New ways to challenge the body in the weight room are frequently explored by lifters. As individuals explore new ways to lift and challenge the upper body, different hand placements are often tested.
In the push-up exercise, research by Cogley et al.1 found that an increased number of muscles were activated in a push-up with a narrow hand placement compared to wide hand placement. In the lat pulldown exercise, a wide grip hand position was shown by Signorile et al.2 to be the best hand placement for latissimus dorsi activation during both phases of the lift.
But what about changing the range of motion of an exercise?
When looking at range of motions (ROM) for exercises, the general rule of thumb is optimal range of motion. Most of the time optimal ROM and full ROM are very similar or the same, but not always. Often the change in ROM is to see if there is an effect on the muscles that are activated.
Paoli, Marcolin and Petrone3 looked at three different ROMs for the sitting dumbbell military press with six experienced lifters. In the study, electrical activity was measured for eight muscles in and around the shoulder. Results showed that the highest electrical activity for this exercise is obtained at full ROM.
If the purpose of changing the ROM is to reduce the involvement of the trapezius muscle without decreasing deltoid activation, then decreased ROMs at heavy loads (>70% 1RM) may be appropriate. But, "if the primary purpose [of the dumbbell military press] is the development of strength, incomplete ROMs should be avoided."
It is always important to look back at the purpose of a change before doing so, but sometimes a minor adjustment can make a big difference. What ways have you adjusted exercises and seen major differences? And of course, what was the purpose of the change?
1Cogley, R.M., Archambault, T.A., Fibeger, J.F., Koverman, M.M., Youdas, J.W., Hollman, J.H. Comparison of Muscle Activation Using various Hand Positions During the Push-up Exercise. J Strength Cond Res 19: 628-633, 2005.
2Signorile, J.F., Attila, J., Zink, J., Szwed, S.P. A Comparative Electromyographic Investigation of Muscle Utilization Patterns using Various Hand Positions During Lat Pull-down. J Strength Cond Res 16: 539-546, 2002.
3Antonio, P., Marcolin, G., Petrone, N. Influence of Different Ranges of Motion on Selective Recruitment of Shoulder Muscles in the Sitting Military Press: An Electromyographic Study. J Strength Cond Res 24(6): 1578-1583, 2010.