Content uploaded by Julien Vantorre
Author content
All content in this area was uploaded by Julien Vantorre on Sep 08, 2014
Content may be subject to copyright.
A REVIEW OF FREESTYLE DIVE STARTS: A BIOMECHANICAL PERSPECTIVE.
Vantorre J. 1, Chollet D. 1 and Seifert L. 1
1 C.E.T.A.P.S. Laboratory UPRES EA 3832: University of Rouen, Faculty of Sports Sciences, France
ABSTRACT
This paper updates swim-start state of the art from a biomechanical standpoint. The contribution of
the swim-start to overall swimming performance was reviewed, including the effects of various
swim-start strategies, and skill effects across the range of swim-start strategies identified in the
literature. The main objective was to determine the techniques on which to focus in swimming
training in the contemporary context of the sport. The phases leading to key temporal events of the
swim-start, like water entry, require adaptations to the swimmer’s chosen technique over the course
of a performance; we thus define the swim-start as the moment when preparation for take-off
begins, to the moment when the swimming pattern begins. A secondary objective is to determine
the role of adaptive variability as it emerges during the swim-start. Variability is contextualized as
having a functional role and operating across multiple levels of analysis: inter-subject (expert versus
non-expert), inter-trial or intra-subject (through repetitions of the same movement), and inter-
preference (preferred versus non-preferred technique). Regarding skill effects, we assume that swim-
start expertise is distinct from swim stroke expertise. Highly skilled swim-starts are distinguished in
terms of several factors: reaction time from the start signal to the impulse on the block, including the
control and regulation of foot force and foot orientation during take-off; appropriate amount of glide
time before leg kicking commences; effective transition from leg kicking to break-out of full
swimming with arm stroking; overall maximal leg and arm propulsion and minimal water resistance;
and minimized energy expenditure through streamlined body position. Swimmers who are less
expert at the swim-start should spend more time in this phase and would benefit from training
designed to reduce: (i) the time between reaction to the start signal and impulse on the block, and
(ii) the time in transition (i.e., between gliding and leg kicking, and between leg-kicking and full
swimming).
KEYWORDS:
Biomechanics, expertise, performance, techniques, variability
LITERATURE SEARCH METHODOLOGY
MEDLINE and ScienceDirect were searched for primary sources using six keywords: expertise,
performance, technique, variability, swimming and start. These were pooled (via Boolean operation
“OR”) and combined (via Boolean operation “AND”) with similarly pooled keywords related to
swimming biomechanics. The proceedings of international congresses on biomechanics and
swimming databases also were searched, from their earliest available records up to November 2012.
Relevant articles were sought on Google Scholar, and the cited articles and reference lists of all
included studies were carefully scrutinized. The articles analyzing swim-starts were restricted to
those written in English. Full publications and abstracts were screened, and all relevant studies were
retrieved. A standardized form was used to select the studies eligible for inclusion. Ultimately, 45
references and eight books were selected from the previously selected articles and books from the
MEDLINE, ScienceDirect and Google Scholar searches; an additional 17 references were retrieved
from the proceedings of sport sciences congresses. Disagreement was resolved by achieving
consensus among the authors, who took into account the size of the population studied and the
swimming skill level for inclusion.
THE START IN A SWIMMING EVENT
Recently, interest in swimming-specific research has begun to accelerate (Pelayo & Alberty, 2011).
Indeed, Vilas-Boas (2010) noted that swimming is now one of the most investigated physical
activities, based on the number of published research articles and the number of countries
represented at international meetings. Part of this rise in interest may be related to the ongoing
modifications in the swimming rules, driven by changes in swimming techniques and technologies, all
of which have inspired new research directions. This includes the swim-start (SW 7 of the FINA rules),
which has undergone several changes from a regulatory point of view. For example, on January 1,
2010, a new kick-start block was introduced, with a raised rear section to assist the track start
technique (Omega OSB11). Competition analysis has provided information on the start time (to 15-
m), turn times (7.5-m into and out of the wall), and finish time (5-m into the wall), as well as the
stroke length, stroke rate and velocity, for each 25-m section of free swimming (Mason & Cossor,
2000). Moreover, the start time has been quantitatively evaluated in relation to the swimming, turn
and finish times in order to assess its contribution to overall performance (Arellano et al., 1996;
Costill et al., 1992; Lyttle & Benjanuvatra, 2005; Mills & Gehlsen, 1996; Vilas Boas et al., 2003). The
results indicate that the start time to 15-m can account for anywhere between 0.8% in long distance
events and 26.1% of the total race time in sprint events (Lyttle & Benjanuvatra, 2005). Moreover,
contrary to the block starts in track and field, in which the athlete has to accelerate from zero to full
running speed, dive swim-starts enable swimmers to enter the water faster than average swimming
speed, which further underlines the great importance of the swim-start in sprints. Effective diving
techniques enable swimmers to exploit the speed generated during the dive and are in line with the
principle of efficiency that drives every phase of the competitive event (Kilduff et al., 2011; Lyttle &
Blanksby, 2011).
ANALYSIS OF SWIMMING START KINEMATICS
Methodology
The studies on the swim-start have analyzed several parameters. Kinematic analyses of swim-start
behavior and performance, for example, have usually compartmentalized the start into distinct
phases, such as block time, flight time and underwater time (Arellano et al., 1996; Cossor and Mason,
2001; Vilas-Boas et al., 2003). More recent studies have assumed that the start actually begins with
the reaction to the start signal and the push from the block (Benjanuvatra et al., 2007; Bishop et al.,
2009; De la Fuentes et al., 2003; Slawson et al., 2012). These trials were recorded at 50 Hz with a
digital video camera placed perpendicularly to the direction of movement. Vantorre et al. (2010a)
used both fixed cameras (placed at 5-m and 15-m) to determine phase limits, and underwater mobile
cameras on a trolley to analyze qualitative variables and stroking parameters like stroke length or
frequency. The forces applied during the push from the starting block were analyzed via custom-
built, instrumented starting blocks. Force curves measured the impulse in the horizontal and vertical
axes (in N.kg-1) (Benjanuvatra et al., 2007; Blanksby et al., 2002; Lee et al., 2001; Slawson et al., 2012;
Vantorre et al., 2010b, 2010c; Vilas-Boas et al., 2003; West et al., 2011). The kinetic analysis of the
block phase quantified the impulse and described its direction relative to the direction of movement
(Benjanuvatra et al., 2007; Blanksby et al., 2002; Lee et al., 2001; Slawson et al., 2012; Vantorre et al.,
2010b, 2010c; Vilas-Boas et al., 2003).
Block Phase
Several studies of swim-start phase kinetics, particularly the reaction time on the starting block and
the flight and entry phases, have drawn parallels with the start in track and field (Ayalon et al., 1975;
De la Fuentes et al., 2003; Issurin & Verbitsky, 2003; Krüger et al. 2003; Miller et al., 2003; Vilas-Boas
et al., 2003; Zatsiorsky et al., 1979). However, from a biomechanical point of view, these starts differ
in many ways. Moreover, among swimmers, the starts also differ according to specialty. Sprint
swimmers need to rotate backwards to bring themselves upright, whereas longer-distance swimmers
need to focus on the distance covered while in the air and the body orientation at water entry. Here,
breaking down the swim-start is not only a spatial matter, but also a matter of motor changes during
the overall start movement. From this perspective, studies on the block phase (Benjanuvatra et al.,
2007; Vantorre et al., 2010a) have shown that two distinct actions must be optimized: a rapid
reaction to the start signal and high impulse generated over the starting block. The studies on the
block phase have usually been kinetic analyses focused on the force applied to the block or on
training programs designed to improve the start (Bishop et al., 2009; Breed & Young, 2003; De la
Fuentes et al., 2003; Lee et al., 2001). The reaction time needs to be as brief as possible, while the
movement phases on the block need to last long enough to maximize the swimmer’s impulse to
achieve high horizontal velocity (Breed & Young, 2003). In other words, a compromise needs to be
struck between spending too much time on the block to create more force and spending too little
time on the block to minimize the time deficit and avoid being “left at the start” (Lyttle et al., 1999).
Flight and Entry Phases
Breaking down a swim-start into its component parts can be challenging as the phases are not always
clear cut. Maglischo (2003) defined water entry as the moment when the hand enters the water. This
definition is widely used to determine the end of the flight phase, during which swimmers need to
jump as far as possible and travel the maximum distance at the high velocity developed during the
block phase (Hubert, Silveira, Freitas, Pereira, & Roesler, 2006; Sanders & Byatt-Smith, 2001). Ruschel
et al. (2007) reported that flight duration is not correlated with start time but that flight distance is
one of the variables that determine starting performance (r=-0.482). Maglischo (2003) noted that the
block phase strongly influences the flight phase by imposing a compromise between the pike and flat
styles for the aerial trajectory (Maglischo, 2003). The pike start has a longer start time, greater take-
off and entry angles, and a shorter distance to head entry into the water than the flat start
(Counsilman, Counsilman, Nomura, & Endo, 1988). Wilson and Marino (1983) showed a shorter 10-m
start time, greater entry angle, shorter distance to water entry, and greater hip angle at entry for the
pike start than for the flat start. However, after five training sessions, Kirner et al. (1989) reported
that the grab start/flat entry showed a shorter 8-m start time and a smaller entry angle than the grab
start/pike entry. Thus, the flat start aims for a quick entry into the water using a flatter body position
and earlier stroking. The pike start creates a smaller hole for water entry (i.e., angle of entry more
vertical to the water surface) with higher velocity due to the influence of gravity, but it requires a
horizontal (body position from the surface) then vertical(until break out the water surface)
underwater recovery, which causes higher resistance. Vantorre et al. (2010a) studied swim-starts and
found that strategies differ, even among elite swimmers. These authors observed that the swim-start
profiles included differences in how the limbs were used to achieve specific trajectory styles, such as
the Volkov start, with the arms back during the leg impulse; or the flight style start, with the arms
directly in front of the head (Vantorre et al., 2010a). However, the swimmer’s task during the flight
phase is not merely to go as far as possible. Mclean et al. (2000) and Vantorre et al. (2010a; 2010b)
showed that swimmers must also generate enough angular momentum to make a clean entry into
the water, which means that they need sufficient time to rotate while in flight in order to enter the
water through a small hole. Arm movements influence angular momentum and during the forward
rotations of the swim-start, a forward arm swing decreases rotation and, inversely, backward
rotations increase body rotation (Bartlett, 2007). Therefore, to manage the angular momentum
generated during the block phase, swimmers can make a flat start (less angular momentum and a flat
trajectory) or a Volkov start with a backward arm swing (more angular momentum and a pike
trajectory) (Seifert et al., 2010; Vantorre et al., 2010d). Swimmers enter the water at an angle
maintained during the descent phase of flight.
Glide Phase
After the aerial phases (block, flight and entry phases), swimmers have to manage the transition
from air to water (Maglischo, 2003), with the glide beginning when the head enters the water and
ending when the head breaks out (Counsilman et al., 1988). After water entry, the swimmer remains
in a streamlined position for as long as possible to maintain the velocity acquired in previous phases
and progressively assumes a horizontal position: this is the glide phase. Cossor and Mason (2001) and
Sanders (2004) indicated that finish performances are highly correlated with the swim-start time
spent underwater during the glide phase. However, few studies have actually measured this, with
most focusing on the aerial phase. De Jesus et al. (2011) showed the importance of the compromise
between underwater velocity and backstroke start performance. Guimaraes and Hay (1985) and Hay
(1988) concluded that glide time is more important to the start phase than either block time or flight
time (explaining 95% of the variance of the starting time for r = 0.97). Maintaining a streamlined
body position after water entry is vital to slowing the loss of velocity. Clear evidence of this is shown
when swimmers are being towed, as they produce greater hydrodynamic resistance in the supine
position than in the prone position (Clarys & Jiskoot, 1975; Counsilman, 1955). These observations
indicate that body shape, rather than surface area, is the decisive component when determining the
proportion of the total resistance. For example, placing one hand on top of the other, as opposed to
positioning the hands in shoulder alignment, caused a 7% decrease in resistance (Bulgakova &
Makarenko, 1966) (Figure 1).
Figure 1. Impact of body shape on flow resistance when the body is pulled (proportion of resistance in relation
to total resistance in gliding position corresponding to 100%) (Bulgakova and Makarenko, 1996)
Given the importance of this phase for starting performance, some authors have developed methods
to quantify the quality of gliding with drag coefficients using computational fluid dynamics analysis
(Naemi et al., 2010; Naemi & Sanders, 2008; Vilas-Boas et al., 2010). Bixler et al. (2007) validated this
tool for swimming studies. The glide factor is the measure of glide efficiency that accounts for the
combined effects of resistive forces and added mass. The quality of gliding is thus measured in terms
of the adopted posture and the flow characteristics around the swimmer’s body. The glide factor
(expressed in meters) is attained when a gliding body (the swimmer) has an initial velocity of 2 m.s-1
and decelerates to 1 m.s-1 in half a second. Naemi & Sanders (2008) showed that this is linked to the
swimmer’s size and shape. The inertial and resistive characteristics of a streamlined body affect the
glide efficiency.
Underwater Propulsion
Swimmers must manage the glide, underwater kicking and the break-out to start swim stroking
(Elipot et al., 2009; 2010; Maglischo, 2003; Vantorre et al., 2010a). Thus, the swim-start is not just
limited to the block and aerial phases, but continues until the swimmer re-surfaces and commences
swim stroking up to the 15-m mark in all strokes except the breaststroke, according to FINA rules.
Few studies have analyzed the underwater phase of the start even though it contributes considerable
distance at the beginning of a race, particularly in the breaststroke (Arellano et al., 1996; Cossor &
Mason, 2001; Guimaraes & Hay, 1985; Vilas-Boas et al., 2003). Cossor and Mason (2001) found a
negative correlation (r =-0.734) between the underwater velocity and the 15-m start time in 100-m
backstroke and 100-m breaststroke events, thereby suggesting the value of high velocity during the
underwater phase to achieve high swim velocity. Some authors have underlined the importance of
quantifying the underwater phase of the start (Sanders, 2002), but few have focused on doing so, or
on underwater leg propulsion (Blanksby et al., 1996; Clothier et al., 2000; Elipot et al., 2010; Lyttle et
al., 1998, 2000; Takeda et al., 2009). Indeed, despite a paucity of data, authors acknowledge that the
underwater phase time is fundamental to achieving an effective swim-start (Sanders, 2004; Vilas-
Boas et al., 2003; Vilas-Boas et al., 2000). This conviction was expressed in the study of Pereira et al.
(2003), who suggested that the time between water entry and the 15-m mark is the most important
variable in swim-start performance. For all strokes other than breaststroke, only the legs are used
during the underwater phase. The underwater phase in breaststroke is specifically defined by the
FINA rules as follows: “after the start and after each turn, the swimmer may take one arm stroke
completely back to the legs during which the swimmer may be submerged. A single butterfly kick is
permitted during the first arm stroke, followed by a breaststroke kick” (SW 7.1 FINA). This
specification has led some authors to analyze the propulsive and gliding actions, and the velocity
during this part of the start (Seifert, Vantorre, & Chollet, 2007; Vilas-Boas et al., 2010). These authors
showed that both national and international swimmers often demonstrate a similar problem: a
negative superimposition of leg propulsion with arm recovery at the pull-out phase, which is resolved
at the first swim stroke. Furthermore, these authors showed that the difficulty in achieving optimal
arm-leg coordination is due to an increase in velocity that limits the scope for adaptive variability. In
freestyle, swimmers generally begin stroking too early, which generates more drag than if they had
continued gliding for an extended period (Sanders & Byatt-Smith, 2001). Elipot et al. (2010) also
emphasized the importance of the relationship between gliding and underwater kicking to maintain
the velocity acquired by the diving start. Houel et al. (2012) stated that swimmers, ideally, should
start dolphin kicks after approximately 6-m of gliding and use an efficient, high rate of kicking. Motor
organization during the underwater phase should be optimized in relationship to these parameters.
A study of expert and non-expert swimmers described the underwater phase as including a leg
kicking phase and actually counted the number of leg undulations (Vantorre et al., 2010c). This
allowed the authors to distinguish gliding from leg propulsion in terms of relative duration and
quantity and pointed to the challenging transitions with regard to the respective parameters. The leg
kicking phase was calculated as the time between the beginning of leg propulsion and arm
propulsion: when kicking and stroking started at the same time, it was equal to 0 seconds; when the
swimmer started kicking before stroking, it was >0 seconds; and when the swimmer started
stroking before kicking, it was <0 seconds.
Kinematic Profiling
Vantorre et al. (2010a) segmented the start into six phases (see Figure 2): (i) block phase (the time
between the signal and the instant the swimmer’s toes leave the block), (ii) flight phase (the time
between the instant the toes leave the block and hand entry), (iii) entry phase (the time between
hand entry and toe immersion), (iv) glide phase (the time between toe immersion and the beginning
of the underwater propulsion of the legs), (v) leg kicking phase (the time between the beginning of
leg propulsion and arm propulsion), and (vi) swimming phase (the time between the beginning of the
first stroke and the arrival of the head at the 15-m mark).
Figure 2. Start phases to 15-m (Vantorre et al., 2010a).
The main objective of swim-start research has been to identify the most effective start technique in
terms of performance. Tools like stepwise regressions can be used to analyze various parts of the
start with a focus on qualitative aspects. For example, Vantorre et al. (2010a) investigated what
expert swimmers do during the underwater phase up to the 15-m mark, analyzing behavioral
parameters such as leg kicking, number of leg undulations, number of arm strokes, and arm
coordination to 15-m. These authors assessed the time spent in each phase and attempted to
determine the most effective profiles for start performances. Using these qualitative parameters,
cluster analysis determined whether the expert swimmers employed the same strategies to achieve
an optimal start. The profiles that emerged were in line with the two main attributes of an effective
start: recognizing the optimal time to stop gliding and begin leg kicking, and optimal transition from
leg undulation to full swimming.
EXPERTISE IN THE SWIMMING START
Definition
Swimming federations often define swimming levels using qualification grids. For maximal facility and
standardization, performances during swimming studies are expressed as trial times and expertise
can be characterized as a percentage of the world record (WR). Performances greater than or equal
to 90% of WR are considered to be elite. Thus, the swimming level is usually based on chronometric
performance. However, chronometric performance is an overly gross measure and may be
insufficient to define expertise, especially for practical purposes. For example, high performance has
been linked to the ability to start well, yet a swimmer can be an expert for the 50-m or 100-m event
(sprint events) but not be within the performance range commensurate a start expert. As previously
noted, the swim-start is one of several parts of an event and deserves to be considered as a distinct
skill. Seifert et al. (2007) and Vantorre et al. (2010c) found that the swim-start influences
coordination during the first strokes after break-out into swimming in both breaststroke and
freestyle. This is due to the high velocity acquired at the start and the glide plus movements
generated during the underwater propulsion period (Seifert et al., 2007; Vantorre et al., 2010c). Each
phase of the swim-start must be carefully coordinated to maximize the contribution to overall
performance.
Trembley and Fielder (2001) observed that swimmers try to obtain the highest explosive power from
the block, which requires a compromise between the optimal movement time and the time taken to
push off from the block. To optimize the block phase, Mason et al. (2006) found that expert
swimmers, regardless of the start technique, generated higher average acceleration on leaving the
block and that take-off angles were important discriminating parameters of performance. Wilson and
Marino (1983) specifically studied the influential factors in the aerial phase and reported low take-off
angles by elite swimmers (21.25 ± 5.59°) and a flight time phase of 0.30 ± 0.04s. Trembley and Fielder
(2001) reported that the best swim-starts were achieved by leaving the block quickly, traveling a
great distance in the air, and making a clean entry into the water with powerful underwater leg
propulsion. The importance of a clean entry and a streamlined glide position to maintain the velocity
acquired during the aerial phase was emphasized, as was the need for swimmers to delay the
moment when they begin stroking (i.e., a velocity greater than the instantaneous average swimming
velocity) (Sanders & Byatt-Smith, 2001). Zatsiorsky et al. (1979) found correlations between the glide
phase and the 5.5-m time (r=0.60 and r=0.94 at p<.05). Pereira et al. (2006) investigated the
underwater phase and showed significant correlations between the maximum depth reached during
the glide and the average velocity of the phase with the 15-m time (r=0.515 and r=-0.645). Less
skilled swimmers showed strong significant correlations (r= 0.98 at p<.05) between the underwater
phase and the start time (Arellano et al., 1996). Bloom et al. (1978) showed that leaving the block
quickly was important, but that sufficient time on the block was also important to generate force and
maximize initial velocity. Another study of underwater phases (Sanders, 2004) showed that expert
swimmers maximize propulsion and minimize resistance notably by adopting a streamlined position
and selecting appropriate glide times and underwater propulsion times before commencing free
stroking.
Skill Level Comparison
Few studies have directly compared expert and non-expert swimmers to characterize performance
using all the start variables. Benjanuvatra et al. (2007) showed significantly higher block values for
horizontal impulse (3.60 ± 0.23 versus 3.17 ± 0.30 N/kg) and lower take-off angles (27.45 ± 5.99°
versus 39.62 ± 13.19°) for elite swimmers. This indicated greater efficiency in the impulse of the
expert swimmers (better orientation of forces compared with the overall direction of the movement
than non-expert). Furthermore, the expert swimmers tried to go as fast and far as possible when
starting, whereas the non-experts had other aims: they tried to organize their limbs with regard to
gravity by managing the translation-rotation compromise during the push on the block, or they tried
to be hydrodynamic during the air-water transition of water entry.
Expertise can also be assessed in terms of adaptability (Warren, 2006), as when a swimmer performs
a start with a non-preferred technique. Sport biomechanists consider movement variability is an
important element with a functional role, and can be analyzed at three levels (Bartlett, Wheat, &
Robins, 2007; Bartlett, 2004).
The first level of analysis is between trials using the same technique (i.e., inter-trial and intra-
individual variability). By assessing multiple repetitions of the same skill, researchers determine the
phases during which variability occurs and then seek to understand how the task performance may
have been altered (Bartlett et al., 2004). For example, in a study based on only three trials for expert
and non-expert swimmers, no significant differences were found in the intra-class correlations (ICC)
for each swimmer of the two groups, nor did the expert swimmers show better reproducibility than
the non-experts (Vantorre et al., 2010c).
The second level of analysis is between the performances of swimmers with the same or different
levels of expertise (i.e., inter-subject variability). Vantorre et al. (2010c) also compared elite and non-
elite swimmers performing swim-starts using ICCs. The experts showed shorter impulse times but
higher impulse values in the horizontal and vertical axes than the non-expert swimmers. The data
indicated that the expert and non-expert swimmers used different strategies for the start and that
each group approached the task in a qualitatively different manner. For the non-expert swimmers,
the main feature was trying not to lose too much time on the start, especially between the reaction
to the starting signal and the impulse on the block. In contrast, the expert swimmers sought to
optimize a short block phase and a powerful, well-directed impulse. A second challenge for the non-
expert swimmers was to manage the transitions between gliding, leg kicking and full swimming,
while the expert swimmers tried to maintain a greater velocity by adopting a more streamlined body
position in order to start free swimming as far as possible from the block.
Vantorre et al. (2010a) and Seifert et al. (2010) used cluster analysis as an additional technique to
evaluate the role of variability between sujects. Seifert et al. (2010) showed that expert swimmers
organized themselves differently and used arm and leg movements during the aerial phase to enter
the water cleanly and as far as possible from the block. Vantorre et al. (2010a) showed that expert
swimmers developed different strategies from the start signal to the 15-m mark to achieve their
optimal performances.
The last level of analysis is inter-preference variability (i.e., between a preferential technique and a
non-preferential one), which could be useful in determining the adaptability of performers as they
manage changes in conditions. Vantorre et al. (2011) studied elite swimmers who habitually used a
grab start,when using both the grab start and the track start, the non-preferred skill. In line with
previous work (Hardt et al., 2009; Benjanuvatra et al. 2004), this study showed less loss of angular
momentum in dimensions other than the direction of movement when the swimmers used the
preferred grab technique; and lower efficiency using the non-preferred track start technique, in part
due to a twisting effect of this technique.
Vantorre et al. (2010a) used cluster analysis and showed that expert swimmers are distinguished by
start profiles, suggesting that a range of strategies can be used to achieve high start performance.
This range of profiles confirmed that each constraint may have more than one solution and, thus,
that expertise is not necessarily characterized by decreased movement variability. Instead, variability
may well reflect personal responses based on anatomy, with each individual finding a different motor
solution to achieve a “good start.” Indeed, in competition, one observes different start techniques
and variations of the same technique existing side by side.
The analysis of variability suggests that practitioners can evaluate which start technique is best suited
to a given swimmer from among a range of possible techniques. This is a process that requires
tracking individual performance changes over time. The final section reviews how swim-starts have
evolved so as to provide practitioners with an overview of the strengths and weaknesses of the start
techniques identified in the literature. A key point to emerge from this review is that swim-start
techniques have co-evolved (and will likely continue to do so) with such factors as rule changes and
starting block technology. In this respect, variability analysis may be a promising method for
remaining up to date with changes in the sport.
THE START TECHNIQUES
Traditional Start Techniques
Swim-start techniques have evolved over time, and an early technique from 50-60 years ago is the
conventional or arm swing start. Some years later, Zatsiorsky et al. (1979) identified two styles of the
conventional start (with forward arm oscillation and complete oscillation), and Lewis (1980) observed
three types (with arms back, with arms swinging back, and with circular oscillation of the arms).
According to Bowers and Cavanagh (1975) and Lewis (1980), the conventional start allows longer
flight distances than the grab start, largely due to the longer block phase. The conventional start is
still sometimes recommended for relay races, where the increasing arm swing on the block does not
appear to influence the swimmer changeover execution time. Otherwise, it is rarely seen in
competition today. For example, at the Sydney Olympics in 2000, no swimmer used this technique
except in relays (Sanders, 2004).
As the start techniques evolved, the track start appeared and was popularized by Rowdy Gaines,
winner of the 100-m freestyle at the 1984 Olympic Games in Los Angeles. This technique was
borrowed from athletics (track and field), with swimmers putting one foot on the front edge of the
block (track start) instead of two (grab start) (Krüger et al., 2003; Miller et al., 2003; Takeda &
Nomura, 2006). With the track start, swimmers can place the body weight on the front edge (front-
weighted track start) or the back of the block (track start slingshot) (Vilas-Boas et al., 2003, 2000;
Welcher et al., 2008). With the grab start, the hands grip the front edge of the block between the
legs or the front outer edges of the block (Lewis, 1980).
Contemporary Techniques
Some start styles combine several techniques, such as the bunch start, where swimmers place their
feet for a track start and the hands for a conventional start (Ayalon et al., 1975). Galbraith et al.
(2008) studied the effect of arm and hand positions with a modified one-handed track start. Another
example is the tuck start, in which the forward movement of the center of gravity is used by
positioning the compact body while the swimmer grasps the sides of the block (Woelber, 1983). The
purpose of the tuck start is to reduce the time interval between the start signal and entry into the
water (Woelber, 1983). A version of the tuck start, called the handle start, was developed to explore
the effect of placing the center of gravity in the most forward position (Blanksby et al., 2002; Pearson
et al., 1998). This study followed the development of the Anti-Wave SuperBlock with handles on the
sides that the swimmers can hold behind the body (Pearson et al., 1998). However, this type of
starting block even if it was approved by FINA is not the norm in international competition. This is
particularly true since the last regulatory changes.
Future of the Start
By adding an adjustable incline, the Omega kick-start block has become the favored block for the
track start (improving it by adding solid support for the rear foot) (Takeda et al., 2012). Studies
indicate a wide range of behaviors from which swimmers can choose, which helps to explain some of
the difficulty in determining a single “best” technique for optimal performance for various strokes
and body morphologies. In any case, few studies have compared the techniques.
Despite the lack of comparative data, it is reasonable to question whether a single ideal start model
exists. Individuals present with different physical, physiological, and anthropometric characteristics.
Therefore, it is likely that several techniques or combinations of techniques can be used to achieve
expertise in the swim-start, and research has shown that a number of profiles do exist. The concept
of inter-individual variability is particularly relevant to understanding the nature of expertise, but it
complicates the job for coaches, who might very well prefer to have a single profile of a world
champion swim-start that they can encourage their swimmers to work toward.
Importantly, in the few studies comparing start techniques (the grab start and track start), a key
limitation has been that, in almost all cases, the authors did not consider the preferred technique of
the swimmers (Blanksby et al., 2002). Kruger et al. (Krüger et al., 2003) did so (the track start for 2
and grab start for 5), but this information was not included in their analysis of the results. It is
possible that experience with a technique may have an impact on start performance. Vilas-Boas et al.
(2003) and Vantorre et al. (2011) considered this by using a dual approach that mixed the technical
effect and the effect of preference. This distinction between the "technical" and "preferential" effect
is essential.
CONCLUSION
This review has contextualized the analysis of the swim-start in terms of its purpose: to balance
arriving as quickly as possible at the end of the start with the added task of setting up the remaining
portion of the swim. The various phases of the start can be described as a series of compromises that
have to be made. The block phase, for example, requires a compromise between saving time by
leaving the block quickly but only after sufficient time to exert a force against the block which
generates a high enough impulse to drive the swimmer as far as possible and enter the water at high
velocity. The notion of compromise also applies to the aerial phase, with the possibility of choosing a
trajectory for water entry through a hole, a flat trajectory and entry, or a trajectory that lies
somewhere in between. However, a common characteristic of these strategies is to achieve aerial
phases with a segmental alignment when the body breaks the surface of the water. The swimmer’s
goal for the start also affects the choice of strategy to achieve a “good start.” Non-expert swimmers
begin stroking earlier than expert swimmers because they have not yet mastered the phases of the
start well enough for it to provide any advantage over an early stroking commencement. Individual
characteristics also influence how each swimmer optimizes the start phases: sprinters versus long-
distance swimmers, high versus low vertical leaps, large versus small body parts, and so on. In this
sense, variability can be contextualized as functional and not as an error with regard to deviation
from any “only one way” to achieve the best start. The coexistence of several start techniques –
position of the feet on the block, arm movement during the flight phase, type of block used, water
depth and swimming stroke – confirms the assumption of compromise and adaptation as inherent
challenges for achieving the best swim-start by any individual.
REFERENCES
Arellano, R., Moreno, F., Martinez, M., & Oña, A. (1996). A device for quantitative
measurement of starting time in swimming. In J. P. Troup, A. P. Hollander, D. Strasse,
S. W. Trappe, J. M. Cappaert, & T. A. Trappe (Eds.), Biomechanics and Medicine in
Swimming VII (pp. 195–200). London: E & FN Spon.
Ayalon, A., Van Gheluwe, B., & Kanitz, M. (1975). A comparison of four racing styles of
racing start in swimming. In Biomechanics and Medicine in Swimming II (pp. 233–241).
Bartlett, R. (2004). Is movement variability important for sports biomechanists? In M.
Lamontagne, G. Robertson, & H. Sveistrup (Eds.), XXIIth International Symposium on
Biomechanics in Sports (pp. 521–524). Ottawa, Canada.
Bartlett, R. (2007). Introduction to sports biomechanics: analysing human movement patterns.
Taylor & Francis e-Library.
Bartlett, R., Wheat, J., & Robins, M. (2007). Is movement variability important for sports
biomechanists? Sports Biomechanics, 6, 224–243.
Benjanuvatra, N., Edmunds, K., & Blanksby, B. (2007). Jumping ability and swimming grab-
start performance in elite and recreational swimmers. International Journal of Aquatic
Research and Education, 1, 231–241.
Bishop, D., Smith, R., Smith, M., & Rigby, H. (2009). Effect of plyometric training on
swimming block start performance in adolescents. Journal of Strength and Conditioning
Research, 23(7), 2137–43.
Bixler, B., Pease, D., & Fairhurst, F. (2007). The accuracy of computational fluid dynamics
analysis of the passive drag of a male swimmer. Sports Biomechanics, 6(1), 81–98.
Blanksby, B., Gathercole, D., & Marshall, R. (1996). Force plate and video analysis of the
tumble turn by age-group swimmers. Journal of Swimming Research, 11, 40–45.
Blanksby, B., Nicholson, L., & Elliott, B. (2002). Biomechanical analysis of the grab, track
and handle starts: an intervention study. Sports Biomechanics, 1(1), 11–24.
Bloom, J., Hosler, W., & Disch, J. (1978). Differences in flight, reaction & movement time
for the grab & conventional starts. Swimming Technique, 34–36.
Bowers, J., & Cavanagh, P. (1975). A biomechanical comparison of the grab and
conventional starts in competitive swimming. In Biomechanics and Medicine in
Swimming II (pp. 225–231).
Breed, R., & Young, W. (2003). The effect of a resistance training programme on the grab,
track and swing starts in swimming. Journal of Sports Sciences, 21, 213–220.
Bulgakova, N., & Makarenko, L. (1966). Sport Swimming. Physical Culture, Education and
Science. Moscow: Russian State Academy of Physical Education.
Clarys, J., & Jiskoot, J. (1975). Total resistance of selected body positions in the front crawl.
In L. Lewillie & J. Clarys (Eds.), Swimming II (Vol. 3, pp. 110–117). Baltimore:
University Park Press.
Clothier, P., McElroy, G., Blanksby, B., & Payne, W. (2000). Traditional and modified exits
following freestyle tumble turns by skilled swimmers. South African Journal for
Research In Sport Physical Education and Recreation, 22, 41–55.
Cossor, J., & Mason, B. (2001). Swim Start Performances at the Sydney 2000 Olympic
Games. In XIXth International Symposium on Biomechanics in Sports (pp. 70–74). San
Francisco.
Costill, D., Maglischo, E., & Richardson, A. (1992). Handbook of sports medicine and
science. Swimming (p. 214). Oxford: Blackwell Scientific Publications.
Counsilman, J. (1955). Forces in swimming two types of crawl stroke. Research Quarterly,
26, 127–139.
Counsilman, J., Counsilman, B., Nomura, T., & Endo, M. (1988). Three types of grab Starts
for competitive swimming. In B. Ungerechts, K. Wilke, & K. Reischle (Eds.),
Biomechanics and Medicine in Swimming V (pp. 81–91). Champaign, Illinois: Human
Kinetics Books.
De Jesus, K., Figueiredo, P., Gonçalves, P., Pereira, S., Vilas-Boas, J., & Fernandes, R.
(2011). Biomechanical analysis of backstroke swimming starts. International Journal of
Sports Medicine, 32, 546–551.
De la Fuentes, B., Garcia, F., & Arellano, R. (2003). Are the forces applied in the vertical
countermovement jump related to the forces applied during swimming start? In J.
Chatard (Ed.), Biomechanics and Medicine in Swimming IX (pp. 99–103). Saint
Etienne: University of Saint Etienne.
Elipot, M., Dietrich, G., Hellard, P., & Houel, N. (2010). High-level swimmers’ kinetic
efficiency during the underwater phase of a grab start. Journal of Applied Biomechanics,
26(4), 501–7.
Elipot, M., Hellard, P., Taïar, R., Boissière, E., Rey, J. L., Lecat, S., & Houel, N. (2009).
Analysis of swimmers’ velocity during the underwater gliding motion following grab
start. Journal of Biomechanics, 42(9), 1367–70.
Galbraith, H., Scurr, J., Hencken, C., Wood, L., & Graham-Smith, P. (2008). Biomechancial
comparison of the track start and modified one-handed track start in competitive
swimming: an intervention study. Journal of Applied Biomechanics, 24, 307–315.
Guimaraes, A., & Hay, J. (1985). A mechanical analysis of the grab starting technique in
swimming. International Journal of Sport Biomechanics, 1, 25–35.
Hay, J. (1988). The status of research on the biomechanics of swimming. In B. E. Ungerechts,
K. Wilke, & K. Reischle (Eds.), Biomechanics and Medicine in Swimming V (pp. 3–14).
Champaign, Ill.: Human Kinetics Books.
Houel, N., Elipot, M., Andrée, F., & Hellard, P. (2013). Influence of angles of attack,
frequency and kick amplitude on swimmer’s horizontal velocity during underwater phase
of a grab start. Journal of Applied Biomechanics, 29(1), 49–54.
Hubert, M., Silveira, G. A., Freitas, E., Pereira, S., & Roesler, H. (2006). Speed variation
analysis before and after the stroke in swimming starts. In Biomechanics and Medicine
in Swimming X (pp. 44–45).
Issurin, V., & Verbitsky, O. (2003). Track Start vs Grab Start: evidence from the Sydney
Olympic Games. In J. Chatard (Ed.), Biomechanics and Medicine in Swimming IX (pp.
213–217). Saint Etienne: Université de Saint Etienne.
Kilduff, L., Cunningham, D., Owen, N., West, D., Bracken, R., & Cook, C. (2011). Effect of
postactivation potentiation on swimming starts in international sprint swimmers. The
Journal of Strength & Conditioning Research, 25(9), 2418–23. Retrieved from
http://journals.lww.com/nsca-
jscr/Abstract/2011/09000/Effect_of_Postactivation_Potentiation_on_Swimming.9.aspx
Krüger, T., Wick, D., Holmann, A., EL-Bahraw, i M., & Koth, A. (2003). Biomechanics of
the grab and track start technique. In J. Chatard (Ed.), Biomechanics and Medicine in
Swimming IX (pp. 219–223). Saint Etienne: University of Saint Etienne.
Lee, C., Huang, C., Wang, L., & Lin, D. (2001). Comparison of the dynamics of the
swimming grab start, squat jump, and countermovement jump of the lower extremity. In
XIXth International Symposium on Biomechanics in Sports (pp. 143–146). San
Francisco.
Lewis, S. (1980). Comparison of five swimming starting techniques. Swimming Technique,
16(4), 124–128.
Lyttle, A., & Benjanuvatra, N. (2005). Start Right? A Biomechanical Review of Dive Start
Performance. Zugriff am.
Lyttle, A., & Blanksby, B. (2011). A review of swimming dive starting and turning
performance. In L. Seifert, D. Chollet, & I. Mujika (Eds.), World Book of Swimming:
From Science to Performance (pp. 425–442). New York: Nova Science publishers.
Lyttle, A., Blanksby, B., Elliott, B., & Lloyd, D. (1998). The role of drag in the streamlined
glide. Journal of Swimming Research, 13, 15–22.
Lyttle, A., Blanksby, B., Elliott, B., & Lloyd, D. (1999). Optimal depth for streamlined
gliding. In K. L. Keskinen, P. V Komi, & A. P. Hollander (Eds.), Biomechanics and
Medicine in Swimming VIII (pp. 165–170). Jyväskylä, Finland: University of Jyväskylä.
Lyttle, A., Blanksby, B., Elliott, B., & Lloyd, D. (2000). Net forces during tethered simulation
of underwater streamlined gliding and kicking techniques of the freestyle turn. Journal of
Sports Sciences, 18, 801–807.
Maglischo, E. W. (2003). Swimming Fastest. Champaign Ill.: Human Kinetics.
Mason, B., Alcock, A., & Fowlie, J. (2006). A kinetic analysis and recommendations for elite
swimmers performing the sprint start. Medicine and Science in Swimming X, 46(1998),
192–195.
Mason, B., & Cossor, J. (2000). What can we learn from competition analysis at the 1999 Pan
Pacific Swimming Championships? ISBS-Conference Proceedings, 75–82.
Mc Lean, S., Holthe, M., Vint, P., Beckett, K., & Hinrichs, R. (2000). Addition of an
approach to a swimming relay start. Journal of Applied Biomechanics, 16, 342–355.
Miller, M., Allen, D., & Pein, R. (2003). A kinetic and kinematic comparaison of the grab and
track starts in swimming. In J. Chatard (Ed.), Biomechanics and Medicine in Swimming
IX (pp. 231–235). Saint Etienne: University of Saint Etienne.
Mills, B., & Gehlsen, G. (1996). A multidisciplinary investigation of the relation of state sport
confidence with preference and velocity of swimming starts. Perceptual and Motor skills,
83, 207–210.
Naemi, R., Easson, W., & Sanders, R. (2010). Hydrodynamic glide efficiency in swimming.
Journal of Science and Medicine in Sport / Sports Medicine Australia, 13(4), 444–51.
Naemi, R., & Sanders, R. (2008). A “hydrokinematic” method of measuring the glide
efficiency of a human swimmer. Journal of Biomechanical Engineering, 130(6), 061016.
Pearson, C., McElroy, G., Blitvich, J., Subic, A., & Blanksby, B. (1998). A comparison of the
swimming start using traditional and modified starting blocks. Journal of Human
Movement Studies, 34, 49–66.
Pelayo, P., & Alberty, M. (2011). The history of swimming research. In L. Seifert, D. Chollet,
& I. Mujika (Eds.), World Book of Swimming: From Science to Performance (pp. xix–
xxvi). New York: Nova Science publishers.
Pereira, S., Araùjo, L., & Roesler, H. (2003). The influence in height and slope of starting
platforms on the starting time of speed swimmers. In J. Chatard (Ed.), Biomechanics and
Medicine in Swimming IX (pp. 237–241). Saint Etienne: University of Saint Etienne.
Pereira, S., Ruschel, C., & Araùjo, L. (2006). Biomechanical analysis of the underwater phase
in swimming starts. In Biomechanics and Medicine in Swimming X (pp. 79–81).
Ruschel, C., Araùjo, L., Pereira, S., & Roesler, H. (2007). Kinematical analysis of the
swimming start: block, flight and underwater phases. In ISBS-Conference Proceedings
(Vol. 1, pp. 385–388).
Sanders, R. (2002). New analysis procedures for giving feedback to swimming coaches and
swimmers. Proceedings of XX ISBS–Swimming, Applied Program Swimming. Caceres:
University of Extremedura, 1–14.
Sanders, R. (2004). Start technique–recent findings. Retrieved from
http://www.coachesinfo.com/index.php?option=com_content&id=134&Itemid=138
Sanders, R., & Byatt-Smith, J. (2001). Improving feedback on swimming turns and starts
exponentially. In XIXth International Symposium on Biomechanics in Sports (pp. 91–
94). San Francisco.
Seifert, L., Vantorre, J., & Chollet, D. (2007). Biomechanical analysis of the breaststroke
start. International Journal of Sport Medecine, 28(11), 970–6.
Seifert, L., Vantorre, J., Lemaitre, F., Chollet, D., Toussaint, H., & Vilas-Boas, J. (2010).
Different profiles of the aerial start phase in front crawl. The Journal of Strength &
Conditioning Research, 24(2), 507–516.
Slawson, S., Conway, P., Cossor, J., Chakravorti, N., & West, A. (2012). The categorisation
of swimming start performance with reference to force generation on the main block and
footrest components of the Omega OSB11 start blocks. Journal of Sports Sciences.
Takeda, T, Ichikawa, H., Takagi, H., & Tsubakimoto, S. (2009). Do differences in initial
speed persist to the stroke phase in front-crawl swimming? Journal of Sports Sciences,
27(13), 1449–54.
Takeda, T, & Nomura, T. (2006). What are the differences between grab and track start? In
Biomechanics and Medicine in Swimming X (pp. 102–105).
Takeda, Tsuyoshi, Takagi, H., & Tsubakimoto, S. (2012). Effect of inclination and position of
new swimming starting block’s back plate on track-start performance. Sports
Biomechanics, 11(3), 37–41.
Trembley, J., & Fielder, G. (2001). Starts, turns and finishes. In The Swim Coaching Bible
(pp. 189–206).
Vantorre, J., Seifert, L., Bideau, B., Nicolas, G., Fernandez, R., Vilas-Boas, J., & Chollet, D.
(2010). Influence of swimming start styles on biomechanics and angular momentum. In
P. Kjendlie, R. Stallman, & J. Cabri (Eds.), Biomechanics and Medicine in Swimming
XI (pp. 180–182). Oslo Nordbergtrykk.
Vantorre, J., Seifert, L., Fernandes, R., Vilas Boas, J., & Chollet, D. (2010). Comparison of
grab start between elite and trained swimmers. International Journal of Sport Medicine,
31(12), 887–93.
Vantorre, J., Seifert, L., Fernandes, R., Vilas-Boas, J., & Chollet, D. (2010a). Kinematical
profiling of the front crawl start. International Journal of Sport Medecine, 31, 16–21.
Vantorre, J., Seifert, L., Fernandes, R., Vilas-Boas, J., & Chollet, D. (2010b). Biomechanical
influence of start technique preference for elite track starters in front crawl. The Open
Sports Sciences Journal, 3, 137–139.
Vilas-Boas, J. (2010). The leon Lewillie memorial lecture: biomechanics and medecine in
swimming, past, present and future. In P. Kjendlie, R. Stallman, & J. Cabri (Eds.),
Biomechanics and Medecine in Swimming XI (pp. 12–19). Oslo Nordbergtrykk.
Vilas-Boas, J., Costa, L., Fernandes, R., Ribeiro, J., Figueiredo, P., Marinho, D., Silva, A.,
Rouboa, A., Machado, L. (2010). Determination of the drag coefficient during the first
and second gliding positions of the breaststroke underwater stroke. Journal of applied
biomechanics, 26(3), 324–31.
Vilas-Boas, J., Cruz, J., Sousa, F., Conceição, F., Fernandez, R., & Carvalho, J. (2003).
Biomechanical analysis of ventral swimming starts: comparaison of the grab-start with
two track-start techniques. In J. Chatard (Ed.), Biomechanics and Medicine in Swimming
IX (pp. 249–253). Saint Etienne: University of Saint Etienne.
Vilas-Boas, J., João Cruz, M., Sousa, F., Conceição, F., & Carvalho, J. (2000). Integrated
kinematic and dynamic analysis of two track start technique. In ISBS-Conference
Proceedings (pp. 113–117). Hong Kong.
Warren, W. (2006). The dynamics of perception and action. Psychological Review, 113, 358–
389.
Welcher, R. L., Hinrichs, R. N., & George, T. R. (2008). Front- or rear-weighted track start or
grab start: which is the best for female swimmers? Sports biomechanics / International
Society of Biomechanics in Sports, 7(1), 100–13.
West, D., Owen, N., Cunningham, D., Cook, C., & Kilduff, L. (2011). Strength and power
predictors of swimming starts in international sprint swimmers. Journal of Strength and
Conditioning Research, 25(4), 950–5.
Wilson, D., & Marino, G. (1983). Kinematic analysis of three starts. Swimming Technique,
30–34.
Woelber, K. (1983). The tuck start: a mean lean. Swimming Technique, 19(4), 35–38.
Zatsiorsky, V., Bulgakova, Nz., & Chaplinsky, N. (1979). Biomechanical analysis of starting
techniques in swimming. In Biomechanics and Medicine in Swimming III (pp. 199–
206).
AUTHORS BIOGRAPHY
Julien VANTORRE
Employment: Part-time lecturer at Rouen University -
Sport Sciences Department.
Degree: PhD.
Research interests: Biomechanics, motor control,
kinesiology applied to swimming.
E-mail: julien.vantorre@univ-rouen.fr
Ludovic SEIFERT
Employment: Lecturer at Rouen University -Sport
Sciences Department.
Degree: PhD.
Research interests: Biomechanics, motor control,
exercise physiology applied to swimming.
E-mail: ludovic.seifert@univ-rouen.fr
Didier CHOLLET
Employment: Full professor, Head of the Sport
Science department at the University Rouen and of the
CETAPS laboratory.
Degree: PhD.
Research interests: Biomechanics, motor control,
exercise physiology applied to swimming.
E-mail: didier.chollet@univ-rouen.fr
KEY POINTS
• Swimmers meet two main constraints during the start movement: travelling more distance in
the air (to get less resistance) and rotate to enter properly in the water.
• Swim start is a sum of compromises in all parts of it, and swim-start expertise is distinct from
swim stroke expertise corresponding to best ways to manage these compromises.
• Variability found is contextualized as having a functional role and operating across multiple
levels of analysis.
