From Charles Poliquin
Build a stronger, more powerful back by knowing which factors affect muscle activation and the 1 RM load in the pull-up and pull-down exercises. Recent studies reveal that best back training results will come from increasing your intensity rather than modifying width or grip placement. Still, it’s good to know how hand placement influences muscle activation. Here’s what new studies tell us.
For pull-ups in which the palms face away from you, the lower trapezius, latissimus dorsi, and infraspinatus are activated to a greater degree than during the chin-up (palms facing toward you). For example, muscle activation of the lats is 130 percent during a pull-up compared to 117 percent during a chin-up. In contrast, chin-ups activate the pectoralis major and biceps brachii (96 percent in the chin-up versus 78 percent in the pull-up) to a greater degree. In addition, one study showed that both hand positions result in near equal recruitment of the external obliques and erector spinae, making them a great bang for your buck exercise.
Research has shown little difference in muscle activation due to grip width changes in chin and pull-ups. For pull-downs, a recent study from Norway compared a narrow (the biacromial distance), middle (1.5 times biacromial distance), and wide (2 times biacromial distance) using an 85 percent of maximal load in the pull-down exercise on muscle activation.
Results showed no differences when the entire movement was considered, but a greater activation in the biceps brachii using the medium compared to the narrow grip during the concentric phase was observed. The lats and infraspinatus had greater activation using the wide grip than the narrow versions during the eccentric phase.
These differences were caused by biomechanical differences since the lever arm from the shoulder joint increases as the grip gets wider. Another outcome was that the narrow grip allowed for a significantly higher 1RM load of 80.3 kg to be lifted compared to the wide grip, which resulted in an average 1RM of 77.3 kg. This indicates that intensity is generally more important than grip width for muscle activation—that is, you’ll get better results by sticking with a grip width that is 1.5 the biacromial distance or less and increasing your training intensity.
For a 16-week Chin-Up Training program to build a stronger back, click here.
Reference
Leslie, K.., et al. The Effect of Grip Width and Hand Orientation on Muscle Activity During Pull-Ups and the Lat Pull-Down. Strength and Conditioning Journal. 2013. 35(1), 75-78.
Andersen, V., et al. Effect of Grip Width on Loading and Muscle Activation in the Lat Pull-down. International Conference on Strength Training. Oslo: Norway. 2012.
Source: http://www.charlespoliquin.com/Blog/…Pull-Dows.aspx
