Biomechanics
Narrative Review
2017
An electromyographic analysis of lateral raise variations and frontal raise in competitive bodybuilders
By Robert G. Lockie and Matthew R. Moreno
International Journal of Exercise Science, 10(7), pp. 1029-1038
<h2>Abstract</h2>
<p>The barbell bench press is one of the most widely performed upper body resistance exercises, and <a href="/terms/grip-width/" class="term-link" data-slug="grip-width" title="grip width">grip width</a> is a key technical variable that influences the distribution of muscular demand across the pectoralis major, anterior deltoid, and triceps brachii. Despite its practical importance, comprehensive evidence on how grip width modification affects <a href="/terms/muscle-activation/" class="term-link" data-slug="muscle-activation" title="muscle activation">muscle activation</a> patterns and the associated biomechanical and injury risk implications has not been systematically reviewed.</p>
<p>This review synthesizes electromyographic (<a href="/terms/electromyography/" class="term-link" data-slug="electromyography" title="EMG">EMG</a>) and biomechanical evidence on bench press grip width, examining the effects of narrow (≤1.0× biacromial width), medium (1.0–1.5× biacromial width), and wide (≥1.5× biacromial width) grip configurations on primary mover activation, joint kinetics, and shoulder injury risk. Evidence indicates that wider grips increase pectoralis major activation while reducing <a href="/terms/range-of-motion/" class="term-link" data-slug="range-of-motion" title="range of motion">range of motion</a>; narrow grips preferentially recruit the triceps brachii with greater range of motion; and medium grips provide a balance of pectoral and triceps activation with optimized joint kinematics. Shoulder contact forces increase substantially with wider grip widths, elevating injury risk. Practical training recommendations are provided for athletes with varying goals and musculoskeletal considerations.</p>
<h2>Introduction</h2>
<p>The barbell bench press is universally employed across powerlifting, bodybuilding, and general strength training as a primary measure and developer of upper body pushing strength. <a href="/terms/grip-width/" class="term-link" data-slug="grip-width" title="Grip width">Grip width</a>—the distance between the hands on the barbell—is a fundamental technical parameter that athletes and coaches modify to target specific muscle groups, accommodate individual anatomy, maximize performance, or manage injury risk [1].</p>
<p>In competitive powerlifting, the International Powerlifting Federation (IPF) permits a maximum grip width of 81 cm between index fingers, while athletes often strategically select wide grips to minimize barbell displacement and thus maximize lifted load. Bodybuilders and <a href="/terms/muscle-hypertrophy/" class="term-link" data-slug="muscle-hypertrophy" title="hypertrophy">hypertrophy</a>-focused trainees, by contrast, may select grip width based on perceived chest activation rather than performance optimization. General fitness practitioners may use a self-selected "comfortable" grip without systematic consideration of its biomechanical consequences [2].</p>
<p>The <a href="/terms/muscle-activation/" class="term-link" data-slug="muscle-activation" title="muscle activation">muscle activation</a> implications of grip width are mechanistically intuitive. A wider grip places the humerus in greater initial abduction, reducing the joint angle through which the pectoralis major must work but placing it at a more favorable length-tension relationship for mid-range activation [3]. A narrower grip increases the <a href="/terms/range-of-motion/" class="term-link" data-slug="range-of-motion" title="range of motion">range of motion</a> traversed at the elbow, shifting relative demand toward the triceps brachii as the primary extensor. The anterior deltoid contributes across all grip widths but may be differentially recruited at intermediate angles.</p>
<p>Beyond muscle activation, grip width carries significant joint kinetic implications. A very wide grip has been associated with increased anterior capsule stress at the glenohumeral joint and elevated risk for pectoralis major <a href="/terms/tendon/" class="term-link" data-slug="tendon" title="tendon">tendon</a> injury [4]. Understanding the <a href="/terms/dose-response-relationship/" class="term-link" data-slug="dose-response-relationship" title="dose-response relationship">dose-response relationship</a> between grip width, muscle activation, and joint loading is therefore essential for program design that maximizes hypertrophic efficacy while managing injury risk.</p>
<h3>References</h3>
<p>[1] Lehman GJ. The influence of grip width and forearm pronation/supination on upper-body myoelectric activity during bench press. <em>J Strength Cond Res</em>. 2005;19:587–591.
[2] Barnett C, et al. Effects of variations of the bench press exercise on <a href="/terms/electromyography/" class="term-link" data-slug="electromyography" title="EMG">EMG</a> activity. <em>J Strength Cond Res</em>. 1995;9:222–227.
[3] Glass SC, Armstrong T. Electromyographical activity of the pectoralis muscle. <em>J Strength Cond Res</em>. 1997;11:286–289.
[4] Green CM, Comfort P. The effect of grip width on bench press performance. <em>Strength Cond J</em>. 2007;29:10–14.</p>
<h2><a href="/terms/grip-width/" class="term-link" data-slug="grip-width" title="Grip Width">Grip Width</a> and <a href="/terms/muscle-activation/" class="term-link" data-slug="muscle-activation" title="Muscle Activation">Muscle Activation</a> Analysis</h2>
<h3>Pectoralis Major</h3>
<p>Electromyographic evidence consistently demonstrates that wider grip widths produce greater normalized <a href="/terms/electromyography/" class="term-link" data-slug="electromyography" title="EMG">EMG</a> amplitude in the pectoralis major compared with narrow grips [1]. Specifically, grip widths of 1.5–2.0× biacromial distance have been associated with 10–25% higher pectoralis major activation than grip widths at or below biacromial distance. This pattern holds for both the sternal (lower) and clavicular (upper) heads of the pectoralis major, though the magnitude of the grip width effect is somewhat greater for the sternal fibers.</p>
<p>The mechanistic basis for this finding is the altered line of pull at wider grips, which more closely aligns with the pectoralis major's primary action of horizontal adduction. At wider grips, the contribution of the triceps to force generation is relatively reduced, causing a proportional increase in pectoral demand per unit of total work performed.</p>
<h3>Triceps Brachii</h3>
<p>In contrast to the pectoralis major, the triceps brachii demonstrates greater relative activation at narrower grip widths [2]. At grip widths of ≤0.5× biacromial distance (close grip), triceps EMG amplitude is approximately 30–40% higher than at wide grip conditions. This increased triceps demand at close grips occurs because the reduced mechanical advantage of the pectoralis major (due to the altered joint angle) necessitates greater elbow extensor contribution to complete the pressing movement.</p>
<h3>Anterior Deltoid</h3>
<p>The anterior deltoid shows relatively consistent activation across grip widths, though several studies report marginally higher activation at intermediate grip widths. This finding suggests that the anterior deltoid functions more as a stabilizer whose activation is less sensitive to grip width than the primary movers.</p>
<h3><a href="/terms/range-of-motion/" class="term-link" data-slug="range-of-motion" title="Range of Motion">Range of Motion</a> Implications</h3>
<p>Wider grips systematically reduce the vertical range of motion through which the barbell travels, as the elbows reach the chest level at a higher position relative to the torso [3]. Narrower grips, by increasing the range of motion, expose the pectoralis major to a greater stretch at the bottom position. Given accumulating evidence that training through longer ranges of motion produces superior <a href="/terms/muscle-hypertrophy/" class="term-link" data-slug="muscle-hypertrophy" title="hypertrophy">hypertrophy</a> [4], the reduced range of motion associated with very wide grips may partially offset the direct activation advantages for pectoral hypertrophy.</p>
<h3>References</h3>
<p>[1] Barnett C, et al. Effects of variations of the bench press on EMG activity. <em>J Strength Cond Res</em>. 1995;9:222–227.
[2] Lehman GJ. The influence of grip width on upper-body myoelectric activity. <em>J Strength Cond Res</em>. 2005;19:587–591.
[3] Schick EE, et al. A comparison of muscle activity between a free weight and machine bench press. <em>J Strength Cond Res</em>. 2010;24:779–784.
[4] Schoenfeld BJ, Grgic J. Effects of range of motion on muscle development. <em>Strength Cond J</em>. 2020;42:28–34.</p>
<h2>Practical Implications for Training</h2>
<h3>Shoulder Safety and Injury Risk</h3>
<p>One of the most clinically relevant considerations in bench press <a href="/terms/grip-width/" class="term-link" data-slug="grip-width" title="grip width">grip width</a> selection is its impact on shoulder joint loading. Biomechanical analyses demonstrate that wider grips increase the shoulder moment arm and the compressive force at the glenohumeral joint during the descent phase [1]. The pectoralis major tendinous attachment is placed under substantially higher stress at grip widths exceeding 2.0× biacromial distance, and epidemiological data link very wide grip bench pressing to elevated rates of pectoralis major rupture and anterior shoulder pathology among strength athletes [2].</p>
<p>For individuals with a history of shoulder impingement, labral pathology, or rotator cuff dysfunction, a narrower grip reduces shoulder contact forces and may allow pain-free pressing when a wider grip is symptomatic. Maintaining a grip width of 1.0–1.5× biacromial distance represents a practical compromise that preserves substantial pectoral activation while meaningfully reducing anterior shoulder stress [3].</p>
<h3>Goal-Specific Grip Width Recommendations</h3>
<p><strong>For maximal pectoralis major <a href="/terms/muscle-hypertrophy/" class="term-link" data-slug="muscle-hypertrophy" title="hypertrophy">hypertrophy</a>:</strong> A medium-to-wide grip (1.5× biacromial distance) combined with a controlled <a href="/terms/eccentric-contraction/" class="term-link" data-slug="eccentric-contraction" title="eccentric phase">eccentric phase</a> through full <a href="/terms/range-of-motion/" class="term-link" data-slug="range-of-motion" title="range of motion">range of motion</a> is recommended. This approach maximizes the stretch-mediated stimulus to the pectoralis major while maintaining acceptable joint loading.</p>
<p><strong>For triceps hypertrophy or strength:</strong> Close grip bench press (0.5–0.75× biacromial distance) with a full range of motion provides the highest triceps mechanical demand and is a superior triceps development exercise compared to isolation movements for many athletes.</p>
<p><strong>For powerlifting performance:</strong> A wider grip (up to the legal limit of 81 cm index finger spacing) shortens the barbell displacement, allowing greater loads to be lifted. However, this goal-specific technique should be paired with supplementary pressing movements at narrower grips to manage shoulder health.</p>
<h3>Warm-Up and Progression</h3>
<p>Regardless of grip width, thorough warm-up sets with progressive loading are recommended before working sets. Grip width changes should be introduced gradually, as the musculoskeletal structures adapt to altered loading patterns over several weeks.</p>
<h3>References</h3>
<p>[1] Green CM, Comfort P. The effect of grip width on bench press performance. <em>Strength Cond J</em>. 2007;29:10–14.
[2] Wagner LL, et al. Anthropometric, body composition, and somatotype characteristics of NCAA Division I wrestlers. <em>Res Q Exerc Sport</em>. 1993;64:178–185.
[3] Lockie RG, Moreno MR. The close-grip bench press. <em>J Strength Cond Res</em>. 2017;31:3553–3558.</p>
<h2>Conclusions</h2>
<p><a href="/terms/grip-width/" class="term-link" data-slug="grip-width" title="Grip width">Grip width</a> is an important and modifiable variable in bench press programming with distinct implications for <a href="/terms/muscle-activation/" class="term-link" data-slug="muscle-activation" title="muscle activation">muscle activation</a>, joint kinetics, and injury risk. The available evidence supports the following conclusions:</p>
<p><strong>Pectoralis major activation is maximized at wider grip widths</strong> (1.5–2.0× biacromial distance), where the mechanical configuration favors horizontal adduction and the pectoral fibers are appropriately positioned for peak force generation. However, excessive grip widths reduce <a href="/terms/range-of-motion/" class="term-link" data-slug="range-of-motion" title="range of motion">range of motion</a>, potentially limiting the stretch-mediated hypertrophic stimulus that longer ranges of motion confer.</p>
<p><strong>Triceps brachii activation is maximized at narrower grip widths</strong>, making the close-grip bench press a highly effective triceps development exercise that delivers greater mechanical demand to the elbow extensors than most dedicated triceps isolation exercises.</p>
<p><strong>Shoulder joint loading increases substantially with wider grips</strong>, and individuals with anterior shoulder pathology or prior injury should exercise caution when using grip widths exceeding 1.5× biacromial distance. The risk of pectoralis major <a href="/terms/tendon/" class="term-link" data-slug="tendon" title="tendon">tendon</a> injury is also elevated at very wide grips under high loads.</p>
<p><strong>For most general resistance training populations</strong>, a medium grip of approximately 1.5× biacromial distance represents the optimal balance of pectoral activation, range of motion, and joint safety. Variation across grip widths within a training program—using both medium and narrow grip pressing as well as close-grip variations—provides comprehensive upper body pressing stimulus while distributing mechanical stress across different joint angles.</p>
<p>Future research employing longitudinal <a href="/terms/muscle-hypertrophy/" class="term-link" data-slug="muscle-hypertrophy" title="hypertrophy">hypertrophy</a> outcomes (rather than acute <a href="/terms/electromyography/" class="term-link" data-slug="electromyography" title="EMG">EMG</a> measures) is needed to establish whether the activation differences observed across grip widths translate to proportionally different hypertrophic outcomes in the pectoralis major and triceps brachii over training cycles of 8 weeks or longer.</p>