[Retracted] Effect of Virtual Reality on Functional Ankle Instability Rehabilitation: A Systematic Review

Table 2

Description of the included studies.

Included studies	Country	Cases		Age/year		VR type	Interventions		Number of Interventions/week	Frequency	Outcome indicators
		VR group	Control group	VR group	Control group		VR group	Control group
Baek et al. 2019 [26]	South Korea	20	22	20.00-29.00		VR box	5 min warm up and stretch.; 20 min VR training: wear VR-HMD (VRbox; Max, China), stand on an unstable support surface (JUMPER; TOGU, Germany) for balance training.; 5 min relax and stretch.	5 min warm up and stretch.; 20 min conventional training: without VR-HMD, stand on an unstable support surface (JUMPER; TOGU, Germany) on both feet for balance training.; 5 min relax and stretch.	3	3 times/week; 20 min/time	①②③④⑤
Kim et al. 2018 [29]	South Korea	10	10	21.80 ± 1.20	22.10 ± 2.40	Nintendo Wii Fit Plus	5 min warm up and stretch.; 20 min VR training: muscle strength and balance strengthening exercises with Nintendo Wii Fit Plus.	5 min warm up and stretch.; 20 min conventional training: ankle muscle strength training in four directions with elastic bands; stand on the aero step (TOGU, Germany) on one foot in situ for balance training.	4	3 times/week; 20 min/time	②
Kim et al. 2019 [25]	South Korea	10	11	21.00 ± 1.20		Nintendo Wii Fit Plus	5 min warm up and stretch.; 20 min VR training: 10 min of muscle strength and 10 min of balance strengthening with Nintendo Wii Fit Plus.; 5 min relaxation activities.	5 min warm up and stretch.; 20 min conventional training: ankle muscle strength training in four directions with elastic bands; balance training in appropriate difficulty with Airex Balance Pad, slide board, donut hall, trampoline, Bosu Pro Balance Trainer, basic balance board and rocker/wobble board package.; 5 min relaxation activities.	4	3 times/week; 20min/time	④
Kim et al. 2020 [27]	South Korea	13	11	21.38 ± 1.00	21.90 ± 1.00	VR BOSS & APP： rope crossing adventure VR	10 min warm up.; 30 min VR training: use mobile comprehensive virtual reality trainer VR BOSS (Smpia; Seoul, Republic of Korea) combined with rope crossing adventure VR APP to perform balance training (1-2 weeks of tightrope walking indoors, 3-4 weeks of tightrope walking between high-rise buildings).	10 min warm up.; 30 min conventional training: static and dynamic balance training such as open/closed eyes, standing on one foot, knee lifting on one leg, one foot standing squat, etc. (1-2 weeks on the ground /wobble balance boards, 3-4 weeks on the balance pads).	4	3 times/week; 30min/time	⑥
Yang et al. 2016 [28]	South Korea	15	15	21.36 ± 2.92	22.04 ± 4.05	Balance trainer	30 min plyometric training: zigzag running, backward running, vertical jumping, agility jumping, side jumping, full speed running, and other sports.; 30 min VR training: VR-based fusion training of neuromuscular postural control: use Aero step (TOGU, Germany) in combination with the Balance trainer (Medica Medizintechink GmbH, Germany) for training.	30 min plyometric training: zigzag running, back running, vertical jump, agility jump, side jump, full speed running.; 30 min conventional training: run on treadmill.	8	3 times/week; 30min/time	⑦⑧⑨

① Ankle proprioceptive sense; ② isokinetic muscle strength (Biodex isokinetic force meter; BMS, Shirley, USA); ③ Y-balance test; ④ 30-second single-leg standing balance test (Biorescue; RM Ingenierie, France/Biodex balance system; BMS, Shirley, USA); ⑤ Romberg's test (Biorescue; RM Ingenierie, France); ⑥ 15-second single-leg standing balance test (Biorescue; RM Ingenierie, France); ⑦ 60-second standing balance test (Biorescue; RM Ingenierie, France); ⑧ CMJA (G-jump; IBTS bioengineering, Italy); ⑨ SLJ (G-jump; BTS bioengineering, Italy). CMJA: countermovement jump with arm swing; SLJ: stance long jump;