Content uploaded by Isabel Martín Fuentes
Author content
All content in this area was uploaded by Isabel Martín Fuentes on Jun 29, 2020
Content may be subject to copyright.
International Journal of
Environmental Research
and Public Health
Review
Evaluation of the Lower Limb Muscles’
Electromyographic Activity during the Leg Press
Exercise and Its Variants: A Systematic Review
Isabel Martín-Fuentes 1, JoséM. Oliva-Lozano 1and JoséM. Muyor 1, 2,*
1Health Research Centre, University of Almería, 04120 Almería, Spain; imf902@ual.es (I.M.-F.);
jol908@ual.es (J.M.O.-L.)
2Laboratory of Kinesiology, Biomechanics and Ergonomics (KIBIOMER Lab.), Research Central Services,
University of Almería, 04120 Almería, Spain
*Correspondence: josemuyor@ual.es
Received: 4 May 2020; Accepted: 24 June 2020; Published: 27 June 2020
Abstract:
The aim of this study was to analyze the literature on muscle activation measured by
surface electromyography (sEMG) of the muscles recruited when performing the leg press exercise
and its variants. The Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA)
guidelines were followed to report this review. The search was carried out using the PubMed, Scopus,
and Web of Science electronic databases. The articles selected met the following inclusion criteria:
(a) a cross-sectional or longitudinal study design; (b) neuromuscular activation assessed during the
leg press exercise, or its variants; (c) muscle activation data collected using sEMG; and (d) study
samples comprising healthy and trained participants. The main findings indicate that the leg press
exercise elicited the greatest sEMG activity from the quadriceps muscle complex, which was shown
to be greater as the knee flexion angle increased. In conclusion, (1) the vastus lateralis and vastus
medialis elicited the greatest muscle activation during the leg press exercise, followed closely by
the rectus femoris; (2) the biceps femoris and the gastrocnemius medialis showed greater muscular
activity as the knee reached full extension, whereas the vastus lateralis and medialis, the rectus
femoris, and the tibialis anterior showed a decreasing muscular activity pattern as the knee reached
full extension; (3) evidence on the influence of kinematics modifications over sEMG during leg press
variants is still not compelling as very few studies match their findings.
Keywords: electromyography; muscle activity; muscle activation; thigh muscles
1. Introduction
The benefits of strength training [
1
] are strongly associated with different components of physical
and mental health including reduced symptoms of depression, decreased lower back pain, and improved
vascular condition, movement control and bone density as well as enhanced self-esteem, among
others [
2
]. In addition, strength training can lead to significant differences in athletic performance by
promoting greater force production, postural strength, ability to respond to stretch shortening cycles,
and an increasing force development rate, which can result in faster muscle activation [3].
Although the selection of strength training exercises depends on the fitness goals (e.g., hypertrophy,
performance, or injury prevention, among others), muscle activation patterns need to be considered.
This is because greater muscle activation, and with it greater surface electromyographic (sEMG)
amplitude and a greater number of motor units recruited, is normally essential for motor control,
skills improvement, and strength and power development [
4
]. In humans, the force of a muscle
contraction is partly regulated by the number, frequency, and synchronization of the motor units
Int. J. Environ. Res. Public Health 2020,17, 4626; doi:10.3390/ijerph17134626 www.mdpi.com/journal/ijerph
Int. J. Environ. Res. Public Health 2020,17, 4626 2 of 15
recruited [
5
,
6
]. Low threshold motor units are mainly recruited in low intensity exercises, whereas both
low and high threshold motor units are recruited during high intensity exercises [
6
] or low intensity
exercises performed to task failure [7].
Consequently, surface electromyography, which consists of a very sensitive voltmeter that detects
increases and decreases in voltage on the sarcolemma, has become a common research tool in sports
sciences for measuring muscle activation [
8
]. Accordingly, sEMG provides trainers and coaches
with valuable information on electrical activity in muscles, in a simple and non-invasive way [
9
].
For example, sEMG amplitude and power spectral analysis are frequently used to examine muscle
fatigue [
10
]. In this sense, an increase in the sEMG amplitude and a reduction in the sEMG spectral
frequency manifest as the fatigue index increases [11,12].
Different studies have shown that muscle activation varies during multi-joint, lower-body strength
training exercises depending on the intensity [
6
,
12
] and the variants of the exercise itself [
12
]. The leg
press is performed using closed-chain kinetic effort [
13
] and the hip and knee extension involves large
lower-body muscle groups (the quadriceps, hamstring, gluteus, and gastrocnemius) [
14
]. The specific
training of these muscle groups is closely related to jumping, running, and athletic performance
in general [
15
]. Consequently, the leg press exercise is widely used for strengthening the lower
limbs [16–19].
Specifically, the leg press and its variants are some of the exercises studied in the scientific
literature [
14
,
15
,
20
–
22
]. Previous studies have found that the knee flexion angle had a significant effect
on muscle activation in the bilateral leg press [
21
,
22
]. For example, biceps femoris activation increases
towards full knee extension [
21
,
22
], whereas the activation levels of the rectus femoris and vastus
medialis decrease [22].
Additionally, certain variations in technique need to be considered when training using the leg
press and its variants. For instance, feet position on the footplate, regarding lower and higher feet
placement [
14
,
15
] or width stance [
15
] have been some studied variants of leg press. For example,
leg press with high feet placement on the footplate showed higher gluteus maximus activity compared
to low feet placement [
14
]. Conversely, low feet placement elicited greater rectus femoris activity
compared to high feet placement [
14
]. On the contrary, Escamilla et al. (2001) [
15
] reported no
significant differences on muscle activity between low and high feet placement.
With respect to feet rotation, the literature is also not compelling. In this regard, some authors
attributed a preferential activation of vastus medialis to the external feet rotation [
15
,
23
], whereas
others assessed the influence of knee external or internal resistance on vastus medialis during leg
press [
20
,
24
]. Finally, various authors have assessed the influence of exercise intensity on muscle
activity during the leg press exercises [6,12,25].
However, to the best of our knowledge, there is no comprehensive review of the literature on
muscle activity during leg press exercises. The gathering of the current evidence is required to clarify
which leg press exercise variant should be used to activate a specific targeted muscle.
The aim of this study, therefore, was to systematically review the current literature on muscle
activity, measured by sEMG, of muscles recruited when performing the leg press exercise and all
its best-known variants. It may provide athletes and coaches with a useful guide for lower limb
strengthening during leg press exercises and its variants regardless of the training goals.
2. Materials and Methods
Search Protocol
The Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) [
26
] guidelines
were followed to report this systematic review. A prior registration process was also conducted by
the Cochrane Collaboration on the PROSPERO database. The quality of the studies was assessed by
two independent reviewers using the PEDro quality scale; this comprised eleven questions, three of
which were rejected due to their inability to blind trainees and researchers [
27
,
28
]. The protocol for
Int. J. Environ. Res. Public Health 2020,17, 4626 3 of 15
this systematic review was registered on PROSPERO (CRD42020162417) and is available in full on the
National Institute for Health Research’s site.
The literature search was performed using the PubMed, Scopus, and Web of Science electronic
databases from December 2019 to January 2020, and included articles published from the databases’
inception up until December 2019.
The search strategy conducted on the different databases used the following related terms, Medical
Subject Heading (MeSH) descriptors, and keywords: (a) PubMed: (“seated leg press” OR “leg press
machine” OR “leg press” OR “angled leg press”) AND (“resistance training” OR “strength training”
OR “resistance exercise” OR “weight lifting” OR “weight bearing”) AND (electromyography OR EMG
OR “muscle activation” OR “muscle activity” OR “sEMG amplitude” OR “neuromuscular activation”
OR “muscle excitation” OR “muscular activity”); (b) Scopus: (TITLE(“seated leg press” OR “leg press
machine” OR “leg press” OR “angled leg press”) AND (“resistance training” OR “strength training”
OR “resistance exercise” OR “weight lifting” OR “weight bearing”) AND (“electromyography” OR
“EMG” OR “muscle activation” OR “muscle activity” OR “sEMG amplitude” OR “neuromuscular
activation” OR “muscle excitation” OR “muscular activity”)); (c) Web of Science: ALL =((“seated leg
press”* OR “leg press machine”* OR “leg press”* OR “angled leg press”*) AND (“resistance training”*
OR “strength training”* OR “resistance exercise”* OR “weight lifting”* OR “weight bearing”*) AND
(electromyography* OR EMG* OR “muscle activation”* OR “muscle activity”* OR “sEMG amplitude”*
OR “neuromuscular activation”* OR “muscle excitation”* OR “muscular activity”*)).
Each article included had to meet all the following inclusion criteria:
(1)
a cross-sectional or longitudinal study design;
(2)
neuromuscular activation assessed during the leg press exercise or its variants;
(3)
EMG data collected using surface electromyography devices;
(4) study samples including healthy and trained participants older than eighteen years of age (with a
minimum of six months resistance training experience).
Resistance training experience and familiarization with exercises may substantially alter the sEMG
elicited during an exercise; for this reason, we only included studies with trained participants [
2
,
29
–
31
].
Studies that assessed upper-limb muscle activation and studies comparing the leg press exercise to
any other lower-limb strengthening exercises were also considered. Although there were no language
restrictions, all the studies selected were written in English. Publications such as abstracts, theses,
books, book chapters, congress reviews, and articles that were not of minimum quality (according to
the protocol description using the PEDro quality scale) were not considered.
Terminology such as “muscular activity”, “muscle excitation”, “neuromuscular activation” or
“sEMG amplitude” have been used in the literature referring to electrical muscle activity. Due to the
heterogeneity of terms used to describe the same concept, “muscle activation” is used for the current
manuscript report.
Two independent reviewers selected the final articles to be included in the review in accordance
with the inclusion and exclusion criteria. The first step consisted of filtering out duplicates. Next,
the titles and abstracts were assessed, which led to a full text reading where necessary. In the case of
disagreement between the two reviewers, a third reviewer was consulted. The search process lasted
approximately three weeks. The identified articles were downloaded into the EndNote version X9
(Clarivate Analytics, New York, NY, USA) software for the subsequent data extraction process. All the
steps followed are fully described in the flow chart (Figure 1).
Int. J. Environ. Res. Public Health 2020,17, 4626 4 of 15
Int. J. Environ. Res. Public Health 2020, 17, x FOR PEER REVIEW 4 of 14
Figure 1. Flowchart.
The information extracted from the selected articles included the reference, the exercise
movements measured, the sample size (n), the gender, the age (years), the experience (years), the
muscles evaluated, the location of the electrodes, the limb tested (non-dominant/dominant), the
sEMG collection method, the sEMG normalization method, the outcomes, and the main findings.
Finally, the selected studies reported muscle activation for every single exercise and muscle
group separately. Thus, sEMG activity was the main data gathered and sEMG data on concentric and
eccentric phases were collected where available.
It was not possible to perform a meta-analysis of the results because there was insufficient
homogeneity of the methodological strategy and the type of analysis carried out in each study. For
this reason, a qualitative results analysis was conducted for this review.
3. Results
3.1. Search Results
A total of 217 studies were identified from the initial database search. Ninety-four of them were
immediately removed because they were duplicates, leading to a total of 123 records for the title and
the abstract screening process. Twenty-seven studies were selected for full text reading; only twelve
of these met the inclusion criteria and were eventually included in the review (Figure 1). Five studies
were rejected directly because the samples included inexperienced participants. All the study
participants reported a minimum of six months resistance training experience; this is because the
experience time and exercise familiarization variable may significantly affect the muscle activation
elicited during an exercise, hence the importance of having a homogeneous and experienced sample
[30–34].
All the selected studies presented a cross-sectional study design with a randomized exercise
testing order. Information regarding the studies’ general description are presented in Table 1. The
selected studies were published between 2001 and December 2019. In addition, the final studies were
Figure 1. Flowchart.
The information extracted from the selected articles included the reference, the exercise movements
measured, the sample size (n), the gender, the age (years), the experience (years), the muscles evaluated,
the location of the electrodes, the limb tested (non-dominant/dominant), the sEMG collection method,
the sEMG normalization method, the outcomes, and the main findings.
Finally, the selected studies reported muscle activation for every single exercise and muscle group
separately. Thus, sEMG activity was the main data gathered and sEMG data on concentric and eccentric
phases were collected where available.
It was not possible to perform a meta-analysis of the results because there was insufficient
homogeneity of the methodological strategy and the type of analysis carried out in each study. For this
reason, a qualitative results analysis was conducted for this review.
3. Results
3.1. Search Results
A total of 217 studies were identified from the initial database search. Ninety-four of them were
immediately removed because they were duplicates, leading to a total of 123 records for the title and
the abstract screening process. Twenty-seven studies were selected for full text reading; only twelve of
these met the inclusion criteria and were eventually included in the review (Figure 1). Five studies were
rejected directly because the samples included inexperienced participants. All the study participants
reported a minimum of six months resistance training experience; this is because the experience time
and exercise familiarization variable may significantly affect the muscle activation elicited during an
exercise, hence the importance of having a homogeneous and experienced sample [30–34].
All the selected studies presented a cross-sectional study design with a randomized exercise testing
order. Information regarding the studies’ general description are presented in Table 1. The selected
studies were published between 2001 and December 2019. In addition, the final studies were categorized
Int. J. Environ. Res. Public Health 2020,17, 4626 5 of 15
as being of good/excellent quality regarding the methodological and data reporting process, according
to the PEDro quality scale.
The range of motion performed during the leg press exercises ranged from 120
◦
to 0
◦
knee flexion,
with 0
◦
being understood as a full knee extension, except for one study which interpreted 180
◦
as the
full knee extension [
33
]. The intensity performed during the exercises was diverse. In fact, some studies
assessed a number of repetitions ranging between 30% and 90% of 1RM [
6
,
12
,
14
,
16
], some measured a
number of maximum repetitions (xRM) [
1
,
15
,
20
], and others assessed the number of repetitions as x% of
body weight (BW) [
24
,
35
]. In contrast, Hahn (2011) [
22
] performed the exercises at isometric positions.
No unified criteria were found regarding the sEMG normalization method. Although
most studies used the % maximal voluntary isometric contraction (%MVIC) normalization
method
[1,12,15,20,22,24,33–35],
other methods were used such as the % root mean square (%RMS)
normalization method [
14
,
20
] and the average mean rectified voltage (MRV) [
21
], thus making it
difficult to deliver consistent outcomes.
Table 1.
General data regarding the exercises tested, the sample size, the participants’ gender and age,
the training experience time, the surface electromyography (sEMG) collection method, the outcomes,
and the main findings of the selected articles.
References Exercises Tested Sample Age (Years) Experience
(Years)
sEMG
Collection
Method
sEMG Activity
Recorded of
Muscles
Main Findings
Escamilla et al.
(2001) [15]
Squat versus leg press
with different feet
positions and stances
(0◦forefoot abduction,
30◦forefoot abduction
during wide and
narrow stances. Leg
press high and low feet
position)
10 men
Lifters 29.6 ±6.5
10.1 ±7.7 Squat,
9.0 ±8.3 Leg
press
4 reps
12RM
Biceps femoris,
semitendinosus,
vastus medialis,
vastus lateralis,
rectus femoris,
and gastrocnemius
Foot abduction position
did not affect thigh
muscles’ activity during
squat and leg press
exercises.
Bolgla et al.
(2008) [35]
Unilateral leg press
versus step-up,
step-down, straight leg
raise, squat, single leg
stance at 30◦and full
knee extension
8 women
and 7 men
Women
22.2 ±2.9,
men
24.5 ±3.2
Trained, not
specified
3 reps 33%
BW Vastus medialis
Vastus medialis activity
was greater during
unilateral leg press than
the rest of the exercises.
Da Silva et al.
(2008) [14]
Leg press with low foot
placement (LPL), high
foot placement (LPH),
and inclined to 45◦
(LP45)
14 women 21.5 ±1.6 >6 months
5 reps
40%–80%
1RM
Gluteus maximus,
biceps femoris,
vastus lateralis,
rectus femoris,
and gastrocnemius
LPL and LP45 elicited
greater rectus femoris
and gastrocnemius
activity at 40% and 80%
1RM.
LPL elicited greater
rectus femoris and
vastus lateralis activity.
LPH elicited greater
gluteus maximus
activity.
Gorostiaga et
al. (2011) [21]Leg press 13 men 34 ±5Trained, not
specified
5–10reps at
~83% 1RM
Vastus medialis,
vastus lateralis,
and biceps
femoris
Vastus medialis and
vastus lateralis activity
decreased progressively
with extension. Biceps
femoris activity was
higher as extension
increased.
Hahn (2011)
[22]
Leg press at 8 distinct
knee angles (30–100◦)18 men 30 ±6.3 Trained, not
specified
3 sets of 3
reps, 24
contractions
per knee
angle.
Maximal
isometric
contraction
Biceps femoris,
vastus medialis,
rectus femoris,
gastrocnemius
medialis,
and tibialis
anterior
Vastus medialis and
rectus femoris activity
decreased with knee
extension. Gluteus
maximus and biceps
femoris activity
increased with knee
extension. Tibialis
anterior activity
increased with knee
flexion, peaking at
90–100◦knee flexion.
Int. J. Environ. Res. Public Health 2020,17, 4626 6 of 15
Table 1. Cont.
References Exercises Tested Sample Age (Years) Experience
(Years)
sEMG
Collection
Method
sEMG Activity
Recorded of
Muscles
Main Findings
Walker et al.
(2011) [33]
Leg press at 2 s
concentric phase and
leg press with explosive
concentric phase
9 men 29 ±4.1 Trained, not
specified
1 single
rep per
each
technique.
40%–60%–80%
1RM
Biceps femoris,
vastus medialis,
vastus lateralis,
and rectus femoris
Vastus medialis and
vastus lateralis activity
decreased progressively
with extension. Biceps
femoris activity
remained low and
consistent from 40
◦
–120
◦
knee flexion. No
significant differences
were observed, for any
muscle, at any loading
intensity, during
explosive contractions.
Peng et al.
(2013) [24]
Leg press versus leg
press with submaximal
isometric hip adduction
force (LP+), and leg
press with vigorous
isometric hip adduct
force (LP++)
10 men 21.0 ±1.4 Trained, not
specified
3 reps per
exercise.
53 kg +
80% BW
Vastus medialis,
vastus lateralis,
and hip adductor
longus
Greater hip adductor
longus activity during
LP++ for concentric and
eccentric phase.
Schoenfeld et
al. (2014) [12]
Leg press at 75% 1RM
(high load) versus 30%
1RM (low load)
10 men 21.3 ±1.5 Resistance
trained >1 year
30% 1RM
to 75%
1RM sets
to failure
Biceps femoris,
vastus medialis,
vastus lateralis,
and rectus femoris
Greater overall muscle
activation during high
load set. Greater vastus
medialis and vastus
lateralis activity than
biceps femoris.
Gonzalez et al.
(2017) [6]
Leg press to failure 70%
1RM and 90% 1RM 10 men 22.8 ±2.7 4.6 ±1.8 years
70%–90%
1RM reps
to failure
Vastus medialis,
vastus lateralis,
and rectus femoris
Vastus lateralis elicited
greater activity than
rectus femoris,
and rectus femoris
elicited greater activity
than vastus medialis.
Greater overall muscle
activation during 90%
1RM.
Machado et al.
(2017) [20]
Leg press inclined 45◦
(LP45), LP45 with
physio ball between
knees, and LP45 with
elastic band around
knees
13 women 22.5 ±2.9 Trained, not
specified
10 reps
70% 10RM
Biceps femoris,
vastus medialis,
vastus lateralis,
and rectus femoris
Greater vastus medialis
activity during LP45
with physio ball between
knees.
Leg press with elastic
band around knees
increased rectus femoris
activity.
Alkner and
Bring (2019)
[1]
Flywheel leg press,
knee extension
isokinetic
dynamometry, barbell
front squat, weight
stack leg press,
and weight stack knee
extension
8 men 28 ±6Trained, not
specified
8 reps
10RM
Vastus medialis,
vastus lateralis,
and rectus femoris
Flywheel technology
and
isokineticdynamometry
induced higher eccentric
muscle activation
compared to traditional
devices like barbells or
weight stack devices.
Saeterbakken
et al. (2019)
[34]
Leg press, Smith
machine and squat
19
women 24.1 ±4.5 4.5 ±2.0 3 reps
1RM
Rectus abdominis,
oblique external,
and erector spinae
Lower trunk muscle
activation during leg
press. Smith machine
and squat elicited similar
muscle activation.
Exercise abbreviations: LPH, high feet leg press; LPL, low feet leg press; LP45, 45
◦
inclined leg press; LP+, leg press
with isometric hip adduction; LP++, leg press with vigorous isometric hip adduction. Other abbreviations: BW,
body weight; MVIC, maximal voluntary isometric contraction; reps, repetitions; RM, repetition maximum.
3.2. Muscles Assessed During Leg Press Exercises and Variants
In terms of sEMG activity, the vastus lateralis and the vastus medialis of the quadriceps are the
muscles that have most been investigated during the leg press exercise and its variants (10/12 studies).
The rectus femoris is the second most investigated muscle (8/12 studies), followed closely by the
biceps femoris (7/12 studies). The muscles least investigated during leg press exercises include the
gastrocnemius medialis (3/12 studies), and the gluteus maximus and the semitendinosus (1/12 studies
each). Furthermore, only three studies reported muscle activation in the concentric and eccentric phase
separately, and all of these identified greater muscle activation during the concentric phase of the
exercise [1,20,21].
Int. J. Environ. Res. Public Health 2020,17, 4626 7 of 15
Due to the heterogeneity of the sEMG normalization methods, it was considered appropriate to
report the results by grouping the studies into three categories: studies assessing muscle activation
during the leg press exercise (Table 2), studies assessing muscle activation during other leg press
variants (Table 3), and studies comparing the leg press with other exercises.
Table 2. Data on sEMG activity for studies assessing the leg press.
References Exercise Biceps
Femoris
Vastus
Medialis
Vastus
Lateralis
Rectus
Femoris
Gastrocnemius
Medialis
Tibialis
Anterior
Hahn (2011) [
22
]
Leg press 100◦~35% MVIC
mean
~83% MVIC
mean n/a~75% MVIC
mean
~22% MVIC
mean
~70% MVIC
mean
Leg press 90◦~40% MVIC
mean
~80% MVIC
mean n/a~73% MVIC
mean
~26% MVIC
mean
~77% MVIC
mean
Leg press 80◦~32% MVIC
mean
~70% MVIC
mean n/a~74% MVIC
mean
~30% MVIC
mean
~43% MVIC
mean
Leg press 70◦~32% MVIC
mean
~75% MVIC
mean n/a~76% MVIC
mean
~40% MVIC
mean
~22% MVIC
mean
Leg press 60◦~55% MVIC
mean
~77% MVIC
mean n/a~77% MVIC
mean
~53% MVIC
mean
~19% MVIC
mean
Leg press 50◦~78% MVIC
mean
~69% MVIC
mean n/a~60% MVIC
mean
~69% MVIC
mean
~18% MVIC
mean
Leg press 40◦~85% MVIC
mean
~64% MVIC
mean n/a~41% MVIC
mean
~77% MVIC
mean
~19% MVIC
mean
Leg press 30◦~83% MVIC
mean
~50% MVIC
mean n/a~23% MVIC
mean
~89% MVIC
mean
~17% MVIC
mean
Walker et al.
(2011) [33]
Leg press 40%
1RM 100–80◦
~19% MVI
mean n/a n/a~55% MVIC
mean n/a n/a
Leg press 40%
1RM 80–60◦
~19% MVIC
mean n/a n/a~31% MVIC
mean n/a n/a
Leg press 40%
1RM 60–40◦
~22% MVIC
mean n/a n/a~18% MVIC
mean n/a n/a
Leg press 40%
1RM 40–20◦
~25% MVIC
mean n/a n/a~9% MVIC
mean n/a n/a
Leg press 40%
1RM 20–0◦
~37% MVIC
mean n/a n/a~6% MVIC
mean n/a n/a
Leg press 60%
1RM 100–80◦n/a~127% MVIC
mean
~120%
MVIC
mean
n/a n/a n/a
Leg press 60%
1RM 80–60◦n/a~115% MVIC
mean
~105%
MVIC
mean
n/a n/a n/a
Leg press 60%
1RM 60–40◦n/a~98% MVIC
mean
~100%
MVIC
mean
n/a n/a n/a
Leg press 60%
1RM 40–20◦n/a~75% MVIC
mean
~80%
MVIC
mean
n/a n/a n/a
Leg press 60%
1RM 20–0◦n/a~69% MVIC
mean
~45%
MVIC
mean
n/a n/a n/a
Leg press 80%
1RM 100–80◦n/a~150% MVIC
mean
~148%
MVIC
mean
n/a n/a n/a
Leg press 80%
1RM 80–60◦n/a~125% MVIC
mean
~120%
MVIC
mean
n/a n/a n/a
Leg press 80%
1RM 60–40◦n/a~110% MVIC
mean
~120%
MVIC
mean
n/a n/a n/a
Leg press 80%
1RM 40–20◦n/a~100% MVIC
mean
~98%
MVIC
mean
n/a n/a n/a
Leg press 80%
1RM 20–0◦n/a~90% MVIC
mean
~65%
MVIC
mean
n/a n/a n/a
Int. J. Environ. Res. Public Health 2020,17, 4626 8 of 15
Table 2. Cont.
References Exercise Biceps
Femoris
Vastus
Medialis
Vastus
Lateralis
Rectus
Femoris
Gastrocnemius
Medialis
Tibialis
Anterior
Peng et al.
(2013) [24]
Leg press
90–75◦n/a~50% MVIC
mean
~55%
MVIC
mean
n/a n/a n/a
Leg press
75–60◦n/a~37% MVIC
mean
~40%
MVIC
mean
n/a n/a n/a
Leg press
60–45◦n/a~33% MVIC
mean
~37%
MVIC
mean
n/a n/a n/a
Leg press
45–30◦n/a~23% MVIC
mean
~29%
MVIC
mean
n/a n/a n/a
Leg press
30–15◦n/a~19% MVIC
mean
~23%
MVIC
mean
n/a n/a n/a
Leg press
15–0◦n/a~15% MVIC
mean
~21%
MVIC
mean
n/a n/a n/a
Schoenfeld et al.
(2014) [12]
Leg press 30%
1RM
~19% MVIC
peak
~74% MVIC
peak
~70%
MVIC
peak
n/a n/a n/a
Leg press 75%
1RM
~72% MVIC
peak
~210% MVIC
peak
~195%
MVIC
peak
n/a n/a n/a
Gonzalez et al.
(2017) [6]
Leg press 70%
1RM n/a~60% MVIC
mean
~75%
MVIC
mean
~59% MVIC
mean n/a n/a
Leg press 90%
1RM n/a~65% MVIC
mean
~79%
MVIC
mean
~68% MVIC
mean n/a n/a
Abbreviations: MVIC, maximal voluntary isometric contraction; RM, repetition maximum; n/a, not available.
Table 3. Data on sEMG activity in studies comparing the leg press with some of its variants.
References Exercise Medial
Hamstrings
Lateral
Hamstrings
Biceps
Femoris
Vastus
Medialis
Vastus
Lateralis
Rectus
Femoris
Gastrocnemius
Medialis
Gluteus
Maximus
Hip
Adductor
Longus
Escamilla et al.
(2001) [15]
Leg press high
feet narrow
stance
~15% MVIC
peak
~13% MVIC
peak n/a n/a~47% MVIC
peak
~39%
MVIC
peak
~14% MVIC
peak n/a n/a
Leg press high
feet wide stance
~20% MVIC
peak
~16% MVIC
peak n/a n/a~50% MVIC
peak
~33%
MVIC
peak
~15% MVIC
peak n/a n/a
Leg press low
feet narrow
stance
~11% MVIC
peak
~12% MVIC
peak n/a n/a~48% MVIC
peak
~46%
MVIC
peak
~22% MVIC
peak n/a n/a
Leg press low
feet wide stance
~15% MVIC
peak
~12% MVIC
peak n/a n/a~50% MVIC
peak
~37%
MVIC
peak
~22% MVIC
peak n/a n/a
Bolgla et al.
(2008) [35]
Unilateral leg
press n/a n/a n/a41% ±19%
MVIC mean n/a n/a n/a n/a n/a
Da Silva et al.
(2008) [14]
Leg press low
feet 40% 1RM n/a n/a~42%
RMS n/a ~50% RMS ~38%
RMS ~26% RMS ~40%
RMS n/a
Leg press high
feet 40% 1RM n/a n/a~44%
RMS n/a ~50% RMS ~27%
RMS ~38% RMS ~37%
RMS n/a
Leg press
inclined 45
◦
40%
1RM
n/a n/a~46%
RMS n/a ~52% RMS ~48%
RMS ~40% RMS ~39%
RMS n/a
Leg press low
feet 80% 1RM n/a n/a~96%
RMS n/a ~95% RMS ~96%
RMS ~77% RMS ~81%
RMS n/a
Leg press high
feet 80% 1RM n/a n/a~85%
RMS n/a ~81% RMS ~63%
RMS ~40% RMS ~115%
RMS n/a
Leg press
inclined 45
◦
80%
1RM
n/a n/a~81%
RMS n/a ~87% RMS ~87%
RMS ~74% RMS ~100%
RMS n/a
Int. J. Environ. Res. Public Health 2020,17, 4626 9 of 15
Table 3. Cont.
References Exercise Medial
Hamstrings
Lateral
Hamstrings
Biceps
Femoris
Vastus
Medialis
Vastus
Lateralis
Rectus
Femoris
Gastrocnemius
Medialis
Gluteus
Maximus
Hip
Adductor
Longus
Peng et al.
(2013) [24]
Leg press n/a n/a n/a
25.53% ±
8.43% MVIC
mean
31.28% ±
11.83%
MVIC mean
n/a n/a n/a
7.44% ±
4.69%
MVIC
mean
Leg press+n/a n/a n/a
26.53% ±
10.06%
MVIC mean
32.36% ±
12.97%
MVIC mean
n/a n/a n/a
11.12% ±
6.55%
MVIC
mean
Leg press++ n/a n/a n/a
26.77% ±
10.21%
MVIC mean
33.84% ±
14.91%
MVIC mean
n/a n/a n/a
20.83% ±
8.58%
MVIC
mean
Machado et al.
(2017) [20]
Leg press
inclined 45◦n/a n/a~17%
RMS ~80% RMS ~70% RMS ~42%
RMS n/a n/a n/a
Leg press 45◦
with physio ball
between knees
n/a n/a~18%
RMS ~100% RMS ~98% RMS ~39%
RMS n/a n/a n/a
Leg press
inclined 45◦
with elastic
band around
knees
n/a n/a~19%
RMS ~43% RMS ~76% RMS ~63%
RMS n/a n/a n/a
Abbreviations: +, leg press with isometric hip adduction; ++, leg press with vigorous isometric hip adduction; MVIC,
maximal voluntary isometric contraction; RM, repetition maximum; RMS, root mean square; n/a, not available.
3.3. Leg Press Exercises
During the leg press, the horizontal movement ranges from a starting position of approximately
90
◦
knee flexion to a final position with the knees totally extended (close to 0
◦
knee flexion), performed
while maintaining a slightly reclined seating position [22].
The quadriceps muscles, both the vastus medialis and the vastus lateralis, elicited the greatest
muscle activation during the leg press, followed closely by the rectus femoris (Table 2). In addition,
greater overall muscle activation was found for all the muscles as the leg press exercise intensity
increased [6,12,33].
Regardless of the intensity applied during each of the five studies, the muscle activation pattern
during the leg press exercise seemed to be similar for all of them (Table 2). The biceps femoris and
the gastrocnemius medialis tended to show greater muscle activation as the knee extended to its
full position [
12
,
22
,
33
]. On the other hand, different outcomes were found for the vastus lateralis,
the vastus medialis, the rectus femoris of the quadriceps, and the tibialis anterior, showing a decrease
in the muscle activation pattern as the knee reached its full extension [22,24,33].
Therefore, peak sEMG activity was found at approximately 90
◦
knee flexion for the vastus lateralis,
the vastus medialis, and the rectus femoris of the quadriceps, as well as for the tibialis anterior [
22
,
24
,
33
].
Furthermore, the biceps femoris and the gastrocnemius medialis presented their peak sEMG activity at
an angle of 30
◦
knee flexion [
22
,
33
]. Additionally, certain authors reported sEMG activity during single
complete repetitions, without dividing the sEMG activity by the specific knee flexion angle [6,12].
3.4. Leg Press Variants
In addition to the leg press exercise itself, we found studies assessing several leg press
variants. Some of them are the inclined leg press (45
◦
) [
1
,
14
,
20
]; the leg press with extra hip
adduction/abduction [
20
]; and the leg press with different feet height on the footplate (i.e., high
and low), feet stances (i.e., narrow or wide), [
15
] and feet rotations on the footplate (0
◦
–30
◦
external
rotation) [
15
]. The unilateral leg press [
35
] is, to the best of our knowledge, a leg press variant that has
hardly been investigated (Table 1).
For instance, Escamilla et al. (2001) [
15
] assessed the leg press exercise using different feet stance
positions, where leg press variants combining high and low, wide and narrow feet stances, and 0
◦
or
30
◦
feet external rotation were evaluated. The sEMG activity showed no significant differences among
the different feet stances [
15
]. In line with these results, Da Silva et al. (2008) [
14
] also reported no
differences using either high or low feet positions during the leg press. However, as exercise intensity
Int. J. Environ. Res. Public Health 2020,17, 4626 10 of 15
increased to 80% 1RM, the gluteus maximus activity was greater when using the high feet position
during the leg press [14].
An inclined leg press with an inclination angle of 45
◦
(LP45) presented the greatest sEMG activity
for the gluteus maximus [
14
] and for the vastus medialis of the quadriceps [
20
] in comparison to rectus
femoris and biceps femoris [14,20].
When the leg press exercise was performed with extra hip adduction resistance (pressing a
ball between the knees), greater hip adductor longus activity was reported [
24
]. There was also
slightly greater vastus medialis activity reported during the leg press exercise with extra hip adduction
resistance compared to the standard leg press [
20
]. Otherwise, leg press with hip abduction (elastic
band around knees) significantly reduced the sEMG elicited by vastus medialis of the quadriceps in
comparison to the standard leg press [20].
Finally, greater vastus medialis activity was found during the unilateral leg press exercise than
during other unilateral weight-bearing exercises, such as the step-up, step-down, or straight leg
raise [35].
4. Discussion
The main aim of the present study was to systematically review the current literature on muscle
activation, measured with sEMG, of the muscles recruited when performing the leg press exercise and
all its most known variants.
The relevant outcomes gathered from the literature revealed that the vastus
medialis
[1,6,12,15,20–22,24,33,35]
and the vastus lateralis of the quadriceps [
1
,
6
,
11
–
15
,
27
] were the
most studied muscles when performing the leg press exercise and its common variants, followed closely
by the rectus femoris of the quadriceps muscles [
1
,
6
,
12
,
14
,
15
,
20
,
22
,
33
]. After this, the musculature
activated most during leg press exercises were the muscles of the quadriceps complex, mainly the
vastus medialis and the vastus lateralis. Indeed, this is the case for almost all the leg press variants
studied [12,22,33].
Only three of the thirteen studies analyzed the sEMG data separately for each phase, reporting
that concentric sEMG activity was greater than eccentric phase sEMG activity [
1
,
20
,
21
]. In the current
literature, it has been widely stated that sEMG activity could significantly differ between the concentric
and eccentric phase [
36
–
38
]. Thus, future studies using sEMG should seriously consider performing
such subdivisions in their research.
4.1. Methodological Gaps Between the Studies
Diversity among the sEMG normalization methods was one of the most difficult issues to deal with
in this review. Five different normalization methods were found among the selected studies (%MVIC,
%RMS, MRV, RMS, and microvolts-
µ
V), making it difficult to deliver consistent outcomes. Furthermore,
the intensity at which exercises were performed was likewise diverse. Muscular activation is directly
dependent on intensity, so wide differences in sEMG values could be seen when performing the same
exercise but at different relative intensities [
6
,
11
,
13
,
27
]. Therefore, the intensity normalization method
should be standardized when comparing several exercises from among the studies in order to achieve
conclusive outcomes. For instance, apparently a ~70% 1RM intensity normalized as %MVIC might
be set as an appropriate intensity for the strength training electromyographic studies [
6
,
12
,
14
,
33
,
34
].
Besides the disparities regarding the intensity and the sEMG normalization methods used in the studies
included in the review, some other differences were found regarding the methodological process.
Even though the well-known Surface ElectroMyoGraphy for the Non-Invasive Assessment of
Muscles (SENIAM) guidelines were followed in many studies [
11
,
15
,
16
,
27
], the criteria for electrode
placement were varied. While certain studies did not even report any of the statements or guidelines
followed [
1
,
6
,
35
], others followed the Cram guidelines [
20
,
24
], and some followed previously reported
recommendations [
14
,
15
]. Nevertheless, surface electromyography data were collected during the
same session for every study included in the review with the aim of avoiding electrode placement bias.
Int. J. Environ. Res. Public Health 2020,17, 4626 11 of 15
The sample sizes ranged between eight and eighteen subjects. Only three studies had a female
sample [
14
,
20
,
34
], and just one evaluated a mixed sample [
35
]. More studies that include women are
needed given the notable anthropometric and biomechanical differences between the sexes; muscle
activation differences could also be found [39–41].
Finally, the inability of blinding trainees and researchers during measurements could be taken as
a limitation for the data processing. However, this is an issue that is expected to have been controlled
within every single study included into the review [27,28].
4.2. Leg Press Exercises
Studies gathered assessing sEMG during leg press agreed on the greatest sEMG activity elicited
by vastus medialis and vastus lateralis in comparison to the rest of the muscles [
6
,
12
,
33
]. Although
exercise intensity was in some studies slightly different, a greater overall sEMG muscle activity was
observed for higher intensities compared to lower intensities [
6
,
12
,
22
,
24
,
33
]. As mentioned above,
it is always advisable to consider exercise intensity during sEMG studies. Our findings provided
useful information regarding sEMG muscle pattern during the leg press and peak sEMG activity of
the muscles. Regardless of exercise intensity, vastus medialis, vastus lateralis, rectus femoris of the
quadriceps, and tibialis anterior showed a decreased muscle activity as the knee extended to its full
extension. Moreover, those muscles apparently showed their peak activity at an angle of 90
◦
of the
knee [
22
,
24
,
33
], whereas biceps femoris and gastrocnemius medialis increased their muscle activity
as the knee extended, showing their peak muscle activity at an angle of 30
◦
knee flexion [
12
,
22
,
33
].
This should be taken as key information in order to choose not only the best exercise for the individual
case, but also the best range of motion when the aim is to target a specific muscle. For example,
this knowledge is indispensable for injury prevention or return to play training programs, where
ranges of motion are sometimes reduced or muscle activity must be controlled to ensure an appropriate
recovery [41,42].
4.3. Leg Press Variants
Escamilla et al. (2001) [
15
] compared several leg press variants, and combined height feet
placement (low and high), feet stance (wide and narrow), and feet abduction (0
◦
–30
◦
), concluding
that the feet position did not affect thigh muscle activation in any of the tested variants. Thus, they
recommended an individual self-selected comfortable feet position during the leg press exercise [
15
].
However, the intensity performed during sEMG data collection was very low (4 repetitions at 12RM
intensity), which might have underestimated the findings [
15
]. More research should be conducted
analyzing higher exercise intensities during the measurements.
On the other hand, some outcomes suggested that the muscle activation in the leg press with low
foot placement (LPL) differed slightly from the muscle activation in the 45
◦
inclined leg press. In this
sense, the leg press with high foot placement (LPH) elicited greater gluteus maximus [
14
] and greater
hamstring muscle activity [
15
] compared to the 45
◦
inclined leg press exercise. Even though posterior
thigh muscle activation is not the focus when performing leg press exercises, LPH could be performed,
for instance, when one needs to decrease the intensity of the anterior thigh muscle activity during leg
press exercise (e.g., for injury prevention) [35].
Furthermore, the leg press with extra hip adduction load (LP+/LP++) was found to be an
interesting alternative when the target was to significantly increase medial thigh muscle activity,
specifically hip adductor longus activation, by adding a ball between the knees to press [
24
]. Executing
the leg press inclined at 45
◦
with a physio ball between the knees (LP45BALL) also means increasing
medial thigh muscle activity, in this case vastus medialis activation, compared to the standard leg
press exercise [
20
]. Similarly, the unilateral leg press exercise showed great vastus medialis muscle
activation. Although the unilateral leg press offers an interesting alternative to the standard leg press
when the aim is to provide a functional perspective for the training program with transfer into daily
activities (e.g., walking or climbing stairs) [
35
], one should consider the differences in absolute intensity
Int. J. Environ. Res. Public Health 2020,17, 4626 12 of 15
that this unilateral exercise permits [
35
]. Overall, given that the literature on this topic remains scarce,
outcomes need to be interpreted with caution.
4.4. Comparison of the Leg Press with Other Exercises
Although our aim did not cover exercises different from leg press and its variants, it would be
interesting to outline some outcomes found within the studies included which compared leg press
exercises and its variants to other exercises.
Bolgla et al. (2008) [
35
] concluded that the unilateral leg press elicited greater muscle activation
for the vastus medialis of the quadriceps compared to other weight-bearing exercises such as the
step-up, step-down, straight leg raise, air squat, or single leg stance. Consequently, the unilateral leg
press could be the exercise of choice when targeting the vastus medialis during unilateral exercises.
In general terms, muscular activity increases as stability decreases. For instance, weight stack
devices (e.g., the leg press machine) tend to facilitate exercise performance, which reduces the possibility
of some synergist muscles taking part in the exercise [
1
,
14
]. Therefore, each exercise variant should
be chosen based on the training goal. For example, different studies exposed leg press exercise as an
optimal alternative within acute phases of rehabilitation and the return to play context in comparison
to free weights, due to the movement stability [2,42,43].
We also found a study comparing the barbell front squat to several devices such as the flywheel
leg press, the isokinetic knee extension dynamometer, the weight stack leg press, and the weight stack
leg extension machine. The results showed that training using flywheel technology and isokinetic
dynamometry provokes higher muscle activation (mainly during the eccentric phase of the movement)
than traditional devices such as weight stack devices (the leg press) or barbells [1].
5. Conclusions
After performing the current systematic review, the following conclusions were reached:
(1)
The vastus lateralis and vastus medialis of the quadriceps are the most investigated muscles in
the leg press exercise and its variants (10/12 studies). The rectus femoris is the next most studied
muscle (8/12 studies), followed closely by the biceps femoris (7/12 studies).
(2)
The vastus medialis and vastus lateralis elicited the greatest muscle activation during the leg
press exercise, followed closely by the rectus femoris.
(3)
The biceps femoris and gastrocnemius medialis tended to show greater muscular activity as the
knee extended to full extension, whereas the vastus lateralis, vastus medialis, rectus femoris of
the quadriceps, and tibialis anterior showed a decrease in the muscular activity pattern as the
knee reached its full extension.
(4) Greater muscle activation during the concentric phase of the exercise was found when these phases
were electromyographically identified. This subdivision should be considered in future research.
(5)
The participants’ training status and resistance training experience must be reported in detail.
(6)
The sEMG normalization method, the intensity during data collection, the electrode placement,
and the sample size and gender should all be standardized to obtain conclusive outcomes.
(7)
It still remains unclear whether kinematics modifications such as knee external or internal
resistance added, different feet stances, feet height, or feet rotations on the footplate may modify
the sEMG elicited. More research is needed to investigate the different feet stances during the leg
press exercise and its variants.
6. Practical Applications
The leg press is a well-known exercise performed in the fitness environment, used mainly to
strengthen the lower limbs. It involves large lower-body muscle groups (the quadriceps, hamstring,
gluteus, and gastrocnemius) and, as a closed-chain kinetic movement, it is closely related to jumping,
running, and athletic performance in general.
Int. J. Environ. Res. Public Health 2020,17, 4626 13 of 15
Regardless of the leg press performed, the quadriceps muscles elicited the greatest muscle
activation, principally the vastus medialis and vastus lateralis, followed closely by the rectus femoris.
These muscles showed their greatest sEMG peak activity at a specific angle of 90
◦
knee flexion, and the
sEMG activity decreased as the knee reached its full extension. In contrast, the biceps femoris increased
its sEMG activity progressively from 90
◦
to 0
◦
knee extension. This is key information in the injury
prevention and return to play context, where the activation of target muscles at particular knee flexion
degrees becomes indispensable information.
Regarding leg press variant exercises, findings are more controversial. Overall, results pointed
out that the influence of the leg press kinematics modifications on the sEMG elicited is not fully clear.
Although some studies cover some leg press variants, more research should be conducted in order
to deliver consistent guidelines. However, we support the idea that a preferred self-selected feet
stance should be encouraged, at least until there is strong evidence reporting a beneficial use of the
so-called variants.
Furthermore, considering that several exercises currently exist that comprise large lower-body
muscle groups, trainers, coaches and practitioners should also bear in mind that weight stack devices
make it possible to train at high intensities while reducing the risk of injury to the athlete. Therefore,
the leg press exercise and its variants could be exercises of choice for any strength training program,
independent of the training goal.
Author Contributions:
Conceptualization, I.M.-F. and J.M.M.; methodology, I.M.-F., J.M.O.-L., and J.M.M.;
validation, I.M.-F., J.M.O.-L., and J.M.M.; investigation, I.M.-F. and J.M.M.; resources, I.M.-F. and J.M.M.;
data curation, I.M.-F., J.M.O.-L., and J.M.M.; writing—original draft preparation, I.M.-F.; writing—review and
editing, I.M.-F., J.M.O.-L., and J.M.M.; visualization, I.M.-F., J.M.O.-L., and J.M.M.; supervision, J.M.M.; project
administration, J.M.M. All authors have read and agreed to the published version of the manuscript.
Funding:
This research was funded by the Proyectos I+D+I Ministerio de Econom
í
a y Competitividad, Gobierno
de España, Grant number DEP 2016-80296-R (AEI/FEDER, UE). Isabel Mart
í
n-Fuentes was supported by a
scholarship funded by the Spanish Ministry of Science, Innovation and Universities, grant number FPU17/03787.
Jos
é
M. Oliva-Lozano was supported by a scholarship funded by the Spanish Ministry of Science, Innovation and
Universities, grant number FPU18/04434.
Conflicts of Interest: The authors declare no conflict of interest.
References
1.
Alkner, B.A.; Bring, D.K. Muscle activation during gravity-independent resistance exercise compared to
common exercises. Aerosp. Med. Hum. Perform. 2019,90, 506–512. [CrossRef] [PubMed]
2. Westcott, W.L. Resistance training is medicine. Curr. Sports Med. Rep. 2012,11, 209–216. [CrossRef]
3.
DeWeese, B.H.; Hornsby, G.; Stone, M.; Stone, M.H. The training process: Planning for strength–power
training in track and field. Part 1: Theoretical aspects. J. Sport Health Sci. 2015,4, 308–317. [CrossRef]
4.
Schoenfeld, B.J.; Peterson, M.D.; Ogborn, D.; Contreras, B.; Sonmez, G.T. Effects of low vs. high load
resistance training on muscle strength and hypertrophy in well-trained men. J. Strength Cond. Res.
2015
,29,
2954–2963. [CrossRef] [PubMed]
5.
Fuglsang-Frederiksen, A.; Rønager, J. The motor unit firing rate and the power spectrum of EMG in humans.
Electroencephalogr. Clin. Neurophysiol. 1988,70, 68–72. [CrossRef]
6.
Gonzalez, A.M.; Ghigiarelli, J.J.; Sell, K.M.; Shone, E.W.; Kelly, C.F.; Mangine, G.T. Muscle activation during
resistance exercise at 70% and 90% 1-repetition maximum in resistance-trained men. Muscle Nerve
2017
,56,
505–509. [CrossRef] [PubMed]
7.
Morton, R.W.; Sonne, M.W.; Farias Zuniga, A.; Mohammad, I.Y.Z.; Jones, A.; McGlory, C.; Keir, P.J.; Potvin, J.R.;
Phillips, S.M. Muscle fibre activation is unaffected by load and repetition duration when resistance exercise
is performed to task failure. J. Physiol. 2019,597, 4601–4613. [CrossRef]
8.
Stegeman, D.; Hermens, H.J. Standards for suface electromyography: The European project surface EMG for
non-invasive assessment of muscles (SENIAM). Enschede Roessingh Res. Dev. 2007,1, 108–112.
9.
Vigotsky, A.D.; Halperin, I.; Lehman, G.J.; Trajano, G.S.; Vieira, T.M. Interpreting signal amplitudes in surface
electromyography studies in sport and rehabilitation sciences. Front. Physiol. 2018,8, 985. [CrossRef]
Int. J. Environ. Res. Public Health 2020,17, 4626 14 of 15
10.
Farina, D.; Merletti, R.; Enoka, R.M. The extraction of neural strategies from the surface EMG. J. Appl. Physiol.
2004,96, 1486–1495. [CrossRef]
11.
Hunter, S.K.; Duchateau, J.; Enoka, R.M. Muscle fatigue and the mechanisms of task failure. Exerc. Sport
Sci. Rev. 2004,32, 44–49. [CrossRef] [PubMed]
12.
Schoenfeld, B.J.; Contreras, B.; Willardson, J.M.; Fontana, F.; Tiryaki-Sonmez, G. Muscle activation during
low versus high load resistance training in well-trained men. Eur. J. Appl. Physiol.
2014
,114, 2491–2497.
[CrossRef] [PubMed]
13.
Ivey, F.M.; Prior, S.J.; Hafer-Macko, C.E.; Katzel, L.I.; Macko, R.F.; Ryan, A.S. Strength training for skeletal
muscle endurance after stroke. J. Stroke Cerebrovasc. Dis. 2017,26, 787–794. [CrossRef]
14.
Da Silva, E.M.; Brentano, M.A.; Cadore, E.L.; De Almeida, A.P.V.; Kruel, L.F.M. Analysis of muscle activation
during different leg press exercises at submaximum effort levels. J. Strength Cond. Res.
2008
,22, 1059–1065.
[CrossRef]
15.
Escamilla, R.F.; Fleisig, G.S.; Zheng, N.; Lander, J.E.; Barrentine, S.W.; Andrews, J.R.; Bergemann, B.W.;
Moorman, C.T. Effects of technique variations on knee biomechanics during the squat and leg press. Med. Sci.
Sports Exerc. 2001,33, 1552–1566. [CrossRef] [PubMed]
16.
Rossi, F.E.; Schoenfeld, B.J.; Ocetnik, S.; Young, J.; Vigotsky, A.; Contreras, B.; Krieger, J.W.; Miller, M.G.;
Cholewa, J. Strength, body composition, and functional outcomes in the squat versus leg press exercises.
J. Sports Med. Phys. Fitness 2018,58, 263–270. [CrossRef] [PubMed]
17.
da R. Orssatto, L.B.; de Moura, B.M.; Sakugawa, R.L.; Radaelli, R.; Diefenthaeler, F. Leg press exercise
can reduce functional hamstring: Quadriceps ratio in the elderly. J. Bodyw. Mov. Ther.
2018
,22, 592–597.
[CrossRef]
18.
Monteiro, E.R.; Steele, J.; Novaes, J.S.; Brown, A.F.; Cavanaugh, M.T.; Vingren, J.L.; Behm, D.G. Men exhibit
greater fatigue resistance than women in alternated bench press and leg press exercises. J. Sports Med.
Phys. Fitness 2019,59, 238–245. [CrossRef]
19.
Harden, M.; Wolf, A.; Russell, M.; Hicks, K.M.; French, D.; Howatson, G. An evaluation of supramaximally
loaded eccentric leg press exercise. J. Strength Cond. Res. 2018,32, 2708–2714. [CrossRef]
20.
Machado, W.; Paz, G.; Mendes, L.; Maia, M.; Winchester, J.B.; Lima, V.; Willardson, J.M.; Miranda, H.
Myoeletric activity of the quadriceps during leg press exercise performed with differing techniques.
J. Strength Cond. Res. 2017,31, 422–429. [CrossRef]
21.
Gorostiaga, E.M.; Navarro-Amezqueta, I.; Gonzalez-Izal, M.; Malanda, A.; Granados, C.; Ibanez, J.; Setuain, I.;
Izquierdo, M. Blood lactate and sEMG at different knee angles during fatiguing leg press exercise. Eur. J.
Appl. Physiol. 2012,112, 1349–1358. [CrossRef] [PubMed]
22.
Hahn, D. Lower extremity extension force and electromyography properties as a function of knee angle and
their relation to joint torques: Implications for strength diagnostics. J. Strength Cond. Res.
2011
,25, 1622–1631.
[CrossRef] [PubMed]
23.
Smith, T.O.; Bowyer, D.; Dixon, J.; Stephenson, R.; Chester, R.; Donell, S.T. Can vastus medialis oblique be
preferentially activated? A systematic review of electromyographic studies. Physiother. Theory Pract.
2009
,
25, 69–98. [CrossRef] [PubMed]
24.
Peng, H.-T.; Kernozek, T.W.; Song, C.-Y. Muscle activation of vastus medialis obliquus and vastus lateralis
during a dynamic leg press exercise with and without isometric hip adduction. Phys. Ther. Sport
2013
,14,
44–49. [CrossRef]
25.
Clark, D.R.; Lambert, M.I.; Hunter, A.M. Trunk muscle activation in the back and hack squat at the same
relative loads. J. Strength Cond. Res. 2017,33, S60–S69. [CrossRef]
26.
Moher, D.; Liberati, A.; Tetzlaff, J.; Altman, D.G. Prisma Group Preferred reporting items for systematic
reviews and meta-analyses: The PRISMA statement. J. Clin. Epidemiol. 2009,6, 1006–1012. [CrossRef]
27.
Neto, W.K.; Vieira, T.L.; Gama, E.F. Barbell hip thrust, muscular activation and performance: A systematic
review. J. Sports Sci. Med. 2019,18, 198–206.
28.
Mart
í
n-Fuentes, I.; Oliva-Lozano, J.M.; Muyor, J.M. Electromyographic activity in deadlift exercise and its
variants. A systematic review. PLoS ONE 2020,15, 1–18. [CrossRef]
29.
Westcott, W.; Winett, R.; Annesi, J.; Wojcik, J.; Anderson, E.; Madden, P. Prescribing physical activity:
Applying the ACSM protocols for exercise. Physician Sportsmed. 2009,37, 51–58. [CrossRef]
Int. J. Environ. Res. Public Health 2020,17, 4626 15 of 15
30.
Calatayud, J.; Vinstrup, J.; Jakobsen, M.D.; Sundstrup, E.; Colado, J.C.; Andersen, L.L. Mind-muscle
connection training principle: Influence of muscle strength and training experience during a pushing
movement. Eur. J. Appl. Physiol. 2017,117, 1445–1452. [CrossRef]
31.
Rutherford, O.M.; Jones, D.A. The role of learning and coordination in strength training. Eur. J. Appl. Physiol.
Occup. Physiol. 1986,55, 100–105. [CrossRef] [PubMed]
32.
Wulf, G. Attentional focus and motor learning: A review of 15 years. Int. Rev. Sport Exerc. Psychol.
2013
,6,
77–104. [CrossRef]
33.
Walker, S.; Peltonen, H.; Avela, J.; Hakkinen, K. Kinetic and electromyographic analysis of single repetition
constant and variable resistance leg press actions. J. Electromyogr. Kinesiol. 2011,21, 262–269. [CrossRef]
34.
Saeterbakken, A.H.; Stien, N.; Pedersen, H.; Andersen, V. Core muscle activation in three lower extremity
with different stability requirements. J. Strength Cond. Res. 2019, 1–6. [CrossRef] [PubMed]
35.
Bolgla, L.A.; Shaffer, S.W.; Malone, T.R. Vastus medialis activation during knee extension exercises: Evidence
for exercise prescription. J. Sport Rehabil. 2008,17, 1–10. [CrossRef]
36.
Ono, T.; Okuwaki, T.; Fukubayashi, T. Differences in activation patterns of knee flexor muscles during
concentric and eccentric exercises. Res. Sports Med. 2010,18, 188–198. [CrossRef]
37.
Matheson, J.W.; Kernozek, T.W.; Fater, D.C.; Davies, G.J. Electromyographic activity and applied load during
seated quadriceps exercises. Med. Sci. Sports Exerc. 2001,33, 1713–1725. [CrossRef]
38.
Komi, P.V.; Linnamo, V.; Silventoinen, P.; Sillanpää, M. Force and EMG power spectrum during eccentric and
concentric actions. Med. Sci. Sports Exerc. 2000,32, 1757–1762. [CrossRef]
39.
Bouillon, L.E.; Wilhelm, J.; Eisel, P.; Wiesner, J.; Rachow, M.; Hatteberg, L. Electromyographic assessment of
muscle activity between genders during unilateral weight-bearing tasks using adjusted distances. Int. J.
Sports Phys. Ther. 2012,7, 595–605.
40.
Schwanbeck, S.R.; Cornish, S.; Barss, T.; Chilibeck, P.D. Effects of training with free weights versus machines
on muscle mass, strength, free testosterone and free cortisol levels. J. Strength Cond. Res.
2020
,34, 1851–1859.
[CrossRef]
41.
Khaiyat, O.A.; Norris, J. Electromyographic activity of selected trunk, core, and thigh muscles in commonly
used exercises for ACL rehabilitation. J. Phys. Ther. Sci. 2018,30, 642–648. [CrossRef] [PubMed]
42.
Trevino, M.A.; Herda, T.J. The effects of training status and muscle action on muscle activation of the vastus
lateralis. Acta Bioeng. Biomech. 2015,17, 107–114. [CrossRef] [PubMed]
43.
El-Ashker, S.; Chaabene, H.; Prieske, O.; Abdelkafy, A.; Ahmed, M.A.; Muaidi, Q.I.; Granacher, U. Effects of
neuromuscular fatigue on eccentric strength and electromechanical delay of the knee flexors: The role of
training status. Front. Physiol. 2019,10, 782. [CrossRef] [PubMed]
©
2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access
article distributed under the terms and conditions of the Creative Commons Attribution
(CC BY) license (http://creativecommons.org/licenses/by/4.0/).
