Identification of the Exercise Load When Using a Balance Exercise Assist Robot.

Objectives: The Balance Exercise Assist Robot (BEAR) is a boarding-type robot developed to improve users' balance performance. However, the exercise load experienced by users of the BEAR remains unclear. Therefore, this study aimed to identify the exercise load of BEAR users.

Methods: Recruited healthy participants were fitted with an expiratory gas analyzer, and instructed to control the avatar displayed on the computer monitor by shifting their weight on the BEAR. Three types of activity (tennis, skiing, and rodeo) were prepared for the BEAR, and the difficulty of each activity had 40 levels. Each balance exercise for each level lasted for 90 s. The BEAR was administered at levels 1, 5, 10, and then up to 40 in steps of 5 for each activity. The major parameters that were evaluated were oxygen consumption (grossVO, netVO), metabolic equivalents (METs), and heart rate (HR). Two-way analysis of variance with Tukey's post hoc test was applied to each level of each activity.

Results: Fourteen healthy participants were recruited. For the rodeo activity, netVO and MET values were significantly higher than those for tennis and skiing at level 20 (tennis vs. skiing vs. rodeo: netVO 114.0±59.7 vs. 160.6±71.1 vs. 205.6±82.9, METs 1.47±0.22 vs. 1.72±0.37 vs. 1.90±0.29) and higher. Furthermore, comparisons within activity types showed that at level 40, netVO and MET were significantly higher than for level 1. The exercise intensity was found to increase along with the exercise level for all three activity types, with rodeo being the highest at 2.74 METs.

Conclusions: The current findings show that the BEAR can be used for balance practice without generating excessive cardiopulmonary stress.