iExergame
rigidity, Ankle inversion
Participants in the IG used the iExergame system, which consists of two wireless inertial sensors (LEGSys™, BioSensics, MA, USA), attached on the dorsal aspect of each foot by an elastic strap (Fig. For the iExergame, an inertial sensor was attached on each foot, which converted ankle joint movement to computer cursor (red circle) movement.The interactive interface screen includes a red square (defined as a cursor), one circle (defined as a home space), and one or more circles (defined as targets). The position of targets placed by the iExergame program depends on the type of desired exercise tasks. Participants were instructed to move the cursor from the home space to the desired target as fast as possible by rotating their ankle joint. Participants were equipped with a sensor on each foot during the exercises. The iExergame system was programmed to selectively read data from the pertinent sensor based on the type of exercise being performed—be it targeted for the right or left foot. Consequently, any movement from the contralateral foot had no influence on the cursor’s motion on the screen. Different gamification features, such as audiovisual rewards, were included to promote engagement and execution of each exercise task. For example, if the participant successfully brought the cursor from the home space to the desired target within 2 s, the target exploded and a bubble burst sound was played. Additionally, if an incorrect target was hit, the participant received audiovisual feedback to correct the error.At the beginning of the iExergame program, each participant received brief instructions on how to perform the exercise. However, participants were not coached by a person during the exercise session, since the iExergame coached the participant via the interactive interface. If required, the program could be reinitiated and/or the complexity of exercise could be adjusted by the nurse who administered the exercise. For example, to complete one trial in the default program, the participant had to rotate their ankle approximately 20°. However, this range of motion could be changed depending on rigidity and frailty of the participants. Similarly, the timing of audiovisual rewards could be adjusted based on the participant’s baseline motor capacity.The complexity of exercises, similar to game levels, was adjusted based on participants’ performance in previous tasks. In this study, the nurse in charge made these adjustments. To guide them, a recommendation chart was provided, which referenced the scores from participants’ prior sessions. This helped tailor the exercise complexity or introduced more cognitively demanding exercises as appropriate. Four levels of complexity were included in the iExergame (Fig. Ankle dorsiflexion and plantarflexion exercise module: Participants needed to plantarflex their ankle joint to bring the cursor from the home space to the target, which was located on the upper part of screen. Then, when the target was hit, participants needed to dorsiflex their ankle joint to bring the cursor back to the home space.Ankle inversion and eversion exercise module: Participants needed to bring the cursor from the home space to the target located on right or left part of the screen, by inverting or everting their ankle in medial and lateral directions.Ankle rotation in random direction exercise module: Targets appeared on random locations of the screen, and participants needed to bring the cursor to the target as soon as they observed the target. These exercise tasks required a combination of ankle dorsiflexion, plantarflexion, inversion, and eversion. This module required more cognitive involvement compared to modules #1 and #2;Trail-making exercise module: This module was similar to #3. However, 5 targets simultaneously appeared on the screen, labeled 1, 2, 3, A, and B. Participants needed to bring the cursor to the targets in the correct order, which was alternating numbers and letters. For example, first the target labeled ‘1’ was hit. Then, the cursor was brought back to home and in the next trial, the target labeled ‘A’ was hit. This module required a combination of memory, cognition, and motor function.The iExergame program includes 4 different modules of exercises. Participants began with simpler exercises and progressed to more complex exercises that required more memory and cognition (from 1–4).