The main reason why the plyometric contraction represents a both economical and efficient characteristic is due to the process of producing, storing and using of the elastic energy and effect of reflex regulation from the central nerve system.

Objective To observe the relationship between duration time of isometric contraction and blood pressure.

Using techniques of sensing and synchronously collecting muscle force and EMG signals,we have develop a muscle isometric contraction test instrument.

Maximum isometric voluntary contraction of ankle dorsiflexors and plantarflexors: comparison of surface electromyography between patients at the acute stage after stroke and age-matched healthy elderly;

Integrated electromy- ography(IEMG)during maximum isometric voluntary contraction(MIVC)of the knee flexors and ankle dorsiflexors in the affected side were recorded and analyzed,and assessed with clinical spasticity index(CSI) before and after t.