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Sports Biomechanics
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An electromyographic comparison of
a modified version of the plank with a
long lever and posterior tilt versus the
traditional plank exercise
Brad J. Schoenfelda, Bret Contrerasb, Gul Tiryaki-Sonmeza, Jeffrey
M. Willardsonc & Fabio Fontanad
a Department of Health Sciences, CUNY Lehman College, Bronx,
NY, USA
b Sport Performance Research Institute New Zealand, AUT
University, Auckland, New Zealand
c Kinesiology and Sports Studies Department, Eastern Illinois
University, Charleston, IL, USA
d School of Health, Physical Education, and Leisure Services,
University of Northern Iowa, Cedar Falls, IA, USA
Published online: 05 Aug 2014.
To cite this article: Brad J. Schoenfeld, Bret Contreras, Gul Tiryaki-Sonmez, Jeffrey M. Willardson
& Fabio Fontana (2014): An electromyographic comparison of a modified version of the plank with
a long lever and posterior tilt versus the traditional plank exercise, Sports Biomechanics, DOI:
10.1080/14763141.2014.942355
To link to this article: http://dx.doi.org/10.1080/14763141.2014.942355
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An electromyographic comparison of a modified version of
the plank with a long lever and posterior tilt versus the
traditional plank exercise
BRAD J. SCHOENFELD
1
, BRET CONTRERAS
2
, GUL TIRYAKI-SONMEZ
1
,
JEFFREY M. WILLARDSON
3
, & FABIO FONTANA
4
1
Department of Health Sciences, CUNY Lehman College, Bronx, NY, USA,
2
Sport Performance
Research Institute New Zealand, AUT University, Auckland, New Zealand,
3
Kinesiology and Sports
Studies Department, Eastern Illinois University, Charleston, IL, USA, and
4
School of Health, Physical
Education, and Leisure Services, University of Norther n Iowa, Cedar Falls, IA, USA
(Received 19 June 2013;accepted 8 April 2014)
Abstract
The purpose of the study was to compare core muscle activation of the tradition prone plank with a
modified version performed with a long-lever and posterior-tilt using surface electromyography. To
further determine if a specific component of this modified plank was more effective than the other in
enhancing muscle activity, the plank with a long lever and the plank with a posterior pelvic tilt were
studied individually. Nineteen participants performed all four variations of the plank for 30 seconds in a
randomized order with 5-minute rest between exercise bouts. Compared to the traditional prone plank,
the long-lever posterior-tilt plank displayed a significantly increased activation of the upper rectus
abdominis (p,0.001), lower abdominal stabilizers (p,0.001), and external oblique (p,0.001). The
long-lever plank showed significantly greater activity compared to the traditional plank in the upper
rectus abdominis (p¼0.015) and lower abdominal stabilizers (p,0.001), while the posterior tilt plank
elicited greater activity in the external oblique (p¼0.028). In conclusion, the long-lever posterior-tilt
plank significantly increases muscle activation compared to the traditional prone plank. The long-lever
component tends to contribute more to these differences than the posterior-tilt component.
Keywords: Core stability, core performance, abdominal muscles, long-lever posterior-tilt plank
Introduction
The prone plank is a popular fitness exercise that has been advocated as beneficial both for
rehabilitation programs (D’Amico, Betlach, Senkarik, Smith, & Voight, 2007) as well as
physical conditioning routines (Hofstetter, Mader, & Wyss, 2011) Beneficial effects of the
prone plank are thought to be related to an improved core stability, defined as “the ability of
passive and active stabilizers in the lumbopelvic region to maintain appropriate trunk and
hip posture, balance and control during both static and dynamic movement” (Reed, Ford,
Myer, & Hewett, 2012). Theoretically, enhanced core stability allows the core musculature
q2014 Taylor & Francis
Correspondence: Brad J. Schoenfeld, Program of Exercise Science, Department of Health Sciences, CUNY Lehman College,
Bronx, NY, USA, E-mail: brad@workout911.com
Sports Biomechanics, 2014
http://dx.doi.org/10.1080/14763141.2014.942355
Downloaded by [Brad Schoenfeld] at 04:54 10 August 2014
to resist applied external forces and maintain postural control in response to a perturbation.
The enhanced core stability may therefore translate into better functional performance.
Traditionally, performance of the prone plank involves assuming a push-up position with
the forearms on the ground and the elbows positioned directly beneath the glenohumeral
joints, spaced shoulder width apart. Lehman, Hoda, & Oliver (2005) showed that the prone
plank elicited 29.5%, 26.6%, 44.6% and 4.98% of maximum voluntary contraction (MVC)
in the internal oblique, rectus abdominis, external oblique and erector spinae musculature,
respectively, in a group of resistance-trained participants. Recently, however, its transfer to
sports skills has been called into question by some researchers (Parkhouse & Ball, 2011;
Shinkle, Nesser, Demchak, & McMannus, 2012). It is possible that the prone plank does not
sufficiently challenge the neuromuscular system in highly fit individuals, thereby limiting
transfer to dynamic performance. As a more challenging alternative, several strength coaches
have promoted modifying the traditional prone plank so that it is performed with a long lever
and posterior tilt (Schoenfeld & Contreras, 2013). Performance of the long-lever posterior-
tilt plank involves actively contracting the gluteal musculature to bring about a posterior
pelvic tilt. The elbows are positioned further toward the head and closer together than in the
prone plank, which increases lever arm length and reduces the base of support. In
combination, these factors conceivably enhance recruitment of the core musculature and
thus may improve sports performance even in well-trained athletes.
The posterior tilting mechanism, created by the force coupling of the hip extensors
(gluteus maximus and hamstrings) and the abdominal musculature (rectus abdominis and
external oblique), is believed to have a particularly strong influence on core muscle activity
(Neumann, 2010). A supine posterior pelvic tilt isometric hold has been shown to elicit
12.2%, 15.9%, 26.3%, 7.3%, and 5.6% of MVC in the lower abdominal stabilizers, upper
rectus abdominis, external oblique, erector spinae, and multifidus musculature, respectively,
in a study involving healthy participants (Vezina & Hubley-Kozey, 2000). These percentages
of activation were approximately duplicated in a subsequent study involving participants
with low back pain (12.4%, 12.9%, 29.7%, 6.5%, and 4.2% of MVC in the lower abdominal
stabilizers, upper rectus abdominis, external oblique, erector spinae, and multifidus,
respectively) (Hubley-Kozey & Vezina, 2002). Moreover, performing hip extension exercise
in posterior pelvic tilt has been shown to lead to increased activation in the gluteus maximus,
rectus abdominis, external oblique, and internal oblique, but not the multifidus or
iliocostalis, when compared to performing hip extension in anterior pelvic tilt or neutral
pelvic positions (Queiroz, Cagliari, Amorim, & Sacco, 2010). Performing double straight leg
lifts in posterior pelvic tilt has been shown to lead to increased activation in the upper rectus
abdominis and lower abdominal stabilizers, but not the rectus femoris, when compared to
performing double straight leg lifts in anterior pelvic tilt or neutral pelvic positions
(Workman, Docherty, Parfrey, & Behm, 2008).
The purpose of the current study was to examine if differences exist in core muscle activity
between the traditional prone plank and the long-lever posterior-tilt plank as determined by
surface electromyography (EMG). Based on the aforementioned research, our first
hypothesis was that the long-lever posterior-tilt plank would elicit significantly greater
muscle activity versus the traditional prone plank. To further determine if a specific
component of the long-lever posterior-tilt plank was more effective than the other in
enhancing muscle activity, the plank with a long lever and the plank with a posterior pelvic tilt
were studied individually by EMG. Our second hypothesis was that the plank with a
posterior pelvic tilt would have a greater effect on muscle activity compared to the plank with
a long lever, and thus provide a greater contribution to the postural stabilizing demands of
the long-lever posterior-tilt plank.
2B.J. Schoenfeld et al.
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Methods
Participants
Nineteen male participants between the ages of 18 and 35 were recruited as a convenience
sample from a university population to participate in this study (mean ^SD age:
23.3 ^4.0 years; height: 178.8 ^7.4 cm; body mass: 80.0 ^8.2 kg; training experience:
5.8 ^4.2 years). All participants were experienced with resistance training, defined as lifting
weights for a minimum of two days a week for one year or more. Participants also had similar
experience performing abdominal exercise. Inclusion criteria required participants to read
and speak English and pass a physical activity readiness questionnaire (PAR-Q). Those
receiving care for any back or abdominal related orthopedic issues at the time of the study
were excluded from participation. Each subject provided written informed consent prior to
participation. The research protocol was approved by the Institutional Review Board at
Lehman College, Bronx, NY.
Procedure
Following consent, participants were prepped for testing by wiping the skin in the desired
areas of electrode attachment with an alcohol swab to ensure stable electrode contact and low
skin impedance. Any visible body hair in these areas was abraded and shaved prior to
preparation. After preparation, self-adhesive disposable silver/silver chloride pre-gelled dual
snap surface bipolar electrodes (Noraxon Product #272, Noraxon USA Inc., Scottsdale,
AZ) with a diameter of 1 cm and an inter-electrode distance of 2 cm were attached parallel to
the fiber direction of the upper rectus abdominis, lower abdominal stabilizers (which
measures a blending of lower rectus abdominis, transverse abdominis, and internal oblique
activity) (Marshall & Murphy, 2005), external oblique, and erector spinae muscles. A
neutral reference electrode was placed over the bony process of the mid-spine. These
methods were consistent with the recommendations of SENIAM (Surface EMG for Non
Invasive Assessment of Muscles) (SENIAM project, 2005). After all electrodes were secured
with medical adhesive tape, a quality check was performed to ensure EMG signal validity.
Instrumentation
Raw EMG signals were collected at 2,000 Hz by a Myotrace 400 EMG unit (Noraxon USA
Inc., Scottsdale, AZ), and filtered by an eighth-order Butterworth band-pass filter with
cutoffs of 20 –500 Hz. Data were sent in real time to a computer via Bluetooth and recorded
and analyzed by MyoResearch XP Clinical Applications software (Noraxon USA Inc.,
Scottsdale, AZ). Signals were rectified by root mean square algorithm and smoothed in real
time. The mean EMG values during each 30-s static action were subsequently compared in
the statistical analysis.
Maximal voluntary isometric contraction
Isometric MVC data were obtained for each muscle tested by performing resisted isometric
actions for the core musculature similar to that described by Lehman et al. (2005). After an
initial warm up consisting of 5 min of light cardiovascular exercise and slow dynamic
stretching in all three cardinal planes, participants performed two different bouts against
manual resistance: (1) a trunk curl up and twist to maximally recruit the upper rectus
abdominis, lower abdominal stabilizers, and external oblique muscles, and (2) an isometric
Long-Lever Posterior-Tilt Plank 3
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prone trunk extension to maximally recruit the erector spinae. For each bout, participants
were asked to slowly increase the force of the contraction so as to reach a maximum effort
after approximately 3 s. Participants then held the maximal contraction for 3 s before slowly
reducing force over a final period of 3 s. This procedure was repeated once for each muscle
following a 60-s rest interval and the highest MVC value was used for normalization
purposes. The mean EMG values for each muscle were expressed as a percentage of MVC.
Exercise description
To ensure proper exercise performance, participants were provided with a familiarization
session where the primary investigator, a certified trainer, gave detailed verbal instruction of
each plank variation. Instruction was supplemented with video demonstration of the
respective movements. Following instruction, participants were asked if they understood the
performance of each movement and any remaining questions were answered with respect to
exercise performance. Descriptions and photos of the exercise variations are provided in
Table I and Figure 1a–d, respectively.
After completion of the familiarization session, participants were asked to perform a given
variation of the plank exercise. Participants held each plank position for 30 s. Verbal
encouragement and coaching were provided during performance to ensure that exercise was
carried out in the prescribed manner. Participants were then given a 5-min rest period and
subsequently asked to perform another variation of the plank. This protocol continued until
all four plank variations were performed. The order of performance for each variation was
randomly assigned utilizing a Latin Square approach to minimize any potential confounding
effects of exercise sequence on results.
Table I. Description of plank variations.
Exercise variation Description
Traditional prone plank Lie face-down with fists on the floor, feet shoulder width apart, and spine and
pelvis in a neutral position. The elbows are spaced shoulder width apart
directly below the glenohumeral joint. Lift the body up on the forearms and
toes, keeping the body as straight as possible. Maintain this position for 30 s.
Long-lever plank Lie face-down with fists on the floor, feet shoulder width apart, and spine and
pelvis in a neutral position. The elbows are spaced 6 inches apar t at nose level.
Lift the body up on the forearms and toes, keeping the body as straight as
possible. Maintain this position for 30 s.
Posterior-tilt plank Lie face-down with fists on the floor, feet shoulder width apart, and spine and
pelvis in a neutral position. The elbows are spaced shoulder width apart
directly below the glenohumeral joint. The gluteal muscles are contracted as
strongly as possible while attempting to draw the pubic bone toward the belly
button and the tailbone toward the feet. Lift the body up on the forearms and
toes, keeping the body as straight as possible. Maintain this position for 30 s.
Long-lever posterior-tilt plank Lie face-down with fists on the floor, feet shoulder width apart, and spine and
pelvis in a neutral position. The elbows are spaced 6 inches apar t at nose level.
The gluteal muscles are contracted as strongly as possible while attempting to
draw the pubic bone toward the belly button and the tailbone toward the feet.
Lift the body up on the forearms and toes, keeping the body as straight as
possible. Maintain this position for 30 s.
4B.J. Schoenfeld et al.
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Statistical analysis
A4(muscles)£4 (exercise variations) two-way ANOVA with repeated measures on the
latter factor was utilized to compare the performance of each exercise variation on the
assessed muscles. The exercise variations were the traditional prone plank, long lever
plank, plank with a posterior pelvic tilt, and the long lever plank with a posterior pelvic tilt;
the muscles assessed were the erector spinae, upper rectus abdominis, lower abdominal
stabilizers, and external oblique abdominis. The dependent variable was normalized EMG
values. Because the sphericity assumption was violated (p,0.01), the Greenhouse-
Geisser correction was applied to correct for violations of the sphericity assumption. Effect
size (partial
h
2
) and observed power statistics were computed for significant main effects.
Post-hoc comparisons were conducted using the Bonferroni procedure. Statistical
significance was set at p#0.05. Statistical analysis was carried out using SPSS 16
(SPSS Inc., Chicago, IL).
Results
Based on the Greenhouse-Geisser correction procedure, a significant (p,0.05) interaction
between exercise variations and muscles was found (F
6.59,158.34
¼8.96; p,0.001;
h
p
2
¼0.27; 1– b¼1.00; see Table II). When comparing the four different muscles across
exercise variations, findings can be summarized as follows: (a) for the erector spinae, there
were no significant differences across exercise variations (Figure 2a, b) for the upper rectus
abdominis, significantly greater activity was noted for the plank with a long lever and long-
lever posterior-tilt plank versus the traditional prone plank (Figure 2b, c) for the lower
Figure 1. Variations of plank exercise: traditional prone plank (a), posterior tilt plank (b), long-lever plank (c), and
long-lever posterior tilt plank (d).
Long-Lever Posterior-Tilt Plank 5
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abdominal stabilizers, significantly greater activity was noted for the plank with a long lever
and long-lever posterior-tilt plank versus the traditional prone plank; also, significantly
greater activity was noted for the long-lever posterior-tilt plank versus the plank with a
posterior pelvic tilt (Figure 2c, and d) for the external obliques, significantly greater activity
was noted for the plank with a posterior pelvic tilt and long-lever posterior-tilt plank versus
the traditional prone plank (Figure 2d).
Differences in EMG activity were also found when comparing the four exercise conditions
across muscles. Bonferroni post-hoc analyses indicated that the erector spinae was less active
than any of the other three muscles during the long-lever plank and long-lever posterior-tilt
plank exercises (p
s
,0.001). For the plank with a posterior pelvic tilt, erector spinae was less
Table II. Summary of EMG values across muscles and exercise variations expressed as percent MVC.
Traditional Long lever Posterior tilt Long lever posterior tilt
Erector spinae 4.84 ^2.27 5.74 ^3.25 6.77 ^3.19 7.10 ^4.27
Upper rectus abdominis 27.26 ^20.60 90.47 ^64.23*
§
54.58 ^34.55 109.74 ^66.30*
§
Lower abdominal stabilizers 37.84 ^25.83 121.05 ^52.45*
§
81.21 ^46.12*153.89 ^88.43*
§
External oblique 50.21 ^36.15 101.79 ^68.80*110.79 ^66.30*
§
148.74 ^70.14*
§
Mean ^SD.
*Significantly different from erector spinae ( p,0.05).
§
Significantly different from the traditional plank condition ( p,0.05).
0.00
2.00
4.00
6.00
8.00
10.00
12.00
Traditional Plank Long Lever Plank Posterior Tilt Plank Long Lever Posterior
Tilt Plank
% MVC
No significant differences across exercise variations.
(a)
0
50
100
150
200
250
300
Traditional Plank Long Lever Plank Posterior Tilt Plank Long Lever Posterior
Tilt Plank
% MVC
*Significantly greater activity Long Lever Plank and Long Lever Posterior Tilt
Plank versus the Traditional Plank; #significantly greater activity Long Lever
Posterior Tilt Plank versus Posterior Tilt Plank (p < 0.05).
(c)
0
50
100
150
200
250
Traditional Plank Long Lever Plank Posterior Tilt Plank Long Lever Posterior
Tilt Plank
% MVC
*Significantly greater activity Posterior Tilt Plank and Long Lever Posterio
r
Tilt Plank versus the Traditional Plank.
(d)
0
20
40
60
80
100
120
140
160
180
200
Traditional Plank Long Lever Plank Posterior Tilt Plank Long Lever Posterior
Tilt Plank
% MVC
*Significantly greater activity Long Lever Plank and Long Lever Posterior
Tilt Plank versus the Traditional Plank (p < 0.05).
(b)
*
*
*
*
#
*
*
Figure 2. Normalized EMG activity of erector spinae (a), upper rectus abdominis (b), lower abdominal stabilizers
(c), and lower external oblique (d) across plank variations.
6B.J. Schoenfeld et al.
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active than the lower abdominal stabilizers (p,0.001) and external oblique (p,0.001).
Differences between muscles were not found for the traditional prone plank exercise.
Discussion and implications
Our first hypothesis was supported in that the long-lever posterior-tilt plank elicited
significantly greater muscle activity versus the traditional prone plank for all muscles with the
exception of the erector spinae (ES). However, our second hypothesis was not supported in
that the plank with a long lever elicited significantly greater muscle activity in the lower
abdominal stabilizers versus the plank with a posterior pelvic tilt, while no significant
differences were seen between these variations in the other muscles evaluated. When
examining the mean values in Table II the long-lever posterior-tilt plank elicited the highest
mean EMG values for all muscles and represented the most difficult of the exercise variations
examined. However, enacting a longer lever tended to have a greater effect for increasing the
muscular demands of the long-lever posterior-tilt plank exercise versus enacting a posterior
pelvic tilt, although the two variations appear to be synergistic in optimizing core activity.
Therefore, when considering postural stabilizing demands the appropriate progression for
practitioners would be as follows: the traditional prone plank, plank with a posterior pelvic
tilt, plank with a long lever, and then the long-lever posterior-tilt plank.
This is the first study to show that a modified version of the traditional plank employing a
long lever and posterior tilt significantly and markedly increases muscle activity in the rectus
abdominis and external oblique as compared to the traditional prone plank. These muscles
are considered essential to core stability and provide support for the lumbar spine during
activities of daily living (Lehman, 2006). Importantly, the modifications associated with the
long-lever posterior-tilt plank are easy to implement and require no special equipment,
making the exercise a highly accessible and convenient option for the general population.
Similar to the results of Lehman et al. (2005), normalized EMG activity of the rectus
abdominis and external oblique during the traditional prone plank was modest in resistance-
trained individuals. The low values obtained in these muscles indicate that the participants
were not significantly challenged by this exercise, at least for the duration of the 30-s bout
employed in this study. These findings indicate that the traditional prone plank is more
suitable for beginners or for rehabilitative purposes as opposed to those with ample training
experience.
It is worthy of mention that considerable inter-individual variation was observed between
participants for the muscles tested in the traditional prone plank. The minimum and
maximum mean values for the erector spinae, upper rectus abdominis, lower abdominal
stabilizers, and external oblique muscles were 2% and 9%, 7% and 83%, 2% and 89%, and
3% and 118%, respectively. Thus, even some well-trained individuals may benefit from the
traditional plank, albeit to a much lesser extent than with the long-lever posterior-tilt plank
and its variants. The mean erector spinae activity for the traditional prone plank, plank with a
long lever, plank with a posterior pelvic tilt, and long-lever posterior-tilt plank was minimal
(5%, 6%, 7%, and 7%, respectively). Based on these data, we can conclude that the erector
spinae muscles are not required to sufficient degree, not even for co-contraction purposes,
for trunk stability during the plank variations examined in this study. Although plank
variations are typically employed for purposes of increasing core stability, it is important to
realize that prone plank variations are “anti-extension” exercises that challenge the anterior
core musculature (Schoenfeld & Contreras, 2011). Additional exercises would need to be
prescribed for purposes of targeting the ES and developing “anti-flexion” stability, or the
ability to resist flexion of the spinal column.
Long-Lever Posterior-Tilt Plank 7
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Contrary to our initial hypothesis, the plank with a long lever had a significantly greater
effect on muscle activity compared to the plank with a posterior pelvic tilt. Apparently,
increasing the distance between the elbows and toes during the plank exercise as we have
done in this study produces a greater challenge to the core musculature than manipulating
pelvic position. Future biomechanical research could examine the combinations of spinal
and pelvic torque in the sagittal plane during the traditional prone plank, plank with a long
lever, plank with a posterior pelvic tilt, and long-lever posterior-tilt plank to further elucidate
the mechanisms contributing to the challenge on the core musculature between the different
exercise variations.
The results of this study have a number of important practical implications. Panjabi
(1992) defined segmental instability “as a significant decrease in the capacity of the
stabilizing system of the spine to maintain the intervertebral neutral zones within the
physiological limits so that there is no neurological dysfunction, no major deformity, and no
incapacitating pain”. Spinal instability is associated with reduced strength and endurance of
the core musculature as well as altered recruitment of these muscles (Hibbs, Thompson,
French, Wrigley, & Spears, 2008; van Dieen, Cholewicki, & Radebold, 2003). It is theorized
that core muscle endurance, as opposed to maximal core strength, is the primary factor in the
etiology of spinal instability and lower back pain for the general public (Lehman, 2006;
McGill, 1998). Static core muscle endurance, in particular, is considered essential to
carrying out everyday activities in a pain-free manner (McGill, 2007; McGill, 2010).
Training to optimize static core endurance requires the performance of isometric exercise for
durations of over 30 s (Faries & Greenwood, 2007). To this end, the traditional prone plank
has been identified as a beneficial exercise for enhancing this fitness variable (Lehman,
2006). While the traditional prone plank could conceivably be effective in improving core
endurance in untrained individuals, the principle of progressive overload dictates that bodily
tissues must be repeatedly challenged over time to foster continued adaptation. The long-
lever posterior-tilt plank can therefore be implemented as part of a progressive core training
regimen to enhance spinal stability and potentially reduce the risk of low back pain as one
acquires training experience.
Stability training has been used to treat patients with segmental instability, clinical
instability, and chronic back pain (Biely, Smith, & Silfies, 2006). It remains questionable,
however, as to whether such training is efficacious (Lederman, 2010). Research indicates
that 90% of low back pain is nonspecific in nature, and that the causes of this type of back
pain are nebulous (Cissik, 2011). This would seem to cast doubt on the ability of core
stability exercise to improve nonspecific low back pain. Furthermore, some researchers have
suggested that progressively overloading the spine during core stability training is risky and it
therefore should be reserved for performance-oriented goals rather than pain prevention
(McGill, 2010). In consideration of these issues, the long-lever posterior-tilt plank may not
be appropriate for those with clinical conditions related to the spine. It is conceivable that the
long-lever posterior-tilt plank could be used as a strategy to improve pelvic awareness and
kinesthesia; particularly to avoid excessive anterior pelvic tilt. Considering that it has been
shown that 85% of males and 75% of females possess anterior pelvic tilt, this may be of
significant importance (Herrington, 2011). Although it has been suggested that anterior
pelvic tilt increases the stress on the lumbar spine (Jull & Janda, 1987), the condition is
common within normal asymptomatic populations and research has failed to show an
association between anterior pelvic tilt and low back pain (Nourbakhsh & Arab, 2002).
Nevertheless, there is evidence that resistance and flexibility training help to improve lumbar
alignment (Scannell & McGill, 2003), and therefore it is plausible that resistance and
flexibility training could alter pelvic tilt angle. It has been suggested, however, that anterior
8B.J. Schoenfeld et al.
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pelvic tilt is advantageous in certain sports such as sprint running (Kritz & Cronin, 2008).
More research is needed to elucidate whether pelvic alignment can be altered through
resistance training; whether these changes lead to increases or decreases in back pain; and
whether these changes positively or negatively affect athletic performance.
The long-lever posterior-tilt plank may be especially beneficial to athletes. A majority of
athletic endeavors require the performer to maintain core stability during highly dynamic
movements, often under highly loaded conditions (Hibbs et al., 2008). The rectus
abdominis, in particular, is thought to play an important role in bracing the spine during
pushing tasks or during the lifting of heavy loads, which are often relevant to sports
performance (Hibbs et al., 2008). The sports of football, rugby, soccer, wrestling, and
hockey, to name a few, all contain horizontal pushing components whereby increased anti-
extension trunk stability could increase performance. Theoretically, increased lumbar and
pelvic stability would prevent the core from buckling, thereby preventing potential injury
while also allowing for the optimal transference of force from the ground to the opponent. A
recent systematic review, however, showed only marginal improvements in athletic
performance from core stability training while at the same time noting that a strong and
stable core provides a necessary foundation for optimal execution of a variety of sporting
movements (Reed et al., 2012). Future research should examine the potential
relationship between the quality of performance in the long-lever posterior-tilt plank and
higher force activities that challenge the ability of the trunk to resist flexion and the transfer to
sports performance. There may be particular benefit of the long-lever posterior-tilt plank to
the sport of powerlifting. Considering that pelvic and lumbar posture are inextricably linked
in the standing position (Levine & Whittle, 1996), and that it has been suggested that
excessive lumbar extension should be avoided at the end range of motion of a deadlift (Bird &
Barrington-Higgs, 2010), the long-lever posterior-tilt plank may lead to improvements in
deadlift performance via increased lockout power relating to a better ability to resist
lumbopelvic deformation subsequent to stronger and more coordinated gluteal and
abdominal musculature at end range of hip extension. Future research should examine the
effects of the long-lever posterior-tilt plank on the deadlift exercise in the sport of
powerlifting.
McGill (1998) contends that performing a posterior pelvic tilt during core exercise may
increase the risk of spinal injury by preloading the annulus and posterior ligaments. It is not
clear whether this would be a risk factor in those with healthy spines. To the authors’
knowledge, no study to date has evaluated the effect of posterior tilt exercise on spinal injury
in any population. Given the aforementioned theoretical rationale, however, it may be
appropriate for individuals with existing disk-related issues, such as flexion-intolerance, to
avoid this maneuver. In such cases, performing the plank with a long lever would seem to be a
viable alternative as it has a greater effect on anterior trunk muscle activation without the
associated risk to spinal structures.
Conclusions
The long-lever posterior-tilt plank offers a more challenging alternative to the traditional
prone plank that results in markedly greater muscle activity of the core musculature.
These findings would appear to have particular relevance for well-trained individuals
given the low core muscle activity seen with the traditional prone plank. Future research
should seek to determine whether the increased muscle activation associated with the
long-lever posterior-tilt plank transfers to improvements in functional performance and
injury prevention.
Long-Lever Posterior-Tilt Plank 9
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Acknowledgement
The authors would like to acknowledge Robert Harris for his assistance in this study.
References
Biely, S. A., Smith, S. S., & Silfies, S. P. (2006). Clinical instability of the lumbar spine: Diagnosis and intervention.
Orthpaedic Physical Therapy Practice,18, 11–19.
Bird, S., & Barrington-Higgs, B. (2010). Exploring the deadlift. Strength and Conditioning Journal,32, 46–51.
Cissik, J. M. (2011). The role of core training in athletic performance, injury prevention, and injury treatment.
Strength and Conditioning Journal,33, 10 – 15.
D’Amico, J., Betlach, M., Senkarik, R., Smith, R., & Voight, M. (2007). Return to golf following left total
hip arthroplasty in a golfer who is right handed. North Amer ican Journal of Sports Physical Therapy: NAJSPT,2,
251– 261.
Faries, M. D., & Greenwood, M. (2007). Core training: Stabilizing the confusion. Strength and Conditioning Journal,
29, 10– 25.
Herrington, L. (2011). Assessment of the degree of pelvic tilt within a normal asymptomatic population. Manual
Therapy,16, 646– 648. doi:10.1016/j.math.2011.04.006
Hibbs, A. E., Thompson, K. G., French, D., Wrigley, A., & Spears, I. (2008). Optimizing performance by improving
core stability and core strength. Sports Medicine,38, 995 – 1008. doi:10.2165/00007256-200838120-00004
Hofstetter, M. C., Mader, U., & Wyss, T. (2011). Effects of a seven-week outdoor circuit training program on swiss
army recruits. Journal of Strength and Conditioning Research.doi:10.1519/JSC.0b013e318245bebe
Hubley-Kozey, C. L., & Vezina, M. J. (2002). Muscle activation during exercises to improve trunk stability in men
with low back pain. Archives of Physical Medicine and Rehabilitation,83, 1100– 1108.
Jull, G., & Janda, V. (1987). Muscles and motor control in lower back pain: Assessment and management. In L.
Twomey (Ed.), Physical therapy of the lower back (1st ed.) (pp. 253– 278). New York: Churchill Livingstone.
Kritz, M., & Cronin, J. (2008). Static posture assessment screen of athletes: Benefits and considerations. Strength
and Conditioning Journal,30, 18 – 27.
Lederman, E. (2010). The myth of core stability. Journal of Bodywork and Movement Therapies,14, 84–98. doi:10.
1016/j.jbmt.2009.08.001; 10.1016/j.jbmt.2009.08.001
Lehman, G. J. (2006). Resistance training for performance and injury prevention in golf. The Journal of the Canadian
Chiropractic Association,50, 27– 42.
Lehman, G. J., Hoda, W., & Oliver, S. (2005). Trunk muscle activity during bridging exercises on and off a swiss
ball. Chiropractic & Osteopathy,13, 14. doi:10.1186/1746-1340-13-14
Levine, D., & Whittle, M. W. (1996). The effects of pelvic movement on lumbar lordosis in the standing position.
The Journal of Orthopaedic and Sports Physical Therapy,24, 130– 135.
Marshall, P. W., & Murphy, B. A. (2005). Core stability exercises on and off a swiss ball. Archives of Physical Medicine
and Rehabilitation,86, 242–249. doi:10.1016/j.apmr.2004.05.004
McGill, S. (2007). Low back disorders: Evidence-based prevention and rehabilitation. Champaign, IL: Human Kinetics.
McGill, S. (2010). Core training: Evidence translating to better performance and injury prevention. Strength and
Conditioning Journal,32, 33 – 46.
McGill, S. M. (1998). Low back exercises: Evidence for improving exercise regimens. Physical Therapy,78,
754– 765.
Neumann, D. A. (2010). Kinesiology of the hip: A focus on muscular actions. The Journal of Orthopaedic and Sports
Physical Therapy,40, 82– 94. doi:10.2519/jospt.2010.3025
Nourbakhsh, M. R., & Arab, A. M. (2002). Relationship between mechanical factors and incidence of low back
pain. The Journal of Orthopaedic and Sports Physical Therapy,32, 447– 460.
Panjabi, M. M. (1992). The stabilizing system of the spine. Part II: Neutral zone and instability hypothesis. Journal
of Spinal Disorders,5, 390–396; discussion 397.
Parkhouse, K. L., & Ball, N. (2011). Influence of dynamic versus static core exercises on performance in field based
fitness tests. Journal of Bodywork and Movement Therapies,15, 517–524. doi:10.1016/j.jbmt.2010.12.001
Queiroz, B. C., Cagliari, M. F., Amorim, C. F., & Sacco, I. C. (2010). Muscle activation during four pilates core
stability exercises in quadruped position. Archives of Physical Medicine and Rehabilitation,91, 86–92. doi:10.
1016/j.apmr.2009.09.016
Reed, C. A., Ford, K. R., Myer, G. D., & Hewett, T. E. (2012). The effects of isolated and integrated ‘core stability’
training on athletic performance measures: A systematic review. Sports Medicine,42, 697– 706. doi:10.2165/
11633450-000000000-00000
10 B.J. Schoenfeld et al.
Downloaded by [Brad Schoenfeld] at 04:54 10 August 2014
Scannell, J. P., & McGill, S. M. (2003). Lumbar posture – Should it, and can it, be modified? A study of passive
tissue stiffness and lumbar position during activities of daily living. Physical Therapy,83, 907– 917.
Schoenfeld, B., & Contreras, B. (2011). Strategies for optimal core training program design. NSCA Performance
Training Journal,10, 20 – 24.
Schoenfeld, B., & Contreras, B. (2013). Exercise technique: The long-lever posterior-tilt plank. Strength and
Conditioning Journal,35, 98 – 99.
SENIAM project. (2005). Recommendations for sensor locations on individual muscles. Retrieved from http://
seniam.org/sensor_location.htm
Shinkle, J., Nesser, T. W., Demchak, T. J., & McMannus, D. M. (2012). Effect of core strength on the measure of
power in the extremities. Journal of Strength and Conditioning Research,26, 373 – 380. doi:10.1519/JSC.
0b013e31822600e5
van Dieen, J. H., Cholewicki, J., & Radebold, A. (2003). Trunk muscle recruitment patterns in patients with low
back pain enhance the stability of the lumbar spine. Spine,28, 834– 841.
Vezina, M. J., & Hubley-Kozey, C. L. (2000). Muscle activation in therapeutic exercises to improve trunk stability.
Archives of Physical Medicine and Rehabilitation,81, 1370– 1379. doi:10.1053/apmr.2000.16349
Workman, J. C., Docherty, D., Parfrey, K. C., & Behm, D. G. (2008). Influence of pelvis position on the activation of
abdominal and hip flexor muscles. Journal of Strength and Conditioning Research,22, 1563 – 1569. doi:10.1519/
JSC.0b013e3181739981
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