VR training has been shown to improve Timed Up and Go a decrease of 1.9 s in Timed Up and Go test compared with a decrease of 1.2 s in control group (
p = 0.040) [
21]. Zettergren et al. found an improvement in Timed Up and Go by 34% as well as gait speed by 42% after VR training twice a week for 8 weeks [
22]. Badarny et al. observed that 65% of patients improved either gait speed or stride length or both by more than 10% with VR training (
p = 0.002) [
23]. These findings are supported by a study by Palacios-Navarro et al. who observed that VR training significantly increased in gait speed (
p = 0.002), reducing the completion time from 12 to 10 s [
24]. de Melo et al. found that compared with conventional training, VR intervention led to faster gait speed (
p = 0.031) and higher Borg score (a measure of physical fitness) (
p = 0.005) [
25], and similarly, Mirelman et al. showed gait speed increased in normal walking (
p = 0.006) and in obstacle negotiation (0.001) and stride increased in normal walking (
p = 0.043) and in obstacle negotiation (
p = 0.019) [
26]. Mirelman et al. also found that UPDRS was significantly (
p = 0.020) increased with VR training [
26]. VR training has also led to improvements in Sitting to Standing Test (
p = 0.010), 10-Metre Walk Test and Performance Orientated Mobility Assessment Test (
p = 0.050) [
21] and 6-Minute Walk Test (
p = 0.043) [
17]. There was only one study on tapping frequency showing VR training had no significant effects in patients with PD [
27]. A number of other studies found VR training led to improvement in gait speed [
12,
15,
18,
20], stride length [
15], Timed Up and Go [
15,
18,
28] and UPDRS [
20,
28]. Although Yang et al. did not find significant improvement in UPDRS [
18].