Weightlifting is a hugely popular culture which is attracting an increasingly large number of people (Reeves et al,. 1998). This incorporates both athletes and coaches using resistance training to supplement their sport-specific training regime along with more gym users training for aesthetic purposes. The bench press is a very popular exercise due to the benefits and adaptations for sports performers requiring high levels of upper body strength. (Sadri et al., 2011). The aim of this article is to examine these varying effects cause through different grip widths upon muscle activation and overall performance.
Major muscles activated during the bench press
The movement is scientifically shown to be extremely effective in developing the pectoralis major muscles, along with both the tricep brachii through extension of the elbow and the anterior deltoid muscles through horizontal adduction of the shoulder (Kellis and Baltzopoulos, 1998). However, the bench press also incorporates many tonic (stabilizing) muscles in conjunction to these major phasic (dynamic muscles) stated. Barnett et al. (1995) looked at EMG activity during the bench press and concluded that the anterior deltoid, the triceps and the latissimus dorsi muscle were the main contributor or stabilizers during the exercise. Grip width during the movement is a prime focus due to the effects it has on many biomechanical principles including bar path and force production along with muscle activation. The typical grip width for the movement is shoulder width or slightly wider apart, although different grip widths may be used to alter the muscles emphasized. It has been suggested that grip width plays a key role in the relative muscular contribution during the exercise as well as the maximal weight that can be lifted (Lehman, 2005).
Effects of grip width on muscle activation
The most commonly expected difference between the wide-grip and close-grip bench press is the difference between triceps and pectoralis major. This is evidenced by Barnett et al. (1995) who found the EMG activity in the triceps decreased with the wider grip width along with an increased activity in the clavicular head of the pectoralis major. This “clavicular head” incorporates the proximal fibers within the pectorals in comparison to the other dominant portion of this muscle activated within the bench press (sternoclavicular head) which showed no consistent change between bench press variations. The study included six experienced male lifters who completed a submaximal lift at 100% and 200% of biacromial width. In addition, Lehman, (2005) compared the same two biacromial width percentages along with a further grip with decreased distance between hands and concluded that the widened grip enhanced the activation of the sternoclavicular head by 18% and 27% respectively.
However, further studies have been conducted into the activation at different grip widths than just wide and narrow grip and have produced conflicting results. Clemons and Aaron, (1997) examined the relationship between grip width and EMG, comparing relative muscular activity, based on a percent of maximum voluntary isometric contraction (%MVIC). The authors used grips widths of 100, 130, 165, and 190% of biacromial width and concluded that increasing grip width increased the activity of all of the muscles analysed, with no apparent differences between any of the muscles in the amount of increase. In addition, subjects showed that the triceps were loaded the most of all the muscles (approximately 110% of MVIC) and there was no difference between the relative loading of the pectoralis major and the anterior deltoid during the lifts (approximately 75% and 95% MVIC). However, methodological limitations of this study included each grip width incorporating the same load may have effected overall performance. An overview of further analysis of the muscle activation during different bench press phases with varied hand widths suggest higher peak forces and EMG recordings observed in the descent rather than the lift phase along with neither peak or mean EMG levels being systematically affected by grip width. However, given that the same load was lifted with smaller vertical and lateral forces it still appears that a wider grip is the most efficient position for performing the bench press.
Effects of grip width on bench press performance
The optimum grip width for enhancing the greatest results during bench press remains a controversial area of study. Despite this, a large number of researchers have shown that a relatively wide grip width (between 180 and 200% of biacromial width) is optimal for maximal bench press performance (Gilbert and Lees, 2003). Possible reasoning for this is due to the widened grip width reducing both the range of motion of the lifter and the final height of the bar. In addition, this is backed up by Wagner et al. (1992) who determined the effects of grip width, chest depth, limb lengths, and bar path on the performance of a maximal bench press. Bench press performance was assessed at six different grip widths. Statistical analysis of the data collected revealed that bench press strength values at the two moderate grip widths (grips 3 and 4) were significantly greater than either the narrow or wide grip widths. The effects of grip width on the magnitude or direction of the resultant force applied to the bar is an area which requires additional research due to a lack of evidenced literature to suggest any clear differences. However, a study by Duffey and Zatsiorsky, (2003) which required subjects to perform push ups at various hand widths indicated a positive correlation between hand width (effectively grip width) and horizontal force. Consequently, it would be expected that as grip width in the bench press increases, the resultant force would be applied in a more outward (lateral) direction.
However, varying grip width during bench press does produce further definite difference. These include both range of motion and torque about the shoulder joint. Most significant findings from the gathered research were that the narrow grip bench press exhibited a greater range of motion and a lower amount of torque about the shoulder within the upper arm segment and the shoulder joints (Rae et al., 1996). Explanations for these results include the fact that in the wide grip the shoulder began in a more horizontally abducted position as previously stated. Despite these horizontal abduction peak values being very similar, the wide grip produced a threefold greater torque about the shoulder joint due to the greater moment arm. However, research by Green and Comfort, (2007) demonstrates that ≤1.5 biacromial width appears to reduce this risk and does not affect muscle recruitment patterns, only resulting in a non-significant difference of ±5% in one repetition maximum. In addition, the study concluded that a wide grip (>1.5% biacromial width) may increase the risk of shoulder injury, including anterior shoulder instability, and pectoralis major rupture.
Conclusion
In conclusion, their remains conflicting views upon the full effects grip width causes as a result of individual differences in experience and due to differences within previous experimental design. On the whole, the wider grip bench press appears to promote the greatest benefits due to increase force production in addition to recruiting greater intensity of muscular contractions leading to possible greater training adaptations. The research gathered clearly indicates the greater activation of triceps when employing a narrower grip however, the results for the pectroalis major remain unclear when comparing mid-grip to wide-grip widths. There has not to date been a thorough and conclusive biomechanical analysis of the exercise whilst comparing grip width. The most successful research attempts have been directed toward vertical plane kinematic, and kinetic analysis of the bar only; and those studies that did examine kinetics estimated forces based on kinematic data. As a strength and conditioning coach it is key to ensure all biomechanical factors influencing a lift are considered to optimize performance and reduce the risk of injury to athletes. As a result, when incorporating the bench press into a weightlifting plan the wider grip variation is superior due to the increased force production created from the reduced range of motion required. However, if incorporating the exercise into a rehabilitation plan or a programme for less advanced athletes then narrower grip variations may be beneficial due to the reduced injury risk highlighted throughout when using a grip of <1.5%.
References
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