The influence of novel compliant floors on balance control in elderly women—A biomechanical study

Abstract

Novel compliant floors aim to decrease the risk for fall-related injury by providing substantial force attenuation during the impact phase of falls. Certain models of compliant flooring have been shown to have limited influence on postural sway and successful completion of dynamic balance tasks. However, the effects of these products on balance recovery mechanisms following an externally induced perturbation have yet to be quantified. We used a floor translation paradigm to induce a balance perturbation to thirteen elderly community-dwelling women. Outcome measures included the displacement rates and margins of safety for both the underfoot centre-of-pressure and whole-body centre-of-mass across two novel compliant floors (SmartCell, SofTile), two basic foam surfaces (Firm-Foam, Soft-Foam) and a standard 'Rigid' floor as a control condition. The centre-of-mass and centre-of-pressure margins of safety, and all centre-of-mass displacement rates, were not significantly lower for the two novel compliant flooring systems compared to the control floor. The centre-of-pressure displacement rates were similar to the control floor for the SmartCell floor condition. The majority of the margin of safety and displacement rate variables for the foam floors were significantly lower than the control condition. This study illustrates that the SmartCell and SofTile novel compliant floors have minimal influences on balance and balance control responses following externally induced perturbations in older community-dwelling women, and supports pilot installations of these floors to inform decisions regarding the development of clinical trials.

Characterization of the protective capacity of flooring systems using force-deflection profiling

“…Interestingly, the safety floors investigated in this study were associated with smaller 'softness' values (slope of the linear portion of the deflection-stress curve during simulated single-leg stance) than most of the flooring conditions studied by Redfern et al [33]. Consequently, compliance-induced proprioceptive feedback impairments may be quite limited for the safety floors we studied, a position supported by the minimal effects on balance control observed for one of these safety floors during quiet stance sway [15], backwards floor translations [15,23] and forward tether-release perturbations [36].…”

“…Thus, a crucial design element for effective safety floors is the ability to provide substantial force attenuation without allowing deflections that may impair balance control during gait and stance activities. Previous studies involving quiet stance and backwards perturbations in elderly individuals revealed clinically insignificant differences in postural sway between some safety floors and traditional floors [15,23]. In order to examine a more dynamic task scenario, the flat-foot stage of single-leg stance during a natural cadence gait-cycle was simulated in this study to contribute to existing literature on locomotor adaptations, footfall deflections and toe-floor clearance distances while walking on compliant surfaces [22,24,25].…”

“…The newest generation of safety floors are designed with the competing demands of force attenuation and fall risk in mind [14,15,22,23]. Several floors of this category use buckling column designs to absorb energy under high energy loading scenarios.…”

The influence of headform orientation and flooring systems on impact dynamics during simulated fall-related head impacts

“…Regarding novel compliant flooring systems, Laing and Robinovitch [18] found that medial-lateral postural sway on a SmartCell floor was not different than on a rigid surface for community-dwelling elderly women, and that scores on the Timed Up and Go test (a predictor of fall risk [54][55][56]) were not different for SmartCell, SofTile and a rigid floor condition. Furthermore, Wright and Laing [57] found that the displacement profiles of both the centre of mass (a balance indicator) and the underfoot centre-of-pressure (a balance control variable) were not affected by SmartCell and SofTile floors in community-dwelling elderly women during backwards perturbations. Despite these encouraging findings, further research is needed to ascertain if and how balance control is affected on these floors during activities of daily living for older adults residing in high-risk settings (retirement homes, nursing homes, hospitals) where NCFs are most likely to be installed.…”

Study protocol for the Flooring for Injury Prevention (FLIP) Study: a randomised controlled trial in long-term care

“…A number of commercially available compliant floors have been shown to substantially attenuate impact forces, including SmartCells, Forbo, Sorbashock and Kradal 24 28 33 35. We selected SmartCells for the FLIP Study for three main reasons: (1) it provided one of the highest degrees of impact force attenuation in our biomechanical tests; (2) to our knowledge, it is the only brand of compliant flooring that has been tested extensively for balance and mobility;24 31 32 and (3) installation during retrofits is straightforward.…”