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The Effect of Grip Width and Hand Orientation on Muscle Activity During Pull-ups and the Lat Pull-down


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The Effect of Grip Width
and Hand Orientation on
Muscle Activity During
Pull-ups and the
Lat Pull-down
Kelly. L. M. Leslie, BSc (Hons) and Paul Comfort, MSc, CSCS*D
Directorate of Sport, Exercise and Physiotherapy, School of Health and Social Care, University of Salford, Salford,
Greater Manchester, United Kingdom
Numerous studies have been
conducted to identify muscle
activity during a range of ex-
ercises for both the lower body
(1,3,10,13,14,16,18) and upper body
(2,7,11). In addition, reviews discus-
sing optimal technique of exercises
such as the squat (4,5,17) and bench
press (9) have been published summa-
rizing the findings of prior research
from electromyographic (EMG) stud-
ies. However, no such review regard-
ing the performance of the variations
of pull-ups or lat pull-downs has been
Previous studies investigating lower
limb muscle activity during variations
of the back squat found that a wide
stance width rather than a narrow
stance width performed at 0–70% of
one repetition maximum (1RM) eli-
cited a 297% greater level of muscle
activity for the gluteus maximus, but
there were no differences for other
lower limb muscles (15). Similarly, an
increased squat depth (half squat 458,
parallel squat 908, full-depth squat 1258
knee flexion) resulted in a greater per-
centage contribution of the gluteus
maximus (3,14). In addition, rotating
the feet (neutral, 30–408medial, 808
lateral rotation) while performing the
squat, regardless of depth and stance
width (75–140% shoulder width), has
been shown to have no noticeable
effect on muscle activity of the thigh
muscles (rectus femoris, vastus medi-
alis, vastus lateralis, adductor longus,
semimembranosus, semitendinosus,
and biceps femoris) (5,6,13,14,18).
Studies that have investigated EMG
activity of upper-body muscles, during
the bench press exercise, highlighted
no significant effect in activity of the
sternocostal head of the pectorialis
major (P.0.05). The narrow grip, how-
ever, significantly increased the activity
of the clavicular head (P,0.01) and the
activity of the triceps brachii (P,0.05)
compared with the wide grip (2,11). In
addition, no significant difference 65%
(P.0.05) in 1RM performance was
identified between grip widths (100
and 200% biacromial width) (2,11). In
comparison, performing a push-up with
hands posterior to the normal hand
position resulted in an increased activa-
tion of the pectoralis major and triceps
brachii (8).
Previous investigations into the effect
that various hand positions, such as
grip width and hand orientation (supi-
nated, pronated, and neutral), have on
electromyography; latissimus dorsi;
performance; specificity
Copyright ÓNational Strength and Conditioning Association Strength and Conditioning Journal | 75
muscle activity during pull-ups and lat
pull-downs have demonstrated that
both grip width and hand orientation
affected muscle activity of selected
muscles (11,12,19,21).
Youdas et al. (21) found the pronated
grip (Figure 1) during pull-ups (56 6
21% maximum voluntary isometric
[MVIC]) to be most effective at acti-
vating the lower trapezius compared
with the supinated grip (45 622%
MVIC). The pronated grip (Figure 2)
also resulted in an increased muscle
activity of the infraspinatus (79 6
56% MVIC) compared with the grip
of the perfect pull-up (71 652%
MVIC), which uses 2 handles with
the ability to rotate 3608(the subject
starts with a pronated grip then the
movement ends with the subject in
a supinated grip). In contrast, the per-
fect pull-up was found to show an
increase of muscle activation of the
latissimus dorsi (130 653% MVIC)
compared with the supinated grip of
the chin-up (117 646% MVIC). The
supinated grip did elicit an increase in
pectoralis major muscle activity (57 6
36% MVIC versus 44 627% MVIC,
respectively) and bicep brachii (96 6
34% MVIC versus 78 632%, respec-
tively) compared with the pronated
variation. It is worth noting that %
MVIC for the latissimus dorsi, during
each variation of the exercises, was
greater than the MVIC for all other
muscles assessed.
Lusk et al. (12) conducted a study to
analyze whether grip width (wide and
narrow) and forearm orientation (supi-
nated and pronated grip performed at
both grip widths) had any effects on
muscle activity during lat pull-downs.
Using 70% 1RM, they found that a pro-
nated grip elicited a 9% greater muscle
activation of the latissimus dorsi as
opposed to a supinated grip. In con-
trast, they found no difference in
biceps brachii or mid-trapezius muscle
activity between a supinated or pro-
nated grip. A similar study investigat-
ing the differences in muscle activity
levels between the wide grip (pulled
to the anterior and posterior) and nar-
row grip (supinated and pronated grip)
lat pull-down, by Signorile et al. (19),
demonstrated that a pronated grip
elicits a higher muscle activation of
the latissimus dorsi compared with
a supinated grip. The pectoralis major
indicated higher muscle activity during
the neutral grip compared with the
pronated grip; although this is clearly
not a pectoral exercise, with Youdas
et al. (21) demonstrating pectoral
activity of only 44–57% MVIC during
various types of pull-ups. The poste-
rior deltoid showed no difference in
muscle activity across all hand orien-
tations. In contrast, Lehman (11)
investigated the muscle activation lev-
els during the lat pull-downs, using a
10RM load, and little difference was
found in the muscle activity between
the pronated and supinated grips for
the latissimus dorsi and the biceps.
Lehman (11) found no significant dif-
ference in the muscle activation of the
biceps and the latissimus dorsi
between the narrow supinated grip
(Figure 2) and wide pronated grip
(Figure 3) lat pull-downs. Interestingly,
they did identify that the highest level
of latissimus dorsi activity is reached
when performing the seated row with
the shoulders retracted. Unfortunately,
as both hand orientation and grip
width were simultaneously altered in
this study, any differences in muscle
activity due to either grip width or
hand orientation are not identifiable.
Similarly, Lusk et al. (12) found that
grip width, during the lat pull-down,
resulted in no difference in latissimus
dorsi, biceps brachii, or mid-trapezius
muscle activity. However, because the
wide grip variation was only slightly
wider than the narrow grip variation,
it may have masked any minor
Only the study by Sperandei et al. (20)
that has compared the wide grip lat
pull-downs with the front and behind
neck with a standardized grip width
and hand orientation demonstrated
higher latissimus dorsi and posterior
deltoid muscle activity during lat pull-
downs to the front, compared with
behind neck. Unfortunately, this study
did not compare between grip widths.
If individuals are to select the behind
neck version of the exercise, it is essen-
tial to ensure that the individual has
adequate range of motion to perform
Figure 1. Close pronated grip hand
Figure 2. Supinated grip hand position.
Figure 3. Wide grip hand position.
Pull-ups and Lat Pull-downs
the exercise safely and effectively
throughout the entire range (Tables 1
and 2).
It is worth noting that the differences
observed between grip widths may be
a result of the differences in range of
motion which occur between a narrow
and wide grip, rather than the actual
positioning of the hands.
It is suggested that when training the
latissimus dorsi using the lat pull-
downs a pronated grip be used or
rotating handles can be used, if avail-
able during pull-ups. A supinated grip,
during pull-ups, tends to result in an
increase in biceps brachii activity;
however, such a hand position may
not be specific for certain sports. Fur-
ther research is required to clarify the
effect of grip width on muscle activity
lat pull-downs.
Kelly L. M.
Leslie is a gradu-
ate from the
Sports Science
program at the
University of
Paul Comfort is
the program
leader for the
MSc Strength
and Condition-
ing at the Uni-
versity of Salford.
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Table 1
Highest muscle activity during variations of pull-ups with different hand
Hand orientation Increased muscle activity
Pronated grip Lower trapezius
Supinated grip Pectoralis major
Biceps brachii
Perfect pull-up (3608rotating handles) Latissimus dorsi
Results are taken from Youdas et al. (21).
Not a pectoral exercise.
Table 2
Highest muscle activity during variations of lat pull-downs with different
hand orientations
Hand orientation Increased muscle activity No difference in muscle activity
Pronated grip Latissimus dorsi (12,19) Middle trapezius (12)
Supinated grip Biceps brachii (12)
Neutral Pectoralis major (19) Posterior deltoid (19)
Greatest muscle activity compared with other variations.
Strength and Conditioning Journal | 77
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Pull-ups and Lat Pull-downs
... Many fitness professionals work under the assumption that variations of pull-up exercises may train different muscles to differing degrees (i.e. pronated grip pull-ups for latissimus dorsi adaptation), however, there is little evidence to support this assumption (Leslie and Comfort, 2013). Additionally, uniformed services (Police, Armed Forces) commonly use pull-up variants to train muscular strength, in different muscles required to perform certain operational tasks, such as repelling and ladder climbing. ...
... Pull-up variants that result in differing levels of muscle activation may inevitably promote different degrees of strength adaption in particular muscles. Hence, it is important for fitness professionals to understand the level of muscle activation in the shoulder-arm-forearm complex when prescribing variations of the pull-up exercise (Leslie and Comfort, 2013). Ricci et al. (1988) analysed activation of seven shoulder and arm muscles during shoulder width supinated and pronated grip pullup exercises; results showed similar activation of muscles irrespective of hand orientation. ...
... Conversely, Youdas et al. (2010) demonstrated significantly greater activation of the lower trapezius during pronated grip when compared to supinated grip pull-ups; while the supinated grip revealed significantly greater activation of the pectoralis major and biceps brachii when compared to the pronated grip. Additional muscles may contribute to different grip orientations (Leslie and Comfort, 2013), however the latter research only analysed four muscles. ...
This study sought to identify any differences in peak muscle activation (EMGPEAK) or average rectified variable muscle activation (EMGARV) during supinated grip, pronated grip, neutral grip and rope pull-up exercises. Nineteen strength trained males (24.9 ± 5 y; 1.78 ± 0.74 m; 81.3 ± 11.3 kg; 22.7 ± 2.5 kg·m¯²) volunteered to participate in the study. Surface electromyography (EMG) was collected from eight shoulder-arm-forearm complex muscles. All muscle activation was expressed as a percentage of maximum voluntary isometric contraction (%MVIC). Over a full repetition, the pronated grip resulted in significantly greater EMGPEAK (60.1 ± 22.5 vs. 37.1 ± 13.1%MVIC; P = .004; Effect Size [ES; Cohen’s d] = 1.19) and EMGARV (48.0 ± 21.2 vs. 27.4 ± 10.7%MVIC; P = .001; ES = 1.29) of the middle trapezius when compared to the neutral grip pull-up. The concentric phases of each pull-up variation resulted in significantly greater EMGARV of the brachioradialis, biceps brachii, and pectoralis major in comparison to the eccentric phases (P = < 0.01). Results indicate that EMGPEAK and EMGARV of the shoulder-arm-forearm complex during complete repetitions of pull-up variants are similar despite varying hand orientations; however, differences exist between concentric and eccentric phases of each pull-up.
... There is a lack of studies about the impact of the exercise technique in the PU performance. However, even small differences in grip width or hand position can affect muscle activation and mechanical variables (Dickie et al., 2017;Leslie & Comfort, 2013). Up until now, differences in PU muscle activation by change in hand orientation (supinated, pronated, neutral and rope grips) have been described (Dickie et al., 2017;Leslie & Comfort, 2013). ...
... However, even small differences in grip width or hand position can affect muscle activation and mechanical variables (Dickie et al., 2017;Leslie & Comfort, 2013). Up until now, differences in PU muscle activation by change in hand orientation (supinated, pronated, neutral and rope grips) have been described (Dickie et al., 2017;Leslie & Comfort, 2013). The scapular kinematics and external forces in three PU techniques (supinated, narrow and wide pronated grips) have also been addressed (Prinold & Bull, 2016). ...
Purpose: The objective of this study was to investigate the influence of the grip width on the power-force-velocity-profile, the maximal strength, and performance during a repetition to failure test in the pull-up exercise (PU). Method: Fourteen trained males performed an incremental loading and repetitions to failure test with the PU exercise using biacromial and free grip widths. Power-force-velocity relationship, 1RM, and repetitions completed were determined. Results: The mean grip width used by participants was 20.04% higher in the free grip width condition (p < .001). There were similar results in the 1RM (p = .954), repetitions to failure test (p = .117), and power-force-velocity profile (p > .05) in both grip width conditions. A stronger relationship was observed between 1RM and repetitions to failure test during the biacromial (R ² = 0.720; p < .001) with respect to the free grip width (R ² = 0.607; p = .002). Conclusion: Therefore, the choice of a free or a biacromial grip width does not affect the maximal strength, power-force-velocity relationship, nor the repetitions to failure during the PU exercise.
... Exercises to improve upper-body muscular hypertrophy and pulling strength are integral parts of strength and conditioning programs for athletes, military professionals, first responders, and clients interested in improving their musculoskeletal fitness and physical performance (3,5,6,(9)(10)(11)(12)(13)(14). Pull-ups have been implemented routinely as physical fitness testing and training tools with persons performing tasks requiring a large upper-body strength-to-body mass ratio. ...
... The glenohumeral or shoulder joints are adducted by concentric actions of the latissimus dorsi, teres major, pectoralis major, subscapularis, infraspinatus, and posterior deltoid muscles (1,2,4,(8)(9)(10)14). The elbows, wrists, and hands are flexed by the biceps brachii, brachialis, brachioradialis, flexor carpi radialis, flexor carpi ulnaris, palmaris longus, flexor digitorum profundus, flexor digitorum superficialis, and flexor policis longus muscles (1,4,6,14). Maximal work and repetitions can be performed by maintaining a smooth and steady, controlled, and self-selected speed during the ascending phase of the pull-up (7). ...
Pull-ups are a multijoint exercise and require minimal equipment to perform. They can be progressed or regressed to increase and improve upper body muscular strength, endurance, hypertrophy, and performance of tasks that require upper body pulling strength. Proper technique and control should not be sacrificed to perform more repetitions.
... In future studies, it would be worthwhile to compare the PAPE response in subjects performing one-arm pull-ups in unassisted and assisted forms and also to determine the magnitude of relief more precisely, perhaps based on the velocity of the movement known to be related to RM magnitude (González-Badillo and Sánchez-Medina, 2010;Loturco et al., 2021;Pérez-Castilla and García-Ramos, 2020). The one-arm pull-up is slightly different in movement structure compared to the power slap, and despite the involvement of the same muscle groups, muscle activation patterns may slightly vary (Dickie et al., 2017;Kozin et al., 2020;Leslie and Comfort, 2013). Considering the criterion of biomechanical similarity between complementary exercises (resistance exercise -explosive exercise), weighted pull-ups performed in the traditional two arms manner may be an exercise that fulfils this condition more fully than one-arm pull-ups. ...
Full-text available
This study aimed to compare the acute effects of performing two kinds of pull-ups: traditional, pronated grip pull-ups performed with two arms and additional weight with loading intensity of 5RM and one-arm pull-ups, on specific upper body climbing power. Twenty-four advanced climbers participated in the study. The International Rock Climbing Research Association (IRCRA) Power Slap Test was chosen to assess specific upper body climbing power. All athletes performed the test under three conditions: control (without a conditioning activity) and both kinds of pull-ups as conditioning activities. Results revealed significant improvements in the Power Slap's distance, power, velocity, and force in 5RM weighted pull-ups, but not in one-arm pull-ups. In the latter case, participants reached higher power values after the conditioning stimulus, but the effect size was small. Also, the differences with the remaining variables (power, speed, and force) were non-significant. The results suggest that weighted pull-ups with a 5RM intensity and not one arm pull-ups seem to be an effective PAPE stimulus. Therefore, the former can be used as a conditioning activity before an explosive climbing exercise such as the Power Slap on a campus board.
... The second step is to calculate the N frequency spectra corresponding to these N time domain signals. Lastly, the N spectra are synthesized into a single frequency spectrum (Leslie & Comfort, 2013;McGill et al., 2014) ...
Full-text available
In this paper, Diagnostic Electromyography (D-EMG) signal interpretation of human arm towards characterization of arm-muscle interaction during various arm movements has been discussed. EMG signals from four important arm muscle (i.e., Bicepsbracci, Tricepsbracci, brachioradialis, and lateral deltoids) are recorded clinically during five different arm movements (i.e., Extension of the forearm, flexion of elbow joint, pronation of forearm, shoulder abduction, and Wrist flexor stretch) under load condition (a load of 2 Kg & 4 Kg maintained during experimental arm movement), the recorded D-EMG signals are properly enveloped within a range of 5–100 Hz and quantized within a proper sampling frequency range to produce a knowledge-based database of muscle activity. In addition, correlation of muscle activity and Power spectral density (PSD) analysis has been carried out towards muscle process discriminating during various arm actions.
... Participants executed three MVIC per muscle; surface EMG signal of all muscular action were taken in random basis. Each muscular activity was held for 3-5 seconds, with one minute rest (Leslie et al., 2013). Peak EMG data recorded during drawing loads. ...
... The lat pull-down exercise is used to optimise neuromuscular adaptations (i.e. strength and muscle hypertrophy) of the latissimus dorsi (LD) muscle (Doma, Deakin, & Ness, 2013;Leslie & Comfort, 2013). However, it is speculated that low levels of strength and fatiguability of the forearm flexor muscles during lat pull-down may prevent some optimal strength gains and muscle hypertrophy in the LD muscle. ...
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The objective of the study was to investigate the effects of using lifting straps on the lat pull-down exercise on maximal strength, number of repetitions, and muscle activation. Twelve resistance-trained men participated (age 27 ± 4 years, body mass 84 ± 10 kg, height 177 ± 6 cm, resistance training experience 6.6 ± 2.4 years). All participants performed the 1RM tests and training protocols either with the lifting straps (WS) or without (WOS). Exercise sessions for both conditions (WS and WOS) consisted of 3 sets to concentric failure with a load of 70% of one repetition maximum (1RM) and rest intervals of 60 s. For the 1RM test, no difference was observed between WS and WOS conditions (96.5 ± 12.7 kg and 96.6 ± 11.9 kg, respectively). There were no differences between the WS and WOS conditions in the number of repetitions per set, total repetitions and latissimus dorsi muscle activation. In conclusion, the findings of this study demonstrate that the use of lifting straps in the lat pull-down exercise by resistance-trained individuals does not promote beneficial effect in the 1RM value, the number of repetitions performed with 70% of 1RM, and muscle activation.
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PURPOSE:There are various variables such as exercise posture, exercise intensity, number of repetitions, and rest time of training for muscle strength development, and these variables are intended to stimulate muscle activity. The purpose of this study was to examine the effects of muscle activation according to grip thickness in pull-up exercise.METHODS: Eleven healthy men were randomly crossover design assigned to pull-up exercise (concentric: 1-s, eccentric: 1-s, 2-s/repetition) to failure. Surface electromyography (EMG) was recorded from the forearm flexors/extensors, biceps brachii, trapezius middle/lower and latissimus dorsi for muscle activation. Using the resulting EMG data, which were filtered of electromyogram artifacts, we calculated the root mean squares (RMS).RESULTS: Dependent-sample t-test produced a result, muscle activity in forearm flexors (p<.01), biceps brachii (p<.01), trapezius middle (p<.01), trapezius lower (p<.01) and latissimus dorsi (p<.05) were significantly increased at thick grip compared to normal grip in pull-up exercise.CONCLUSIONS:This study suggested that the thicker the grip, the higher the muscle activation. Using a grip thickness as one of the variables for training programs is considered as a method to stimulate muscle activity.
The lat pulldown is an open kinetic chain, multijoint exercise that is appropriate for novice, intermediate, and advanced level exercisers and can be performed with a number of types f equipment and requires minimal equipment to perform. It can be progressed or regressed to increase and improve upper body muscular strength, endurance, hypertrophy, and performance of tasks that require upper body pulling strength. Its utility as a safe and effective strength development tool is predicated on sound instruction, effective supervision, and proper execution.
This study aimed to: (a) determine the inter-rater reliability of the proposed muscle dysmorphia criteria, (b) investigate if muscle dysmorphia (MD) represented a syndrome of frequently co-occurring symptoms, and (c) determine the level of correlation between the proposed MD criteria and the Muscle Appearance Satisfaction Scale. Men (N = 48) aged 18 years and older who were currently participating in resistance training were assessed using the Muscle Appearance Satisfaction Scale and a one-on-one interview. Two qualified psychologists assigned a diagnosis of MD to those participants who appeared to meet the proposed criteria for MD. Inter-rater reliability and the frequency of co-occurring symptoms in participants were assessed. The correlation between MD and the Muscle Appearance Satisfaction Scale was explored. The inter-rater reliability between the researchers was low (Cohen's kappa = .39; p ≤ .05). A Binomial test revealed that MD represented a syndrome of frequently co-occurring symptoms; there was a significant probability (>.70) of a participant with one diagnostic symptom of MD (criterion 2a or 3) to exhibit another symptom (criterion 1) of the disorder. Point-biserial correlation indicated that the proposed MD criteria, excluding criterion 2b, were significantly correlated with the total score of the Muscle Appearance Satisfaction Scale and its subscales, excluding Muscle Satisfaction. The study provides some evidence to question the acceptance of the proposed MD criteria.
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summary: There are many variations of the squat technique, including stance width, foot positioning, and squat depth. However, research indicates that the optimal squat technique is a wide stance (>= shoulder width) with natural foot positioning, unrestricted movement of the knees, and full depth while the lordotic curve of the lumbar spine is maintained with a forward or upward gaze. (C) 2007 National Strength and Conditioning Association
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This experiment investigated the effects of varying bench inclination and hand spacing on the EMG activity of five muscles acting at the shoulder joint. Six male weight trainers performed presses under four conditions of trunk inclination and two of hand spacing at 80% of their predetermined max. Preamplified surface EMG electrodes were placed over the five muscles in question. The EMG signals during the 2-sec lift indicated some significant effects of trunk inclination and hand spacing. The sternocostal head of the pectoralis major was more active during the press from a horizontal bench than from a decline bench. Also, the clavicular head of the pectoralis major was no more active during the incline bench press than during the horizontal one, but it was less active during the decline bench press. The clavicular head of the pectoralis major was more active with a narrow hand spacing. Anterior deltoid activity tended to increase as trunk inclination increased. The long head of the triceps brachii was more active during the decline and flat bench presses than the other two conditions, and was also more active with a narrow hand spacing. Latissimus dorsi exhibited low activity in all conditions. (C) 1995 National Strength and Conditioning Association
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summary: Bodybuilders, athletes, and recreational lifters select a grip width during the bench press that they believe will produce a greater force output. Research has demonstrated that a wide grip (> 1.5 biacromial width) may increase the risk of shoulder injury, including anterior shoulder instability, atraumatic osteolysis of distal clavicle, and pectoralis major rupture. Reducing grip width to <=1.5 biacromial width appears to reduce this risk and does not affect muscle recruitment patterns, only resulting in a +/-5% difference in one repetition maximum. (C) 2007 National Strength and Conditioning Association
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Based on electromyographic (EMG) studies, an anterior (in front of the face) wide grip with a pronated forearm has been recommended as the optimal lat pull-down (LPD) variation for strengthening the latissimus dorsi (LD) (Signorile, JF, Zink, A, and Szwed, S. J Strength Cond Res 16: 539-546, 2002; Wills, R, Signorile, J, Perry, A, Tremblay, L, and Kwiatkowski, K. Med Sci Sports Exerc 26: S20, 1994). However, it is not clear whether this finding was because of grip width or forearm orientation. This study aimed to resolve this issue by comparing wide-pronated, wide-supinated, narrow-pronated, and narrow-supinated grips of an anterior LPD. Twelve healthy men performed the 4 grip variations using an experimentally determined load of 70% of 1 repetition maximum. Two trials of 5 repetitions were analyzed for each grip type. Participants maintained a cadence of 2-second concentric and 2-second eccentric phases. The grip widths were normalized for each individual by using a wide grip that corresponded to their carrying width and a narrow grip that matched their biacromial diameter. Surface EMG of the LD, middle trapezius (MT), and biceps brachii (BB) was recorded, and the root mean square of the EMG was normalized, using a maximum isometric voluntary contraction. Repeated-measures analysis of variance for each muscle revealed that a pronated grip elicited greater LD activity than a supinated grip (p < 0.05), but had no influence of grip type on the MT and BB muscles. Based on these findings, an anterior LPD with pronated grip is recommended for maximally activating the LD, irrespective of the grip width (carrying width or biacromial diameter).
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The squat is one of the most frequently used exercises in the field of strength and conditioning. Considering the complexity of the exercise and the many variables related to performance, understanding squat biomechanics is of great importance for both achieving optimal muscular development as well as reducing the prospect of a training-related injury. Therefore, the purpose of this article is 2-fold: first, to examine kinematics and kinetics of the dynamic squat with respect to the ankle, knee, hip and spinal joints and, second, to provide recommendations based on these biomechanical factors for optimizing exercise performance.
During knee rehabilitation, squats are a commonly used closed kinetic chain exercise. We have been unable to locate data reporting electromyographic (EMG) activity of lower extremity musculature during maximal effort squats and the contribution of gastrocnemius and gluteus maximus muscles. Therefore, the purposes of this study were (a) to quantify EMG activity of selected lower extremity muscles during a maximal isometric squat and during a maximal voluntary isometric contraction (MVIC), and (b) to determine ratios between the vastus medialis oblique (VMO) and vastus lateralis (VL) during maximal isometric squat and MVIC testing. Twenty-three subjects participated in a single testing session. Results are as follows: intraclass correlations for MVIC testing and squat testing ranged from .60 to .80 and .70 to .90, respectively. Percentage MVIC during the squat was as follows: rectus femoris 40 ± 30%, VMO 90 ± 70%, VL 70 ± 40% hamstrings 10 ± 10%, gluteus maximus 20 ± 10%, and gastrocnemius 30 ± 20%. No statistical difference existed in VMO:VL ratios during MVIC or squat testing. We conclude that large variations in muscle recruitment patterns occur between individuals during isometric squats.
The purpose of this study was to determine the relationship between motor unit recruitment within two areas of the pectoralis major and two forms of bench press exercise. Fifteen young men experienced in weight lifting completed 6 repetitions of the bench press at incline and decline angles of +30 and -15[degrees] from horizontal, respectively. Electrodes were placed over the pectoralis major at the 2nd and 5th intercostal spaces, midclavicular line. Surface electromyography was recorded and integrated during the concentric (Con) and eccentric (Ecc) phases of each repetition. Reliability of IEMG across repetitions was r = 0.87. Dependent means t-tests were used to examine motor unit activation for the lower (incline vs. decline) and upper pectoral muscles. Results showed significantly greater lower pectoral Con activation during decline bench press. The same result was seen during the Ecc phase. No significant differences were seen in upper pectoral activation between incline and decline bench press. It is concluded there are variations in the activation of the lower pectoralis major with regard to the angle of bench press, while the upper pectoral portion is unchanged. (C) 1997 National Strength and Conditioning Association
This study compared a conventional pull-up and chin-up with a rotational exercise using Perfect·Pullup™ twisting handles. Twenty-one men (24.9 ± 2.4 years) and 4 women (23.5 ± 1 years) volunteered to participate. Electromyographic (EMG) signals were collected with DE-3.1 double-differential surface electrodes at a sampling frequency of 1,000 Hz. The EMG signals were normalized to peak activity in the maximum voluntary isometric contraction (MVIC) trial and expressed as a percentage. Motion analysis data of the elbow were obtained using Vicon Nexus software. One-factor repeated measures analysis of variance examined the muscle activation patterns and kinematic differences between the 3 pull-up exercises. Average EMG muscle activation values (%MVIC) were as follows: latissimus dorsi (117-130%), biceps brachii (78-96%), infraspinatus (71-79%), lower trapezius (45-56%), pectoralis major (44-57%), erector spinae (39-41%), and external oblique (31-35%). The pectoralis major and biceps brachii had significantly higher EMG activation during the chin-up than during the pull-up, whereas the lower trapezius was significantly more active during the pull-up. No differences were detected between the Perfect·Pullup™ with twisting handles and the conventional pull-up and chin-up exercises. The mean absolute elbow joint range of motion was 93.4 ± 14.6°, 100.6 ± 14.5°, and 99.8 ± 11.7° for the pull-up, chin-up, and rotational exercise using the Perfect·Pullup™ twisting handles, respectively. For each exercise condition, the timing of peak muscle activation was expressed as a percentage of the complete pull-up cycle. A general pattern of sequential activation occurred suggesting that pull-ups and chin-ups were initiated by the lower trapezius and pectoralis major and completed with biceps brachii and latissimus dorsi recruitment. The Perfect·Pullup™ rotational device does not appear to enhance muscular recruitment when compared to the conventional pull-up or chin-up.
The purpose of this work was to evaluate the activity of the primary motor muscles during the performance of 3 lat pull-down techniques through surface electromyography (EMG). Twenty-four trained adult men performed 5 repetitions of behind-the-neck (BNL), front-of-the-neck (FNL), and V-bar exercises at 80% of 1 repetition maximum. For each technique, the root mean square from the EMG signal was registered from the pectoralis major (PM), latissimus dorsi (LD), posterior deltoid (PD), and biceps brachii (BB) and further normalized in respect to that which presented the highest value of all the techniques. A series of two-way repeated measures analysis of variance was used to compare the results, with Tukey-Kramer as the post hoc test and alpha = 0.05. During the concentric phase, PM value showed the FNL to be significantly higher than V-bar/BNL and V-bar higher than BNL. During the eccentric phase, FNL/V-bar was higher than BNL. For LD, there was no difference between techniques. PD presented BNL higher than FNL/V-bar and FNL higher than V-bar in the concentric phase and BNL higher than V-bar in the eccentric phase. BB exhibited BNL higher than V-bar/FNL and V-bar higher than FNL in both concentric and eccentric phases. Considering the main objectives of lat pull-down, we concluded that FNL is the better choice, whereas BNL is not a good lat pull-down technique and should be avoided. V-bar could be used as an alternative.
Many strength trainers believe that varying the stance width during the back squat can target specific muscles of the thigh. The aim of the present work was to test this theory measuring the activation of 8 thigh muscles while performing back squats at 3 stance widths and with 3 different bar loads. Six experienced lifters performed 3 sets of 10 repetitions of squats, each one with a different stance width, using 3 resistances: no load, 30% of 1-repetition maximum (1RM), and 70% 1RM. Sets were separated by 6 minutes of rest. Electromyographic (EMG) surface electrodes were placed on the vastus medialis, vastus lateralis, rectus femoris, semitendinosus, biceps femoris, gluteus maximus, gluteus medium, and adductor maior. Analysis of variance and Scheffè post hoc tests indicated a significant difference in EMG activity only for the gluteus maximus; in particular, there was a higher electrical activity of this muscle when back squats were performed at the maximum stance widths at 0 and 70% 1RM. There were no significant differences concerning the EMG activity of the other analyzed muscles. These findings suggest that a large width is necessary for a greater activation of the gluteus maximus during back squats.