The power clean is a component of the clean and jerk Olympic lift and is also commonly utilised as a training exercise in the training programs for several sports and individual athletes. However, no studies have explored the electromyographical (EMG) activation of the major muscles that are used during this exercise. The aim of the present study was to examine muscle activation during different loading conditions of the power clean exercise for the following muscles: gastrocnemius (GS), vastus lateralis (VL), transversus abdominus (TA), multifidus (MU), erector spinae (ES) and trapezius (TR). Methods: Eight experienced lifters performed five maximal voluntary contraction (MVC) exercises followed by three sets of three power clean repetitions at 70%, 80% and 90% of their 1 repetition maximum, in andomised order. The peak and mean values for each load were calculated and normalised to the highest EMG value recorded during the power clean or the MVC exercise. Results: There was a significant increase with load for the peak EMG values of the ES (p=0.002) and the mean EMG values for the GS (p=0.002) and VL (p=0.049). There was a trend for increasing EMG with load for the other muscles, but no other comparisons reached significance. Interestingly, peak EMG values were significantly greater during the power clean than the maximal voluntary contraction in the MU and ES muscles. Discussion: The findings suggest that when athletes attempt to increase lifting loads from 70 to 90%, performance can be improved if activation of the ES, GL and VL is increased. The relative contribution of each muscle group in the force generation required for the lift is, however, not known, and it cannot be suggested that these muscles are prioritised over others in training. Indeed, there was a trend of increase in muscle activation with load for all muscles, which suggests that performance could potentially be improved if activation of all six muscles tested in the present study increases. The peak EMG values recorded during the power clean exceeded in many cases those of the MVC exercise, a phenomenon previously noted by other researchers (e.g. Soderberg and Knutsen, 2000). This finding suggests that if the power clean exercise is used in training programmes it could have positive effects in muscle activation and, therefore, force development of the muscles tested in the present study. The findings also suggest that the power clean could be used as an MVC exercise for the MU and ES in future EMG studies.
© Copyright 2012 17th Annual Congress of the European College of Sport Science (ECSS), Bruges, 4. -7. July 2012. Veröffentlicht von Vrije Universiteit Brussel. Alle Rechte vorbehalten.