Gastrocnemius muscle activation during plantar flexion with different feet positioning in physically active young men

BACKGROUND: Varying exercise parameters, such as angles of movement, can cause different activation patterns within muscle compartments. Therefore, it is expected that feet positioning variations could influence gastrocnemius activity. OBJECTIVE: Compare gastrocnemius activation during plantar flexion with feet pointing forwards (FO), inwards (IN) and outwards (OU). METHODS: Sixteen physically active men (21 +/- 2 years; 1.75 +/- 0.06 meters and 74.8 +/- 7.2 kg), performed 3 sets of 10 repetitions in each of the following experimental conditions: plantar flexion with feet pointing FO, IN and OU. The root mean square (RMS) of the muscular activation of both gastrocnemius heads was analyzed in each set by electromyography. RESULTS: For the medial head of the gastrocnemius, the OU condition presented greater RMS values when compared to the IN (z = 3.41; p < 0.001) and FO (z = 2.37; p <= 0.017) conditions. For the lateral head, however, the IN condition demonstrated greatest RMS when compared with OU (z = 3.20; p = 0.001) and FO (z - 3.25; p - 0.001) conditions. CONCLUSIONS: These results suggest that it is possible to create greater activation sites in the gastrocnemius. Trainers and practitioners could use this to prescribe exercise more efficiently, possibly correcting asymmetries in athletes, especially body builders.