Biomechanics and Medicine in Swimming XI

Analyses of Instruction for Breath Control While
Swimming the Breaststroke
hara, h. 1 , Yoshioka, A. 2 , Matsumoto, n. 2 , nose, Y. 2 , Watanabe,
r. 3 , shibata, Y. 4 , onodera, s. 2
1 Kokugakuin University, Faculty of Human Development, Yokohama, Japan
2 Kawasaki University of Medical Welfare, Kurashiki, Okayama, Japan
3 Atomi University, Faculty of Literature, Saitama, Japan
4 Tokyo Gakugei University, Department of Sports & Health Science, Tokyo,
Japan
The purpose of this research was to clarify the important factors preventing
swimming apnea. We conducted the experiment with seven subjects
using four pressure transducers simultaneously. These were connected to
the control unit and the data were analyzed to detect pressure changes
with the face in three different positions. We verified that trained swimmers
vary the amount of air blown out of the nose and mouth independently.
There was an interval between exhaling from the nose to exhaling
from the mouth. In the case of instruction for beginners, in order to
prevent swimming apnea it is effective if the instructor has the learner
pronounce “Mnn” with the nose, then once that is completed, pronounce
“Pha” or “Pa” from the mouth to blow out.
Key words: swimming apnea, inhalation, nasal pressure, pronouncing,
oral pressure
IntroductIon
One of the difficulties while developing swimming technique is how
to control breathing. Breath control is important for the acquisition of
swimming skills such as stroke movement of arms and legs, and swimming
faster in the various swimming strokes.
However, it is not clear what the trigger for inhalation is while
swimming. In the exhalation phase, water pressure helps exhalation.
Otherwise, inhalation is more arduous than on land because water pressure
works to resist the enlarging of chest volume. Even trained swimmers
occasionally take in water during inhalation while swimming. Why
are these kinds of mistakes occurring?
It is the purpose of this study to clarify the important factors preventing
swimming apnea, or the unintentional water-blockage of the
airways.
Methods
The design of this experiment was approved by the Department of General
Planning, Research Cooperation Section of Kokugakuin University.
We explained the purpose and methods of this study to the subjects
in verbal and written form, and informed consent was obtained from
all. The seven subjects who voluntarily participated in this study were
healthy university students; four students were trained in swimming but
three were not skilled swimmers. The only female subject was a trained
swimmer and other six students were male. We measured nasal cavity
and oral cavity pressure while simulating the breaststroke motion,
using four pressure transducers (SPC-464; Miller Instruments) simultaneously.
These were connected to the control unit (TCB-500; Miller
Instruments) by cables (TEC-10D; Miller Instruments). The equipment
had been tested and verified in earlier work (3). One transducer
was placed just beside the nose to measure water depth pressure at the
nostril level (Channel: 1). The second was inside the nasal passage for
measuring nasal cavity pressure (Ch: 2). The third was placed on the
cheek at the level of the mouth to measure water depth pressure at this
level (Ch: 3). The fourth was placed in the mouth for measuring oral
cavity pressure (Ch: 4). Data were recorded on LogWorx (Distributed
Design Corporation) program with the Recorder (EFA400; Distributed
Design Corporation).
chaPter5.education,adviceandBiofeedBack
The data were analyzed to detect the pressure changes in three
positions of the face. Position 1: Nose above the water surface but
the mouth was in the water. Position 2: Nose and a mouth were both
immersed in water. Position 3: Face was rising up and immersing down
into water, simulating swimming the breaststroke.
results
Position 1: The nasal pressure and oral pressure did not change at the
same time in the case of exhaling except for one subject, who was not
a skilled swimmer. His nasal pressure changed with oral pressure. But
after blowing out from the mouth in the water, almost all nasal pressures
rose momentarily.
Position 2: In the case of strong exhaling from the nose, the nasal pressure
and oral pressure changed simultaneously. On the other hand, at
the moment of strong exhalation from the mouth, the nasal pressure did
not elevate. (Fig.1)
Exhalation
from mouse in
water
Water depth pressure curve at nostril level
Nasal cavity pressure curve
Water depth pressure curve at mouth level
Oral cavity pressure curve
Exhalation
from mouse in
water
Figure 1. The data obtained from Position 2: At the moment of strong
exhalation from mouth, the nasal pressure (Ch2) did not rise. In this
experiment, the pressure curves were not correlated between nasal and
oral spaces (Ch4).
Position 3: We verified, using pressure sensors attached simultaneously in
nose and mouth, that trained swimmers vary independently the amount
of air blown out of the nose and mouth airways. There was some timelag
between exhaling from the nose to exhaling from the mouth, and
this occurred while swimmers were face up above the surface of the water.
In Position 3, the end of positive oral pressure was delayed 0.38sec.
(Average) from the end of nasal positive pressure in trained subjects, and
in untrained subjects, the delayed time was 0.11sec. (Ave.).
Exhalation from
nose in water
Exhalation
from mouse in
water
Interval between
nose to mouse
exhalation
Figure 2. The data obtained from Case.3 (Simulation of breaststroke
swimming) in this experiment by the trained subject: The nose was rising
from water surface just before the mouth. After the nose has risen,
delayed exhalation from the mouth was observed (Ch4), and nasal pressure
(Ch2) did not retain high values.
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