Observations on concurrent contraction of flexor muscles in the flexion reflex

Open Access
Publisher Website
Google Scholar
Abstract
The “flexion reflex,” flexing the limb (hind) at hip, knee and ankle, is elicitable from any one of a number of the various afferent nerves of the limb. It reveals to inspection little difference whichever be the particular afferent nerve stimulated. That the flexion evoked cannot, however, be strictly the same under excitation of the several different nerves has been already shown (5). To examine further the differences it thus presents as evoked from the several nerves we have taken simultaneous myograms from paired flexor muscles under provocation of the reflex from various different afferent limb-nerves. The muscle pairs selected have been (1) a hip-flexor and a knee-flexor (tensor fasciæ femoris and semitendinosus) together, (2) a hip-flexor and an ankle-flexor (tensor fasciæ femoris and tibialis anticus) together, and (3) a knee-flexor and an ankle-flexor (semitendinosus and tibialis anticus) together. I. — Method . The preparation (cat) has, after spinal transection in the anterior lumbar region and immediately subsequent decerebration under deep anæsthesia, been made ready for the myograph by appropriate isolation of the test muscles. The method of fixation and attachment to the myograph has been as described in previous communications, except that for tibialis anticus the freed tendon has been passed round a small light pulley allowing in its case a horizontal pull on the myograph. The resting tension of the two muscles has been adjusted for near equality. In using tensor f. femoris for the myograph distinction was made between its long anterior portion, tens. f. fem. longus, and its short posterior portion, tens. f. fem. brevis. Most of the observations with it were made on the former, the tens. f. f. brevis being cut away, though not always to equal extent. The myograph employed is of isometric pattern and records optically: its description is given as an Appendix to this paper; it is a further modification of the myograph described in a previous communication (6). The afferent nerve, bared and cut, has been stimulated by single or double-shock series of various frequency delivered from a coreless coil fed by a 2-volt battery.

This publication has 3 references indexed in Scilit: