Medicine. — “Sùnple and alternating footclonus.” By Prof. 1. K. A. 
WeRTHEIM SALOMONSON. 
(Communicated at the meeting of May 28, 1921). 
In ORDENSTEIN’s thesis, written under CHarcor and published 
in 1863, the first exact description of footelonus is to be found. 
Since then it has been the subject of much investigation and of 
many publications. From these last it would seem that the mecha- 
nism as yet has not been fully elucidated. We know that footclonus 
is produced by rhythmical contractions of the calf-muscles, but there 
is some doubt about the behaviour of the anterior muscle group. 
Are these muscles at rest during the clonus, or is clonus caused by 
alternate contractions of the tibialis anticus group and the triceps 
surae? Is the clonus a simple or an alternate one? Dusois, working 
under Cuarcot, described it in 1868 as an alternate phenomenon. 
In 1875 it was represented as a simple clonus solely caused by the 
action of the triceps surae by ErB and by Wesrranr. Brocq and 
ONANOFF are of opinion that the tibialis anticus actively participates 
in the movement. PrtitcLerc says the same, but he thinks that the 
tibialis contractions cannot be felt (?). STERNBERG vindicates an alter- 
nating character only for the spontaneous footclonus, the ordinary 
footclonus being caused by rhythmical contractions of the soleus-group 
only. Crocg is of the same opinion. 
The observation of a patient in whom I was able to elicit a 
perfectly isolated clonus of the musc. extensor longus hallucis and 
likewise an isolated clonus of the m. tibialis anticus, caused me to 
construct an apparatus for graphically recording the contractions of 
the separate muscles of the leg. Once fixed to the leg, the apparatus 
could be used whilst the limb performed the most violent movements 
during a footclonus. A pair of metallic clamps were fastened on 
the leg, one resting on the upper part of the tibia, the other on 
the malleoli. A thinwalled brass tube connects the clamps. This tube 
proved to keep its position in relation to the tibia during any move- 
ments of the foot or of the leg itself. I could therefore use the tube 
as a support for two Marry receiving capsulae, each bearing a small 
pelotte, which pressed on the muscle, the contractions of which 
were to be recorded. The thickening of the muscle was inscribed 
