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Core Muscle Activation in Suspension Training Exercises

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DOI: 10.1515/hukin-2017-0023

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 Journal of Human Kinetics volume 56/2017, 61-71 DOI: 10.1515/hukin-2017-0023 61
Section I – Kinesiology

Core Muscle Activation in Suspension Training Exercises

by
Giovanni Cugliari1,2, Gennaro Boccia3,4

A quantitative observational laboratory study was conducted to characterize and classify core training
exercises executed in a suspension modality on the base of muscle activation. In a prospective single-group repeated-
measures design, seventeen active male participants performed four suspension exercises typically associated with core
training (roll-out, bodysaw, pike and knee-tuck). Surface electromyographic signals were recorded from lower and
upper parts of rectus abdominis, external oblique, internal oblique, lower and upper parts of erector spinae muscles
using concentric bipolar electrodes. The average rectified values of electromyographic signals were normalized with
respect to individual maximum voluntary isometric contraction of each muscle. Roll-out exercise showed the highest
activation of rectus abdominis and oblique muscles compared to the other exercises. The rectus abdominis and external
oblique reached an activation higher than 60% of the maximal voluntary contraction (or very close to that threshold,
55%) in roll-out and bodysaw exercises. Findings from this study allow the selection of suspension core training
exercises on the basis of quantitative information about the activation of muscles of interest. Roll-out and bodysaw
exercises can be considered as suitable for strength training of rectus abdominis and external oblique muscles.
Key words: core stability, core strength, electromyography, abdominal muscles.

Introduction
In recent years, core training has been region (such as shoulders and pelvic muscles).
widely studied since it has been considered a However, literature concerning core training
pivotal issue in health, rehabilitation and sports sometimes fails to distinguish between concepts
performance (Hibbs et al., 2008). However, the of core stability and core strength. Faries and
definition of the core varies with the Greenwood (in Hibbs and Thompson, 2008)
interpretation of the literature (Hibbs and formulated the following clear definitions: core
Thompson, 2008). Anatomically, the core region stability refers to the ability to stabilize the spine
has been described as the area bounded by the as a result of muscle activity, while core strength
abdominal muscles in the front, by paraspinal and refers to the ability of muscles’ contractions to
gluteal muscles in the back, by diaphragm on the produce and transfer force as a result of muscle
top and by pelvic floor and girdle musculature at activity. Since strength and motor control are
the bottom (Richardson et al., 1999). The core complementary qualities, the core training
represents the connection between lower and programmes can target mainly, but not
upper limbs and should be considered as a exclusively, at muscle strengthening and/or motor
functional unit in which different muscles control of core musculature. Motor control
interact, even if not located in the thoraco-lumbar training seems to require low intensity

1 - Department of Brain and Behavioral Sciences, Unit of Medical and Genomic Statistics, University of Pavia, Italy..
2 - Department of Medical Sciences, University of Torino, Torino, Italy.
3 - CeRiSM Research Center “Sport, Mountain, and Health”, Rovereto, (TN), Italy.

4 - Motor Science Research Center, School of Exercise & Sport Sciences, SUISM, Department of Medical Sciences, University of

Turin. 12, Torino, Italy.

.
Authors submitted their contribution to the article to the editorial board.
Accepted for printing in the Journal of Human Kinetics vol. 56/2017 in March 2017.
62 Core Muscle Activation in Suspension Training Exercises

stabilization exercises focused on efficient and Esco, 2014), whereas others investigated the
integration of low threshold recruitment of local effect of the application of suspension system on
and global muscle systems. Conversely, core core muscle activity in push exercises (Calatayud
strength training seems to require high intensity et al., 2014; McGill et al., 2014; Snarr and Esco,
and overload training of the global muscle 2013). Further investigation of these exercise
system. Vezina and Hubley-Kozey (2000) approaches is needed to understand their
suggested that core stability programmes should influence on muscle activation and joint load
include muscle activation below 25% of maximum levels.
voluntary contraction (MVC), while core strength The primary purpose of this study
training should include activation higher than therefore, was to examine differences in core
60% of MVC to result in strength benefits. muscle activation across four full-body linkage
The available evidence suggests that to exercises using a suspension training system.
adequately train the core muscles in athletes, These exercises were chosen from a spectrum of
strength and conditioning specialists should focus whole body linkage exercises focused on the
on implementing multi-joint full body exercises, anterior core musculature executed in instable
rather than core-specific exercises (Martuscello et conditions, including a roll-out, bodysaw, pike,
al., 2013). Exercises involving the full body and knee-up. Although the selected exercises
linkage such as plank exercises, have been were mainly focused on anterior slings, we
advocated to enhance the capacity of transmitting wanted to provide a comprehensive view of core
force through the body linkage (Schoenfeld et al., muscle activation by monitoring rectus
2014). Training with labile systems has been abdominis, internal and external oblique, and
documented to offer unique opportunities for paraspinal muscles. It was hypothesized that
linkage training challenges (McGill et al., 2015). significant differences would be found in core
Several studies examined core muscle activation muscles among exercises. The second aim of the
during the execution of various exercises on stable study was to determine which of these exercises
and unstable surfaces (for a review see: Behm et would reach the threshold of 60% of MVC,
al., 2010). The use of unstable surfaces contacting expected to be high enough to increase muscle
the subject’s feet or hands is becoming popular in strength. It was hypothesized that the four
strength training. Instability can be obtained exercises would elicit muscle activity in excess of
through the use of many devices and techniques 60% of MVC in the rectus abdominis, i.e. the
including, but not limited to, unstable platforms muscle on which the main focus was put
such as Bosu or Swiss balls. More recently, considering the selected exercises.
suspension training systems have been added to
the list of instability training devices.
Material and Methods
In suspension training, lower or upper Seventeen healthy participants were
limbs are hung with straps free to oscillate. Many recruited (age 27.3±2.4 years, body height 172±5
core directed exercises are designed with such a cm, body mass 69.2±9.3 kg). All participants were
device, creating a wide variety of challenges. physically active, declaring three practice sessions
These exercises consist of multi-planar and multi- per week of resistance training. The participants
joint movements, and are executed with complex had no prior experience with suspension training
techniques. It is important to quantify the muscle exercises. Inclusion criteria for study participation
contraction intensity since it is a key factor in were as follows: no past or present neurological or
establishing training effects induced by this sort of musculoskeletal trunk or limb pathology, no
exercises. Although considerable research has cardiorespiratory disease, no history of
examined more traditional means of instability abdominal, shoulder or back surgery, and no
training (Behm and Drinkwater, 2010), little psychological problems. Participants were
previous research has evaluated the effects of instructed to refrain from performing strenuous
suspension training on muscle activation. In physical activity in the 24 hours preceding all
particular, some studies focused on core-directed experimental sessions. All participants signed a
exercises (Atkins, 2014; Byrne et al., 2014; written informed consent form. The study was
Czaprowski et al., 2014; Mok et al., 2014; Snarr previously approved by the research ethics

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by Giovanni Cugliari and Gennaro Boccia 63

committee of the Department of Medical Sciences, asked to refrain from physical activity 24 hours
University of Turin. before the measurements. During the
The surface electromyographic (EMG) measurement session, participants performed 4
signals were obtained from six trunk muscles with exercises with the use of suspension straps (TRX®
concentric bipolar electrodes (CoDe, Spes Medica, suspension trainer; Fitness Anywhere LCC, San
Battipaglia, Italy). Before the placement of the Francisco, CA, USA) in random order. The
electrodes, the skin was slightly abraded with exercises were selected based on a previous study
adhesive paste and cleaned with water in (Behm and Drinkwater, 2010) that indicated them
accordance to SENIAM recommendation for skin as important in developing core strength.
preparation (Hermens et al., 2000). The electrodes At the beginning of the measurement
were placed according to the instructions session, three MVC exercises were performed
described in previous methodological works twice for 5 s, with 2 min rest between them. The
(Beretta Piccoli et al., 2014; Boccia and Rainoldi, following standardized exercises (Ng et al., 2002)
2014) – lower rectus abdominis: on the lower part were used to activate maximally the trunk
of the rectus abdominis, 3 cm lateral to the muscles (Figure 1):
midline; upper rectus abdominis: on the upper 1. Upper rectus abdominis (URA)
part of the rectus abdominis, 3 cm lateral to the and lower rectus abdominis (LRA): body supine
midline; external oblique: 14 cm lateral to the with hips and knees flexed 90°, with feet locked.
umbilicus, above the anterior superior iliac spine Participants flexed the trunk (i.e. crunch
(ASIS); internal oblique: 2 cm lower with respect execution) against resistance at the level of the
to the most prominent point of the ASIS, just shoulders;
medial and superior to the inguinal ligament; 2. External oblique (EO) and internal
lower erector spinae: 2 cm lateral to the L5-S1; oblique (IO): side-lying with the hip at the edge of
upper erector spinae: 6 cm lateral to the L1-L2. the bench and feet locked by a second operator.
The electrodes were placed only on the left Participants performed side-bend exercise against
(randomly chosen) side of the body; the reference resistance at the level of the shoulder;
electrode was positioned on the wrist. 3. Lower erector spinae (LES) and
The signal of a biaxial electrogoniometer upper erector spinae (UES): prone position with
(SG 150, Biometrics Ltd, Gwent, UK) positioned at ASIS at the edge of the bench and feet locked by a
the level of the shoulders (for the roll-out and second operator. Participants performed a back
bodysaw) or the hips (for the pike and knee-tuck), extension against resistance at the level of the
depending on which joint was more involved shoulders.
during the exercise, was used as a trigger to The suspension system handles were
highlight exercise repetitions. The electrodes were positioned 15 cm from the ground. Participants
fixed using extensible dressing (Fixomull®, were required to achieve a range of motion
Beiersdorf). The EMG signals were synchronized with the correct technique execution and to
with the electrogoniometer signal, amplified maintain a neutral position of the spine and pelvis
(EMG-USB, OT Bioelettronica, Torino, Italy), in each exercise. A certified strength and
sampled at 2048 Hz, bandpass filtered (3-dB conditioning coach monitored the exercise
bandwidth, 10- 450 Hz, 12 dB/oct slope on each performance to ensure that the exercise was
side), and converted to digital data by a 12-bit properly executed considering its technique. Each
A/D converter. Samples were visualized during exercise was repeated three times and lasted 6 s. A
acquisition and then stored in a personal metronome set at 30 beats per minute was used to
computer using OT BioLab software (version 1.8, ensure proper timing (with 4 beats for each
OT Bioelettronica, Torino, Italy) for further repetition): 2 s from the initial position to the final
analysis. position (concentric phase); 2 s of maintenance
The participants recruited were instructed (isometric phase); and 2 s returning to the starting
with regard to the correct technique of suspension position (eccentric phase). The exercises were
exercise and the MVC procedure during the first performed with 3 min of rest in-between to allow
experimental session conducted one week before complete recovery. The random order of the
the measurement session. The participants were exercises allowed to mitigate the effects of

© Editorial Committee of Journal of Human Kinetics

64 Core Muscle Activation in Suspension Training Exercises

cumulative fatigue on EMG estimates. Each Results are expressed as medians (Interquartile
session lasted approximately 90 min. The Range, IR).
following exercises were used (Figure 2):
1) Roll-out: participants assumed an
Results
inclined standing position while placing each All participants managed to complete
hand on the strap handles, with elbows and wrists each exercise trial and thus, were included in the
placed below the shoulders, arms perpendicular data analysis. Figure 3 shows the box plots of the
to the floor and shoulders flexed approximately activation values (% of MVC) of each muscle
45°; they then performed a shoulder flexion during the four exercises. Muscle activation
moving the hands forward; (Median, IR) expressed as percentage values of
2) Bodysaw: participants assumed a prone ARV normalized to MVCs is reported in Table 1.
position, they placed elbows below the shoulders, The normalized LRA activity was 140%
both forearms touching the floor, while placing (IR, 89%) of MVC during the roll-out, 100% (IR,
each foot on the strap handle; participants then 42%) of MVC during the bodysaw, 57% (IR, 36%)
flexed the shoulders and extended the elbows of MVC during the pike and 54% (IR, 50%) of
pushing the body backwards; MVC during the knee-tuck. The normalized LRA
3) Pike: participants assumed a push-up values were significantly higher (p < 0.01) during
position with the feet in strap handles, then they the roll-out and bodysaw compared to the pike
flexed hips to approximately 90°, while keeping and knee-tuck. The roll-out exercise showed
the knees fully extended; significantly greater activation (p < 0.01) than the
4) Knee-tuck: participants assumed a push- bodysaw.
up position while placing each foot in the strap The normalized URA activity was 67%
handle, then they flexed both hips and knees to (IR, 78%) of MVC during the roll-out, 57% (IR,
approximately 90°, bringing the knees forward. 52%) of MVC during the bodysaw, 41% (IR, 48%)
The average rectified value (ARV) of EMG of MVC during the pike and 44% (IR, 41%) of
signals was computed off-line with numerical MVC during the knee-tuck. The normalized URA
algorithms using non-overlapping signal epochs values were significantly higher (p < 0.01) during
of 0.5 s (Hibbs et al., 2011). The epoch with the the roll-out compared to the pike and knee-tuck.
highest ARV was chosen as reference in the The normalized EO activity was 71% (IR,
MVCs. The second and third repetitions of each 44%) of MVC during the roll-out, 59% (IR, 33%) of
exercise were analyzed. The mean value of ARV MVC during the bodysaw, 55% (IR, 21%) of MVC
over the two repetitions was calculated for each during the pike and 42% (IR, 7%) of MVC during
muscle and normalized with respect to the the knee-tuck. The normalized EO values were
maximum ARV obtained during the significantly higher (p < 0.01) during the roll-out
correspondent MVC. compared to the knee-tuck.
The normality assumption of the data was The normalized IO activity was 40% (IR,
evaluated with the Shapiro-Wilk test; 31%) of MVC during the roll-out, 32% (IR, 20%) of
homoscedasticity and autocorrelation of the MVC during the bodysaw, 23% (IR, 20%) of MVC
variables were assessed using the Breusch-Pagan during the pike and 18% (IR, 26%) of MVC during
and Durbin-Watson tests. The differences the knee-tuck. During all exercises the normalized
between exercises (pike – bodysaw – knee-tuck – IO values were not significantly higher (p < 0.01).
roll-out) and between muscles (LRA – URA – EO The normalized LES activity was 9% (IR,
– IO – LES – UES) were compared with the 2-way 5%) of MVC during the roll-out, 4% (IR, 3%) of
analysis of variance (ANOVA). For the purpose of MVC during the bodysaw, 12% (IR, 7%) of MVC
this report, only the results concerning differences during the pike and 8% (IR, 5%) of MVC during
between exercises were presented. For multiple the knee-tuck. During all exercises the normalized
comparisons, the Tukey test was used. The level LES values were not significantly higher (p < 0.01).
of significance was set at p < 0.01. Statistical The normalized UES activity was 11% (IR,
analyses were conducted using the R statistical 6%) of MVC during the roll-out, 8% (IR, 6%) of
package (version 3.0.3, R Core Team, Foundation MVC during the bodysaw, 9% (IR, 4%) of MVC
for Statistical Computing, Vienna, Austria). during the pike and 6% (IR, 5%) of MVC during

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by Giovanni Cugliari and Gennaro Boccia 65

the knee-tuck. During all exercises the normalized The roll-out exercise showed significantly
UES values were not significantly higher (p < (p < 0.01) higher activation compared to the
0.01). bodysaw (16%, CI 8-23%), pike (26%, CI 18-33%)
Table 2 shows the estimate (difference of and knee-tuck (29%, CI 21-37%). Pike and knee-
means) at 95% of the confidence interval after tuck exercises showed significantly higher
Tukey multiple comparisons; in this case only activation compared to the bodysaw of 10% (2-
"exercise factor" was considered. 8%) and 13% (6-21%).

Figure 1
Standardized exercises used to maximally activate trunk muscles:
Lower rectus abdominis and upper rectus abdominis (left);
Internal oblique and external oblique (middle);
Lower erector spinae and upper erector spinae (right).

Figure 2
Initial and final positions of each exercise: 1) Roll-out; 2) Bodysaw; 3) Pike; 4) Knee-tuck.

© Editorial Committee of Journal of Human Kinetics

66 Core Muscle Activation in Suspension Training Exercises

Figure 3
Each box plot shows the muscle activation (as percentage of maximum
voluntary contraction) during exercise.
Whiskers indicate variability outside the upper and lower quartiles.

Table 1
Muscle activation (Median, IR) expressed as percentage values
of electromyographic amplitude normalized to maximum voluntary contraction.
Results of the two-way ANOVA after Tukey multiple comparisons
are reported as symbols; p<0.01.

Lower rectus Upper rectus External Internal Lower erector Upper erector
abdominis abdominis oblique oblique spinae spinae
Pike 57 (36) ǂ § 41 (48) ǂ 55 (21) 23 (20) 12 (7) 9 (4)

Bodysaw 100 (42) ǂ Ф Ψ 57 (52) 59 (33) 32 (20) 4 (3) 8 (6)

Knee-tuck 54 (50) ǂ § 44 (41) ǂ 42 (7) ǂ 18 (26) 8 (5) 6 (5)

Roll-out 140 (89) § Ф Ψ 67 (78) Ф Ψ 71 (44) Ψ 40 (31) 9 (5) 11 (6)

Ф indicates statistically significant difference between

the indicated exercise (explained in row) with respect to the pike
§ indicates statistically significant difference between
the indicated exercise (explained in row) with respect to the bodysaw
Ψ indicates statistically significant difference between
the indicated exercise (explained in row) with respect to the knee-tuck
ǂ indicates statistically significant difference between
the indicated exercise (explained in row) with respect to the roll-out

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by Giovanni Cugliari and Gennaro Boccia 67

Table 2
Estimate at 95% of the confidence interval after Tukey multiple comparisons
with the "exercise factor" considered. The estimate shows
the difference of means (% of maximum voluntary contraction).
* indicates the statistical significance of the adjusted p-value.

Exercises Estimate Lower CI (95%) Upper CI (95%)

Bodysaw – Roll-out -16 * -23 -8

Pike – Roll-out -26 * -33 -18

Knee-tuck – roll-out -29 * -37 -21

Pike – Bodysaw -10 * -18 -2

Knee-tuck – Bodysaw -13 * -21 -6

Knee-tuck – Pike -3 -11 4

Discussion followed by bodysaw, pike and knee-tuck

exercises (Table 2). The roll-out showed the
Suspension training has become highest activation of rectus abdominis and
increasingly popular as a training tool. Despite oblique muscles compared to other exercises.
this popularity, relatively little research exists on However, not all muscles responded in the same
the effects of such training on muscle activation way across exercises. Although LRA showed
magnitude. The first objective of the study was to much greater activation in roll-out and bodysaw
investigate the activation differences of four compared to pike and knee-tuck exercises, the
exercises (roll-out, bodysaw, pike and knee-tuck) other muscles showed smaller differences. These
to better characterize suspension training. Our findings could suggest that in the exercises
findings indicate that suspension exercises could characterized by shoulder flexion (such as roll-out
be an effective strategy to reach high to very high and bodysaw), the increased requirement of core
activation of abdominal muscles such as the stability was reflected more by the lower rectus
rectus abdominis and external oblique. abdominis.
To facilitate comparisons between According to Vezina and Hubley-Kozey
exercises and previous studies, we categorized (2000), the exercises that generate muscle activity
muscle activation into four levels according to greater than 60% of MVC might be more
previous studies, with <21% as low, 21–40% as conducive to developing muscular strength. The
moderate, 41–60% as high, and >60% as very high rectus abdominis (both parts) and EO reached
(Escamilla et al., 2010). Exercises used in the activation higher than 60% of MVC (or very close
present study provide a range of medium to high to that threshold, 55%) in the roll-out and
intensity exercises through which participants or bodysaw; consequently these exercises can be
athletes can progress during a training or considered suitable for strength training of these
rehabilitation programme (Blanchard and muscles. Although in the knee-tuck and pike, the
Glasgow, 2014) (Figure 2). Roll-out exercise was rectus abdominis and EO did not reach the
the most challenging for core musculature, threshold of 60%, they presented high activation

© Editorial Committee of Journal of Human Kinetics

68 Core Muscle Activation in Suspension Training Exercises

levels (41-60% MVC). While strengthening of the levels were higher than previously reported
core is important, an activation level below 60% values obtained during the execution of the roll-
might be beneficial in increasing muscle out with the Swiss-ball (about 50-60% for rectus
endurance within the core. Since the core muscles abdominis) (Escamilla and Lewis, 2010; Marshall
are primarily composed of type I fibres and Desai, 2010) and similar to the values
(Haggmark and Thorstensson, 1979), muscular reported with the use of the Power Wheel, being
endurance should also be a major concern when very high for URA (76%) and LRA (81%)
designing strength and conditioning programmes (Escamilla et al., 2006). In the pike, we found high
(Vezina and Hubley-Kozey, 2000). Due to large activation of LRA (57%) and URA (41%). The
demand for muscle activation, all the proposed values reported for the pike executed with the
exercises might be appropriate for extremely fit Swiss ball (Escamilla and Lewis, 2010) and Power
individuals in the latter stages of a progressive Wheel (Escamilla and Babb, 2006) were similar for
abdominal strengthening or rehabilitation URA (Swiss ball 47%; Power Wheel 41%) and
programme. LRA (Swiss ball 55%; Power Wheel 53%). In the
Erector spinae muscles resulted in being knee-tuck, we observed high activation of LRA
activated at low and very low intensity. This is an (54%) and URA (44%). Otherwise, the values
expected result as all exercises focused on anterior reported for the knee-tuck executed with the
abdominal wall muscles. This finding confirms Swiss ball (Escamilla and Lewis, 2010) and Power
that in the herein selected whole-body linkage Wheel (Escamilla and Babb, 2006) were lower for
exercises, the activation of core muscles can be both URA (Swiss ball 32%; Power Wheel 41%)
mainly focused on abdominal muscles while and LRA (Swiss ball 35%; Power Wheel 45%).
keeping the paraspinal muscles involved with low Our findings suggest that the two parts of
intensity. the rectus abdominis can be activated differently
Although no direct comparison can be according to the needs of the motor task (Kibler et
made between the selected suspension exercises al., 2006). This finding could be explained by the
compared to previously reported similar possibility to (voluntary or involuntary) modulate
exercises, it is possible to highlight the following the activation ratio between rectus abdominis
differences. We can compare only the activation of parts in order to achieve the best control of the
the rectus abdominis, since for oblique muscles core region. This could be justified by the
we used a different normalization exercise than metameric innervation of rectus abdominis
the other three studies. Plank exercises are muscles (Duchateau et al., 1988), although this
frequently included in spine stabilization issue is still controversial (Monfort-Panego et al.,
programmes as a means of improving motor 2009). However, LRA muscles were generally
control for spine stabilization. When plank more active than URA because of confounding
exercises are performed on stable or unstable methodological factors. MVCs of the LRA and
support surfaces, the reported activation level of URA in fact were estimated by a standardized
the rectus abdominis and EO ranges from low to exercise to activate maximally the trunk muscles:
moderate (Garcia-Vaquero et al., 2012). When it could be argued that the same exercise fully
executed in suspension condition, rectus activated URA whereas it failed to fully activate
abdominis muscles also showed moderate LRA. Hence, the EMG amplitude recorded during
activation (Byrne and Bishop, 2014). Only when MVC was not the maximum achievable.
the planks were performed with a similar Consequently, throughout experimental exercises,
technique (instability on lower limb and shoulder LRA seemed relatively more active than URA
flexion) was the activation similar to that reported because its reference value of MVC was
here, which was very high for the rectus underestimated.
abdominis (McGill and Andersen, 2015). A few methodological limitations of our
Therefore, we can assume that our exercises were study warrant further consideration. In some
more challenging than an isometric plank in a cases, ARV estimates of EMG signals exceeded the
stable condition. MVC reference values (ARV higher than 100%).
In the roll-out, we found very high This inconsistency might be due to incomplete
activation of LRA (140%) and URA (67%). These activation during MVC (as in the case of the lower

Journal of Human Kinetics - volume 56/2017 http://www.johk.pl

by Giovanni Cugliari and Gennaro Boccia 69

rectus abdominis) and other confounding factors systems and reducing the problem of crosstalk
related to EMG technique (relative shift of muscle from nearby muscles (Farina and Cescon, 2001).
belly with respect to electrodes occurring in Conclusions
dynamic tasks and different activation between Findings from this study, based on
isometric and dynamic tasks, among others). electromyographic analysis, showed that roll-out
As widely reported, variability of exercise was the most challenging. Moreover, roll-
muscular activation between participants was out and bodysaw exercises executed in
high. This suggests that performing these suspension activated the rectus abdominis and
exercises, some individuals might produce more external oblique muscles at intensities higher
or less activation than the average activity than, or very close to, 60% of the maximum
indicated here. Although 17 individuals voluntary contraction. Based on these findings,
participated in this research, the differences in we can assume that roll-out and bodysaw
their fitness level and exercise experience could exercises can be used to adequately strengthen the
have affected the performance of the exercises and antero-lateral, superficial aspect of the core
the resulting activation levels. region, and thus they can be considered core
Crosstalk between muscles was strength exercises. These findings appear to have
minimized by using an innovative detection particular relevance for well-trained individuals
system based on concentric-ring electrodes which given the high demand imposed by these
had been reported as having higher spatial exercises.
selectivity compared to the traditional detection

Acknowledgements
This work was supported by Funding for Innovation Projects under grant Project HExEC, PQR FESR
2007/1013

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Journal of Human Kinetics - volume 56/2017 http://www.johk.pl

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Corresponding author:
Gennaro Boccia,
1) CeRiSM Research Center “Sport, Mountain, and Health”, via del Ben 5/b, 38068, Rovereto, (TN), Italy.
2) Motor Science Research Center, School of Exercise & Sport Sciences, SUISM, Department of Medical
Sciences, University of Turin. 12, piazza Bernini, 10143, Torino, Italy.
Address: 12, piazza Bernini, 10143, Torino, Italy;
Telephone: +39 0117764708
Fax: +39 011748251
E-mail gennaro.boccia@unito.it

© Editorial Committee of Journal of Human Kinetics

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