By means ot Moire method, barographic examination, and EMG examination the response ot axial system on artiticially evoked types ot sitting positions was investigated in the complex ot 23 students. There were chosen three types ot sitting positions (incorrected sitting position without the use ot aids, sitting position on a sitting wedge, and sitting on an unstable surface - overball). The time ot measuring tor each type ot the sitting position were 2 minutes. Results showed the key position ot pelvis. Abdominal muscles were the most activated in position on the balt. Spread ot the pressures on sitting tubercles was lowered on the sitting wedge.

        Key words: EMG, Moire method, barography, sitting posture