The Biomechanics of the Push-up

Abstract

THE PUSH-UP IS WIDELY USED BY FITNESS PROFESSIONALS TO DEVELOP UPPER-BODY STRENGTH, POWER, AND LOCAL MUSCULAR ENDURANCE. ALTHOUGH THE LOAD DURING A PUSH-UP IS LIMITED BY AN INDIVIDUAL'S BODYWEIGHT AND ANTHROPOMETRY, MANY BIOMECHANICAL VARIATIONS OF THE EXERCISE CAN BE PERFORMED. THESE VARIATIONS MAY INVOLVE ALTERING HAND AND FOOT POSITIONS, WHICH IMPACTS MUSCLE RECRUITMENT PATTERNS AND JOINT STRESSES. THE IMPLICATIONS OF THESE VARIATIONS MAY BE OVERLOOKED WITH RESPECT TO THE INDIVIDUAL NEEDS AND GOALS OF THE CLIENT.

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COLUMN EDITOR: Paul Sorace, MS, RCEP, CSCS*
The Biomechanics of the
Push-up: Implications for
Resistance Training
Programs
Bret Contreras, MA, CSCS,
1
Brad Schoenfeld, MSc, CSCS, NSCA-CPT,
2
Jonathan Mike, USAW, CSCS, NSCA-CPT,
3
Gul Tiryaki-Sonmez, PhD,
4
John Cronin, PhD,
5
and Elsbeth Vaino, BS, CSCS
6
1
Department of Sport Science, Auckland University of Technology, Auckland, New Zealand;
2
Department of Exercise
Science, Lehma n College, Bronx, New York;
3
University of New Mexico, Albuquerque, New Mexico;
4
Department of
Health Science, City University of New York, Lehman College, Queens, New York;
5
Sports Performance Research
Institute, Auckland University of Technology, Auckland, New Zealand; and
6
Ottawa Osteopathy and Sports Therapy,
Ottawa, Canada
SUMMARY
THE PUSH-UP IS WIDELY USED BY
FITNESS PROFESSIONALS TO
DEVELOP UPPER-BODY
STRENGTH, POWER, AND LOCAL
MUSCULAR ENDURANCE.
ALTHOUGH THE LOAD DURING A
PUSH-UP IS LIMITED BY AN INDI-
VIDUAL’S BODYWEIGHT AND
ANTHROPOMETRY, MANY BIOME-
CHANICAL VARIATIONS OF THE
EXERCISE CAN BE PERFORMED.
THESE VARIATIONS MAY INVOLVE
ALTERING HAND AND FOOT POSI-
TIONS, WHICH IMPACTS MUSCLE
RECRUITMENT PATTERNS AND
JOINT STRESSES. THE IMPLICA-
TIONS OF THESE VARIATIONS MAY
BE OVERLOOKED WITH RESPECT
TO THE INDIVIDUAL NEEDS AND
GOALS OF THE CLIENT.
INTRODUCTION
T
he push-up has long been advo-
cated as a means to assess local
muscular endurance of the upper
body . A variety of timed and untimed
push-up tests are commonly employed
as part of a fitness assessment, and these
tests have been validated across a wide
range of populations (23). Moreover,
research shows a high correlation
between push-up ability and the number
of bench press repetitions performed as
a percentage of body weight (1), thus
providing an efficient and inexpensive
alternative to free weight testing.
In fitness settings, push-ups are widely
used to develop upper-body strength,
power, and muscular endurance. They
are staple exercises in fitness and gym
classes; they are used by strength and
conditioning professionals to train
athletes in sports such as baseball (10),
boxing (22), and martial arts (13), and
they play a prominent role in the basic
training programs of the U.S. Military
(18). Plyometric push-ups are consid-
ered essential for optimizing stretch-
shortening cycle–induced adaptations
for the upper body (21).
Although the load during a push-up is
limited by an individual’s bodyweight
and anthropometry, many biomechan-
ical variations of the exercise can be
performed to alter muscle activity by
providing either a lesser or greater
challenge to the target musculature.
These variations most often involve
altering hand and foot positions, which
impacts muscle recruitment patterns
and joint stresses (3,15). Other varia-
tions include using various implements
such as unstable surfaces, suspension
training devices, and specially designed
Copyright Ó National Strength and Conditioning Association Strength and Conditioning Journal | www.nsca-scj.com
41

push-up equipment. However, the
implications of these variations often
are not well understood with respect
to the individual needs and goals of
the client. Therefore, the purpose of
this column is 2-fold: first, to examine
the research pertaining to the biome-
chanical aspects of the push-up;
second, to make practical recommen-
dations for their application to exercise
performance.
THE BIOMECHANICS OF THE
PUSH-UP
The standard push-up requires a general
stiffening of the knee joints, hip joints,
pelvis,andspinetokeepthebodyin
a straight line from head to feet while
the shoulders and elbows flex and
extend to raise and lower the body
and the scapulae retract and protract
to facilitate glenohumeral range of
motion. Table 1 showcases biomechan-
ical data found in the literature regard-
ing the standard push-up exercise.
Push-ups can be performed with a mul-
titude of variations to bring about dif-
ferent muscular recruitment patterns.
The knee push-up shortens the lever,
which reduces bodyweight loading to
54% in the top position and 62% in the
bottom position (19) and substantially
reduces prime mover (9) and core mus-
culature requirements (11).
Perhaps the most popular variations
are achieved by altering hand position.
Although a number of potential hand
positions exist, the most common clas-
sifications include wide base (15 0%
shoulder width), normal base (shoul-
der width), and narrow base (50%
shoulder width) (9). It is commonly
believed that the wide base activates
the pectoralis major to a greater degree
than the other positions, whereas the
narrow base optimizes the activation of
the triceps brachii (8). This is consistent
with the basic principles of applied anat-
omy. Specifically, the pectoralis major is
a primary horizontal flexor, and flaring
the elbows would seemingly improve
the muscle’s length-tension relationship,
thereby facilitating its ability to generate
greater force (12). On the other hand,
a narrow base with the elbows held
close to the body would place the pec-
torals in a biomechanically disadvanta-
geous position, thus requiring greater
force output from the triceps brachii.
However, electromyographic (EMG)
studies evaluating muscle recruitment
patterns during push-up performance
Table 1
Biomechanical data pertaining to the standard push-up
Relative load 69% of bodyweight in top position (2)
75% of bodyweight in bottom
position (2)
Compressive spinal loading on L4/L5 1,838 N (1)
Prime mover mean muscle activation normalized to maximum voluntary contraction Pectoralis major 61% (1)
Triceps brachii 66% (1)
Anterior deltoid 42% (1)
Upper-body stabilizer and synergist muscle activation normalized to maximum voluntary
contraction
Latissimus dorsi 11% (1)
Biceps brachii 4% (1)
Posterior deltoid 17% (4)
Upper trapezius 45% (3)
Middle trapezius 18% (3)
Lower trapezius 27% (3)
Serratus anterior 56% (3)
Core muscle activation normalized to maximum voluntary contraction Psoas 24% (1)
External oblique 29% (1)
Internal oblique 10% (1)
Transverse abdominis 9% (1)
Rectus abdominis 29% (1)
Rectus femoris 10% (1)
Erector spinae 3% (1)
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suggest that narrow base push-ups not
only elicit greater activation of the tri-
ceps brachii compared with the wide
base position but also promote superior
activation of the sternal head of the pec-
toralis major as well (4,9).
What is not clear in these studies is
whether performance was carried out
in the transverse plane (i.e., elbows
flared) or the sagittal plane (i.e., elbow
close to the body). Contrary to popu-
lar belief, when the hands are placed in
a very narrow position, it tends to
encourage flaring of the elbows, orient-
ing movement into the transverse
plane. If these studies did indeed show
greater activity of the sternal head in
the sagittal plane, further research is
warranted to clarify the reason for this
apparent paradox. Moreover, given
that the clavicular head of the pector-
alis major is a primary shoulder flexor
(17), it can be theorized that push-ups
performed in the sagittal plane would
maximize the activity of this portion of
the muscle. To the authors’ knowledge,
this has yet to be investigated.
In addition, shifting the torso forward
or rearward relative to the hands
Figure 1. Standard push-up.
Figure 2. Upper-body suspended push-
up.
Figure 3. Between-bench push-up.
Figure 4. Self-assisted one-arm push-up.
Table 2
Push-up variations for novice, intermediate, and advanced exercisers
Novice variations Wall push-up
Torso-elevated push-up
Knee push-up
Intermediate
variations
Standard push-up (figure 1)
Wide base push-up
Narrow base push-up
Rapid countermovement push-up
Torso-shifted forward push-up
Torso-shifted rearward push-up
Feet-elevated push-up
Upper-body suspended push-up (e.g., TRX) (figure 2)
Hands on stability ball push-up Hands on BOSU ball push-up
Perfect Push-up
Handle grip push-up
Fall push-up (from knees)
Staggered base push-up
Alternating side-to-side push-up
One legged push-up
Between-bench push-up(figure 3)
Advanced variations Clapping push-up
Self-assisted one-arm push-up (figure 4)
One arm push-up
Weighted-vest push-up
Weighted push-up (plates on back)
Elastic band-resisted push-up (figure 5)
Chain push-up (draped over back) (figure 6)
Strength and Conditioning Journal | www.nsca-scj.com
43

affects the muscular recruitment pat-
terns. Shifting the torso forward relative
to the hands results in an increased pec-
toralis major activity and a decreased
triceps brachii activity compared with
the normal base position. Shifting the
torso rearward relative to the hands
results in slightly increased pectoralis
major and triceps brachii activity (9).
Foot position also is often al tered to
vary muscle recruitment. Recently,
Ebben e t a l. (5) assessed the peak ver-
tical ground reaction forces of push-
up variations including the standard
push-up and those performed from
the knees, with feet elevated on
a 30.5-cm box and a 61.0- cm box,
and with hands elevated on these
boxes. Push-ups with the feet ele-
vated produced a higher ground
reaction force than all other push-
up variations. When expressed as
a percentage of total body mass, the
order from least to greatest load pro-
gressed from the hands elevated on
a 61.0-cm box (41% of bodyw eight),
tothekneepush-up(49%),tothe
hands elevated on a 30.5-cm box
(55%), to the regular push-up (64%),
to the feet elevated on a 30.5-cm box
(70%), and finally to the feet elevated
on a 61.0-cm box (74%).
Another push-up variation involves
the use of unstable surfaces. Compared
with standard push-ups, BOSU (Hed-
strom Fitness, Ashland, Ohio) push-
ups have been shown to increase the
activity of some of the scapular stabil-
izers, namely, the upper, mid, and
lower trapezius fibers; however serratus
anterior activity was diminished (20).
Research by Lehman et al. (15) reported
that elevating the feet above the hands
had a greater stimulus on scapulothora-
cic stabilizing musculature than placing
the hands on an unstable surface (i.e.,
stability ball). From a training perspec-
tive, it is more challenging and demand-
ing for the shoulder girdle stabilizers to
perform push-ups with the feet elevated
on a bench and the hands on the
ground than to perform push-ups with
the hands on a stability ball and the feet
on the ground.
Lehman et al. (14) found that push-ups
with the hands placed on a stability ball
significantly increased the activation of
triceps brachii. Stability ball push-ups
also increased pectoralis major, rectus
abdominis, and external oblique activa-
tion compared with push-ups on
a bench from the same angle, whereas
push-ups with the feet placed on a sta-
bility ball did not affect muscle activity
compared with push-ups with the feet
on a bench from the same angle. In
addition, Marshall and Murphy (16)
showed that triceps brachii and
abdominal EMG activity was signifi-
cantly greater when performing push-
ups off stability balls compared with
stable surfaces from flat and elevated
positions. These results indicate that
the stability ball seems to only increase
the muscle activity during exercises
where the unstable surface is the pri-
mary base of support. From a muscle
activation standpoint, it therefore
appears to be more effective to perform
exercises such as stability ball and
BOSU push-ups in comparison with
stable surface push-ups as long as torso
angle remains constant and the hands
are placed on the unstable piece of
equipment rather than the feet.
Push-ups can also be performed with
suspension devices and implements
specially designed to facilitate changes
in hand positions. Beach et al. (2)
showed that suspended push-ups acti-
vated more core musculature than
standard push-ups. One such device,
the B OSU Perfect Push-up, is pur-
ported to be biomechanica lly engi-
neered to achieve better results from
push-up workouts. The efficacy of this
claim was investigat ed by Youd as et al.
(24) who used EMG to evaluate the
muscle activity in the Perfect Push-up
versus standard push-ups. Muscle
activation was evaluated during the
performance of push-ups using 3 dif-
ferent hand positions: normal base,
wide base, and narrow base. The
muscles studied included the tri ceps
brachii, pectoralis major, serratus
anterior, and posterior deltoids. Anal-
ysis of EM G f ailed to show any sig-
nificant differences between the
groups, leading researchers to con-
clude that Perfect Push-up handgrips
do not seem to increase the muscular
recruitment when compared with the
standard push-ups.
Finally, speed of movement can be
altered to change push-up biomechan-
ics. Explosive push-ups have been com-
pared in terms of peak force, rate of
force development, and peak impact
force. Garcia-Masso et al. (7) examined
the fall push-up (an explosive push-up
starting from a tall-kneeling position,
falling to a knee push-up position, and
returning to the tall-kneeling position),
jump push-up (an explosive push-up
starting from standard position, where
the upper body leaves the ground and
becomes airborne before returning to
standard position), and countermove-
ment push-up (a rapid push-up
Figure 5. Elastic band-resisted push-up.
Figure 6. Chain push-up (draped over
back).
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characterized by fast eccentric, reversal,
and concentric phases but does not
involve leaving the ground) and found
that the countermovement push-up,
which was performed with maximal
speed, exhibited the highest peak force
and rate of force development. Given
that this is the only variation that does
not encounter impact forces, it appears
that the countermovement push-up is
a safe and effective choice for explosive
variations if one wishes to maximize the
aspects of upper-body power. Clapping
push-ups have been shown to outper-
form standard, slow eccentric, 1 hand
on medicine ball, staggered hands,
hands on 2 balls, 2 hands on 1 ball, rapid
countermovement, 1 arm, and alternat-
ing plyometric push-up variations in
pectoralis major and triceps brachii
activity (6). Advanced forms of plyo-
metric push-ups could be problematic
for individuals with back issues, given
that an alternating plyometric push-up
using a medicine ball has been shown to
induce 6,224 N of compressive forces on
the lumbar spine (6).
Additional alterations can be employed
to decrease or increase the challenging
nature of the exercise. For example, wall
push-ups (leaning forward with hands
against the wall) and knee push-ups
(knees on the floor) are appropriate
for those with limited upper-body
strength, whereas push-ups using 1
arm or 1 leg can make the movement
sufficiently challenging even for those
who are highly fit. Furthermore,
a weighted vest, elastic bands, chains,
and/or various unstable implements
can be employed to further challenge
the upper-body musculature. Table 2
illustrates some push-up variations, cat-
egorized into the levels of difficulty.
CONCLUSION
Push-ups can be an excellent exercise
for improving muscle strength and
endurance. It is imperative that practi-
tioners possess adequate knowledge of
push-up variations to optimize the
challenge on the target musculature
without compromising proper form
and risking injury. The biomechanical
information contained herein can
serve as a guideline to prescribe proper
progressions and regressions to
achieve desired outcomes.
Bret Contreras is a practicing strength
coach and is currently pursuing his PhD
at AUT University.
Brad Schoenfeld is a lecturer in the
exercise science program at CUNY
Lehman College and a doctoral student
at Rocky Mountain University.
Jonathan Mike is a doctoral candidate
in exercise physiology at the University of
New Mexico.
Gul Tiryaki-Sonmez is an associate
professor in the department of health
science at CUN Y Lehman College and
program director of their exercise science
program.
John Cronin is a Professor in Strength
and Conditioning at AUT University,
NZ and an Adjunct Professor at Edith
Cowan University.
Elsbeth Vaino is a strength and con-
ditioning consultant and personal trainer.
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