Neuromuscular responses to different resistance loading protocols using pneumatic and weight stack devices.

Year: 2013  Country: Finland   Study Population: 15 healthy young men without regular strength training background

Peltonen H, Häkkinen K, Avela J. Neuromuscular responses to different resistance loading protocols using pneumatic and weight stack devices. Journal of Electromyography and Kinesiology 2013;23(1):118-124.

Objective

To study acute neuromuscular fatigue after hypertrophic (HL), maximal strength (MSL), and power (PL) loadings performed with pneumatic versus weight stack devices. The study also examined single repetition loading characteristics in order to reveal possible differences between the loading devices, potentially explaining at least partly the differences between the acute responses.

Methods

Subjects performed single explosive repetitions with different loads and performed three different resistance training sessions using bilateral pneumatic (Hur) and weight stack resistance (David) knee extensor devices in a seated position.

Acute responses were assessed by measuring maximal voluntary contraction (MVC), corresponding quadriceps-EMG and resting and superimposed twitch torques. Activation level was calculated from the twitch torques.

Outcome

The decreases in maximal isometric torque were greater after the hypertrophic and maximum strength loadings compared to the power loading on both variable resistance devices. 

In this study population the weight stack device induced greater levels of peripheral fatigue during HL. It also led to large central fatigue during MSL and PL. On the other hand, on the pneumatic device contraction velocity with low loads was higher compared to the weight stack device.