Daily globe. [volume] (St. Paul, Minn.) 1878-1884, 1883-05-19
IN OARSMAN'S STROKE.


So far the action of the muscles es-
sentially concerned in the performance
OF the "stroke" have been considered.
There are muscles concerned in the
supplemental actions, viz: Those con-
cerned in the performance of respira-
ton. Seated at the stern of an eight
oar one notices that the frequency Of
the respiratory act is directly proper
tional to the quickness of the stroke.
At an ordinary paddle the Inspirations
will be about twenty-eight per minute,
as compared with the normal frequency,
eighteen to twenty, observed when the
individuals are taking ordinary walking
exercise. On quickening the respira-
lions increase in frequency, but lose in
depth, and at racing pace often amount
to thirty-six and thirty weight per minute.
Inspiration is effected in the act of
coming forward" the breath is held
during the stroke and there is sudden
expiration between the conclusion and
the commencement of fresh effort.
The full extension of the arms forward
of course aids considerably in the ex-
pansion of the chest; while the alb
dominal muscles contract in order to
steady the contents Of that cavity and
prevent their undue propulsion down
ward by the descent of the diaphragm.
Expiration is effected chiefly by the re-
coil of these forces, the tension being
heightened by the breath being held
during the stroke, and also by the
action of the internal intercostal mus
cles, whose action in cases of extraor-
binary respiratory effort is about one
fourth more powerful than that of
the external intercostals, the muscles of
inspiration. Expiration, too, as we have
already stated, is materially aided by
bringing the handle of the oar to the
chest. This, too, is very important
part of the stroke, for the finish" is
nearly of equal importance as the
"catch." If contraction of the biceps
commences too soon, then the stroke is
not rowed out; if deferred too late, the
contraction is too vehement, and the oar
is brought out with a Jerk. While the
oar is being rowed to the chest the ell
bows, by the action Of the pectoralis
magnus, should be brought well to the
sides. Violent contraction Of the fex-
ors of the forearm, however, is not de-
sirable, having tendency to bring the
oar out of the water with jerk. A
great advantage, moreover, is gained by
bringing the arms sharply and closely
to the side at the end of the stroke; it
aids the respiratory act. Experiments
on the dead body clearly show that
when artificial respiration is performed
according to Sylvester's method more
air can be forced out of the chest when
the arms are brought firmly and closely
in contact with the chest walls than
when the experimenter is simply con-
tented with raising and depressing
them. The stroke is now at an end,
and two subsidiary actions have to be
performed before it's recommencement
the drawing forward the slide, and
execution of the feather. The former
is almost instantaneously performed by
vigorous and powerful contraction of
the hamstring muscles-musclesw which
before the introduction of the slide were
comparatively idle. The slide there
fore has introduced more work into the
stroke, and, indeed, may also be consid-
cred to be a third action.-M Medical
| Ne1DS.