The paper presents the results of studying changes in human locomotion biomechanics following the 21-day exposure to dry immersion. Participants were 8 normal male subjects at the age of 45.3 ± 5.4 years who were tested twice on days 14 and 7 before DI and immediately after its completion. After 21 days in immersion, significant changes in the clearance between the foot and bar in the range from 5 to 30 cm were observed only when the obstacle was 30 cm high. It is noteworthy that step length also reduced during crossing lower obstacles. Therefore, after DI we observed changes in two motor task parameters (stepping over an obstacle), i.e. widening of the clearance between the foot and bar, and decrease of the step length. © 2020 Slovo Ltd. All rights reserved.