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Williams, MJ, Gibson, N, Sorbie, GG, Ugbolue, UC, Brouner, J, and Easton, C. Activation of the gluteus maximus during performance of the back squat, split squat, and barbell hip thrust and the relationship with maximal sprinting. J Strength Cond Res 35(1): 16-24, 2021-The purpose of this research was to compare muscle activation of the gluteus maximus and ground reaction force between the barbell hip thrust, back squat, and split squat and to determine the relationship between these outcomes and vertical and horizontal forces during maximal sprinting. Twelve, male, team sport athletes (age, 25.0 ± 4.0 years; stature, 184.1 ± 6.0 cm; body mass, 82.2 ± 7.9 kg) performed separate movements of the 3 strength exercises at a load equivalent to their individual 3 repetition maximum. The ground reaction force was measured using force plates and the electromyography (EMG) activity of the upper and lower gluteus maximus and was recorded in each leg and expressed as percentage of the maximum voluntary isometric contraction (MVIC). Subjects then completed a single sprint on a nonmotorized treadmill for the assessment of maximal velocity and horizontal and vertical forces. Although ground reaction force was lower, peak EMG activity in the gluteus maximus was higher in the hip thrust than in the back squat (p = 0.024; 95% confidence interval [CI] = 4-56% MVIC) and split squat (p = 0.016; 95% CI = 6-58% MVIC). Peak sprint velocity correlated with both anterior-posterior horizontal force (r = 0.72) and peak ground reaction force during the barbell hip thrust (r = 0.69) but no other variables. The increased activation of gluteus maximus during the barbell hip thrust and the relationship with maximal running speed suggests that this movement may be optimal for training this muscle group in comparison to the back squat and split squat.
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ACTIVATION OF THE GLUTEUS MAXIMUS DURING
PERFORMANCE OF THE BACK SQUAT,SPLIT SQUAT,
AND BARBELL HIP THRUST AND THE RELATIONSHIP
WITH MAXIMAL SPRINTING
MICHAEL J. WILLIAMS,
1,2
NEIL V. GIBSON,
2
GRAEME G. SORBIE,
1,4
UKADIKE C. UGBOLUE,
1,5
JAMES BROUNER,
3
AND CHRIS EASTON
1
1
Institute for Clinical Exercise & Health Science, University of the West of Scotland, United Kingdom;
2
Oriam, Scotland’s
Sports Performance Centre, Heriot-Watt University, United Kingdom;
3
School of Life Sciences, Pharmacy, and Chemistry,
Kingston University, United Kingdom;
4
School of Social & Health Sciences, Sport and Exercise, Abertay University, United
Kingdom; and
5
Department of Biomedical Engineering, University of Strathclyde, Glasgow, United Kingdom
ABSTRACT
Williams, MJ, Gibson, N, Sorbie, GG, Ugbolue, UC, Brouner, J,
and Easton, C. Activation of the gluteus maximus during
performance of the back squat, split squat, and barbell hip
thrust and the relationship with maximal sprinting. J Strength
Cond Res XX(X): 000–000, 2018—The purpose of this
research was to compare muscle activation of the gluteus
maximus and ground reaction force between the barbell hip
thrust, back squat, and split squat and to determine the rela-
tionship between these outcomes and vertical and horizontal
forces during maximal sprinting. Twelve, male, team sport ath-
letes (age, 25.0 64.0 years; stature, 184.1 66.0 cm; body
mass, 82.2 67.9 kg) performed separate movements of the 3
strength exercises at a load equivalent to their individual 3
repetition maximum. The ground reaction force was measured
using force plates and the electromyography (EMG) activity of
the upper and lower gluteus maximus and was recorded in
each leg and expressed as percentage of the maximum volun-
tary isometric contraction (MVIC). Participants then completed
a single sprint on a nonmotorized treadmill for the assessment
of maximal velocity and horizontal and vertical forces. Although
ground reaction force was lower, peak EMG activity in the
gluteus maximus was higher in the hip thrust than in the back
squat (p= 0.024; 95% confidence interval [CI] = 4–56%
MVIC) and split squat (p= 0.016; 95% CI = 6–58% MVIC).
Peak sprint velocity correlated with both anterior-posterior hor-
izontal force (r= 0.72) and peak ground reaction force during
the barbell hip thrust (r= 0.69) but no other variables. The
increased activation of gluteus maximus during the barbell
hip thrust and the relationship with maximal running speed
suggests that this movement may be optimal for training this
muscle group in comparison to the back squat and split squat.
KEY WORDS strength training, bilateral exercises, unilateral
exercises, ground reaction force, electromyography
INTRODUCTION
Axial loaded strength exercises, such as the back
squat, are often regarded as a fundamental com-
ponent of strength programs designed to increase
lower-body strength and power (23,38). Tradi-
tional squatting exercises can be further subdivided into
bilateral and unilateral derivatives, although they seem to
be equally as efficacious for developing power and lower-
body strength (24,36). Nevertheless, these movements do
not always improve sprint speed (15). During maximal
sprinting, ground contact seems to occur with the hips in
a neutral to slightly extended position, with the gluteus mus-
culature shown to be the biggest contributor to hip exten-
sion torque (13,18). This position is not replicated by
traditional squatting exercises, and this lack of movement
specificity between the back squat and sprinting mechanics
may explain conflicting reports within the literature regard-
ing its ability to improve running speed (6,15). Although
exercises that elicit vertical forces initiate the gluteal muscles
(particularly the gluteus maximus) in a hips-flexed position,
activation is reduced when the hips are neutral or slightly
extended (8). If strength and or force production in this
position is a limiting factor when sprinting, the back squat
may not be the most suitable exercise to prescribe.
Conversely, horizontal force production is a key com-
ponent in the optimization of acceleration and maximal
sprint speed (4,5,20,27,33), highlighting the importance of
incorporating exercises that develop horizontal forces in
Address correspondence to Dr. Chris Easton, chris.easton@uws.ac.uk.
00(00)/1–9
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training programs. Indeed, when used in combination with
exercises that promote vertical force production, horizon-
tally orientated exercises have been shown to improve
sprint speed and peak power (2,26). Whether the effect of
exercises that use horizontal force expression can stimulate
improvements in maximal sprint speed without the inclu-
sion of traditional squatting exercises has yet to be eluci-
dated. Recent research, however, has proposed the use of
the barbell hip thrust as an alternative means of training the
posterior chain musculature of the lower body (8,9). This
exercise has been shown to elicit greater gluteus maximus
and hamstring activation when compared with the back
squat in strength-trained females and higher anterior-
posterior horizontal forces (9). The barbell hip thrust al-
lows strength to be developed with the hips in an extended
position and via a horizontal force production, which may
be of greater relevance to sprinting (13) (Figure 1).
Although this approach would appear to contravene the
training philosophy of specificity, it does conform to the
theory of dynamic correspondence; although not identical
to the activity of sprinting, the barbell hip thrust replicates
the muscular patterns, synchronicity, and energy produc-
tion involved during training (35).
Despite recent research (8,9,11) comparing the barbell hip
thrust with other bilateral strength exercises and its relation to
physical parameters, including sprint acceleration and jump
performance, to our knowledge, there are no comparisons
between unilateral strength exercises and the barbell hip thrust.
Furthermore, previous research has not determined whether
there is any relationship between gluteus maximus activity and
force production during strength exercises or maximal sprint-
ing. The primary aim of the present study, therefore, was to
determine the difference between muscle activation and force
production during the bilateral squat, unilateral split squat, and
barbell hip thrust. A secondary objective was to determine the
association of the aforementioned dependent variables with
speed, and horizontal and vertical forces during maximal
sprinting. The experimental hypothesis was that the barbell
hip thrust would elicit higher mean and peak gluteus maximus
activity when compared with the back squat and split squat,
and these variables would be more strongly associated with
parameters of maximal running performance.
METHODS
Experimental Approach to the Problem
In the first part of this experiment, measurements of ground
reaction force and electromyography (EMG) of the gluteus max-
imus were recorded in team sport athletes during 3-repetition
maximum efforts of the barbell hip thrust, bilateral squat, and
unilateral split squat. Data were then analyzed to determine
Figure 1. Diagram annotated to show equipment and positional requirements of the barbell hip thrust (permission given by the participant for photographs to be
included in this publication).
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whether there were any differences between the 3 different
exercises. In the second part of the experiment, participants
completed a single maximal sprint effort on a nonmotorized
treadmill while speed, horizontal force, and vertical force were
measured. Data were then analyzed to assess whether there was
any association between the variables of muscle activation and
force measured during the 3 different strength exercises with
metrics of maximal running performance.
Subjects
Twelve, male, team-sport athletes volunteered to participate
in the study (mean 6SD age, 25.0 64.0 years; stature, 184.1
66.0 cm; body mass, 82.2 67.9 kg) who had 4.0 61.0 years
of strength training experience. Subjects had experience in all
3 exercises; however, they were used to varying degrees by
each individual within their own training regimens. Inclusion
criteria required participants to be aged between 18 and 35
years, have a minimum of 3 years resistance training expe-
rience, and able to safely perform each of the 3 exercises
with external load. All participants provided written
informed consent, and the study was approved by the
School of Science and Sport Ethics Committee at the
University of the West of Scotland.
Figure 2. A) Mean gluteus maximus EMG activation for all 3 exercises expressed as a percentage of the maximum isometric voluntary contraction. Data are
presented as mean 6SD. *Significantly greater than the back squat. Significantly greater than the split squat. B) Peak gluteus maximus EMG activation for all
3 exercises expressed as a percentage of the maximum isometric voluntary contraction. Data are presented as mean 6SD. *significantly greater than the back
squat. Significantly greater than the split squat.
Figure 3. Peak ground reaction force in each leg for all 3 exercises. Data are presented as mean 6SD.Significantly greater than the hip thrust. Significantly
greater than the split squat.
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Procedures
Assessment of Three Repetition Strength. Participants performed
3-repetition maximum testing on each resistance exercise.
Participants performed a standardized warm-up comprising
dynamic movement patterns designed to target the gluteal
musculature, including external resistance via the use
of minibands. Immediately after the warm-up, participants
completed submaximal loads in each of the 3 exercises to
determine the 3 repetition maximum as advocated by Baechle
and Earle (30). This procedure incorporated 5–10 repetitions
with a light to moderate load, progressing to heavier sets of 3
repetitions, until the 3 repetition maximum was determined.
The order in which the exercises were assessed was random-
ized, and participants were allowed to self-select recovery time
between exercises. The barbell back squat was performed with
feet placed slightly wider than shoulder width apart with the
bar secured across the upper trapezius musculature (30). Sub-
jects descended until the top of the thigh was deemed parallel
to the floor, which was continually cued by the researcher
throughout the lifts. The barbell split squat was performed
with the same bar position but in a split stance, with the for-
ward foot placed flat on the floor and the rear knee slightly
flexed to allow for a heel raised foot position on the trailing leg.
The barbell hip thrust was performed with the subject’s upper
back pressed against a weight bench, with feet placed slightly
wider than shoulder width apart and the bar positioned across
the hips, as advocated by Contreras et al. (8).
Maximal Voluntary Isometric Contraction Assessment. Partici-
pants completed the aforementioned warm-up before per-
forming progressive submaximal lifts until they felt prepared
to perform their 3-repetition maximum lifts as determined
during the initial trial. To prepare the subject for electrode
placement, their skin was shaved using a Bic hand razor and
sterilized with an alcohol swab to reduce electrical imped-
ance (1,34). A pair of Ag-AgCl surface conductive gel elec-
trodes (Blue Sensor; Ambu, Ballerup, Denmark) were then
applied with an interelectrode distance of 2 cm in alignment
with the fiber direction of the gluteus maximus using posi-
tional guidelines described elsewhere (14). Electrodes were
attached to both the upper and the lower segment of the
gluteus maximus on both sides of the body. A line was drawn
between the posterior superior iliac spine and the greater
trochanter; the upper electrode was placed approximately
5 cm above and laterally to the midpoint of this line given
the diagonal direction the muscle fibers course. The lower
electrode was positioned approximately 5 cm below and
medially to the same line. Electrodes were secured to the
skin with tape to avoid movement artifacts (21). Maximum
voluntary isometric contraction (MVIC) testing was then
performed for the gluteus maximus musculature using a stand-
ing glute squeeze technique (3,10). This value was used as
a reference for the normalization of data.
EMG and Force Assessment During Resistance Exercises. On
completion of MVIC testing, participants rested for 4 minutes
Figure 4. Correlation between peak anterior-posterior horizontal force during sprinting and peak sprint velocity.
EMG of the Gluteus Maximus During Strength Exercise
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before completing the barbell hip thrust, unilateral split
squat, and bilateral squat in a randomized order using a basic
counterbalanced design. Participants were instructed to
complete a 3-repetition maximum lift for each exercise
according to loads previously established with 4 minutes
rest between exercises (30). Two fixed and embedded force
plates (AMTI Optima 400600; Advanced Mechanical Tech-
nology, Inc, Boston, MA, USA) were used to measure
ground reaction force at a sampling rate of 1,000 Hz cali-
brated according to the manufacturer’s guidelines. Partici-
pants were instructed to place 1 foot on each of the force
plates for the bilateral squat and barbell hip thrust. For the
split squat, participants were required to position their forward
leg onto the force plate; for the split squat, 3-repetition maxi-
mum lifts were completed on both legs. A portable squat rack
was set up in front of the force plates for the bilateral and
unilateral split squats. The barbell hip thrust was performed
with the upper back supported on a 17-inch-high bench as
indicated in Figure 1. An EMG system (Myon AG 320;
Schwarzenberg, Switzerland) was used to collect raw EMG
signals at 1,000 Hz, which were filtered using Myon proEMG
software (Myon; Schwarzenberg, Switzerland). EMG signals
for all 3 repetitions of each set were filtered using a 10–450
Hz band-pass filter and smoothed using root mean square with
a 50-millisecond window (12). The EMG data are presented as
the mean of the 4 EMG electrode sites for each of the 3 ex-
ercises to allow comparisons between unilateral and bilateral
data. Mean and peak data were normalized to MVIC collected
during the preassessment glute squeeze. Force plate data are
presented as the mean of both legs for each of the 3 exercises to
allow comparisons between unilateral and bilateral data.
Maximal Sprint Assessment. Following the strength assess-
ments, participants rested for 10 minutes before performing
a maximal linear sprint on a Woodway Force nonmotorized
treadmill (Woodway Force 3.0; Woodway USA, Inc, Wau-
kesha, WI, USA). Participants performed 3 submaximal
warm-up sprints to habituate themselves with the treadmill.
After a 5-minute rest, they were instructed to complete
a maximal effort sprint during which maximal horizontal and
vertical forces and velocity were determined.
Statistical Analyses
All statistical analyses were conducted using Statistical
Package for the Social Sciences (SPSS 22.0; IBM, Corp,
Armonk, NY, USA). The distribution of the data was first
assessed using a Shapiro-Wilk test. One-way repeated-
measure analysis of variance (ANOVAs) was used to
compare mean and peak EMG values between strength
exercises. Differences in ground reaction forces were as-
sessed between strength exercises and between legs using
a 2-way repeated-measures ANOVA. Any significant main
effects were further analyzed by applying Bonferroni cor-
rections for pairwise comparisons. Effect sizes (M1 2M2/
Figure 5. Correlation between peak force during the barbell hip thrust and peak sprint velocity.
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SD) were calculated using Cohen’s dvalues and defined as
small (0.20), medium (0.50), and large (0.80) (10). Pearson’s
product-moment correlations were also used to determine
the relationship between peak sprinting velocity and selected
variables. Statistical significance was accepted at p,0.05,
and 95% confidence intervals (95% CIs) are presented with p
values.
RESULTS
Exercise Loads
The 3-repetition maximum exercise loads for the barbell hip
thrust (157 629 kg; 1.9 60.3 3body mass) were higher
than both the back squat (117 639 kg; 1.4 60.3 3body
mass; p= 0.001) and the split squat (68 623 kg; 0.8 60.2 3
body mass; p,0.001). The 3-repetition maximum loads for
the back squat was higher than the split squat (p,0.001).
Mean Activation
The barbell hip thrust displayed higher mean gluteus maxi-
mus activation than both the back squat (d= 1.29; p= 0.005;
95% CI = 10–55% MVIC) and split squat (d= 1.24; p=
0.006; 95% CI = 9–54% MVIC; Figure 2A). There was no
difference in mean gluteus maximus activation between the
squat and split squat (d= 0.05; p= 1; 95% CI = 11–13%
MVIC).
Peak Activation
The barbell hip thrust displayed higher peak gluteus maximus
activation than both the squat (d= 1.08; p= 0.024; 95% CI =
4–56% MVIC) and split squat (d= 1.08; p= 0.016; 95% CI =
6–58% MVIC, Figure 2B). There was no difference in peak
gluteus maximus activation between the squat and split squat
(d= 0.07; p= 1; 95% CI = 15–19% MVIC).
Peak Ground Reaction Force
There were no difference in peak ground reaction force
between left and right legs in any 3 of the strength exercises
(Figure 3) Peak force in the right foot was lower in the
barbell hip thrust compared with the back squat (d= 2.98;
p,0.001; 95% CI = 416–1,012 N) and the split squat (d=
2.24; p,0.001; 95% CI = 412–740 N). Peak force in the left
foot was also lower in the barbell hip thrust compared with
the back squat (d= 2.80; p,0.001; 95% CI = 596–1,130 N)
and the split squat (d= 1.80; p,0.001; 95% CI = 412–740
N). Peak force was higher in the back squat than compared
with the split squat in the left leg (effect size = 0.66; p=
0.019; 95% CI = 45–534 N) but not the right leg (p= 0.18).
Maximal Sprinting
Peak anterior-posterior horizontal force during sprinting
significantly correlated with peak velocity (r= 0.72; p=
0.008), but there was no relationship between peak vertical
force and peak velocity (r= 0.232; p= 0.47). Peak force
during the barbell hip thrust significantly correlated with
peak sprint velocity (r= 0.69; p= 0.014). There was a weak
relationship between maximal sprint velocity and peak force
in both the bilateral squat and the unilateral split squat, but
neither reached statistical significance (r= 0.52, p= 0.086; r
= 0.53, p= 0.076, respectively). Peak gluteus maximus activa-
tion for each exercise did not correlate with peak sprint
speed (all p.0.05) (Figures 4 and 5).
DISCUSSION
The objective of the present study was to compare muscle
activation of the gluteus maximus and ground reaction force
between the barbell hip thrust, back squat, and split squat
and to determine the relationship between these outcomes
and vertical and horizontal forces during maximal sprinting.
In agreement with our experimental hypothesis, the barbell
hip thrust elicited significantly higher mean and peak gluteus
maximus activation than the back squat and the split squat
when performing 3-repetition maximum lifts despite a lower
peak ground reaction force in this movement. These data
support recent research with female athletes that demon-
strated a higher gluteus maximus activation in the barbell
hip thrust compared with the back squat (9). The present
study further extends these findings by demonstrating that
peak sprint velocity significantly correlated with both peak
horizontal sprint force and peak barbell hip thrust force.
The results of the present study align with findings of
Contreras et al. and suggest that greater peak and mean
activation of the gluteus maximus occurs in the barbell hip
thrust compared with the back squat. Recent extensive pilot
studies by Contreras et al. (9) have suggested that the gluteus
maximus elicits peak EMG activation at the shortest muscle
length in hip hyperextension. Several researchers have con-
cluded that peak gluteus maximus activation during the back
squat occurs on the ascendancy from the bottom of the lift in
a hip’s flexed position and that activation increases with load
(40). However, Contreras et al. (9) found that during iso-
metric holds of both the barbell hip thrust (fully extended
position) and back squat (fully flexed position), the former
produced significantly greater mean and peak EMG activa-
tion in the gluteus maximus.
Although there have been numerous studies comparing
unilateral to bilateral strength exercises, to the knowledge of
the authors, this is the first study to compare a unilateral
exercise to the barbell hip thrust. The results showed that
although there were no differences between the 2 squat
movements, the barbell hip thrust elicited significantly
greater gluteus maximus activation than the split squat. The
similarity in gluteus maximus activation between the squat
movements may appear surprising given that peak ground
reaction force and the summated total load across both front
limbs in the semiunilateral split squat was higher than in the
bilateral back squat (1.6 vs. 1.4 3body mass, respectively).
Given that an increased load has been shown to increase
muscle activation (32), it may be presumed that the addi-
tional load during the split squat would have produced high-
er gluteus maximus activation than in the back squat. In this
instance, however, the unilateral strength exercise produced
similar EMG activation of the gluteus maximus. These
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findings are similar to that of Jones et al. (17) who found no
difference in gluteus maximus activity between unilateral and
bilateral exercises despite discrepancies in relative load. Mus-
cle activity was not measured in the support leg in either the
present study or in the previous work (17), which may
explain some of this disparity and highlights the necessity
for further research in this area.
Training with traditional squat movements does not
always lead to an improvement in maximal sprinting speed
(15), although this is often a desired outcome given several
studies have demonstrated enhancements in this ability
(22,36). Given that sprint velocity appears to be more depen-
dent on horizontal force production than on vertical force
production (4,19,31), this is perhaps not surprising. Indeed,
in the present study, horizontal force production signifi-
cantly correlated with maximal sprint velocity. Furthermore,
the data presented here demonstrate that peak barbell hip
thrust ground reaction force significantly correlated with
maximal sprint velocity. Although the vertically oriented
back squat and split squat elicited higher ground reaction
forces than the barbell hip thrust, the correlation between
these values and maximal sprinting speed did not reach sta-
tistical significance. Although speculative, this suggests that
force production during the barbell hip thrust may be asso-
ciated with sprint performance in team sport athletes. Fur-
thermore, horizontal anteroposterior-based exercises, such
as the barbell hip thrust, may be more effective for improving
maximal sprint speed than either squat movement. Indeed,
Contreras et al. (11) reported that a 6-week barbell hip thrust
training intervention led to improved 20-m sprint times with
no improvement in a group completing back squat training.
This presents a compelling case that the orientation of force
application is an important factor in determining maximal
sprint performance. Squats and their derivatives are clearly
staples in the field of strength and conditioning; however,
understanding how movement mechanics accentuate force
development is becoming an important factor in exercise
selection.
Despite a positive relationship between horizontal sprint
force and maximal sprint velocity, gluteus maximus activation
did not correlate with maximal sprint velocity. This perhaps
is not surprising given the findings of Morin et al. (28) that
generation of horizontal force during sprinting was linked
with a better activation of the hamstring muscles just before
ground contact. Because the barbell hip thrust and back
squat both produce significantly greater gluteus maximus acti-
vation when compared with biceps femoris (8), the lack of
correlation between muscle activation and sprint velocity
in this study is perhaps to be expected. On the other hand,
muscle activation during a hamstring-dominant exercise
may be more strongly associated with maximal sprint
performance.
The assessment of sprint performance in this study was
conducted using a nonmotorized treadmill. Although this
treadmill is regarded as a valid and reliable means of
assessing short sprint performance (16), some may question
how closely it replicates sprinting outdoors. For example,
running on a treadmill eliminates air resistance, which is
likely to be meaningful during sprinting exercise (37). Fur-
thermore, given the individual is tethered at the hips and has
to manually move the treadmill belt with their feet, one
could argue that this encourages an inclined position,
decreasing the involvement of the postural musculature.
However, McKenna and Riches (25) demonstrated that in-
dividuals use similar sprinting technique on the nonmotor-
ized treadmill to over ground sprinting. Furthermore, Morin
and Se
`ve (29) reported that individuals performing sprint
accelerations on the nonmotorized treadmill produce similar
physical and technical movements to outdoor sprint
accelerations.
In the present study, only 2 force plates were used, both
positioned beneath the feet during the barbell hip thrust
exercise. However, at the top of the lift, it is likely that a large
portion of the vertical force will be exerted through the
bench itself. As such, we would suggest that in future
research, an additional plate is placed under the bench or
structure supporting the back in order that the ground
reaction forces can be more fully quantified. A further
potential limitation of the present study was the use of
surface EMG to measure muscle activity. The limitations of
this technique have been discussed extensively by De Luca
(12) and include muscle fiber movement, cross talk from
adjacent musculature, and extrinsic factors, such as volume
of subcutaneous fatty tissue, and that electrodes may not
detect all active motor units. Additionally, EMG peaks
may potentially be artifacts given that the EMG signal not
only includes muscle movement information but also noise
components that are unpreventable despite efforts being
made to filter out these unwanted components (12). To
reduce potential cross talk, the surface electrodes were posi-
tioned within the middle of the muscle belly of the gluteus
maximus and applied in parallel arrangement to the muscle
fibers, with a center to center interelectrode distance of 2 cm.
Further to this, the upper and lower gluteus maximus have
been shown to activate uniquely (9). However, because in
the current study data from these musculature were aver-
aged, it has not been possible to determine how the upper
and lower fibers correlate with sprinting independently.
Despite some of the positive findings in the present study
between commonly used strength exercises and sprinting,
the data obtained is mechanistic in nature; therefore, the
author suggests that future training studies are required to
show transference to sprinting and to verify the proposed
theories.
PRACTICAL APPLICATIONS
Given that maximal sprint speed correlated with horizontal
force production but not vertical production, using exercises
that develop force in the horizontal plane may provide
superior transfer to sprint-based performance. Furthermore,
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the present study has demonstrated maximal sprinting speed
to be correlated with peak force production during the
barbell hip thrust but neither of the 2 vertical squat move-
ments. Applied practitioners can incorporate the barbell hip
thrust into their strength programs based on data indicating
that it has the capacity to elicit greater gluteus maximus activ-
ity than both the back squat and split squat and that it is
more likely to lead to a greater increase in horizontal force
production. Based on these data, it is proposed that perform-
ing anteroposterior strength exercises, such as the barbell hip
thrust, and focusing on methods to increase horizontal force
during sprinting may be effective in improving maximal
sprint performance. During maximal sprinting, it appears
toe off at ground contact occurs with the hips in a slightly
hyperextended position, which could be a key component as
to why barbell hip thrust force production is a better indi-
cator of maximal sprint velocity (13,18). This is not to sug-
gest that the barbell hip thrust should be used as
a replacement for more traditional vertical orientated exer-
cises given they have also been shown to improve sprint
performance (23,39).
ACKNOWLEDGMENTS
The results of the present study do not constitute endorse-
ment by the authors or the National Strength and Condi-
tioning Association. This project was partly funded by
Oriam: Scotland’s Sport Performance Centre.
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... Recently, there has been an increase in the popularity of the barbell hip thrust, a type of bridging exercise performed against an external barbell resistance, used to develop the hip extensor musculature. Since its introduction to the literature by Contreras et al. [4], the hip thrust has gained popularity within the biomechanics and strength and conditioning communities due to evidence of superior gluteal activation characteristics compared with more conventional resistance training exercises such as the back squat or deadlift variations [5][6][7][8]. ...
... sprinting) based on the "force-vector hypothesis" [10,12]. Studies have investigated the influence of hip thrust on sprint [10,13,14] or jump [10,11] performance, as well as the relationships between the hip thrust and sprint performance measures [8,12]. Based on the force-vector hypothesis, the hip thrust should provide a mechanical advantage over traditional standing barbell exercises that elicit a relative vertical orientation of the resultant force vector. ...
... Based on the force-vector hypothesis, the hip thrust should provide a mechanical advantage over traditional standing barbell exercises that elicit a relative vertical orientation of the resultant force vector. Correlational analyses have supported these ideas by evidencing stronger relationships between hip thrust kinetic measures and sprint performance, compared with vertically oriented exercises [8,12]. However, evidence from training studies is currently equivocal, with Contreras et al. [10] indicating sprint and vertical jump improvements were superior following hip thrust and front squat training interventions, respectively, whereas the hip thrust has recently been found to elicit equal improvements in vertical and horizontal jumping performance [11]. ...
Article
Full-text available
Barbell hip thrust exercises have risen in popularity within the biomechanics and strength and conditioning literature over recent years, as a method of developing the hip extensor musculature. Biomechanical analysis of the hip thrust beyond electromyography is yet to be conducted. The aim of this study was therefore to perform the first comprehensive biomechanical analysis the barbell hip thrust. Nineteen resistance trained males performed three repetitions of the barbell hip thrust at 70% one-repetition maximum. Kinematic (250 Hz) and kinetic (1000 Hz) data were used to calculate angle, angular velocity, moment and power data at the ankle, knee, hip and pelvic-trunk joint during the lifting phase. Results highlighted that the hip thrust elicits significantly ( p < 0.05) greater bilateral extensor demand at the hip joint in comparison with the knee and pelvic-trunk joints, whilst ankle joint kinetics were found to be negligible. Against contemporary belief, hip extensor moments were not found to be consistent throughout the repetition and instead diminished throughout the lifting phase. The current study provides unique insight to joint kinematics and kinetics of the barbell hip thrust, based on a novel approach, that offers a robust evidence base for practitioners to guide exercise selection.
... This notion is supported by the effectiveness of this exercise compared to axially loaded exercises for augmenting sprinting ability (Abade et al., 2019;Contreras et al., 2017), although not a universal finding Jarvis et al., 2019). Cross-sectionally, moderate to nearly perfect relationships between HT peak force (Williams et al., 2021) and mean power (Loturco et al., 2018) and sprinting ability have been reported; however, to our best knowledge, no previous studies have utilized the FVP profiling concept to assess HT-specific neuromuscular function while concurrently evaluating its relationship to sprint ability or sprint-specific neuromuscular function. Thus, it is currently unknown to which extent the F-v relationships of maximal effort sprinting and hip thrusting are inter-related. ...
... In light of previous reports regarding the distinctiveness of vertical and horizontal FVP profiles (Jimenez-Reyes et al., 2018 ;Marcote-Pequeno et al., 2019) and the apparent connection between HT performance and sprint acceleration capacity (Loturco et al., 2018 ;Williams et al., 2021), the present study sought to elucidate whether this connection extends towards similar neuromuscular capabilities, thus additionally exploring (Samozino et al., 2008) whereas the HT data points are products of double mathematical integration using high-frequency video analysis (Balsalobre-Fernandez et al., 2017. Table 1. ...
... the importance of force orientation specificity for assessment of neuromuscular function. In contrast to Loturco et al.(Loturco et al., 2018), who reported strong-to-excellent relationships between HT power output and sprint velocities over distances ranging from 10 to 150 m and Williams et al. (Williams et al., 2021), who observed a moderate relationship between peak HT force and peak sprint velocity, no such relationships could be observed in the present study. Several methodological discrepancies between these studies could explain the contrasting observations. ...
Article
Comprehensive information regarding neuromuscular function, as assessed through force-velocity-power (FVP) profiling, is of importance for training optimization in athletes. However, neuromuscular function is highly task-specific, potentially governed by dissimilarity of the overall orientation of forceapplication. The hip thrust (HT) exercise is thought to be of relevance for sprinting considering its antero-posterior force orientation and considerable hip-extensor recruitment, however, the association between their respective FVP profiles remains unexplored. Therefore, to address the concept of force orientation specificity within FVP profiling, the maximal theoretical neuromuscular capabilities of 41 professional male footballers (22.1 ± 4.1 years, 181.8 ± 6.4 cm, 76.4 ± 5.5 kg) were assessed during sprint acceleration, squat jumping (SJ) and the HT exercise. No significant associations were observed for maximal theoretical force or velocity between the three FVP profiling modalities, however, maximal theoretical power (Pmax) was correlated between sprinting and SJ (r = 0.73, P < 0.001) and HT and SJ (r = 0.44, P = 0.01), but not between sprinting and HT (r = 0.18, P = 0.36). In conclusion, although Pmax may be considered a somewhat universal lower-extremity capability, neuromuscular function is associated with substantial task-specificity not solely governed by the overall direction of force orientation.
... In this vein, previous studies have reported activation levels ranging from moderate to low (<25 % MVIC) for gluteus maximus in unloaded supine bridge on the floor (Ekstrom et al., 2007;Jang et al., 2013;Kim & Park, 2016). Thus, it appears that the suspended supine bridge (with an additional effect of vibration) is as demanding for the gluteus maximus as the traditional supine bridge exercise and are not sufficiently challenged to reach high and very high activation values (>40% MVIC) in the gluteus maximus, as happens with the single-leg bridge (Ekstrom et al., 2007;Lehecka et al., 2017), the WBV supine bridge (Marín & Cochrane, 2021) or the barbell hip thrust ( Andersen et al., 2018;Contreras et al., 2016b;Williams et al., 2021). Therefore, although the gluteus maximus is the prime supine bridge mover, its activation is still low. ...
... In this vein, previous studies have reported activation levels ranging from moderate to low (< 25% MVIC) for gluteus maximus in unloaded supine bridge on the floor (Ekstrom et al., 2007;Jang et al., 2013;Kim and Park, 2016). Thus, it appears that the suspended supine bridge (with an additional effect of vibration) is as demanding for the gluteus maximus as the traditional supine bridge exercise and are not sufficiently challenged to reach high and very high activation values (> 40% MVIC) in the gluteus maximus, as happens with the single-leg bridge (Ekstrom et al., 2007;Lehecka et al., 2017), the WBV supine bridge (Marín and Cochrane, 2021) or the barbell hip thrust (Contreras et al., 2016;Andersen et al., 2018;Williams et al., 2021). Therefore, although the gluteus maximus is the prime supine bridge mover, its activation is still low. ...
Thesis
Full-text available
Nowadays, suspension devices are one of the most widely used pieces of equipment to produce perturbation and strengthen most muscle groups globally. However, there is a lack of evidence of their effects on the lower limb. Thus, the main objective of this doctoral thesis was to quantify force production, muscle activity and the magnitude of perturbation in the Bulgarian squat and other lower extremity exercises under unstable conditions. Eighteen studies were analysed for a systematic review (study 1) and 75 physically active participants were recruited to perform the different cross-sectional studies on the effects of suspension devices, unstable surfaces, and mechanical vibrations (vibration platform and superimposed vibration) on lower limb exercises (studies 2-6). It was confirmed that lower body activation had only been previously investigated in the suspended hamstring curl (study 1). Position and pace (70 bpm) were determinants for the force exerted on the suspension strap in the Bulgarian squat (study 2). The suspension device in the Bulgarian squat increased the vertical ground reaction forces (study 3). The force production was higher on the device when the level of instability was low (study 3 and 4), but for muscle activity the device was just as demanding as a traditional exercise (study 3). Increased perturbation enhanced muscle activation (studies 3, 4, 5) and the magnitude of instability in the Bulgarian squat and barbell half-squat (studies 4 and 5). Thus, superimposed vibration on a suspension device becomes a challenge to increase the level of perturbation and improve strength, muscular endurance, and stabilisation (study 6). In addition, load cells are a suitable and practical tool to assess the forces exerted on suspension devices, and the use of an accelerometer makes it possible to determine the magnitude of the perturbation offered by different equipment providing instability by measuring the acceleration of the body's centre of mass.
... The primary finding of this study can be linked to the differences in muscle activity in relation to the degree of knee angle. Yamashita (1988) first demonstrated that when the knees and hips simultaneously extend, the contribution of the GMax is diminished, which was also observed by , Andersen et al. (2018) and Williams et al. (2018). Each of those studies provided evidence demonstrating the decrease in GMax contribution in exercises involving more knee extension. ...
Article
Hip extensor muscles are critical to sport performance as events requiring sprinting and forceful landings are highly dependent on these muscles. Despite biomechanical differences between the barbell hip thrust (BHT) and the barbell glute bridge (BGB), both are biomechanically efficient ways to load this musculature for training purposes. Research investigating the differences in muscular activity between the BHT and BGB has yet been conducted. The aim of this study was to investigate, through surface electromyography, if one exercise is more optimal than the other in producing greater muscle activation for specific hip extensor muscles. Ten male participants completed a two-part study protocol. Results revealed the BHT elicited significantly greater muscle activity within the vastus lateralis for peak and mean outcomes; however, the BGB elicited significantly greater muscle activity in the upper and lower gluteus maximus for peak and mean outcomes and mean outcome in the gluteus medius. Current findings suggest, the BGB is, at minimum, a superior substitute for the BHT for eliciting a larger magnitude of activity in the gluteus maximus. Future studies between the two exercises are warranted to discern which produces greater hypertrophy and whether adaption of the BHT or BGB transfers more optimally to sport performance.
... In this vein, previous studies have reported activation levels ranging from moderate to low (< 25% MVIC) for gluteus maximus in unloaded supine bridge on the floor (Ekstrom et al., 2007;Jang et al., 2013;Kim and Park, 2016). Thus, it appears that the suspended supine bridge (with an additional effect of vibration) is as demanding for the gluteus maximus as the traditional supine bridge exercise and are not sufficiently challenged to reach high and very high activation values (> 40% MVIC) in the gluteus maximus, as happens with the single-leg bridge (Ekstrom et al., 2007;Lehecka et al., 2017), the WBV supine bridge (Marín and Cochrane, 2021) or the barbell hip thrust (Contreras et al., 2016;Andersen et al., 2018;Williams et al., 2021). Therefore, although the gluteus maximus is the prime supine bridge mover, its activation is still low. ...
Article
Full-text available
Traditionally in strength and conditioning environments, vibration has been transmitted using platforms, barbells, dumbbells, or cables but not suspension devices. This study aimed to examine the effects on the lower limb of applying superimposed vibration on a suspension device. Twenty-one physically active men and women performed supine bridge and hamstring curl exercises in three suspended conditions (non-vibration, vibration at 25 Hz, and vibration at 40 Hz). In each exercise condition, the perceived exertion scale for resistance exercise (OMNI-Res) was registered, and the electromyographic signal was assessed for gastrocnemius (medialis and lateralis), biceps femoris, semitendinosus, gluteus maximus, and rectus femoris. A linear mixed model indicated a significant fixed effect for vibration at 25 Hz and 40 Hz on muscle activity in suspended supine bridge (p < 0.05), but no effect for suspended hamstring curl (p > 0.05). Likewise, the Friedman test showed a significant main effect for vibration at 25 Hz and 40 Hz in suspended supine bridge (p < 0.05) but not for suspended hamstring curl (p > 0.05) on OMNI-Res. Post hoc analysis for suspended supine bridge with vibration at 25 Hz showed a significant activation increase in gastrocnemius lateralis (p = 0.008), gastrocnemius medialis (p = 0.000), semitendinosus (p = 0.003) activity, and for semitendinosus under 40 Hz condition (p = 0.001) compared to the non-vibration condition. Furthermore, OMNI-Res was significantly higher for the suspended supine bridge at 25 Hz (p = 0.003) and 40 Hz (p = 0.000) than for the non-vibration condition. Superimposed vibration at 25 Hz elicits a higher neuromuscular response during the suspended supine bridge, and the increase in vibration frequency also raises the OMNI-Res value.
Article
Background: Postural balance represents a fundamental movement skill for the successful performance of everyday and sport-related activities. There is ample evidence on the effectiveness of balance training on balance performance in athletic and non-athletic population. However, less is known on potential transfer effects of other training types, such as plyometric jump training (PJT) on measures of balance. Given that PJT is a highly dynamic exercise mode with various forms of jump-landing tasks, high levels of postural control are needed to successfully perform PJT exercises. Accordingly, PJT has the potential to not only improve measures of muscle strength and power but also balance. Objective: To systematically review and synthetize evidence from randomized and non-randomized controlled trials regarding the effects of PJT on measures of balance in apparently healthy participants. Methods: Systematic literature searches were performed in the electronic databases PubMed, Web of Science, and SCOPUS. A PICOS approach was applied to define inclusion criteria, (i) apparently healthy participants, with no restrictions on their fitness level, sex, or age, (ii) a PJT program, (iii) active controls (any sport-related activity) or specific active controls (a specific exercise type such as balance training), (iv) assessment of dynamic, static balance pre- and post-PJT, (v) randomized controlled trials and controlled trials. The methodological quality of studies was assessed using the Physiotherapy Evidence Database (PEDro) scale. This meta-analysis was computed using the inverse variance random-effects model. The significance level was set at p < 0.05. Results: The initial search retrieved 8,251 plus 23 records identified through other sources. Forty-two articles met our inclusion criteria for qualitative and 38 for quantitative analysis (1,806 participants [990 males, 816 females], age range 9–63 years). PJT interventions lasted between 4 and 36 weeks. The median PEDro score was 6 and no study had low methodological quality (�3). The analysis revealed significant small effects of PJT on overall (dynamic and static) balance (ES = 0.46; 95% CI = 0.32–0.61; p < 0.001), dynamic (e.g., Y-balance test) balance (ES = 0.50; 95% CI = 0.30–0.71; p < 0.001), and static (e.g., flamingo balance test) balance (ES = 0.49; 95% CI = 0.31–0.67; p<0.001). The moderator analyses revealed that sex and/or age did not moderate balance performance outcomes. When PJT was compared to specific active controls (i.e., participants undergoing balance training, whole body vibration training, resistance training), both PJT and alternative training methods showed similar effects on overall (dynamic and static) balance (p = 0.534). Specifically, when PJT was compared to balance training, both training types showed similar effects on overall (dynamic and static) balance (p = 0.514). Conclusion: Compared to active controls, PJT showed small effects on overall balance, dynamic and static balance. Additionally, PJT produced similar balance improvements compared to other training types (i.e., balance training). Although PJT is widely used in athletic and recreational sport settings to improve athletes’ physical fitness (e.g., jumping; sprinting), our systematic review with meta-analysis is novel in as much as it indicates that PJT also improves balance performance. The observed PJT-related balance enhancements were irrespective of sex and participants’ age. Therefore, PJT appears to be an adequate training regime to improve balance in both, athletic and recreational settings.
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Studies comparing children and adolescents from different periods have shown that physical activity and fitness decreased in the last decades, which might have important adverse health consequences such as body fat gain and poor metabolic health. The purpose of the current article is to present the benefits of high-intensity multimodal training (HIMT), such as CrossFit, to young people, with a critical discussion about its potential benefits and concerns. During HIMT, exercise professionals might have an opportunity to promote positive changes in physical function and body composition in children and adolescents, as well as to promote improvements in mental health and psychosocial aspects. Moreover, this might serve as an opportunity to educate them about the benefits of a healthy lifestyle and overcome the perceived barriers for being physically active. In technical terms, the characteristics of HIMT, such as, the simultaneous development of many physical capacities and diversity of movement skills and exercise modalities might be particularly interesting for training young people. Many concerns like an increased risk of injury and insufficient recovery might be easily addressed and not become a relevant problem for this group.
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Collins, KS, Klawitter, LA, Waldera, RW, Mahoney, SJ, and Christensen, BK. Differences in muscle activity and kinetics between the goblet squat and landmine squat in men and women. J Strength Cond Res XX(X): 000-000, 2021-Squat exercise variations are widely used and extensively researched. However, little information exists on the goblet squat (GBS) and landmine squat (LMS) and differences between men and women. This study investigated the differences in muscle activity and kinetics between the GBS and the LMS in 16 men and 16 women. Five repetitions of each squat type were performed loaded at 30% of their body mass. Vertical and anteroposterior ground reaction forces for the eccentric and concentric phases and peak vertical force were recorded with a force plate. Electromyographic (EMG) signals were recorded for the vastus medialis (VM), vastus lateralis (VL), semitendinosus (ST), and biceps femoris (BF). Normalized mean EMG values and ground reaction forces were analyzed with repeated measures analysis of variance (p < 0.05). Significant main effects for squat condition and sex were found. The LMS reduced activity in the quadriceps (VM and VL) muscles and vertical forces, while increasing posterior horizontal forces. In the LMS, men showed decreased ST activity, whereas women had decreased BF activity. Women exhibited greater quadriceps activity in both the GBS and LMS and greater ST in the LMS. Women also produced greater eccentric vertical force in both the GBS and LMS and less posterior horizontal forces in the LMS. The LMS may be useful to balance hamstring to quadriceps activity, increase horizontal loading, and reduce vertical loading. Conversely, the GBS can better target quadriceps activity and increase vertical loading. Sex differences should be considered for training programs that include the GBS and LMS.
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Joint kinetic characteristics during the eccentric phase are important in resistance exercises because eccentric actions with elastic potential energy storage lead to the energy recoil with large joint moment and power generation during the subsequent concentric phase. Previous studies assessed the force production capacity in the barbell hip thrust; however, these were reported by the methodology using only surface electromyographic amplitudes recorded in the lower back and thigh muscles and did not focus on eccentric action. This study aimed to determine kinetic characteristics of lumbosacral, hip and knee joints of sprinters during the eccentric and concentric phases in a barbell hip thrust, compared to those of deadlift and back squat. Eleven well-trained male sprinters participated in this study. Each participant performed two full ranges of motion repetition using their previously determined six-repetition maximum loads. During strength exercises, reflective marker displacements attached to the body and a barbell were captured using 22 high-speed cameras, and ground reaction forces were captured using 4 force plates simultaneously. In the barbell hip thrust, as well as deadlift, the peak values of the lumbosacral and hip extension moments were generated almost immediately after the eccentric phase and were 24% and 42% larger than those in the back squat, respectively. In the knee joint, the largest was the peak extension moment in the back squat (155 ± 28 Nm), followed in order by that in the barbell hip thrust (66 ± 33 Nm) and that in the deadlift (24 ± 27 Nm). These demonstrated that a barbell hip thrust, as well as deadlift, can be a resistance exercise to strengthen the lower back and posterior thigh muscles. Thus, these resistance exercises may be able to be used separately according to their intended purposes, enabling transformations of strength training to specific dynamic motions such as sprint running.
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McCurdy, K, Walker, J, Kelly, C, and Polinski, M. Hip and knee extensor activation during the hip thrust and rear-foot-elevated split squat in trained females. J Strength Cond Res 35(5): 1201-1207, 2021-The aim of the study was to compare hip and knee extensor muscle activation between the hip thrust (HT) and rear-foot-elevated split squat (RFESS) within different depths and the entire range of motion. Twenty, young adult female subjects (age, 20.9 ± 1.3 years; height, 164.6 ± 7.5 cm; mass 63.2 ± 8.8 kg) with an intermediate level of resistance training experience completed the study. Three repetitions were completed at 80% of the 1-repetition maximum. Gluteus maximus, vastus lateralis, and the medial (semitendinosus and semimembranosus) and lateral (biceps femoris) hamstrings electromyographic data were compared at the top, middle, and bottom one-third of the hip range of motion and for the entire repetition. A repeated-measures analysis of variance was used to test significance set at p ≤ 0.05. All 4 muscles revealed higher (p < 0.001) activation at the top position of the HT compared with the middle and bottom, whereas higher scores (p < 0.001) were found in the bottom position during the RFESS. The HT revealed greater activity (p < 0.001) than the RFESS in all muscles at the top, whereas the RFESS showed higher scores (p < 0.001) than the HT in all muscles in the bottom position. For the entire repetition, the RFESS produce significantly greater vastus lateralis activation (59.4 vs 43.6%). The data indicate that the greatest effect for the HT is demonstrated in the top position and at the bottom for the RFESS. Thus, we recommend to implement both exercises in a training program to maximize gluteus maximus and hamstring activation across the full range of motion. For the greatest vastus lateralis activation, the RFESS is recommended.
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