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Girevoy sport (GS) has developed only recently in the West, resulting in a paucity of English scientific literature available. The aim was to document kettlebell trajectory of GS athletes performing the kettlebell snatch. Four elite GS athletes (age = 29-47 years, body mass = 68.3-108.1 kg, height 1.72-1.89 m) completed one set of 16 repetitions with a 32.1 kg kettlebell. Trajectory was captured with the VICON motion analysis system (250 Hz) and analysed with VICON Nexus (1.7.1). The kettlebell followed a 'C' shape trajectory in the sagittal plane. Mean peak velocity in the upwards phase was 4.03 ± 0.20 m s-1, compared to 3.70 ± 0.30 m s-1 during the downwards phase, and mean radial error across the sagittal and frontal planes was 0.022 ± 0.006 m. Low error in the movement suggests consistent trajectory is important to reduce extraneous movement and improve efficiency. While the kettlebell snatch and swing both require large anterior-posterior motion, the snatch requires the kettlebell to be held stationary overhead. Therefore, a different coaching application is required to that of a barbell snatch.
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Snatch Trajectory of Elite Level Girevoy (Kettlebell) Sport Athletes and its Implications 1 to Strength and Conditioning Coaching 2
James A. Ross¹, Cameron J. Wilson¹, Justin W.L. Keogh² ³ 4, Kuok Wai Ho¹, and 3 Christian Lorenzen¹. 4
¹ School of Exercise Science, ACU, Melbourne, Australia 5
Postal address: 115 Victoria Parade, Fitzroy VIC 3065 6
2 Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Australia 7
Postal address: 14 University Drive, Robina QLD 4226 8
3 Sports Performance Research Institute New Zealand, AUT University, Auckland, New 9 Zealand 10
4 Cluster for Health Improvement, Faculty of Science, Health, Education and 11 Engineering, University of the Sunshine Coast 12
Phone Number: +61 411 570 484 Email: james.ross33@yahoo.com 13
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Snatch Trajectory of Elite Level Girevoy (Kettlebell) Sport Athletes and its Implications 3 to Strength and Conditioning Coaching 4
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Abstract 1
Girevoy sport (GS) has developed only recently in the West, resulting in a paucity of 2
English scientific literature available. The aim was to document kettlebell trajectory of 3
GS athletes performing the kettlebell snatch. Four elite GS athletes (age = 29-47 years, 4
body mass = 68.3-108.1 kg, height 1.72-1.89 m) completed one set of 16 repetitions 5
with a 32.1 kg kettlebell. Trajectory was captured with the VICON motion analysis 6
system (250 Hz) and analysed with VICON Nexus (1.7.1). The kettlebell followed a ‘C’ 7
shape trajectory in the sagittal plane. Mean peak velocity in the upwards phase was 8
4.03 ± 0.20 m s ¹, compared to 3.70 ± 0.30 m s ¹ during the downwards phase, and 9
mean radial error across the sagittal and frontal planes was 0.022 ± 0.006 m. Low error 10
in the movement suggests consistent trajectory is important to reduce extraneous 11
movement and improve efficiency. While the kettlebell snatch and swing both require 12
large anterior-posterior motion, the snatch requires the kettlebell to be held stationary 13
overhead. Therefore, a different coaching application is required to that of a barbell 14
snatch. 15
Key Words: Kettlebell, Resistance Training, Snatch 16
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INTRODUCTION 1
Kettlebell exercise was initially seen at the end of the 17th century in Russia, where 2
strongmen used 16 kg, 32 kg and 48 kg kettlebells to demonstrate feats of strength at 3
fairs, festivals and circuses [1, 2]. The first kettlebell sport, or ‘Girevoy sport’ (GS) 4
competition was held in 1948 and fourteen years later, GS was included into the 5
national sports of Russia [1]. Over the past ten years, kettlebell training has become 6
increasingly popular as a form of resistance training for athletes and members of the 7
general population, coinciding with increased participation in GS competition. Whilst the 8
versatility of kettlebells allows the performance of many exercises; swings, jerks, clean 9
and jerks, and snatches are some of the most commonly performed kettlebell 10
movements. 11
The snatch is typically performed with a barbell in Olympic weightlifting events, although 12
dumbbell and kettlebell versions are becoming more popular. The kettlebell snatch is 13
performed in a biathlon or as a standalone event in GS competitions. The competition 14
takes place on a weightlifting platform and has a time limit of ten minutes per set. The 15
biathlon is scored as the total number of repetitions performed from two exercises: the 16
jerk followed by the snatch, each of ten minutes duration, with at least an hour between 17
exercises. The snatch is performed with one hand change permitted per set and is 18
considered the most technical event in GS [1]. Elite individuals perform the kettlebell 19
snatch with a 32 kg kettlebell during the ten minute competition, with the current 20
absolute world record standing at 238 snatches. 21
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It has been suggested that kettlebell training is a useful mode of training to improve 1
aerobic fitness [3-5],vertical jump [6-9] and back squat performance [7, 9]. Previous 2
research utilising a 32 kg 2-handed kettlebell swing demonstrated similar power outputs 3
and a larger impulse, compared to the jump squat with 40% 1RM [8]. A training study 4
comparing the chronic effects of kettlebell swings and jump squats was reported to 5
significantly improve vertical jump and back squat 1RM. However, the kettlebell group 6
had a smaller improvement in the vertical jump, yet larger improvement in back squat 7
performance [7]. Of the two interventions that investigated the effects of kettlebell 8
training on the cardiorespiratory system, only one found improvements. It is possible 9
that the reason for the lack of improvement was due to the low training dosage of 10-15 10
minutes three times a week with 70% adherence [10]. In contrast, 30-45 minutes of 11
training twice a week, using a combination of kettlebell exercises including the snatch, 12
was found to improve VO2peak by 13.8% during a progressive kettlebell snatch set [5]. 13
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Generally, only qualitative descriptions of the kettlebell snatch during elite performance 15
are available. The International Kettlebell Sport & Fitness Academy has described the 16
snatch as comprising six components [11]. As seen in Figure 1, the start and finish are 17
referred to as “fixation”. This is where the kettlebell is locked out overhead. The three 18
components of the downwards phase include: the drop, re-gripping, and back swing, 19
while the upwards phase involves the forward swing, acceleration pull, and hand 20
insertion (refer to Figure 1). 21
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Figure 1 about here 1
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Figure 2 about here 3
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Figure 2, point 1 represents fixation. In this position, the handle of the kettlebell rests 5
diagonally across the palm and the ball rests on the back of the wrist and forearm [11]. 6
The drop is initiated by a counter movement of the torso away from the kettlebell. At 7
approximately the same time, the shoulder begins to extend, and the elbow supinates 8
and flexes [1, 11]. Between the ‘drop’ and the ‘back swing’ the handle is repositioned 9
(re-gripped) from the palm to the fingers [11]. This portion of the downwards trajectory is 10
indicated at approximately Figure 2, point 2. At the start of the back swing the knees are 11
slightly flexed and the torso remains upright, until the kettlebell passes between the 12
legs, whereby the hips flex and the knees extend (finishing at Figure 2, point 3). The 13
forwards swing phase consists of the kettlebell moving forward between the legs via hip 14
extension and knee flexion. The acceleration pull (approximately Figure 2, point 4) 15
begins as the kettlebell passes the knees. This is the most powerful motion in the 16
snatch, and involves knee and hip extension, ipsilateral torso rotation and elbow flexion 17
[11]. It ends when the kettlebell is once again re-gripped (hand insertion). During the 18
hand insertion phase, the elbow is extended and the torso rotates contralaterally [11]. 19
This rotates the kettlebell, moving the handle from the fingers to the palm, bringing it 20
into contact with the wrist and forearm [11]. The kettlebell comes to rest in the overhead 21
position whilst in fixation, and the process is then repeated (see Figure 1). It has been 22
suggested that in the upwards and downwards phases the kettlebell follows somewhat 1
different trajectories [1]. To our knowledge, only one study has examined the technique 2
of the kettlebell snatch [12], reporting that novice participants extend the hips, knees 3
and ankles simultaneously, and swing the kettlebell through the sagittal plane. The 4
kettlebell snatch was further described to have rapid muscle activation-relaxation 5
cycles, producing relatively large posterior shear forces on the spine [12]. 6
This proposed trajectory of the snatch performed with a kettlebell appears quite different 7
to that of the snatch performed with barbells or dumbbells. The barbell snatch and 8
power snatch has been shown to follow an ‘S’ or reverse ‘S’ shaped trajectory, 9
characterised by an initial small displacement of the barbell rearwards, then forwards 10
and rearwards again [13, 14]. This type of trajectory allows the weightlifter to move 11
through the first pull and transition phase, and to adopt the power position prior to the 12
second pull. The power position may allow for the generation of very large power 13
outputs during the second pull [15]. Elite weightlifters were found to have an anterior 14
posterior range of -0.096±0.07 m during successful barbell snatch attempts. In contrast, 15
the trajectory of a dumbbell power snatch is displaced forwards then rearwards [16]. 16
During competition, the barbell snatch is performed with a bilateral grip for one maximal 17
repetition. Conversely, the kettlebell snatch is performed unilaterally and traditionally 18
utilises multiple repetitions in competitions. The duration and technique used in the 19
upwards and downwards phases may both be of importance. Additionally, the 20
kettlebells displaced centre of mass sits below the wrist. This makes it much harder to 21
safely fail a single maximal lift of a kettlebell snatch, compared to that of a barbell or 22
dumbbell snatch. This may suggest the kettlebell snatch is better suited to higher 23
repetitions than the barbell snatch and as such may be a better tool for increasing 1
energy expenditure and developing aerobic and anaerobic conditioning. 2
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In comparison to the barbell snatch, the unilateral nature of the kettlebell snatch allows 4
for greater degrees of freedom, which may result in a larger choice of techniques. 5
However, the unique shape of the kettlebell may necessitate a modified approach to 6
training and technique, in contrast to that of a barbell. The material and body of 7
knowledge available to coaches regarding kettlebell exercises for training purposes is 8
limited. The present study aimed to investigate the kettlebell trajectory of elite kettlebell 9
lifters during the snatch. This information is especially important for coaches and 10
strength and conditioning specialists looking to prescribe higher repetition snatch 11
movements for their athletes. As a training tool, the kettlebell snatch may be better 12
suited to higher repetitions. Comparatively, this may require different applications to that 13
of the barbell snatch, traditionally utilising one repetition in competition. 14
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METHOD 16
Testing Procedures 17
Four elite participants performed 16 repetitions over one minute with one 32 kg 18
kettlebell. Repetitions 2-16 were compared to help determine the variation in the 19
trajectory as these repetitions all had a downward phase preceding the upward. 20
Kettlebell trajectory was captured with the VICON Motion Analysis System (250 Hz) and 21
analysed with VICON Nexus (1.7.1). The cadence of 16 repetitions per minute was 1
selected based on similar cadences sustained during either training or competition. 2
Participants 3
Four elite kettlebell sport athletes (originating in Russia or Kyrgyzstan), who had all won 4
at least one world championship in biathlon (jerk and snatch) and/or held past or current 5
world records in the snatch, were recruited. In their most recent competition, which 6
occurred within 12 months of data collection, all lifters performed between 80-100% of 7
the current world record number of lifts with a 32kg kettlebell for their respective weight 8
categories. All participants held the rank of ‘Master of Sport International Class’ or 9
‘Honored Master of Sport’, (as issued by the Ministry of Sports of Russia, or the USSR 10
State Committee for Physical Culture and Sport). The four participants had the following 11
characteristics: age = 29-47 yr, body mass = 68.3-108.1 kg, and height = 1.72-1.89 m. 12
This study was approved by the Institutional Review Board. Informed consent was 13
given, in the presence of a translator if required. 14
Procedures 15
Six VICON infrared cameras were placed around a weightlifting platform in a position to 16
capture three dimensional motion of the kettlebell during the snatch. The infrared 17
cameras captured the movement of reflective markers placed on the kettlebell. The 18
system was calibrated dynamically by waving an L-wand with five reflective markers in 19
the area that the kettlebell would pass through, in accordance to the manufacturer’s 20
instructions. This was repeated until all cameras had an RMS error under 0.2% [17]. 21
The point of origin was then set in the middle of the platform, to calibrate the cameras 22
positions. A professional-grade kettlebell (Iron Edge, Australia), with a mass of 32.1 kg 1
was used as its dimensions are the standard requirement for kettlebell sport. Two 2
markers (14 mm x 12.5 mm in diameter) were placed on the kettlebell at the base of 3
each handle to avoid contact with the athlete and to ensure consistent position. 4
Participants were required to perform a warm-up they would typically perform prior to 5
performing the kettlebell snatch. Chalk, sand paper and a spray bottle were provided to 6
ensure that the handle was prepared to their individual lifting requirements. After the 7
marker set had been placed, each lifter stood on a platform and performed one set of 8
snatches for 16 repetitions over 1 minute with their self-selected hand. This pace was 9
selected as it was the competition pace for one or more of the athletes, was attainable 10
by novice and intermediate athletes (albeit with lighter loads), and commonly performed 11
in training and competition. An analogue clock was placed in view to allow consistent 12
pace. 13
Kettlebell trajectory was subsequently determined by attaining the midpoint of the two 14
markers. After each trial had been performed the markers were manually labelled using 15
VICON Nexus software. A frame-by-frame review of each trial was undertaken to 16
ensure there was minimal error caused by unlabelled markers. After this review took 17
place a Woltering spline filter was applied to fill any gaps (less than 20 frames) in the 18
trajectories [18]. These gaps in the trajectories were calculated by the markers past 19
trajectory, velocity and acceleration. 20
Time displacement data was used to determine the trajectory and velocity in three 21
dimensions of motion. For ease of interpretation resultant velocity was used. Four 22
points of each repetition of the kettlebell trajectory were analysed: 1) fixation; 2) 23
midpoint of the downwards phase; 3) end of the back swing; and 4) midpoint of the 1
upwards phase (see Figure 2). 2
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These four points were identified the moment the kettlebells trajectory changed from an 4
anterior to posterior direction, or vice versa. The mean position from all 15 repetitions at 5
these four points was the goal position. These four points were used as a reference to 6
determine the error in one and two dimensions. The absolute error (AE, including 7
vertical error, anterior-posterior error and medio-lateral error) illustrated the distance in 8
metres from the goal in one dimension [19]. The radial error (RE, including sagittal 9
plane error and frontal plane error) signified the distance in metres from the goal in two 10
dimensions [19]. The RE was calculated by using the following formula: 11
Equation 1. (RE in the sagittal plane = ) 12
Equation 2. (RE in the frontal plane = ) 13
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The anterior-posterior (AP), medio-lateral (ML) and vertical displacements were 15
calculated from the end of the back swing to the midpoint of the trajectory for AP and 16
ML, and to fixation for the vertical displacement range. Comparisons in the lifters’ 17
trajectories were also made using an anterior-posterior to vertical ratio (APV), and 18
medio-lateral to vertical (MLV) ratio. The end of the back swing to fixation mean 19
displacement range was used to determine the vertical portions of the ratios. 20
Statistical Analyses 21
Data has been presented as means and standard deviations unless stated otherwise. 1
Descriptive statistics were used to determine the amount of kettlebell AP, ML motion 2
and variation for each lifter. Effect size (ES) and paired t-tests with two tails were used 3
to compare the midpoint of the upwards and downwards phases for each repetition. The 4
magnitude of the effect was considered trivial ES <0.2, small ES 0.2-0.6, moderate 0.6-5
1.2, large ES 1.2-2.0, very large ES 2.0-4.0 and extremely large ES > 4.0 [20]. The AE 6
and RE for repetitions 2-16 were calculated. The first repetition was ignored because it 7
started from the ground and not in fixation. The variation was determined at the same 8
four points, listed above. AE was calculated in AP, ML and vertical planes of motion. RE 9
was calculated in the sagittal and frontal planes. 10
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RESULTS 12
Trajectory 13
In the sagittal plane, the trajectory of the kettlebell snatch followed a C-path for all 14
participants through the upwards and downwards phases (Figure 3). Figure 3 illustrates 15
the kettlebell sagittal plane trajectory for the four subjects, whilst Figure 4 represents the 16
kettlebell trajectory in the frontal plane of motion. 17
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Figure 3 about here 19
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Figure 4 about here 21
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Ratios and displacement 2
Table 1 illustrates the kettlebell displacement ranges and ratios. The APV and MLV 3
ratios indicate that the C-path followed a larger radius during the upwards than 4
downwards phase for all participants. Participants B, C, and D had a relatively smaller 5
MLV ratio ranging from 0.05-0.13 for both phases compared to participant A, who had a 6
relatively larger MLV ratio of 0.31 ± 0.01 and 0.26 ± 0.02 for the upwards and 7
downwards phases, respectively. 8
Table 1 about here 9
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Table 2 shows the AP, ML and vertical displacement ranges between the upwards and 11
downwards phases. The downwards phase represents the smallest arc, compared to 12
the upwards phase. The range between the upwards and downwards phases was 13
largest in the AP, compared to the ML differences in all lifters. 14
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Table 2 about here 16
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Velocity 18
Participants’ peak kettlebell resultant velocity ranged from moderate to extremely large 19
ES difference, whereby the upwards phase was faster than the downwards phase for all 20
lifters, except lifter A (see Table 3). Figure 5 shows the typical velocity of the kettlebell 1
as it moved from the downwards phase to the upwards phase. The two peaks in velocity 2
occurred approximately in the re-gripping phase and during the acceleration pull. The 3
two noted times in which velocity reached zero were at fixation, and momentarily 4
between the back and forwards swing. 5
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Figure 5 about here 7
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Table 3 about here 9
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Movement Variability 11
Table 3 shows AE, RE and displacement range for the three dimensions for each 12
participant. The AE and the RE indicate that the kettlebell trajectory was highly 13
consistent at each of the four points for all four participants. 14
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Table 4 about here 16
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DISCUSSION 18
Three dimensional motion analysis was used in this study to document kettlebell snatch 1
kinematics performed by elite kettlebell athletes. The main findings were that despite 2
some differences between the four athletes, significant commonalities emerged: 1) 3
there was a ‘C’ shape trajectory during the downwards and upwards phases of the 4
snatch; 2) the ‘C’ shape followed a narrower trajectory during the downwards phase; 5
and 3) the resultant velocity time graph resembled an ‘M’ shape. 6
One marked similarity was the narrow ‘C’ shape trajectory on the way down and a wider 7
‘C’ shape on the way up. The smaller radius on the way down may be due to several 8
reasons. During the initiation of the downwards phase it was noticed that all athletes 9
moved their bodies away from the kettlebell. This allowed for the kettlebell to fall as 10
closely as possible to the base of support. Following the initial counter movement the 11
athlete flexes and supinates the elbow [1, 11]. The supination of the elbow may help to 12
reduce the movement of the kettlebell through the AP plane and minimise grip stress 13
(and subsequent fatigue) during the transition into the re-gripping phase. The flexion of 14
the elbow may also minimise the AP movement of the kettlebell, thereby again placing 15
the kettlebell as close to the base of support as possible. The large radius from the 16
forwards swing to the start of the acceleration pull may help to minimise the centripetal 17
force acting on the grip. Following the acceleration pull, the hand insertion phase guides 18
the kettlebell onto the back of the wrist. The grip must relax during this phase to help 19
facilitate a smooth transition into fixation. Reducing the stress on the grip may help to 20
prolong performance as anecdotally grip endurance is considered the weakest link in 21
elite GS athletes. Paying particular attention to the hand insertion will also help to 22
reduce the potential for the kettlebell to have heavy contact upon the forearm, and 23
therefore reduce the risk of musculoskeletal injury to the distal forearm. Strength and 1
conditioning coaches need to be aware of this before their athletes progress the 2
kettlebell snatch. 3
Movement was remarkably consistent for all athletes in the frontal and sagittal planes. 4
This is most likely to minimise energy expenditure and therefore fatigue over the ten 5
minute event. The most consistent of the four points was the fixation phase which had a 6
RE range of 0.008 ± 0.006 m and 0.023 ± 0.016 m, in both sagittal and frontal planes. 7
This would suggest that a consistent fixation phase is of the upmost importance. Low 8
endpoint variability is most useful to ensure that the mass of the kettlebell is over the 9
shoulder in all three planes. If this was not the case, greater energy and time would be 10
used fixating or locking out the kettlebell overhead. Within the limitations of the research 11
it can be concluded that elite kettlebell sport athletes maintain a consistent trajectory, 12
particularly at some of the key positions of the movement. Maintaining consistent 13
fixation may be key in increasing the reproducibility of the trajectory as it marks the start 14
and finish of the lift. The trajectory of the kettlebell for athletes A and C followed a 15
similar path during both the downwards and upwards phases in the sagittal plane, whilst 16
the vertical midpoints were at a relatively similar level for lifters A and C (0.022 ± 0.015 17
m and 0.034 ± 0.020 m trajectory difference, respectively). In contrast, the trajectory for 18
athletes B and D were visibly separated and the vertical midpoint of the ‘C’ shape 19
occurred in different vertical positions in the upwards and downwards phases (0.062 ± 20
0.030 m and 0.094 ± 0.028 m, respectively) (Figure 3). These differences in trajectory 21
could be explained by: 1) greater trunk rotation in the acceleration pull phase; 2) the 22
degree of plantar flexion in the upwards or downwards phase; 3) a larger shift 23
backwards during the downwards phase; 4) the position of the upper extremity; and 5) 1
possibly anthropometrical differences. Unfortunately, the present study only assessed 2
the motion of the kettlebell, however, future studies may be useful to better describe the 3
relationship between the kettlebell and lifters kinematics. Potentially, technique may 4
differ over the course of the ten minutes due to fatigue or changes in cadence, however, 5
these differences were beyond the scope of the present study. 6
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Based on the kettlebell kinematics, it appears that different strategies were used to 8
prolong performance in the different lifters. Lifter A displayed the largest MLV range in 9
the upwards and downwards phases, which may produce fatigue in the contralateral 10
musculature to a greater extent. In novice athletes, the mean activation of the lower 11
erector spinae performing the kettlebell snatch with a sagittal plane trajectory was 54.2 12
± 18.3 and 61.3 ± 16.3 % MVC for the ipsilateral and contralateral sides, respectively 13
[12]. Lifter A may increase the demands of the contralateral musculature further by 14
increasing the ML moment arm (which is reflected in his MLV ratio). This may increase 15
the requirements of the torso to resist or control lateral flexion to a greater extent, in an 16
effort to offset fatigue for the last five minutes. In doing so, they may possibly spare the 17
ipsilateral side for subsequent effort following the hand switch as it will become the 18
contralateral side at the five minute mark. Thus, having a larger MLV ratio trajectory 19
may be a strategy to help spread the loading across different muscle groups during the 20
left and right hand efforts. This strategy may be particularly useful during biathlon, as 21
athletes must perform the jerk, which predominantly takes place in the sagittal plane 22
one or two hours prior to the snatch, and may still be experiencing fatigue from this 23
effort [3, 4]. Lifters B, C and D had much smaller MLV ratios compared to lifter A. The 1
dominant AP trajectory in lifters B, C and D suggests that their strategy requires 2
relatively symmetrical loading, resulting in less effort by a single muscle group, thus 3
prolonging performance. A sagittal plane dominant trajectory similar to lifters B, C and D 4
may offer strength and conditioning coaches a technique with the greatest ease of 5
application. Conversely, lifter A’s style may be useful in a GS setting, however it would 6
require a coach to monitor both sagittal and frontal planes of motion, with respect to the 7
kettlebell trajectory. 8
As previously stated, upward phase horizontal displacement of the kettlebell was 9
greater than the downward phase equivalent for all lifters, perhaps to reduce the 10
centripetal load on the fingers. Increasing kettlebell velocity may further increase the 11
centripetal stress on the fingers. Two peaks in velocity between the upwards and 12
downwards phases were observed across all lifters. The first peak occurred 13
approximately in the re-gripping phase, and the second generally in the acceleration pull 14
phase. Lifters B, C and D had slower peak velocities in the downwards phase, whereas 15
lifter A’s peak velocity was greatest during the downwards phase. Reducing the velocity 16
on the downwards phase could help to reduce stress placed on the finger flexors, 17
however it could also increase the time needed to perform each repetition, which may 18
be counter-productive to the objective of the sport which is to perform as many 19
repetitions as possible in 10 minutes. Strength and conditioning coaches should be 20
aware that in addition to the obvious effect of altering the kettlebell mass, different 21
cadences and/or anthropometric factors may result in different kettlebell velocities. 22
Therefore, an increase in cadence may result in greater velocity in the downwards 23
phase and a faster eccentric phase. This increase in repetition velocity may result in 1
greater grip and systemic fatigue, which may only be sustainable over shorter time 2
periods. 3
Conclusion 4
The kettlebell snatch trajectory of elite GS athletes follows a ‘C’ shaped path. There 5
were two differently shaped ‘C’ trajectories, one with a smaller radius on the downwards 6
phase, and the other a larger during the upwards phase. Kettlebell displacement 7
occurred predominantly in the sagittal plane, although varying and relatively smaller 8
amounts of horizontal displacement were recorded in the frontal plane. Within the 9
upwards and downwards phases, low movement variability appears an important factor, 10
particularly in the overhead fixation position. With the kettlebells potential large degrees 11
of freedom, individual athlete style may affect their trajectories. 12
Additionally, there were two peaks in velocity which occurred in the upwards and 13
downwards phases. This technique easily facilitates multiple repetitions due to its 14
cyclical upwards and downwards phases. This research has shown that the kettlebell 15
snatch can be performed with consistent kettlebell trajectories and velocities for 15 16
repetitions by elite GS athletes in a relatively unfatigued state. 17
Practical application 18
The kettlebell snatch may be a useful option as an alternative to high repetitions of the 19
barbell snatch, as it can be performed consistently. This may be particularly useful for 20
strength and conditioning coaches, wishing to program an explosive total body 21
movement such as the snatch for higher repetitions. Additionally, the unilateral and 22
swinging nature of the kettlebell may provide a unique stimulus. Programming a snatch 1
for higher repetitions may increase the metabolic and grip demands [5]. These 2
components may also be important factors in sports that require a combination of 3
strength and endurance qualities. Grip strength is an important component of Judo 4
competition [21]. Grappling sports such as Judo, freestyle and Greco-Roman wrestling 5
typically involve tournament formats and a progressive increase in fatigue and grip 6
strength loss occurs with each bout during these tournaments [22-25]. The kettlebell 7
snatch may have potential application in these sports, as it may promote increased 8
levels of local muscular endurance. In contrast, the barbell snatch has been well 9
researched and is an effective stimulus for power adaptations [15]. Its trajectory follows 10
an ‘S’ shape which is predominantly vertical, allowing for positions which maximise 11
power output. Therefore, the barbell snatch would be most appropriately programmed 12
for lower repetitions, in contrast to the kettlebell snatch, which may be better suited to 13
higher repetitions. The kettlebell snatch has a cyclical component, as it contains an 14
upwards and downwards phase. Following a ‘C’ trajectory will help to prolong 15
performance and in turn training volume, which may allow for greater training outcomes. 16
Problems may arise if a lifter attempted to apply an ‘S’ trajectory to the kettlebell, which 17
may not be appropriate or attainable, and may cause the hand insertion and fixation 18
phases to occur too closely together (when the arm is vertical). This may lead to greater 19
impact upon the forearm, thus increasing the risk of injury. Evidently, kettlebell snatch 20
technique should not be taught in the same manner as the barbell snatch. 21
22
Limitations 23
The small sample size recruited is the major limitation within this research, however the 1
athletes involved are all elite within GS, making them of particular interest. Due to time 2
constraints and international travel stress, the lifters were unable to perform 10 minute 3
sets at a competition pace for this study. This would have offered an insight into their 4
trajectories in a fatigued state. A total of 16 repetitions were studied over one minute. 5
The number of repetitions performed was at competition pace for the two lighter lifters. 6
However, this was below competition pace for the two heavier lifters. 7
8
Acknowledgments 9
The authors would like to thank IKSFA (www.IKSFA.com), WKC 10
(www.worldkettlebellclub.com), Sergey Rudnev and the other athletes for taking part in 11
the research. No financial support was taken from these organizations. We would also 12
like to thank Dr. Brett O’Connell for his technical support. 13
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References 1
1. Tikhonov, V.F., Suhovey, A.V. and Leonov D.V., Fundamentals of Kettlebell 2 Sport: teaching motor actions and methods of training: a manual, Soviet Sport, 3 2009. 4 2. Tsatsouline, P., Enter the Kettlebell!, Dragon Door Publications, Inc., St. Paul, 5 MN., 2006. 6 3. Farrar, R.E., Mayhew, J.L. and Koch, A.J., Oxygen cost of kettlebell swings, 7 Journal of Strength & Conditioning Research, 2010, 24(4), 1034-1036. 8 4. Hulsey, C.R., Soto, D.T., Koch, A.J. and Mayhew, J.L., Comparison of kettlebell 9 swings and treadmill running at equivalent rating of perceived exertion values, 10 Journal of Strength & Conditioning Research, 2012, 26(5), 1203-1207. 11 5. Beltz, N., Erbes, D., Porcari, J.P., Martinez, R., Doberstein, S. and Foster, C., 12 Effects of kettlebell training on aerobic capacity, muscular strength, balance, 13 flexibility, and body composition, Journal of Fitness Research, 2013, 2(2), 4-13.
14 6. Jay, K., Jakobsen, M. D., Sundstrup, E., Skotte, J. H., Jørgensen, M. B., 15 Andersen, C. H., and Andersen, L. L., Effects of kettlebell training on postural 16 coordination and jump performance: a randomized controlled trial, Journal of
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30 & health, 2011. 37(3), 196-203.
31 11. Rudnev, S., Kettlebell sport coach manual, IKSFA, 2010.
32 12. McGill, S.M. and L.W. Marshall, Kettlebell swing, snatch, and bottoms-up carry: 33 back and hip muscle activation, motion, and low back loads. Journal of Strength 34 & Conditioning Research, 2012. 26(1), 16-27.
35 13. Stone, M. H., O'Bryant, H. S., Williams, F. E., Johnson, R. L., and Pierce, K. C., 36 Analysis of bar paths during the snatch in elite male weightlifters. Strength &
37 Conditioning Journal, 1998. 20(4), 30-38. 38 14. Winchester, J.B., J.M. Porter, and J.M. McBride, Changes in bar path kinematics 39 and kinetics through use of summary feedback in power snatch training. Journal
40 of Strength & Conditioning Research, 2009. 23(2), 444-454. 41 15. Garhammer, J., A review of power output studies of Olympic and powerlifting: 42 Methodology, performance prediction, and evaluation tests. Journal of Strength & 43 Conditioning Research, 1993. 7(2), 76-89.
44
16. Lauder, M.A. and J.P. Lake, Biomechanical comparison of unilateral and bilateral 1 power snatch lifts. Journal of Strength & Conditioning Research, 2008. 22(3), 2 653-660. 3 17. Ho, K. W. L., Williams, M. D., Wilson, C. J., and Meehan, D. L., Using Three-4 Dimensional Kinematics to Identify Feedback for The Snatch: A Case Study. 5 Journal of Strength & Conditioning Research, 2011. 25(10), 2773-2780. 6 18. Woltring, H.J., A FORTRAN package for generalized, cross-validatory spline 7 smoothing and differentiation. Advances in Engineering Software, 1986. 8(2), 8 104-113. 9 19. Magill, R., Motor Learning: Concepts and Applications, Boston, MA,WCB 10 McGraw-Hill. 1998, 20-21. 11 20. Hopkins, W.G., Linear Models and Effect Magnitudes for Research, Clinical and 12 Practical Applications. Sportscience, 2010, 49-57. 13 http://www.sportsci.org/2010/wghlinmod.htm 14 21. Miarka, B., Panissa, V. L. G., Julio, U. F., Del Vecchio, F. B., Calmet, M., and 15 Franchini, E., A., comparison of time-motion performance between age groups in 16 judo matches. Journal of sports sciences, 2012. 30(9), 899-905. 17 22. Bonitch-Góngora, J. G., Bonitch-Domínguez, J. G., Padial, P., and Feriche, B., 18 The effect of lactate concentration on the handgrip strength during judo bouts. 19 Journal of Strength & Conditioning Research, 2012. 26(7), 1863-1871. 20 23. Branco, B. H. M., Massuça, L. M., Andreato, L. V., Miarka, B., Monteiro, L., 21 Marinho, B. F., and Fanchini, E., Association between the Rating Perceived 22 Exertion, Heart Rate and Blood Lactate in Successive Judo Fights (Randori). 23 Asian Journal of Sports Medicine, 2013. 4(2), 125-130. 24 24. Barbas, I., Fatouros, I. G., Douroudos, I. I., Chatzinikolaou, A., Michailidis, Y., 25 Draganidis, D., and Theodorou, A. A., Physiological and performance 26 adaptations of elite Greco-Roman wrestlers during a one-day tournament. 27 European journal of applied physiology, 2011. 111(7), 1421-1436. 28 25. Kraemer, W. J., Fry, A. C., Rubin, M. R., Triplett-McBride, T., Gordon, S. E., 29 Koziris, L. P., and Newton, R. U., Physiological and performance responses to 30 tournament wrestling. Medicine and science in sports and exercise, 2001. 33(8),
31 1367-1378. 32 33 34
35 36 37 38 39 40 41 42 43 44 45
FIGURES 1 2
3 Figure 1. Phases of the kettlebell snatch. 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Fixation Drop Re-gripping Back Swing Forward Swing Acceleration
Pull Hand
Insertion Fixation
Downwards Phase Upwards Phase
1 Figure 2. An example of the four points of error in the kettlebell snatch. 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
28
1 Figure 3. Sagittal plane kettlebell trajectory. 2 3 4 5 6 7 8 9 10 11 12 13 14
1 Figure 4. Frontal plane kettlebell trajectory. 2 3 4 5 6 7 8 9 10 11 12 13 14
1 Figure 5. Typical KB resultant velocity-time curve for respective participants. 2 3 4 5 6 7 8 9 10 11 12 13 14 15
TABLES
Table 1. Mean displacement ranges (m) and ratios for respective participants
Lifter A Lifter B Lifter C Lifter D
Up Phase Down Phase Up Phase Down Phase Up Phase Down Phase Up Phase Down Pha
s
APV 0.67 ± 0.02 0.63 ± 0.03 0.66 ± 0.02 0.60 ± 0.02 0.60 ± 0.02 0.56 ± 0.02 0.66 ± 0.02 0.60 ± 0.0
1
MLR 0.31 ± 0.01 0.26 ± 0.02 0.13 ± 0.03 0.13 ± 0.03 0.05 ± 0.02 0.06 ± 0.02 0.08 ± 0.02 0.07 ± 0.0
1
Vertical 1.265 ± 0.024 1.265 ± 0.024 1.240 ± 0.020 1.240 ± 0.020 1.393 ± 0.016 1.393 ± 0.016 1.466 ± 0.020 1.466 ± 0.
0
AP 0.845 ± 0.014 0.798 ± 0.027 0.820 ± 0.016 0.744 ± 0.025 0.834 ± 0.024 0.783 ± 0.035 0.967 ± 0.014 0.877 ± 0.
0
ML 0.394 ± 0.018 0.329 ± 0.031 0.166 ± 0.036 0.165 ± 0.34 0.065 ± 0.026 0.080 ± 0.035 0.113 ± 0.015 0.103 ± 0.
0
All data are mean+standard deviations. APV: Anterior-Posterior to Vertical ratio, MLV: Medio-lateral to Vertical ratio.
Table 2. Three dimensional ranges and effect size between the midpoint of the
upwards and downwards phases (m).
Lifter A Lifter B Lifter C Lifter D
AP
ES 0.049 ± 0.023**
1.99 0.076 ± 0.029**
4.19 0.046 ± 0.026**
2.06 0.090 ± 0.017**
6.67
ML
ES 0.070 ± 0.020**
3.30 0.018 ± 0.013
0.06 0.035 ± 0.022
0.61 0.014 ± 0.008*
0.59
Vertical
ES 0.022 ± 0.015**
1.29 0.062 ± 0.030**
3.45 0.034 ± 0.020
0.51 0.094 ± 0.028**
5.34
All data are mean + standard deviations. AP: Anterior-posterior, ML: Medio-lateral,
*Significant difference in positions of upwards and downwards phases (p < 0.05),
** Significant difference in positions of upwards and downwards phases (p < 0.01).
Table 3. Mean resultant velocity (m.s¹) of respective participants.
Phase Lifter A Lifter B Lifter C Lifter D
Upwards
Downwards
ES
3.95 ± 0.4
4.00 ± 0.04
-1.19**
3.88 ± 0.03
3.52 ± 0.05
7.45**
4.03 ± 0.13
3.39 ± 0.09
3.21**
4.27 ± 0.04
3.83 ± 0.02
12.05**
All data are mean + standard deviations.
** Significant difference in resultant velocity of upwards and downwards phases (p <
0.01).
Table 3. Displacement range, radial error and absolute error for respective
participants (m)
Lifter A Lifter B Lifter C Lifter D
Phase Anterior-Posterior
End Back Swing
Range
AE
RE (APV)
0.054 ± 0.015
0.012 ± 0.09
0.023 ± 0.016
0.033 ± 0.012
0.010 ± 0.04
0.023 ± 0.09
0.072 ± 0.024
0.019 ± 0.013
0.024 ± 0.013
0.044 ± 0.012
0.010 ± 0.007
0.019 ± 0.012
Acceleration
Pull
Range
AE
RE (APV)
0.032 ± 0.009
0.008 ± 0.005
0.015 ± 0.008
0.058 ± 0.014
0.010 ± 0.010
0.017 ± 0.012
0.066 ± 0.023
0.019 ± 0.013
0.028 ± 0.014
0.050 ± 0.011
0.008 ± 0.008
0.015 ± 0.012
Fixation
Range
AE
RE (APV)
0.039 ± 0.010
0.007 ± 0.006
0.008 ± 0.006
0.105 ± 0.028
0.022 ± 0.015
0.023 ± 0.016
0.094 ± 0.028
0.022 ± 0.017
0.023 ± 0.016
0.067 ± 0.021
0.018 ± 0.010
0.018 ± 0.010
Re-gripping
Range
AE
RE (APV)
0.105± 0.026
0.016± 0.008
0.022 ± 0.020
0.069 ± 0.020
0.016 ± 0.011
0.024 ± 0.011
0.090 ± 0.023
0.017 ± 0.015
0.032 ± 0.027
0.050 ± 0.015
0.011 ± 0.008
0.021 ± 0.009
Phase Medio-Lateral
End Back Swing
Range
AE
RE (MLV)
0.062 ± 0.016
0.013 ± 0.010
0.023 ± 0.016
0.078 ± 0.024
0.019 ± 0.014
0.023 ± 0.009
0.051 ± 0.018
0.016 ± 0.007
0.024 ± 0.013
0.031 ± 0.009
0.007 ± 0.005
0.019 ± 0.012
Acceleration
Pull
Range
AE
RE (MLV)
0.051 ± 0.017
0.015 ± 0.008
0.015 ± 0.008
0.062 ± 0.016
0.015 ± 0.009
0.017 ± 0.012
0.056 ± 0.015
0.011± 0.009
0.028 ± 0.014
0.046 ± 0.012
0.008 ± 0.009
0.015 ± 0.012
Fixation
Range
AE
RE (MLV)
0.062 ± 0.020
0.018± 0.009
0.018 ± 0.008
0.105 ± 0.026
0.019 ± 0.017
0.020 ± 0.016
0.090 ± 0.025
0.019 ± 0.016
0.020 ± 0.015
0.044 ± 0.014
0.012 ± 0.008
0.012 ± 0.007
Re-gripping
Range
AE
RE (MLV)
0.097 ± 0.027
0.021 ± 0.015
0.025 ± 0.017
0.073± 0.018
0.014± 0.012
0.023 ± 0.012
0.108 ± 0.030
0.024 ± 0.013
0.037 ± 0.027
0.069 ± 0.019
0.015 ± 0.011
0.023 ± 0.009
Phase Vertical
End Back Swing 0.093 ± 0.024 0.077 ± 0.022 0.058 ± 0.016 0.074 ± 0.020
Range
AE 0.018 ± 0.015 0.019 ± 0.009 0.012 ± 0.009 0.015 ± 0.011
Acceleration
Pull
Range
AE 0.044 ± 0.014
0.012 ± 0.007 0.058 ± 0.016
0.011± 0.008 0.069 ± 0.022
0.018 ± 0.011 0.061 ± 0.016
0.012 ± 0.011
Fixation
Range
AE 0.004 ± 0.001
0.001 ± 0.001 0.018 ± 0.005
0.004 ± 0.003 0.019 ± 0.005
0.004 ± 0.003 0.012 ± 0.004
0.003 ± 0.002
Re-gripping
Range
AE 0.055 ± 0.017
0.012 ± 0.008 0.071± 0.019
0.015 ± 0.007 0.144 ± 0.036
0.025± 0.024 0.055 ± 0.018
0.015 ± 0.009
All data are mean+SD, unless otherwise stated. AE: absolute error. RE: radial error
APV: Anterior-Posterior to Vertical ratio, MLV: Medio-lateral to Vertical ratio.
... To date, the barbell snatch has received much attention and reviews of the literature have demonstrated it to be an effective exercise for strength and power development (Escamilla, Lander & Garhammer, 2000;Garhammer, 1993). In contrast, the kettlebell snatch has only just started to receive research attention (Falatic et al., 2015;Lake, Hetzler & Lauder, 2014;McGill & Marshall, 2012;Ross et al., 2015). In a classic kettlebell competition, the winner is the person who completes the most snatch lifts within a 10 min period. ...
... Additionally, to perform a valid repetition the kettlebell must be locked out motionless overhead at the conclusion of each repetition. The overhead position is known as fixation, which was found to have the lowest movement variability compared to the end of the back swing, and the midpoints of the upwards and downwards phases within its trajectory (Ross et al., 2015). It has been proposed that due to the kettlebell's unique shape and its resulting trajectory, the unilateral kettlebell snatch may be better suited for performing multiple repetitions than a single maximum effort (Ross et al., 2015). ...
... The overhead position is known as fixation, which was found to have the lowest movement variability compared to the end of the back swing, and the midpoints of the upwards and downwards phases within its trajectory (Ross et al., 2015). It has been proposed that due to the kettlebell's unique shape and its resulting trajectory, the unilateral kettlebell snatch may be better suited for performing multiple repetitions than a single maximum effort (Ross et al., 2015). Specifically, the kettlebell snatch trajectory follows a 'C'-shaped path as it can move in between the athlete's legs (Ross et al., 2015), in contrast to an 'S'-shaped trajectory of the barbell snatch (Ho et al., 2014;Newton, 2002), which moves in front of the knees facilitating a double knee bend. ...
Article
Full-text available
Background Kettlebell lifting has gained increased popularity as both a form of resistance training and as a sport, despite the paucity of literature validating its use as a training tool. Kettlebell sport requires participants to complete the kettlebell snatch continuously over prolonged periods of time. Kettlebell sport and weightlifting involve similar exercises, however, their traditional uses suggest they are better suited to training different fitness qualities. This study examined the three-dimensional ground reaction force (GRF) and force applied to the kettlebell over a 6 min kettlebell snatch set in 12 kettlebell-trained males. Methods During this set, VICON was used to record the kettlebell trajectory with nine infrared cameras while the GRF of each leg was recorded with a separate AMTI force plate. Over the course of the set, an average of 13.9 ? 3.3 repetitions per minute were performed with a 24 kg kettlebell. Significance was evaluated with a two-way ANOVA and paired t -tests, whilst Cohen?s F (ESF) and Cohen?s D (ESD) were used to determine the magnitude. Results The applied force at the point of maximum acceleration was 814 ? 75 N and 885 ? 86 N for the downwards and upwards phases, respectively. The absolute peak resultant bilateral GRF was 1,746 ? 217 N and 1,768 ? 242 N for the downwards and upwards phases, respectively. Bilateral GRF of the first and last 14 repetitions was found to be similar, however there was a significant difference in the peak applied force ( F (1.11) = 7.42, p = 0.02, ESF = 0.45). Unilateral GRF was found have a significant difference for the absolute anterior?posterior ( F (1.11) = 885.15, p < 0.0001, ESF = 7) and medio-lateral force vectors ( F (1.11) = 5.31, p = 0.042, ESF = 0.67). Discussion Over the course of a single repetition there were significant differences in the GRF and applied force at multiple points of the kettlebells trajectory. The kettlebell snatch loads each leg differently throughout a repetition and performing the kettlebell snatch for 6 min will result in a reduction in peak applied force.
... The overhead position is known as 32 fixation, which was found to have the lowest movement variability compared to the end of the 33 back swing, and the midpoints of the upwards and downwards phases within its trajectory ( Ross 34 et al. 2015). It has been proposed that due to the kettlebell's unique shape and its resulting 35 trajectory, the unilateral kettlebell snatch may be better suited for performing multiple repetitions 36 than a single maximum effort ( Ross et al. 2015). Specifically, the kettlebell snatch trajectory 37 follows a 'C' shaped trajectory as it can move in between the athlete's legs ( Ross et al. 2015), in 38 contrast to an 'S' shaped trajectory of the barbell snatch ( Newton 2002), which moves around the 39 knees. ...
... It has been proposed that due to the kettlebell's unique shape and its resulting 35 trajectory, the unilateral kettlebell snatch may be better suited for performing multiple repetitions 36 than a single maximum effort ( Ross et al. 2015). Specifically, the kettlebell snatch trajectory 37 follows a 'C' shaped trajectory as it can move in between the athlete's legs ( Ross et al. 2015), in 38 contrast to an 'S' shaped trajectory of the barbell snatch ( Newton 2002), which moves around the 39 knees. In elite kettlebell sport, the kettlebell snatch also involves a downwards phase which 40 follows a smaller radius compared to the kettlebell's upwards phase ( Ross et al. 2015). ...
... Specifically, the kettlebell snatch trajectory 37 follows a 'C' shaped trajectory as it can move in between the athlete's legs ( Ross et al. 2015), in 38 contrast to an 'S' shaped trajectory of the barbell snatch ( Newton 2002), which moves around the 39 knees. In elite kettlebell sport, the kettlebell snatch also involves a downwards phase which 40 follows a smaller radius compared to the kettlebell's upwards phase ( Ross et al. 2015). The 41 downwards phase gives it more of a cyclical natural than the barbell snatch, where the barbell is 42 dropped from the overhead recovery position, thus allowing a training stimulus in both the 43 upwards and downwards phases. ...
Article
Full-text available
Background. Kettlebell lifting has gained increased popularity as both a form of resistance training and as a sport, despite the paucity of literature validating its use as a training tool. Kettlebell sport requires participants to complete the kettlebell snatch continuously over prolonged periods of time. Kettlebell sport and weightlifting involve similar exercises, however their traditional uses suggest they are better suited to training different fitness qualities. This study examined the three dimensional ground reaction force (GRF) and force applied to the kettlebell over a six minute kettlebell snatch set in 12 kettlebell trained males. Methods. During this set, VICON was used to record the kettlebell trajectory with nine infrared cameras while the GRF of each leg was recorded with a separate AMTI force plate. Over the course of the set, an average of 13.9 ± 3.3 repetitions per minute were performed with a 24 kg kettlebell. Significance was evaluated with a two-way ANOVA and paired t-tests, whilst Cohen’s F (ESF) and Cohen’s D (ESD) were used to determine the magnitude. Results. The applied force at the point of maximum acceleration was 814 ± 75 N and 885 ± 86 N for the downwards and upwards phases, respectively. The absolute peak resultant bilateral GRF was 1746 ± 217 N and 1768 ± 242 N for the downwards and upwards phases, respectively. Bilateral GRF of the first and last 14 repetitions was found to be similar, however there was a significant difference in the peak applied force (F (1.11) = 7.42, p = 0.02, ESF = 0.45). Unilateral GRF was found have a significant difference for the absolute anterior-posterior (F (1.11) = 885.15 p < 0.0001, ESF = 7.00) and medio-lateral force vectors (F (1.11) = 5.31, p = 0.042, ESF = 0.67). Discussion. Over the course of a single repetition there were significant differences in the GRF and applied force at multiple points of the kettlebells trajectory. The kettlebell snatch loads each leg differently throughout a repetition and performing the kettlebell snatch for six minutes will result in a reduction in peak applied force.
... The overhead position is known as 32 fixation, which was found to have the lowest movement variability compared to the end of the 33 back swing, and the midpoints of the upwards and downwards phases within its trajectory ( Ross 34 et al. 2015). It has been proposed that due to the kettlebell's unique shape and its resulting 35 trajectory, the unilateral kettlebell snatch may be better suited for performing multiple repetitions 36 than a single maximum effort ( Ross et al. 2015). Specifically, the kettlebell snatch trajectory 37 follows a 'C' shaped trajectory as it can move in between the athlete's legs ( Ross et al. 2015), in 38 contrast to an 'S' shaped trajectory of the barbell snatch ( Newton 2002), which moves around the 39 knees. ...
... It has been proposed that due to the kettlebell's unique shape and its resulting 35 trajectory, the unilateral kettlebell snatch may be better suited for performing multiple repetitions 36 than a single maximum effort ( Ross et al. 2015). Specifically, the kettlebell snatch trajectory 37 follows a 'C' shaped trajectory as it can move in between the athlete's legs ( Ross et al. 2015), in 38 contrast to an 'S' shaped trajectory of the barbell snatch ( Newton 2002), which moves around the 39 knees. In elite kettlebell sport, the kettlebell snatch also involves a downwards phase which 40 follows a smaller radius compared to the kettlebell's upwards phase ( Ross et al. 2015). ...
... Specifically, the kettlebell snatch trajectory 37 follows a 'C' shaped trajectory as it can move in between the athlete's legs ( Ross et al. 2015), in 38 contrast to an 'S' shaped trajectory of the barbell snatch ( Newton 2002), which moves around the 39 knees. In elite kettlebell sport, the kettlebell snatch also involves a downwards phase which 40 follows a smaller radius compared to the kettlebell's upwards phase ( Ross et al. 2015). The 41 downwards phase gives it more of a cyclical natural than the barbell snatch, where the barbell is 42 dropped from the overhead recovery position, thus allowing a training stimulus in both the 43 upwards and downwards phases. ...
Article
Full-text available
Background. Kettlebell lifting has gained increased popularity as both a form of resistance training and as a sport, despite the paucity of literature validating its use as a training tool. Kettlebell sport requires participants to complete the kettlebell snatch continuously over prolonged periods of time. Kettlebell sport and weightlifting involve similar exercises, however their traditional uses suggest they are better suited to training different fitness qualities. This study examined the three dimensional ground reaction force (GRF) and force applied to the kettlebell over a six minute kettlebell snatch set in 12 kettlebell trained males. Methods. During this set, VICON was used to record the kettlebell trajectory with nine infrared cameras while the GRF of each leg was recorded with a separate AMTI force plate. Over the course of the set, an average of 13.9 ± 3.3 repetitions per minute were performed with a 24 kg kettlebell. Significance was evaluated with a two-way ANOVA and paired t-tests, whilst Cohen’s F (ESF) and Cohen’s D (ESD) were used to determine the magnitude. Results. The applied force at the point of maximum acceleration was 814 ± 75 N and 885 ± 86 N for the downwards and upwards phases, respectively. The absolute peak resultant bilateral GRF was 1746 ± 217 N and 1768 ± 242 N for the downwards and upwards phases, respectively. Bilateral GRF of the first and last 14 repetitions was found to be similar, however there was a significant difference in the peak applied force (F (1.11) = 7.42, p = 0.02, ESF = 0.45). Unilateral GRF was found have a significant difference for the absolute anterior-posterior (F (1.11) = 885.15 p < 0.0001, ESF = 7.00) and medio-lateral force vectors (F (1.11) = 5.31, p = 0.042, ESF = 0.67). Discussion. Over the course of a single repetition there were significant differences in the GRF and applied force at multiple points of the kettlebells trajectory. The kettlebell snatch loads each leg differently throughout a repetition and performing the kettlebell snatch for six minutes will result in a reduction in peak applied force.
... Bell trajectory during a 32 kg single-arm snatch performed by four elite kettlebell sport lifters was reported to be similar between lifters and highly consistent within lifters. Anthropometric differences were suggested to most likely influence movement and performance efficiency [70]. On an unstable surface, reduction in trunk and knee flexion angles and reduced shoulder range of motion were reported during an overhead swing [71]; an expected compensation strategy to increase stability. ...
... Only 4 studies published in English have investigated kettlebell sport. Two involved acute biomechanical analysis of kettlebell exercises [5,70], 1 involved the development of a kettlebell snatch protocol for kettlebell sport that could be used in the laboratory [83], and 1 was a University study showing medium to huge effect size changes in standing long jump, strength and throw performance, although with high risk of bias the results are unreliable [102]. ...
Article
Full-text available
Background: A scoping review of scientific literature on the effects of kettlebell training. There are no authoritative guidelines or recommendations for using kettlebells within a primary care setting. Our review objectives were to identify the extent, range and nature of the available evidence, to report on the types of evidence currently available to inform clinical practice, to synthesise key concepts, and identify gaps in the research knowledge base. Methods: Following the PRISMA-ScR Checklist, we conducted a search of 10 electronic databases from inception to 1 February 2019. There were no exclusions in searching for publications. A single reviewer screened the literature and abstracted data from relevant publications. Articles were grouped and charted by concepts and themes relevant to primary care, and narratively synthesised. Effect sizes from longitudinal studies were identified or calculated, and randomised controlled trials assessed for methodological quality. Results: Eight hundred and twenty-nine records were identified to 1 February 2019. Four hundred and ninety-six were screened and 170 assessed for eligibility. Ninety-nine publications met the inclusion criteria. Effect sizes were typically trivial to small. One trial used a pragmatic hardstyle training program among healthy college-age participants. Two trials reported the effects of kettlebell training in clinical conditions. Thirty-three studies explicitly used 'hardstyle' techniques and 4 investigated kettlebell sport. Also included were 6 reviews, 22 clinical/expert opinions and 3 case reports of injury. Two reviewers independently evaluated studies using a modified Downs & Black checklist. Conclusions: A small number of longitudinal studies, which are largely underpowered and of low methodological quality, provide the evidence-informed therapist with little guidance to inform the therapeutic prescription of kettlebells within primary care. Confidence in reported effects is low to very low. The strength of recommendation for kettlebell training improving measures of physical function is weak, based on the current body of literature. Further research on reported effects is warranted, with inclusion of clinical populations and investigations of musculoskeletal conditions common to primary care. There is a need for an externally valid, standardised approach to the training and testing of kettlebell interventions, which better informs the therapeutic use of kettlebells in primary care.
... The squat swing is performed with increased range of motion of the ankles and knees (16), thus resembling a quarter squat and requiring shorter hamstring muscle lengths than the hip hinge style. The double knee extension swing is common to kettlebell sport and is used during the kettlebell snatch in an effort to promote an efficient trajectory (25,26). In contrast to the other two types of swings, it does not have simultaneous knee and hip extension in both the upwards and downwards phases (16). ...
... In comparison, the double knee extension requires a fairly unique technique, which has no real resemblance to other commonly used exercises and may be more complex to teach than other kettlebell swings. From a kettlebell sport perspective, as the double knee extension had the lowest hamstring muscle activation across all variables, the swing may be the preferred choice to use where endurance is required, such as during a kettlebell snatch discipline in competition, where a maximum number of snatches are performed within ten minutes (26). In contrast, the kettle bell swing may be better suited as a power training stimulus compared to the kettlebell snatch. ...
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... Physiological parameters such as the heart rate, oxygen consumption, muscle activity and lactate in various kettlebell training protocols have been measured for various kettlebell exercises [1,[5][6][7][8][9], suggesting that kettlebell sport can increase the aerobic capacity [1,8]. Biomechanical parameters of kettlebell exercises have been analyzed by goniometers [9] and video tracking [7,[10][11][12][13][14]. Forces in the kettlebell sport have been measured with accelerometers [6] and force platforms [1,2,5,11,[14][15][16][17], sometimes together with video tracking of the kettlebells [2,5,15,18]. ...
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