Spinal Motor Control Adaptations to Explosive Strength Training

Graduation date: 2015The nervous system has an integral role in rapid torque production of the lower extremity, which is often necessary for proper motor response to a dynamic environment. The nervous system is complex with numerous pathways, including spinal motor control networks, which influence the ability to move. However, few studies have investigated the influence of spinal motor control mechanisms on this ability to produce torque rapidly, often measured by the rate of torque development (RTD), after an explosive strength training program. Therefore, the purpose of this study was to investigate spinal motor control mechanisms following a three week explosive strength training program of the plantarflexors. Specifically, RTD, H-reflexes, supraspinal neural drive as measured by V-waves, and postsynaptic inhibition as measured by recurrent inhibition, were investigated during explosive contractions. The dependent variables used to measure these physiological characteristics were RTD from 0-100 ms, H[subscript max] to M[subscript max] ratio (H[subscript max]:M[subscript max]), V-wave to M[subscript max] ratio (V:M[subscript max]), and percent recurrent inhibition at both 10% and 30% of M[subscript max]. None of these dependent variables showed a significant interaction or main effects across either group (control and training) or time (pre-test and post-test). Although expected that changes would occur in spinal motor control mechanisms, it is unknown if lack of changes are related to the training program's failure in producing significant adaptations related to RTD. More research is necessary to more fully understand the role of spinal motor control mechanisms on adaptations following explosive strength training