The purpose of this study was to evaluate the effects of two ICM programs in processing speed, lower-body strength, and body composition in community dwellings at risk of falling. This is the first study that evaluated the effects of a psychomotor intervention combined with WBV training, and only the second study that investigated the effects of a psychomotor intervention as a fall prevention program . Overall, the present study results evidenced that both programs were accepted and well tolerated by participants. They were effective for fall and injury prevention. Considering both programs effectiveness on the risk factors for falls, our findings indicate that either EG1 or EG2 was beneficial by inducing similar improvements in cognitive function (processing speed) and physical function (lower-body strength). The improvements on these risk factors were clinically relevant as they were all a large ES. Furthermore, despite an increase on BMD within EG1, the EG2, which combined the psychomotor intervention and the WBV training, led to additional benefits on more bone mass variables, namely on BMD, BMC, T-Score, and Z-score, with a large ES in all these variables. Highlighting both programs' beneficial effects, the number of falls in both EGs decreased after the 24-week intervention. Moreover, the benefits induced by the programs were maintained in the cognitive risk factors for falls after their cessation. In fact, after the no-intervention 12-week follow-up, the enhancements in the processing speed were unchanged, particularly in the EG2. However, there were relevant physical risk factors for falls whose benefits induced by the intervention programs were lost. Namely, the lower-body strength, in which the improvement induced by the intervention programs was reversed. Likewise, the enhancements in bone mass induced by the programs, which is important to prevent fall-related injuries such as fractures, were not maintained, particularly in the EG2.
Concerning the adherence rate and tolerability, few ICM studies were carried out over 24-weeks, three times per week, in community dwellings. In this line, compared to our EGs, the 24-week study of Boa Sorte Silva et al.  showed a lower mean adherence (83.3% vs. 70%), and higher values to reach the exercise intensity in the original Borg RPE scale (13.1 vs. 15-17). The prediction of compensatory sessions in case of health problems may be an effective strategy in reducing absenteeism.
Regarding the processing speed of our study participants, both EGs showed significant improvements at the post-intervention, with slightly higher effect sizes in EG1, whereby the WBV training did not lead to additional benefits. Our results are consistent and superior to other ICM programs in community dwellings. After 24 weeks of an ICM intervention (resistance/balance training + computerized cognitive training), the participants (74.5 ± 3.8 years) of the study of Sipila et al.  performed the TMT-A and TMT-B tests in less than 3.4% and 8.3% of the time, respectively; compared to the present study, our EGs executed the TMT-A and TMT-B at least 19% in less time. The specificity of the computerized cognitive training initially supervised and after some sessions individually and unsupervised may be a factor to explain these differences. An unsupervised ICM intervention (exergames under different postural conditions) was also carried out in the 16-week study of Schoene et al. , and no significant improvements were observed in participants (82.0 ± 7.0 years) performance in the TMT-A (37.1 ± 19.2 vs. 32.8 ± 12.2 s) and TMT-B variables (110.9 ± 60.0 vs. 107.7 ± 47.7 s). Finally, the 12-week study of Desjardins-Crépeau et al.  focused on an interactive program (stretching and toning exercises + dual-task training program) significantly improved the processing speed by 15.3% in the TMT-A test, whereby no significant differences in the TMT-B variable were detected. Likewise, the previous study has been supervised, and participants (73.2 + 6.3 years) also performed computerized cognitive training. Despite the preceding studies have shown significant improvements in several domains of executive function, it appears that supervised ICM interventions, like our programs, without resorting to computerized cognitive training can lead to additional improvements in information processing. Moreover, the diversity of group exercises proposed present in our programs, as dual-task paradigms, targeting the enhancement of specific cognitive domains and brain regions as the prefrontal cortex could help explain our study results. In this way, it is recommended that fall prevention programs should have these characteristics. Thus, these findings must be interpreted with caution. Considering the effects of the programs' cessation, the processing speed improvement induced by both programs was maintained at the follow-up evaluation, especially within EG2. These findings are in line with other studies. In the study of Blasco-Lafarga and colleagues , after 14 weeks of detraining, the executive function results showed a slight decrease. Whereby cognitive function losses seem to be less sensitive to a detraining period. This is important because cognitive improvements, particularly in processing speed, directedly reduces the risk of falls and can attenuate decline physical function over ten years .
With respect to physical function, namely in lower-body strength, both programs induced similar improvements. This is an unexpected finding because the WBV training has been referred to as an effective program for improving muscle strength, alone or combined with other programs . Therefore, it would be expected that an intervention that combines WBV and a psychomotor intervention, that was also included strength stimulation, would obtain additional benefits in terms of muscle strength than the psychomotor intervention alone. At the post-intervention, both EGs significantly increase the number of repetitions performed in the “30CST” (EG1: 45.2%; EG2: 42.9%), with similar effect sizes. These results support the findings in previous studies, as Desjardins-Crépeau et al.  study, in which only the mixed aerobic and resistance training combined with cognitive training led to an increase superior to 45% in the number of repetitions. Also, compared to the 12-week study of Hsien-Te Peng and colleagues , our EGs achieve a more accentuated increase in the number of repetitions than their ICM EG that improved 10.1% (21.8 ± 6.9 vs. 24.0 ± 6.4). For the maximal strength of the knee extensors and flexors, despite an increase of 8.9% in the variable “Isokinetic peak torque (extension 60º)”, within EG2, it was not significant. However, these results are in accordance with other ICM studies that presented an increase of 10.9% at the knee extension force after 12 months of intervention . The fact that both programs included majority resistance strength exercises could help to explain these results. Therefore, these results recommend that the ICM programs designed for fall prevention should include resistance strength exercises. However, for enhancements in maximal strength, both programs should be more focused on muscle strength and power exercises, possibly through plate-loaded machines, and the sessions' intensity level at the RPE scale should target values between 13 to 15 . Nevertheless, the specificity of a psychomotor intervention, mainly oriented to corporeality and self-awareness, does not incorporate and reach these high intensities on a session. After the 12-week follow-up, improvements induced by both programs in lower-body strength, particularly in the “30CST” variable, were reversed. These findings are similar to those from Blasco-Lafarga et al. study , which developed an ICM program (strength + cardiovascular exercises under dual-task paradigms). These authors pointed out that the effects of detraining were more marked in muscle strength than in other physical function outcomes, being muscle strength the physical function capability with more sensitivity to an intervention program and the respective detraining. Also, the previous study evidenced a higher sensitivity at the second detraining moment, showing a decrease in the number of repetitions at the “30CST” (-15.7%), whereas, in the present study, this decrease was superior to -21%, in both EGs. Considering our intervention programs' specificity, the results highlight the need for detraining periods to be less than 12 weeks, which are in line with recommendations of Blasco-Lafarga and colleagues' study . Another recommendation is implementing a home-based program including strength exercises, while the psychomotor intervention is not restarted.
In what refers to body composition, compared to the psychomotor intervention program, the combined intervention not only induced improvements on BMD, but also in BMC, T-Score, and Z-score, with a larger ES in all variables. Thus, these improvements within EG2 were more visible at an osteogenic level than muscular strength and muscle mass levels, as described above, which could positively influence fracture risk. The vibration exposure could lead to a more effective stimulation of bone formation, increasing the BMD and BMC. Furthermore, these results suggest that adding only ~5 minutes per session of WBV training in a psychomotor intervention can lead to additional benefits. Given the lack of ICM studies focused on body composition changes, the comparison of our study with other studies is limited. Contrary to the present study, the 24-week study of Marín-Cascales and colleagues  found a significant decrease in total fat mass, either in the WBV group or the multicomponent program group (aerobic and drop jumps exercises), in postmenopausal women. These authors also found no changes in total lean mass and BMD in both groups. The findings of the previous study as regards total lean mass are consistent with our study findings. In fact, the best method to improve muscle mass or lean body mass is still unclear, and future investigations are needed since muscle weakness increases the risk of falling [5, 20]. Also, it is interesting the observation that our psychomotor intervention with low material effort also achieved significant improvements on BMD. Thus, our psychomotor intervention can also be recommended as an effective therapy to minimize bone loss. Concerning the improvements in BMC, our study evidenced superior improvements than the multicomponent 24-month program of Englund and colleagues . In the previous study, their EG, which includes strengthening, aerobic, balance, and coordination exercises, increase 3.5% BMC, while our EG1 and EG2 increase 5.3% and 11.4%, respectively, despite only the EG2 presented significant improvements. Therefore, our EG2 could positively influence the prevention of bone demineralization. At the follow-up these improvements were reversed, especially in EG2, suggesting the importance of a non-cessation WBV training in body composition; these results were followed by the normative data comparisons of the T-score and Z-score variations, in which lower mean scores represent an inferior bone density.
Lastly, a significant reduction in fall occurrence was observed in both EGs at the post-intervention, especially within EG2, which showed a lower number of falls. Despite the WBV training low frequency (15 Hz) used within EG2 to ensure a safe intervention, the mechanical stimulation and higher muscle activation provided by the WBV could lead to a larger protective effect of the combined program for falls. The psychomotor intervention for fall prevention of Freiberger and colleagues  reported the fall occurrence over the previous six months at baseline and during the 12-month follow-up, and no significant differences were observed. Likewise, few ICM programs include the number of falls as the main outcome. The 16-week study of Gschwind et al. , which include a virtual-reality intervention program, showed a decrease in the incidence of falls in EG (-68.0%). However, alongside the specificity of a virtual-reality intervention, the retrospective falls of the previous study were collected over the previous 12 months at baseline, whereby comparisons to our study should be interpreted with caution. One of the first studies to directly evaluate the effects of WBV training on falls also showed a significant decrease in falls rate only in the combined 18-month program (multicomponent physical training + WBV). However, these results are difficult to compare to our study given the long-term intervention, exclusively postmenopausal women participants, and the higher frequency used (25–35 Hz) on the WBV .
Recommendations for future studies should include more psychomotor measures potentially linked with falls as a body scheme or knowledge of body parts impairments. Furthermore, physiological assessments as the collection of the brain-derived neurotrophic factor levels or an electroencephalogram to evaluate more precisely the effects of a psychomotor intervention on brain neuroplasticity can also be incorporated. Regarding the strengths of the present study, we highlight the RCT design that includes a follow-up and the intervention length. Our study also has some limitations. First, this study followed a single-blinded design. Second, the dropout rate (14.3%) was high; however, it was lower than other interactive cognitive-motor fall prevention programs , and the sample size remained were sufficient to detect significant changes, according to the G*Power software. Third, participants were not randomly assigned by gender (i.e.: first females, second males). Fourth, nutritional supplementation as vitamin D intake was not controlled, which could allow a more efficiently calcium absorption potentializing the impact of both programs in bone mass; however, the impact of vitamin D supplementation on BMD in older adults is still inconclusive . Lastly, despite the predominance of female participants in our study, it was under the results presented in other studies . However, despite the limitations and as mentioned above, this study was carried out with a sample size with sufficient power to allow the generalization of the results to the target population, whereby is recommended the implementation of a psychomotor intervention program as a fall prevention program.