Abstract
The aim of the present study was to examine the acute effect of a brief submaximal percutaneous electrical stimulation (PES) of the knee extensor(KE) muscles as a conditioning activity on the isokinetic peak torque (PT) and average power (AP). Eighteen male students aged 20–25 years performed maximal voluntary concentric isokinetic knee extensions at angular velocities of 60 and 180°/s in control (CON) trial (without prior PES application), followed by a PES trial after 30 min rest period. In PES trial, a conditioning submaximal (25% of the maximal voluntary isometric contraction force) isometric tetanic contraction of the KE muscles was induced by a 7 s direct PES at 100 Hz, interspersed after 3 min with testing of voluntary isokinetic performance. No significant differences in isokinetic knee extension PT and AP were observed between PES and CON trial at 60°/s. However, a significantly greater (p < 0.05) isokinetic PT (8.9%) and AP (8.2%) were observed in PES trial compared to CON trial at 180°/s. In conclusion, application of a brief high-frequency submaximal PES may enhance isokinetic strength and power of the KE at a moderate but not at a low angular velocity.