Biomechanics and Medicine in Swimming XI

-ARM
*
5
BiomechanicsandmedicineinswimmingXi
Force (N)
298
160
140
120
100
80
60
40
20
0
B
*
*
SW ARM 1-ARM
*
1 2 3 4 5
Left arm strokes
Figure 3. Force measured in the right (A) and left (B) arm-stroke during 40
five arm-strokes of each test. SW: full-stroke, ARM: arms only, 1ARM: 20
using one arm test.
dIscussIon
The findings of the present study indicate that a reliable measurement
of swimming force for each arm can be achieved using tethered swimming.
The procedure used for the separation of arm-strokes during front
crawl was proved to be valid when it was compared with over-water and
under-water video recordings. Using three different tethered swimming
tests (full-stroke, arms only, single arm) no differences were observed
between right and left arm-stroke force.
Previous studies have shown a high reliability for the measurement of
the maximum swimming force in a 10 s tethered swimming test (Kjendlie
& Thorsvald 2006). However, there are no data concerning the reliability
of measuring the force output during a single arm-stroke during tethered
swimming. In order to measure the force of each arm-stroke independently
during a test, a valid separation of the strokes is required. In the
present study the time calculated to complete each arm-stroke from a
video and from a hand-held trigger was similar (p>0.05). This means that
the input of the electrical signal using a hand-held trigger can separate
arm-strokes with validity (ICC=0.974 and 0.939). In practice, the force
variation within this time frame can be measured. Applying these procedures
with a group of young swimmers, the force was measured with reliability
(ICC=0.985 and 0.975, p