The Effects of Exergaming on Sensory Reweighting and Mediolateral Stability of Women Aged Over 60: Usability Study.

BACKGROUND: Older adults tend to experience difficulties in switching quickly between various reliable sensory inputs, which ultimately may contribute to an increased risk of falls and injuries. Sideward falls are the most frequent cause of hip fractures among older adults. Recently, exergame programs have been confirmed as beneficial tools for enhancing postural control, which can reduce the risk of falls. However, studies to explore more precisely which mechanism of exergaming directly influences older women's ability to balance are still needed. OBJECTIVE: Our aim was to evaluate, in a single-group pretest/posttest/follow-up usability study, whether Kinect exergame balance training might have a beneficial impact on the sensory reweighting in women aged over 60. METHODS: A total of 14 healthy women (mean age 69.57 [SD 4.66] years, mean body mass index 26.21 [SD 2.6] kg/m2) participated in the study. The volunteers trained with the commercially available games of Kinect for Xbox 360 console 3 times (30 minutes/session) a week over a 6-week period (total of 18 visits). Participants' postural sway in both the anteroposterior (AP) and mediolateral (ML) directions was recorded with NeuroCom Balance Master 6.0. To assess and measure postural sensory reweighting, the Modified Clinical Test of Sensory Interaction in Balance was used, where volunteers were exposed to various changes in visual (eyes open or eyes closed) and surface conditions (firm or foam surface). RESULTS: In the ML direction, the Kinect exergame training caused a significant decrease in the sway path on the firm surface with the eyes open (P<.001) and eyes closed (P=.001), and on the foam surface with the eyes open (P=.001) and eyes closed (P<.001) conditions compared with baseline data. The follow-up measurements when compared with the baseline data showed a significant change in the sway path on the firm surface with the eyes open (P<.001) and eyes closed (P<.001) conditions, as well as on the foam surface with the eyes open (P=.003) and eyes closed (P<.001) conditions. Besides, on the firm surface, there were no significant differences in sway path values in the AP direction between the baseline and the posttraining measurements (eyes open: P=.49; eyes closed: P=.18). Likewise, on the foam surface, there were no significant differences in sway path values in the AP direction under both eyes open (P=.24) and eyes closed (P=.84) conditions. CONCLUSIONS: The improved posturography measurements of the sway path in the ML direction might suggest that the Kinect exergame balance training may have effects on sensory reweighting, and thus on the balance of women aged over 60. Based on these results, Kinect exergaming may provide a safe and potentially useful tool for improving postural stability in the crucial ML direction, and thus it may help reduce the risk of falling.

Trunk alignment in different standing positions in healthy subjects and stroke patients -a comparative study with a simple method for the everyday practice.: Trunk alignment in healthy and stroke subjects.

OBJECTIVES: Weight-bearing (WB) on the lower extremities is an important outcome parameter in the rehabilitation of poststroke hemiparesis. However, the patients often regain this ability by compensatory movement patterns. METHODS: Our goal was to characterize with a simple method the trunk alignment of healthy subjects and stroke patients (n = 17 for both groups) during standing and following lateral weight shift (WS). To describe trunk alignment, five markers were placed on the subjects' back, and the angles of the trunk at both sides were defined by the lines drawn from the posterior angle of the acromion and the iliac crest on the same body side to the seventh thoracic spinal process. Weight distributions on the lower extremities during standing and lateral WS were determined with a force platform. RESULTS: The patients had significantly limited WB capacity on their paretic limb, which was accompanied with significant asymmetry in the trunk alignment during standing and following WS to the paretic side. DISCUSSION: Our results show that this patient population tends to use abnormal compensatory movement patterns to optimize weight shifting, and changes of trunk alignment play a key role in this. This should be taken into consideration during rehabilitation.

Effects of exercise programs on balance in older women with age-related visual problems: a pilot study.

AIM: This study aimed to compare the effects of two exercise programs on balance and risk of falls in older women with age-related visual dysfunction. METHODS: Participants living in a residential home were randomly allocated to Group I (n=21) receiving a progressive, tailored multimodal exercise program in addition to the standard osteoporosis exercise program or Group II (n=20) receiving the standard osteoporosis exercise program alone. At baseline, and after the 6-month exercise program outcomes were measured. RESULTS: After the exercise program there was significant between-group difference in favor of the Group I in Timed Up and Go (TUG) test (p=0.001), but not in Berg Balance score (p=0.130), and Barthel Activity Index (p=0.662). In Group I the risk of falls reduced by 46%, but this result was not significant (RR=0.54, 95% CI 0.294-1.007). The mean length of event-free time was significantly longer in the Group I than in Group II (18.5 weeks, 95% CI 15.4-21.7 vs. 14.8 weeks, 95% CI 11.1-18.4; p=0.049). CONCLUSION: If the current osteoporosis guideline is applied for older adults with low vision, it would be worthwhile putting more emphasis on the inclusion of patient-tailored strength and balance exercises to improve balance and potentially reduce the risk of falls.

When does mechanical plantar stimulation promote sensory re-weighing: standing on a firm or compliant surface?

The purpose of this study was to investigate the effect of different types of mechanical stimulation of the sole on standing postural stability in healthy, young adults. Fifty subjects (34 women, 16 men; mean age 23 ± 2 (mean ± SE)) stood barefoot on fixed force plates both with open and closed eyes on firm surface and then on compliant surface (foam). A modified clinical test of sensory interaction on balance protocol was employed to assess the center of gravity (COG) excursions along anteroposterior (AP) and mediolateral (ML) axes on each surface and visual condition. After the baseline measurement, a stimulation was applied with an elastic spiked layer topped to the firm and then foam surface, and the COG excursions were measured during the stimulation, and then at least 30 min after the stimulation of the spiked layer, we used 10 min of manual static and glide pressure applied to the plantar surface of both feet. Immediately after manual stimulation, static balance parameters were measured again. Results showed that after manual stimulation, the sway path with closed eyes decreased significantly on the AP and ML directions on firm surface conditions. The spiked layer caused significantly decreased sway path on firm platform in both directions, but it was ineffective on compliant surface. Our results established that the activation of plantar mechanoreceptors by 10-min manual stimulation can partially compensate subjects for the absence of visual input and the lack of accurate pressure information from the supporting surface, too.

Postural control in elderly subjects participating in balance training.

The changes in postural control in elderly people after an 8-week training course were characterized. Static postural stability was measured during standing on a single force platform first with the eyes open and then with the eyes closed. Body sway was analysed on a force plate in groups of elderly and of young subjects. Half of the elderly subjects then took part in the training course. The posturographic measurements were repeated after the course. The sway in anteroposterior (AP) and mediolateral (ML) directions was subjected to spectral analysis. The frequency spectrum of the platform oscillations was calculated by fast Fourier transformation in the intervals 0.1-0.3, 0.3-1 and 1-3 Hz. It was found that the sway path was longer and the frequency power was higher in the elderly group. The training caused a significant improvement in functional performance, but a significantly longer sway path was observed after the training in the ML direction. The frequency analysis revealed a significantly higher power after 8 weeks without visual control in the ML direction in the training group in the low and the middle frequency bands. The results suggest that the participants' balance confidence and the control of ML balance improved in response to the training. The higher ML frequency power exhibited after the training may be indicative of a better balance performance. Thus, the increase in the sway path in this age group did not mean a further impairment of the postural control.

Postural control in athletes participating in an ironman triathlon.

We studied the degree of dependence on vision of static postural control among ten male adult ironmen and ten healthy subjects (firemen, control group) who took part in regular physical activity, and the perturbations of equilibrium after prolonged exercise in ironmen. Static postural stability was measured during standing on a single-force platform alternating between eyes open and eyes closed. First, body sway was analysed on a force plate in both groups, and the athletes then took part in an ironman triathlon. The measurement was repeated after the race. The sway in both directions was subjected to spectral analysis. The frequency spectrum of the platform oscillations was calculated by fast Fourier transformation in the intervals 0-0.3, 0.3-1 and 1-3 Hz. The sway path in both directions and the total path were significantly lower in the ironmen than in the control group without vision, and the absence of visual control caused a significant increase in sway in both directions in the control group, but not in the ironmen. The frequency analysis revealed a higher level of stability in the medio-lateral direction with closed eyes. The endurance race caused increases in both the total sway path only with closed eyes, and these changes were significant at higher frequency bands. These results indicate that ironmen are more stable and less dependent on vision for postural control than the control subjects, and the prolonged stimulation of the proprioceptive, vestibular and visual inputs in the endurance race causes a significant disturbance in postural control.