Biomechanics and Medicine in Swimming XI

BiomechanicsandmedicineinswimmingXi
swimming economy is required. More fundamental research was provided
by Klauck, who developed a forward dynamics model to predict
swimmer’s velocity on an “if/what” basis.
In this volume, the concept of Critical Velocity, and associated parameters,
were revisited (Clipet et al.; Dopsaj et at.; Ogita and Miyashita;
Rodriguez et al.; Soares et al.; Takahashi et al.; Wakayoshi and
Ogita;), but with particular emphasis on their possible contribution to
the assessment of anaerobic components of swimming performance. The
SL drop intensity was, once again, sustained as a valuable indicator of
relevant aerobic training intensities (Dekerle et al.; Nomura and Shimoyama).
More direct approaches to this domain included VO 2 kinetics
(Baron et al.; Fernandes et al., Ogita et al.; Rodriguez and Mader;
Rodriguez et al.), and assessment methods (Cardoso et al.), among other
relevant metabolic parameters, opening new perspectives on the importance
of O 2 metabolism for swimming training and performance. In the
mean time, Strumbelj et al. provided evidence that maximal [La] and
minimal pH values do not differ between maximal efforts from 100 to
400 m performed by 200 to 400 m specialists, underpinning the importance
of both aerobic and anaerobic metabolism in swimming.
Psychological aspects of swimming were also considered (Sugano et
al.; Vikander and Stallman; Zientek), as well as talent selection (Bügner
and Hohmann; Saavedra et al.) and the influence of maturation, training
and competition on the evolution of swimming performance (Hellard
et al.).
BMS X (2006)
In the last volume of the BMS series, some new research interests and
methods were included, particularly relevant in the hydrodynamics domain.
“Particle Image Velocimetry” (PIV) was introduced (Kamata et
al.; Matsuuchi et al.; Miwa et al.; Yamada et al.) as a technique of flow
visualisation and quantification (applied to mono-fin, sculling, butterfly
kick and hand movement during front crawl). Results support previous
assumptions about the importance of unsteady flow to swimming
propulsion, and practical consequences were extracted (Ungerechts and
Klauck). The introduction of “Computational Fluid Dynamics” (CFD)
approaches into the series also distinguishes this volume (Lyttle and
Keys). These authors studied the underwater kicking action, showing
that large and low frequency kicks seem to be better than small and
high frequency ones. Experimentally, Gavilán et al. further concluded
that the waving energy transfer along the body starts from the hips,
and that the upper body is mainly a stabilizer. The same problem was
addressed by Sugimoto et al., who used the computer model proposed
by Nakajima to estimate the propulsive action of each body part during
underwater dolphin kick. Toussaint et al. reported very high front
crawl propulsive efficiency values at also high swimming velocities. They
considered that the arm rotation and the associated axial flow possibly
established at very high velocities allow bringing added water mass to
the propelling segments, enhancing efficiency.
Another area of great interest in this volume was the movement coordination,
reinforced by efforts on pattern recognition (Oghi; Oliveira
et al.), that allow fast video-based evaluation solutions and feedback
(Soons et al.). Chollet et al. analysed the effect of technical mistakes in
backstroke coordination, and Schnitzeler et al. (a) studied the stability
of coordination during maximal and sub-maximal swims. Seifert et al.
(a) compared objective (kinematical parameters obtained from digitalization)
and subjective approaches (based on expertise), to assess stroke
phases in coordination studies. A similar interest was shown by Schnitzler
et al. (b, c) who used mechanical velocimetry to increase the capacity
to discriminate the propulsive phases during one stroke cycle in order
to empower traditional coordination analysis. Tella et al. also combined
IVV, coordination and fatigue studies, and found that IVV empowers
the understanding of the coordinative changes that occur with fatigue.
IVV and acceleration were again a central topic of research. Mechanical
velocimetry was used by Craig et al. and other authors. Using
this method, Pedersen and Kjendlie reported significant reductions in
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the mean maximal velocity when breathing every cycle, compared with
controlled breathing. Soares et al. used the IVV frequency spectrum to
analyze changes in the mechanical output profile during a maximal 50
m test, presumably allowing the evaluation of “energetic dominancy
transitions” relevant for speed training. CM and hip IVV were compared
(Capitão et al.; Morouço et al.), being considered to provide similar patterns,
and Barbosa et al. analyzed the relationship of IVV of the CM to
energy cost of swimming considering the four competitive strokes, and
controlling the velocity effect.
Fatigue was explored through an EMG frequency spectrum decrease
during an exhaustive 4 x 50 m front crawl test (Caty et al.).
Further use of EMG was proposed by Hohmann et al. to analyse the
backstroke start technique to which Krüger et al. added kinematic and
kinetic parameters. Takeda and Nomura compared the GS and the TS
analyzing the take-off velocity and its extensional and rotational components,
underlining the importance of the rear leg action during the
TS. Seifert et al. (b) also analyzed starts, but for breaststroke events,
considering the coordination of the actions during the underwater cycle.
This was the main discriminating parameter of an Olympic breaststroke
medalist after the admittance of the butterfly kick. Turns were studied
by Pereira et al. using kinematical and kinetic variables. As expected,
peak normalized horizontal force exerted on the wall was determinant
for performance. Prinz and Patz also studied the flip turn, analyzing the
effects of the tuck index, the depth of the wall contact, and the contact
time on the velocity of push-off.
Pedagogical and didactical aspects of swimming also received a
deeper analysis in this volume. Havriluk measured the effects of an instructional
intervention of one week duration on swimming technique
using biomechanical parameters such as hand force to time curves and
active drag. The main effects were observed on drag. Different instructional
programs were also compared (Invernizzi et al., a, b), including
heuristic and analytical approaches. Heuristic approaches were shown
to be preferable.
Critical velocity and critical power concepts were once more investigated
(Dekerle et al. a, b; Filipatou et al.; Greco et al.), inclusively based
on reduced distances (Thanapoulos et al.), and applied to define training
sets for velocities above the anaerobic threshold (Wakayoshi et al.). Reis
and Alves showed that critical velocity and v4 changes similarly with
training for age group swimmers. To further analyze metabolic transition
zones, the anaerobic ventilatory threshold (Morais et al., a) and the
VO 2 at the lactate threshold (Morais et al., b) were studied. In the same
perspective, Machado et al. proposed a mathematical based method to
assess the individual anaerobic threshold, and Kjendlie and Stallman
verified the validity of non-paced tests for the same use. Complementarily,
Shimoyama et al. observed that OBLA changes are mainly determined
by physiologic rather than biomechanical factors. VO 2 and
other respiratory, ventilatory and cardiologicaly relevant parameters
were analysed (Fernandes et al., Machado et al., Madeira et al., a, b,
Querido et al., Strumbelj et al.). The effects of using a respiratory snorkel
on the breathing frequency in front crawl were also studied (Kapus et
al.). Physiological (VO 2 max., v@OBLA, [La]max) and biomechanical
(active drag, maximal propulsive power) characteristics of an Olympic
female gold medalist were provided by Ogita et al. and compared with
elite college swimmers. The results showed that it was not the physiologic
parameters that distinguished the Olympic champion, but a slight
drag reduction observed at high swimming velocities, emphasizing the
relevance of the biomechanical factors to excel in swimming.
Specific training modes also attracted attention. Peaking and tapering
(Issourin et al.), altitude training (Marcadé et al.), assisted (Pretto
et al.) and resisted (Llop et al., Mavridis et al.) training were addressed.
Water-polo was extensively studied (Bratusa and Dopsaj; Bratusa et
al.; Dopsaj et al.; Klauck et al.; Platanou and Geladas; Stirn and Strojnik;),
but also life-saving ( Juntunen et al.), triathlon (Bernavent et al.),
water running wearing wet vest (Stallman et al., a, b), and synchronised
swimming (Homma and Homma, a, b; Ito) were considered. Ito anal-