The power output of lower extremities and the
height of rise of the body mass center during vertical
jumps were measured on a force plate with a Kistler
amplifier for counter-movement jumps (CMJ), akimbo
counter-movement jumps (ACMJ) and spike jumps
(SPJ). The amplifier was connected to a PC via an
A/D converter. The MVJ v. 3.4. software package
(“JBA” Zb. Staniak, Poland) was used for taking the
measurements. In the physical model applied, the
subject’s body mass bouncing on the platform was
reduced to a particle affected by the vertical components
of external forces: the body’s gravity force and
the vertical component of ground reaction force. The
maximal power and maximal height of rise of the