Reprinted from the New York Medical Journal for January £9, 1887. 
A NEW METHOD OF TESTING THE “KNEE-KICK 
WARREN P. LOMBARD, M. D 
It is the desire of the writer to cal! the attention of 
physicians, and more especially of those interested in nerv- 
ous diseases, to a very simple and delicate method of test- 
ing the so-called tendon reflex of the knee, or “ knee-kick.” 
Aside from its precision, this method will recommend itself 
to the practitioner because it can easily be employed on pa- 
tients who are confined to the bed. As soon as a convenient 
method of striking the ligamentum patellae a blow of known 
force has been devised, the method will gain a new impor- 
tance, because it lends itself readily to simple means of re- 
cording the extent of the movement, and will thus enable 
the physician to keep an accurate record of the condition of 
his patient, and of the changes which the “knee-kick” may 
undergo in the course of disease. 
which is considerably heavier than the ordinary percussion 
hammer. 
Improvements upon this method will readily suggest 
themselves ; such as to make the thigh immovable by let- 
ting it rest in a splint which is molded to its inner and 
posterior surface, and which is fastened to a firm support; 
to fix the foot in a suitable swing; and to let the cord 
from which it is suspended come from a pulley at the 
ceiling. 
By means similar to those described, a marked “knee- 
kick ” may often be got from a patient who by the ordinary 
methods of examination would exhibit little or none. The 
delicacy of the method depends on the fact that the muscle 
is relieved of the weight of the leg, and its slightest con- 
traction enn, therefore, cause a visible movement. By this 
means some rather curious results have been obtained. A 
marked “knee-kick” was observed in the case of one sub- 
ject during sound sleep. The re-enforcements described by 
Dr. Weir Mitchell (“Medical News,” February 13 and 20, 
1886) were admirably illustrated. In short, the method 
seems to meet all the requirements of the investigator. 
Last winter the writer made a seri:s of experiments, in 
the physiological laboratory of the College of Physicians 
and Surgeons, upon the time required for the development 
of a contraction of the quadriceps muscle in response to a 
blow on the ligamentum patellae, as compared with the in- 
tervals elapsing when the muscle was stimulated directly 
by a faradaic current, and reflexly by an irritant applied 
to the skin near the knee (“ American Journal of the 
Medical Sciences,” January, 1887, p. 88). These experi- 
ments demanded a more delicate means of testing the 
“ knee-kick ” than any in general use. After a time an 
appliance was found which satisfied all the requirements. 
It is unnecessary to describe the method followed in this 
laboratory research, for it is not feasible for the general prac- 
titioner ; the following imitation of this method, however, 
can be employed in all places and at all times. 
The extent of the motion of the foot, and consequently 
of the contraction of the quadriceps muscle, may be record- 
ed by the following simple arrangement; A string may be 
fastened b}7 one end to the heel, and by the other to a strip 
of elastic, which, in turn, is attached to a firm upright sup- 
port. The support can then be placed in such a position 
that the string shall be tense, shall be horizontal, and shall 
form a right angle with the long axis of the leg. The writ- 
ing mechanisni may consist of a piece of wire bent to form 
a T, the horizontal arms of which can be fastened to the 
string, while the free end of the stem can rest on a paper, 
coated with lamp-black, and secured to a board, which is 
placed directly beneath. 
Let the patient lie on his side, the leg to be examined 
being uppermost. Place a cushion or roll of cloth between 
the thighs, so as to separate the knees, and, as far as possi- 
ble, to fix the thigh of the limb to be studied. Support the 
foot of the leg to be examined by a sling, formed of a loop 
of bandage, or of a towel, suspended from a cord. Grasp 
the cord as far from the foot as may be, letting the hand 
be directly over the ankle, that the leg may swing freely 
and the degree of flexion of the knee be determined entirely 
by the tension of the muscles. Strike the ligamentum pa- 
tellae with an instrument which has a rounded edge and 
A contraction of the quadriceps muscle will extend the 
leg, stretch the elastic, and, by drawing the wire across the 
blackened surface, leave a record of the extenfrof the move- 
ment. Such a tracing can readily be fixed by passing the 
paper through the ordinary brown shellac varnish. Crude 
as such a method is, it would enable valuable records to be 
obtained with but little trouble.