How this information
can be used
Regardless of the type of dive start used, the ultimate goal is the
same: the swimmer must react to the starting signal and leave the blocks
rapidly, at an appropriate take-off angle and with as much forward velocity as
can be generated. (Lyttle, & Benjanuvatra, 2013)
Conflicting results have been found when researching the most effective
swimming dive.
Lyttle and Benjanuvatra (2013) state, “Previous studies comparing dive
start techniques have usually produced conflicting results”. Some have
suggested that the Grab start is superior to the track start and other studies
have found no difference between the grab and track starts. A third group of
studies have concluded that the track start is superior to the grab start.
However Blanksby et al (2002) state, “Most studies have found the grab
start to be superior to the conventional start”
Vilas-Boas
et al (1975) conducted a research to compare two variants of the track-start
technique for ventral swimming races with the more often performed grab start.
Finding pointed out that, despite several biomechanical differences all of them
seem equally valuable, because all the differences noticed above water,
vanished once the water glide took place.
A
study done by Blanksby et al (2002) compares the grab, track and handle starts
in a swimming race. Videography was used to analyse these starts before and
after a practice period. The performance criterion measure was time to 10 metres.
Swimmer performed two of each dive at pre and post-practice sessions, with the
fastest dive chosen to use for the test. Reaction movement, block and flight
times, flight distance, and their centre of mass and the set position were each
measured.
|
|
Grab
|
Handle
|
Track
|
|
Pre-intervention
|
Mean
(SD)
|
Mean
(SD)
|
Mean
(SD)
|
|
10m
time
|
4.64
|
4.67
|
4.67
|
|
Reaction
time(RT)
|
0.21
|
0.22
|
.023
|
|
Movement
time (MT)
|
0.65
|
0.63
|
0.64
|
|
Block
time (BT)
|
0.86
|
0.83
|
0.88
|
|
Flight
time (FT)
|
0.32
|
0.24
|
0.30
|
|
Flight
distance (FD)
|
3.23
|
3.01
|
2.73
|
|
CM
position
|
-0.29
|
-0.05
|
-0.58
|
|
|
|
|
|
|
Post-intervention
|
|
|
|
|
10m
time
|
4.52
|
4.46
|
4.57
|
|
Reaction
time (RT)
|
0.20
|
0.19
|
0.19
|
|
Movement
time (MT)
|
0.63
|
0.50
|
0.66
|
|
Block
time (BT)
|
0.82
|
0.69
|
0.85
|
|
Flight
time (FT)
|
0.30
|
0.24
|
0.29
|
|
Flight
distance (FD)
|
3.27
|
2.99
|
3.28
|
|
CM
position
|
0.26
|
0.15
|
-0.68
|
(Blanksby,
Nicholson, & Elliot, 2002)
There
was no specific difference in time to 10 m for swimmers using a grab start,
handle start or track start before or after the practice sessions. However the
time to the 10 m time did improve in the track and grab start following the
practice sessions. (Blanksby, Nicholson, & Elliot, 2002)
Conclusion
Competitive
swimming is a very mathematical sport and ultimately winning comes down to a
matter of one millionth of a second. Swimming is a highly prodigious sport in
the Olympic games, a lot of time, effort and money is used at perfecting every
aspect of a race, with upmost importance being placed on the dive as it can win
or loose a race. Many factors can contribute to producing the optimal
trajectory of a swimming dive. The main principles for all three dives are
block time (reaction time), flight time water time, all including several
variables. Other aspects that should be considered are the equipment (the block),
the swimmers body contortions, and the specific dive chosen. However ultimately
like in many other sports there is no ideal swimming dive that can be used for
everyone: individual testing is needed to determine each swimmers optimum
technique.
