Authors
Henryk Król
Jerzy Kukuczka Academy of Physical Education in Katowice, Department of Biomechanics, 72a Mikołowska Street, 40-065, Katowice, Poland
Bartłomiej Garbaciak
Former student, Jerzy Kukuczka Academy of Physical Education in Katowice, Faculty of Physical Education,, Katowice, Poland