
agreed on simultaneous pub-
lication.20 In investigating this phenomenon, Westphal
I
Figure 2. William Gowers recommended eliciting the knee
jerk by striking the patellar tendon with the ulnar surface
of the
hand
(left)
or
apercwsion hammer (right).23
identified basically the same features as Erb, but while
Erb regarded the knee jerk
as
a simple reflex, Westphal
incorrectly thought it resulted from direct excitation of
the quadriceps muscle.20.21
Early recommendations
for
eliciting reflexes.
In
the several decades following Erb’s and Westphal’s de-
scriptions of the knee jerk, the number of reflexes de-
scribed proliferated wildly. Not surprisingly, the
nomenclature and techniques for eliciting these newly
described tendon reflexes varied considerably. In 1875,
Erb had recommended obtaining what he called the
“patellar-tendon reflex” by striking the tendon with
either a finger or a percussion hammer.19 Westphal
similarly recommended eliciting the “knee phenome-
non” by percussing the patellar ligament “lightly
but.
.
.
quickly with a finger-best when the index fin-
ger
is
put on top of the middle finger and the former
is
accelerated downward-or even more effectively with a
percussion hammer.”20 In the 18809, William Gowers
(1845-1915) recommended obtaining the “knee jerk” or
“myotatic reflex” by striking the patellar tendon with
the ulnar surface of the hand (figure
‘i!).22*23
“Now and
then, when very slight, a percussion hammer
. . .
or a
stethoscope with an india-rubber edge
to
the ear piece
elicits it more readily.”22
In the next several decades, tapping tendons with
percussion hammers became the preferred technique.
Some neurologists even championed specific models of
percussion hammers. Charcot (1825-1893), for example,
recommended a Skoda percussion hammer for obtain-
ing the knee jerk.I8 Joseph Babinski (1857-1932), Char-
cot’s pupil,
was
also an advocate of hammers: “One
should not.
. .
[elicit muscle stretch reflexes]
.
.
.
with
the side of the hand
. .
. .
One would be better served
to
use a percussion hammer..
.
.”24
In Germany, neu-
rologist Bernhard Berliner was one of the most ada-
mant advocates of hammers, since he felt “it is not very
elegant
to
percuss the knee or achilles tendon with a
paper weight, the edge of
a
large electrode, the foot of a
laboratory stand, a table lamp, or similar devices.”25
Reflex hammers.
Because
of
inadequacies of percus-
sion hammers for eliciting muscle stretch reflexes, a
November
1989
NEUROLOGY
39
1543
by DOUGLAS LANSKA on October 31, 2011www.neurology.orgDownloaded from
variety of hammers were developed specifically for this
purpose. As noted by Berliner,25
Not uncommonly,
the
standard percussion hammers
are
inadequate for
the
testing of tendon reflexes,
such
as
in
patients
with
physiologically weak re-
flexes,
in
pathologically hyperactive states, and
in
individuals
who, despite all attempts, remain tense.
Even
if,
with
sufficient patience and some inconve-
niencingof the patient, one
will
almost always obtain
a usable result,
this
goal
can
be
achieved faster and
more comfortably
by
using
an
instrument which, for
one,
is
heavier
than
the
usual
percussion
hammer,
and
secondly,
strikes
the tendon over
a
larger sur-
face
. .
. .
With
the small head of
the
common percus-
sion
hammer,
the achilles tendon, especially
in
the
supine
patient, cannot
always
be
struck securely.
Some then resort
to
turning
the
hammer around and
striking
with
the
handle’s edge,
a
method
which
again
is
not
elegant,
and
is
unpleasant
to
the
patient.
Troemner’s comments were similarz6:
Examination of deep tendon
reflexes
[requires]
.
. .
a
hammer which
is
heavy enough
to
facilitate
brief
but
forceful
percussion
of
the
tendon without eliciting
pain.
. .
.
In order
to
elicit this reliably, the com-
monly used or recommended
small
percussion ham-
mers, stethoscopes,
house
keys, and percussion
with
the ulnar surface of
the
hand
may
be
insufficient.
In addition to the greater weight and larger striking
surface of these new “reflex hammers,” some hammer
designers incorporated
a
handle with
a
pointed
tip
to
facilitate testing of cutaneous refle~es,~~.~~
a
ruler along
the handle,9J0.27 and a pin, brush, or other
tools
for
testing ~ensation.~J~.~~
The first “reflex hammer”
was
probably the tri-
angular-headed hammer designed by John Madison
Taylor in Philadelphia in
1888.28-z9
Krauss (1894)F7
Berliner (1910),25 Dejerine
(ca
1910),9 Struempell
(ca
1910),9 Troemner (1910),26 Babinski (1912),24 Wintle
(1925)
,7
and othersg developed popular reflex hammers.
Some reflex hammers, such as Ebstein’s “reflex and
sensibility tester” (1912),9J0 and the Queen Square ham-
mer
(ca
1925),7 were modifications
of
previously devel-
oped percussion hammers. Ebstein, for example, modi-
fied Wintrich’s percussion hammer
of
1841 by adding a
removable brush
to
the head, and
a
centimeter ruler and
a removable pin
to
the handle (figure 1, ~ight):~JO
Being
fully
aware that
such
combinations
may
im-
pair
an instrument’s functioning, I have introduced
into the
tip
of
the
shaft
of
[Wintrich’s
hammer]
a
needle
with
a
round.
. .
head, held
in
place
with
a
screw
segment.
This allows testing of
sensation
for
“sharp”
and
“dull,”
as
well
as
the
elicitation
of
ab-
dominal reflexes and
so
forth.
In addition
I
have
straightened
the
slightly
curved shaft.
. .
to
facili-
tate
proper
use
of
the
centimeter
scale,
which.
. .
is
engraved
on
both
sides
. . . .
The inserted small hair-
brush
. . .
can
be
used
to
test
light
touch during the
sensory
examination
.
. . .
[The
hammer] can, there-
fore,
be
properly
called a reflex and
sensibility
te~ter.~
Since many neurologists found that the lightweight
percussion hammers were ineffective or produced in-
1644
NEUROLOGY
39
November
1989
(Photograph courtesy of
the College of Physicians
of Philadelphia);
(B)
Versions
of
the
Taylor reflex hammer:
left,
ca
190436; right,
ca
1920. (From
The
illustrated catalog
of
a
complete
line
of
standard
surgical
instruments,
Boston: Codman
&
Shurtleff Inc.,
ca
1920:15).
(C)
American
Academy of Neurology
logo,
incorporating the
Taylor reflex hammer
and
a
tuning fork.
consistent
result^,*^^^^^^^
the most consistent feature of
the new reflex hammers was their greater weight. The
Taylor hammer (approximately
60
to
70
grams) was
considered heavy when
it
was
intr~duced.~‘ Later ham-
mers were even heavier, weighing between
80
and 140
grams, and some current versions of the Troemner and
Queen Square hammers weigh over
200
grams. The
added weight of the head, combined in some cases with
a
longer, flexible handle, increased the hammer’s effec-
tiveness, but the applied force
was
sometimes taken
to
extremes,
as
indicated by Berliner’s claim that his ham-
mer “allows, in almost all instances, the elicitation of an
existing achilles reflex through the patient’s
Because of the considerable force applied by reflex
hammers, Troemner recommended a pleximeter when
using a hammer
to
elicit reflexes: he felt a pleximeter
protected “sensitive persons from the striking ham-
mer,” and allowed for the elicitation of “percussory
muscle reflexes” [eg, deep abdominal reflexes]
.3z
Most
neurologists found, however, that the tendons (except
the biceps brachii) were best struck directly. With the
development
of
softer rubber striking surfaces and a
more refined techique, the need for
a
pleximeter
was
eliminated.
The Taylor hammer.
John Madison Taylor
(1855-1931) (figure 3A) received his medical degree from
the University of Pennsylvania in 1878, and then prac-
ticed pediatrics, neurology, and physical medicine in
by DOUGLAS LANSKA on October 31, 2011www.neurology.orgDownloaded from
Figure
4.
S.
Weir Mitchell examining Cioil War veterans at
the Infirmary
for
Nervous Disease in Philadelphia
(January,
1902).
In his right hand, Mitchell
is
holding a
Taylor hammer. J. Madison Taylor
is
seated to the right
of
the patient. (Photograph courtesy
of
National Library
of
Medicine).
Philadel~hia.~~ From 1882
to
1896 he was the personal
assistant of
S.
Weir Mitchell at the Philadelphia
Orthopedic Hospital and Infirmary for Nervous Dis-
ease. It was during the early part of his experience at the
Orthopedic Hospital that Taylor developed the first
true
reflex hammer (figure 3B).29 The Taylor hammer
was praised and popularized by
S.
Weir Mit~he11,*~-~~
and by C.K.
mill^,^^^^^
who considered
it
“the best ham-
mer for tapping the much-abused patellar ligament.”36
Taylor exhibited his new hammer
at
the February 27,
1888 meeting of the Philadelphia Neurological Societym
with William Osler and Charles
K.
Mills present in the
audience.
As
noted in the minutes of the meeting:
[Taylor’s hammer was] devised
to
serve as nearly as
possible all ends for which a hammer is likely
to
be
called into use by clinicians. This feature at least
would, [Taylor] thought, commend it. In shape it is a
cone flattened on the opposite side, with apex and
base carefully beveled or rounded, of about the thick-
ness throughout of the human index finger. The
material is moderately
soft
rubber. It is held by
an
encircling band
of
metal midway between the apex
and base transversely, and from it, on the edge, de-
pends the straight handle. The handle is rigid though
light, it being Dr. Taylor’s opinion that this had
better be under the full control of the wielder.
If
elastic
as
recommended by some,
an
element
of
un-
certainty enters in the degree
of
force used in the
blow. The special feature of this hammer is that the
shape
of
the striking surface is like the outer surface
of
the extended hand, palm downward, which
is
most
often
used
in obtaining tendon jerk. The rounded
apex end is adopted
[sic]
to
reach the biceps tendon
at the bend of the arm [and, according
to
S.
Weir
Mitchell,
“to
get muscle responses by a direct blow
on the muscle.”28]
. . .
.
This little
tool
will also well
serve
to
elicit chest sounds,
to
percuss the abdomen,
and in fact, is useful whenever an elastic hammer is
A
B
Figure
5.
(A)
William Christopher Krauss.
(B)
The Krauss
reflex hammer
(1904).27
needed. The material being
of
soft
rubber, the blow
does not hurt the intercepting fingers as does the
hammer usually employed
to
strike the tendons and
muscles.
It
is made by Snowdon [Brothers’ Surgical
Instruments
Co.]
of Philadel~hia.~~
The early versions of the hammer had an open loop
handle, but some versions after about 1920 had a solid
handle with a pointed tip for eliciting cutaneous reflexes
(figure 3B). Decades later, the American Academy of
Neurology incorporated the Taylor hammer into its
logo (figure
30.
Taylor’s interest in muscle stretch reflexes was
sparked largely by
S.
Weir Mitchell’s interest in reflexes
at the Infirmary for Nervous Disease (figure
4).
From
1886
to
1890,
Mitchell published a series of papers re-
lated
to
reflexes, which showed that they could be rein-
forced with sensory stimuli or, in support of
Jendrassik’s 0bservation,3~ with voluntary contraction
of other muscle groups.28~38-40 He also introduced the
symbols KJ+, KJ+
+,
and KJ- for exaggerated, ex-
cessively exaggerated, and depressed knee jerks.ls In
addition, Mitchell’s pupils made a number
of
important
contributions: Morris Lewis described the jaw jerk,23-41
and Guy Hinsdale and
J.
Madison Taylor investigated
the crossed adductor refle~.~*.~~
The Krauss hammer.
William Christopher Krauss
(1863-1909) (figure
5A)
received his medical degree in
1886 from the Bellevue Hospital Medical College, and
after 2 further years of study in Berlin, Germany, he
practiced neurology and pathology in Buffalo, New
November
1989
NEUROLOGY
39
1646
by DOUGLAS LANSKA on October 31, 2011www.neurology.orgDownloaded from
:i”
N
N
E
A
B
Figure
6.
(A)
The Troemner repex hammer
(1910).26
(B)
Henry Woltman holding a Troemner hammer.47
(Photograph courtesy
of
Donald Mulder, MD).
Y~rk.~~
In the course of his career, he designed several
new instruments, including “a neuro-topographical
bust, an improved tape measure, a new urethral elec-
trode, a pedo-dynam~rneter,~~ and a neurological per-
cussion hammer.”44 The Krauss hammer (figure
5B)
was
one of the earliest reflex hammers
to
incorporate
modifications for testing sensation as well as
Krauss exhibited his hammer at the 20th annual meet-
ing of the American Neurological Association held in
Washington, DC in 1894.27 It was manufactured by the
G.
Tiemann Company of New York.*’ According
to
Krau~s~~:
Having had occasion to make constant use of [a
percussion] hammer in my private and hospital prac-
tice,
I
have devised some improvements and modi-
fications which widen the field of its usefulness, thus
making it more serviceable
to
those engaged in neu-
rological research. The hammer is constructed after
the French pattern having a heavy metallic head
fixed to a flattened oval handle seventeen centi-
metres long.
As
a hammer it may be used
to
examine
the tendon and muscular reflexes,
to
percuss the
head spine, superficial nerves, etc. The handle (a)
[see
figure] being of hard rubber becomes
warm
on
friction, while the head being of metal remains cold,
thus offering the means of examining the sense of
heat and the sense of cold, fulfilling the requirements
of [a] thermo-aesthesiometer. The cap (c) when re-
moved discloses a triangular spear head about one-
half centimetre long, while at the other end of the
hammer head is the rounded rubber points-the two
ends furnishing, therefore, a sharp and a dull point
for examining for anaesthesia or hyper-
aesthesia
.
. . .
The spear is divisible into two por-
tions, one securely fixed upon the hammer head, the
other moveable upon a metallic slide upon which is
engraved the metric and English scales. This ar-
rangement furnishes an excellent aesthesiometer
and is as accurate and convenient
as
any on the
market. Replacing the cap (c) and removing the cap
(e) a camel’s hair brush is exposed, giving a
soft
1646
NEUROLOGY
39
November
1989
Figure
7.
The Berliner reflex hammer
(1910).
(Photograph
courtesy
of
the Dittrick Museum
of
Medical History,
Cleveland,
OH).
surface, while the metallic cap (c) gives a
hard
sur-
face. The hammer is conveniently carried in the
pocket, and
has
served me with much satisfaction.
The Troemner
hammer.
German neurologist Ernst
L.O.
Troemner (1868-1930) was director
of
the Neu-
rological Hospital at
St.
Georg
in
Hamburg and pro-
fessor of the University of Hamburg. In 1910, he
developed a reflex hammer (figure 6A), which subse-
quently became very popular in Germany and in the
United
State~.*~~~~
In describing his hammer, Troemner
A
frequently-experienced urge stimulated me.
.
.
to
construct a totally usable hammer, partly based on
an older French model. The hammer, which is all
metal, weighs approximately
100
grams, is
22
cen-
timeters long, lies comfortably in the hand, and has a
head of
0
centimeters width, with knobs of rubber at
both ends which can be easily exchanged. The large
head is designed
for
use on the large tendons of the
extensor surfaces (patellar, achilles, triceps reflexes)
and especially for eliciting periosteal and joint re-
flexes which can be quite painful with the
use
of
smaller hammers, espcially in hyperalgetic patients.
The smaller head is used for percussion of flexor
tendons (biceps humeri, biceps femoris, and semi-
tendinosus)
.
.
. .
The smooth handle of the hammer
can
be easily cleaned and in a pinch
may
be utilized
as a tongue blade.
Its
sharpened edge, in addition,
elicits cutaneous and vascular reflexes. The hammer
is being fabricated by B.B. Caw1 in Frankfurt [and
Krauth and Company in Hamb~rP~~], costs
8
marks, and contains
2
substitute rubber
heads..
.
.
My personal experience in several hun-
dred healthy persons and patients with nervous dis-
eases,
newborns
as
well
as
elderly, who in part were
evaluated with my new hammer, demonstrated
much greater constancy of most tendon reflexes
throughout all ages than has been previously ac-
knowledged.
Ebstein: in a paper on percussion hammers, argued
against the practice of using the hammer shaft
as
a
tongue blade:
For hygienic reasons, nowadays, a physician would
hardly utilize the hammer’s shaft
as
a tongue de-
pressor
as
Seitz used
to
do.
.
.
since the tip of the
shaft is customarily used
to
elicit, for instance, the
plantar reflex or Babinski reflex from the sole of the
foot.
. . .
by DOUGLAS LANSKA on October 31, 2011www.neurology.orgDownloaded from
Figure
8.
The
2 reflex hammers
illustrated by Babinski in his
1912 monograph.24 The one on
the right
has
come
to be
called
a
“Babinski hammer.”
In 1927, Dr. Henry W. Woltman (1889-1964) (figure
6B), then associate professor of neurology at the Mayo
Clinic, spent 6 months in Europe visiting the leading
neurological centers (C.W. Nelson, personal communi-
~ation).~~-~~ In Hamburg, he
was
greatly impressed by
the balance and design of the Troemner hammer.
Woltman bought several of the hammers for himself
and his colleagues in Rochester, Minne~ota.~~ Subse-
quently, the Troemner hammer became a tradition
among Mayo Clinic neurologists,46 and, for many years,
gold-plated Troemner hammers were given to emeritus
professors and
to
distinguished visiting neurologists
(J.P.
Whisnant and D.W. Mulder, personal communi-
cations).
The Berliner hammer.
The German neurologist
Bernhard Berliner described his reflex hammer in 1910
(figure 7).25
I constructed a hammer which [has a sufficiently
heavy head and a large striking surface], and which
in every case proved more useful and comfortable for
the testing of tendon reflexes than the common per-
cussion hammers. Such a device
has
not been avail-
able commercially and it appears, therefore, justified
to
introduce this hammer into our instrumentarium.
The device has the shape of a hatchet, and an edge
covered with rubber, which always strikes the ten-
don along its total width
.
.
. .
It
is
made of metal and
nickel-plated. The handle is tapered at the end and
may be used for testing skin reflexes
.
. .
.
It is being
produced by Louis and
H.
Lowenstein, Berlin. The
shape and larger weight of the new hammer facili-
tates easy and reliable testing of the achilles tendon
reflex in all instances, even in the supine patient
. .
.
.
The Babinski/Rabiner hammer.
French neu-
rologist Joseph Fransois Babinski is
best
known for the
“toe phenomenon,” which he described in 1896.48 In
1912, Babinski wrote
a
monographz4 on reflexes, in
which he described
2
reflex hammers (figure
8):
Here I will describe two which are the most fre-
quently used. One of them
is
composed
of
a handle
of
nickel-plated steel which is
20-25
cm. long and fixed
at the center with a disk which is made
of
the same
Figure 9.
Abraham Rabiner.
(Photograph
courtesy
of
the
National Library
of
Medicine).
substance and which
has
at its circumference a fur-
row filled with a ring of rubber. In the second type,
which has an advantage of being able
to
more easily
fit
into a pocket, the handle is basically the same as
the
first
type of hammer, but the disk is replaced by a
rectangular plaque which is found in the same plane
as the handle and is equally provided with a rubber
ring in its peripheral canal. These hammers are en-
dowed with elasticity which conforms
to
the func-
tion on which they are called
to
fulfill.
The former hammer, with the head fixed perpendicular
to
the shaft, has come
to
be called a “Babinski hammer”
(figure
8,
right), although it seems that Babinski’s role
was
more of popularization than invention or develop-
ment.
Around 1920, Babinski and other neurologic col-
leagues met in Vienna for a “black tie affair.’’ One of
those present was American neurologist Abraham
Rabiner (1892-1986) (figure 9). “Following the dinner,
during the cigar and brandy stage.
.
.
he and Babinski
got into a discussion with fellow colleagues on the phys-
iology of the Babinski response” (R.J. Schwartzman,
personal communication, based upon conversations
with Rabiner). Rabiner noted that Babinski had never
proposed a mechanism for the response and offered his
own belief, based largely on phylogenetic speculations,
that the Babinski sign was due
to
“removal of the
pyramidal influences..
.
[producing] a reversion
to
a
lower scale with
a
preponderating influence of the extra-
pyramidal system.”49 Babinski and Rabiner disagreed
strongly. “This discussion was very heated and there
was some pushing and shoving and other nonprofes-
sional physical activity” (R.J. Schwartzman, personal
communication). Following this altercation, Babinski
gave Rabiner his own personal reflex hammer “as a
token of support” (figure 10A). Rabiner brought the
hammer back
to
New York and had a modified version
produced in which the shaft could be screwed into the
shank either perpendicular or parallel
to
the head
(fig-
ure
10B).
Rabiner’s version combined the best features
of both hammers described in Babinski’s 1912 mono-
graph.24.
November
1889
NEUROLOGY
39
1547
by DOUGLAS LANSKA on October 31, 2011www.neurology.orgDownloaded from
1
1
A
8
Figure
10.
(A) The hammer that Babinski gave to Abraham
Rabiner, and that Rabiner later gave to Robert
J.
Schwartzman. (Photograph courtesy of Robert
Schwartzman,
MD).
(B) The Rabiner reflex hammer. The
head can be attached parallel (left) or perpendicular (right)
to
the shaft.
The Queen Square hammer.
The Queen Square
hammer was apparently modeled after an earlier chest
percussion hammer introduced by Henry Vernon of the
Great Northern Hospital in 1858 and manufactured by
“Messrs. Whicker and Blaise, of St. Jame’s-street”
(fig-
ure
11)
.7J2
Vernon’s hammer
consists of a slender tapering handle of whalebone,
eight inches in length, surmounted by a sphere of
bell-metal, weighing one ounce. The sphere of metal
is
grooved deeply in an equatorial direction, and a
stout ring
of
caouchouc [India rubber] is let into the
groove,
as a cushion upon which
to
strike. Such
is
the
instrument-simplicity itself.]*
Macdonald Critchley attributed the Queen Square
version of the Vernon hammer
to
a Miss Wintle, who
was the head nurse of physiotherapy and radiology at
the National Hospital for Nervous Diseases, Queen
Square, London.7 Because she was responsible for the
electrotherapeutic instruments, she was nicknamed
“Sister Electrical.” Around 1925, she “hit upon the
happy device of fitting a ring pessary
to
a solid brass
wheel, and mounting this upon a stick of bamboo
. . .
.”
(Macdonald Critchley quoted by S~hiller).~ The bam-
boo cane was flexible, approximately
8
inches long and
‘/4
inch in diameter
(R.D.
Snyder, personal communica-
tion). On one end, a rubber ring was tightly
fitted
on a
11/2-inch diameter brass disk; the other end was sharp-
ened to a point for use in eliciting plantar and abdomi-
nal responses. “The result was a heavy, springy, and
completely painless hammer..
.
.
For years she made
these herself.
. .
and sold them
to
post graduate stu-
dents.
.
.
[and] resident medical officers.
.
. .
(Mac-
donald Critchley quoted by S~hiller).~
Conclusion.
According to Schiller, in 1875 Erb and
Westphal “hit upon the unique spot in the body where
scientific purity and simplicity reign because only
2
1648
NEUROLOGY
39
November
1989
dc
I
1
Figure
11.
The Vernon percussion hammer
(1858)12
was
the
precursor of the Queen Square reflex hammer.
neurons are involved in the [muscle stretch] re-
flex.
. . .
While neither reflexes nor hammers were
much newer than pitchforks, they helped in the con-
struction of a new edifice: the functioning nervous sys-
tem
as
an assembly of interdependent and hence
variably active reflexes.
. .
.”7
The assessment of re-
flexes is now an indispensible part of the neurologic
examination, and the reflex hammer is a critical
tool
for
that assessment.
Acknowledgments
The author gratefully acknowledges the assistance and information
provided by Arthur
K.
Asbury, David
Y.
Cooper, Robert B. Daroff,
Noble
J.
David, James M. Edmonson, Terry Hambrecht, Thomas A.
Horrocks, Glenda Jenkins, Mary Jo Lanska, Mark Lloyd, Jan Martin,
Mario F. Mendez, Donald W. Mulder, Clark W. Nelson, Polly
Rabiner, Bernd Remler, Betty Rabiner Rothfeld, Peritz Scheinberg,
Robert
J.
Schwartzman, Russell D. Snyder, and Jack
P.
Whisnant.
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NEUROLOGY
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1989;39;1542Neurology
Douglas J. Lanska
The history of reflex hammers
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