Biomechanics and Medicine in Swimming XI

on Swimming Medicine, and marked the first impulse for the increase
of these areas in the BMS series. From the compared evidence, however,
it should be supposed that the BMS series still supports the relevance of
Biomechanics compared to other swimming science domains, an importance
which, considering the global scientific scene, should be reinforced
in the future.
A DEEPER ANALYSIS OF BMS SERIES CONTENTS
Despite previous data suggesting that the BMS series is not coping
with the general progression of scientific research regarding the balance
between different scientific domains, its deeper content analysis seems
to clearly demonstrate that BMS books played, and continue to play,
a decisive role in the promotion and spreading of swimming scientific
knowledge, always keeping pace with peer reviewed indexed literature,
but particularly assuming a very relevant catalytic role in encouraging
future steps forward in the progress of swimming science. It is obvious
that the BMS series does not contain all the relevant swimming research,
not even in the biomechanics domain, but it can be hypothesized
that the knowledge included satisfactorily covers all, or almost all, of the
relevant progresses that swimming science has achieved over the years.
We will now survey the ten BMS books (I to X, disregarding their original
titles), highlighting those contributions that, in our view, strongly
contributed to the above named effects. We will focus our attention
mainly on both experimental and theoretical original contributions.
BMS I (1971)
In this volume, Counsilman introduced the revolutionary concept of
quasi-static lift (L) theory on human swimming propulsion (P), and
Kent and Atha analysed different transient body position effects on
breaststroke drag (D) using passive drag towing methodology, but
suggesting the need of future active drag (Da) assessments. P and D
periodical changes during a swimming cycle are expected considering
coordinative analysis (Nemessuri and Vaday; Vaday and Namessuri), as
well as, consequently, the existence of an acceleration profile, represented
by intra-cycle velocity variations - IVV (Miyashita). The Astrand and
Englesson “Aquatic Swim-mill” - the first swimming flume -, was probably
the “must” in instrumentation progress presented in BMS I. The
first results on VO 2 measurements at different velocities using this ergometer
were produced by Holmér. Goldfuss and Nelson related swimming
actions to the measured tethered force exerted by the swimmer,
in what seem to be the first combination of both image and force data.
Electromyography - EMG - (Barthels and Adrian) was also used as it
was assumed to be the “unique” solution to monitor muscular activity
during swimming despite serious normalization difficulties (Lewillie).
In parallel to the presented experimental approaches, Seireg and Baz
presented the first complete mathematical analysis of the human biomechanics
of swimming in the sagittal plane (x and y equations of linear
motion and z joint torques).
BMS II (1975)
This volume fulfilled some of the higher expectations that emerged from
the previous book. Serious improvements occur in the development of
new instrumentation, namely for image acquisition, particularly to allow
dual-media observation of the swimmer (under and overwater views)
(McIntyre and Hay). Van Manen and Rijken resume the experiments
conducted in The Netherlands Ship Model Basin, underlining the “towing
carriage” that allowed new incursions in the measurement of P and
D. In this regard, a very contemporary question was discussed in those
days: the effect of swimsuits on D, showing that wearing a suit, compared
to a naked situation, reduces D in females by about 9%. Using the
“towing carriage”, Rennie et al. calculated Da combining load (positive
and negative extra loads), the energy cost of swimming and efficiency
(e), following one of the most well-known swimming biophysical relationships:
VO 2 net/d = Da/e, where VO 2 net is the aerobic exercise
Oxygen consumption subtracted of the basal VO 2 and d is swimming
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distance. The authors concluded that men have a higher Da and energy
cost (VO 2 net/d) than their female counterparts and a similar e,
and that VO 2 net/d rises with hydrostatic torque. Holmér used the same
approach, and concluded that Da values are 1.5 to 2 times higher than
passive D.
The importance of IVV analysis was once more stressed. Bober
and Czabanski used the IVV combined with film images to investigate
breaststroke coordination changes with mean velocity and Barthels and
Adrian related hand kinematics with hip acceleration using film analysis.
Sixteen millimeter film was also used, synchronized with EMG telemetric
signals, to evaluate handicapped swimmers performing breaststroke,
front crawl and backstroke (Maes et al.).
As in BMS I, also in BMS II some essays on mathematical modeling
were published (Francis and Dean; Jensen and Blanksby).
BMS III (1979)
The third volume was biomechanically marked by two contributions
extensively referred to in swimming literature, one related to D, and
the other to P. Clarys extensively reviewed the state of the art in D
hydrodynamics and its relationship to morphology, and used the already
described “Towing Carriage” to assess Da. On the other hand, Schleihauf
developed and experimentally supported the L and propulsive drag
(Dp) theory of swimming propulsion. Once again the global dynamical
effect of P and D changes during the stroke cycle motivated researchers
to analyse IVV: Holmér used linear accelerometry and integration
to assess swimming velocity, and Vervaecke and Persyn analysed coordination
of the breaststroke kick related to anthropometric, flexibility
and force data. Piette and Clarys used an EMG telemetric system to
compare competitive and non-competitive front crawl swimmers using
different normalization procedures and Okamoto and Wolf reported,
for the first time in the BMS series, the use of fine-wire electrodes in
the aquatic environment.
In BMS III only one mathematical modeling approach to swimming
biomechanics was included ( Jensen and McIlwain), aiming to
estimate segmental forces and joint torques in the dolphin kick. Swimming
starts, however, were extensively studied (Disch et al.; Stevenson
and Morehouse; Zatsiorsky et al.), and the first paper on swimming
turns of the series appears (Nicol and Krüger), studying the forces exerted
on the wall using force plates.
BMS III also included several relevant contributions on “Training
Methods”, starting the tendency for a progressive enlargement of the
interest domains of the series.
BMS IV (1983)
This volume was a combined proceedings book of the Biomechanics in
Swimming and the FINA Swimming Medicine congresses, promoting
an increase of the included scientific domains. P and D were, once more,
central topics. Schleihauf et al. extended previous contributions to the
study of the propulsive potential of the forearm and to arm joint torques.
Still in the P domain, one of the first papers on the propulsive effect
generated by undulatory swimming movements was included, comparing
dolphins and butterflyers (Ungerechts), underlying the importance
of the quantification of the added mass effect to understand P and D.
In another paper Ungerechts showed that the Re number does not represent
satisfactorily the flow regimen around bodies that change form
periodically, providing a historical contribution to the hydrodynamics of
swimming. Da was once again revisited (Kemper et al.). It was shown
that for much higher velocities (1.73 vs. 1.15 m/s), skilled swimmers are
submitted to a much lower Da value (32.2 vs. 57.0 N), though passive
drag values are similar at 0.75 m/s (22.5 vs. 21.2 N), relatively to their
non elite counterparts. Ohmichi et al. (1983) measured the waves caused
by swimmers using a “Wave High Meter”, and comparing different velocities
and strokes.
Nigg proposed a model to estimate the added work associated with
IVV in swimming (3% extra work performed for velocity variations of
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