Compliant Flooring Research Articles

Finite element analysis of hip fracture risk in elderly female: The effects of soft tissue shape, fall direction, and interventions

This study investigates the effects of fall configurations on hip fracture risk with a focus on pelvic soft tissue shape. This was done by employing a whole-body finite element (FE) model. Soft tissue thickness around the pelvis was measured using a standing CT system, revealing a trend of increased trochanteric soft tissue thickness with higher BMI and younger age. In the lateroposterior region from the greater trochanter, the soft tissues of elderly females were thin with a concave shape. Based on the THUMS 5F model, an elderly female FE model with a low BMI was developed by morphing the soft tissue shape around the pelvis based on the CT data. FE simulation results indicated that the lateroposterior fall led to a higher femoral neck force for the elderly female model compared to the lateral fall. One reason may be related to the thin soft tissue of the pelvis in the lateroposterior region. Additionally, the effectiveness of interventions that can help mitigating hip fractures in lateroposterior falls on the thigh-hip and hip region was assessed using the elderly female model. The attenuation rate of the femoral neck force by the hip protector was close to zero in the thigh-hip fall and high in the hip fall, whereas the attenuation rate of the compliant floor was high in both falls. This study highlights age-related changes in the soft tissue shape of the pelvis in females, particularly in the lateroposterior regions, which may influence force mitigation for the hip joint during lateroposterior falls.

Association Between Falls, Head Impacts, and Mortality Among Older Adults in Long-Term Care

ObjectivesResidents in long-term care (LTC) are at high risk for falls, and falls in LTC often result in impact to the head, with clinical consequences that may be challenging to detect. We examined whether the survival of LTC residents associates with falls and fall-related head impacts. DesignProspective cohort study. Setting and ParticipantsThis study was conducted in 2 Vancouver-area LTC homes where falls were captured on video from surveillance cameras. A total of 232 participants (133 females, 99 males) experienced at least 1 fall captured on video, among whom 84% (n = 194) died between January 2011 and January 2020. The mean age at death was 86.5 (SD = 8.5) years, and the mean survival time after enrollment to this study was 3.8 (SD = 2.1) years. MethodsUnivariable and multivariable models were used to determine how survival time depended on the rate of falls (falls per 365 days), the percentage of falls on video involving head impact, sex, age at death, and baseline physical and cognitive status. ResultsOn average, participants experienced 6.2 (SD = 7.0) falls per 365 days, and 36.9% (SD = 36.3) of video-captured falls resulted in head impact. In multivariable analyses, an increase of 1 fall per 365 days resulted in a 4.2% higher risk of death [hazard ratio (HR) = 1.042, 95% CI 1.023-1.062, P < .001]. A 1% increase in falls involving head impact resulted in an 0.5% higher risk of death (HR 1.005, 95% CI 1.001-1.010, P = .015). Participants who experienced head impact in all video-captured falls had a 50% higher risk for death than those who always avoided head impact. Conclusions and ImplicationsSurvival in LTC is associated with the rate of falls and percentage of falls involving head impact. Improved efforts are required to prevent falls in LTC, and reduce the frequency and consequences of head impacts during falls (eg, through compliant flooring).

Effects of flooring on static and dynamic balance in young and older adults

BackgroundReducing fall-related injuries is difficult due to the multi-factorial nature of falls, and challenges in implementing injury-preventative strategies. While safety floors are effective at absorbing energy and reducing fall-related impact forces, the low stiffness component of these floors may impair an individual’s balance and mobility, thereby increasing fall risk. Research question: Therefore, the objective of this study was to investigate the influence of compliant flooring (i.e., safety flooring) on balance and mobility in young and older adults. Methods: Kinematics were measured with inertial measurement units from 20 young and 10 older adults. Static balance was evaluated during quiet stance on three flooring surfaces (traditional, safety, foam) with three stance positions (regular, tandem, one-legged). Mobility was evaluated using the 3 m timed-up-and-go test on two flooring surfaces (traditional, safety). Results: All participants were able to complete quiet standing trials on normal and safety flooring surfaces; however, most older adults could not complete one-legged stance trials or standing on foam. Significant age-related effects were observed for several balance and mobility tasks, particularly during the more challenging tandem stance condition, and the dynamic timed-up-and-go mobility test. In contrast, the introduction of safety flooring (compared to traditional flooring) had limited effects on balance/mobility (1 of 16 outcome variables showed negative effects). Significance: Overall, the findings demonstrate minimal effects of a novel safety floor compared to the age-related differences, and provide insights to assist researchers, consumers, and industry stakeholders in the development of environments that support safe movement and maintained independence for older adults.

Engineering design of optimized reinforced concrete floor grillages

A new reinforced concrete beam grillage floor system is proposed as a lightweight alternative to traditional solid flat or waffle slabs used in construction. For the first time, beam grillage optimization has been paired with design code compliant floor plate design, for single and multi-bays of a building. The investigated floor slabs are novel, in that the depths of the grillage T-beams and their reinforcement are tailored for the local strength demands. This engineering efficiency gives rise to significant savings of approximately 40–50% in the quantities of concrete and steel needed compared to flat slabs. For the multi-bay studies, it was found that moving the location of the supporting columns could further decrease the volume of material required, by over 50% compared to a standard grid layout. Given the urgent need to reduce the volume of material consumed in construction projects, this appears to challenge traditional floorplate layouts. The research shows that digital optimization tools can be paired with standard design code rules to deliver significantly more sustainable building designs, though these benefits need to be balanced against the construction challenges associated with the more complex geometries that generally result.

Injuries from falls by older adults in long-term care captured on video: Prevalence of impacts and injuries to body parts

BackgroundFalls are the leading cause of injuries in older adults. However, most falls in older adults do not cause serious injury, suggesting that older adults may fall in a manner that reduces the likelihood of impact to body sites that are most vulnerable to injury. In this observational study of falls in long-term care (LTC), we tested whether body parts differed in their probability of impact and injury.MethodsWe recorded and analyzed videos of 2388 falls by 658 LTC residents (mean age 84.0 (SD = 8.1); 56.4% female). We used Linear Mixed Models to test for differences between body parts in the probability of impact and injury, and injury when impacts occurred.ResultsInjuries were reported in 38.2% of falls, and 85.9% of injuries involved direct impact to the injured body part. Impact occurred most often to the hip/pelvis (probability (standard error) = 0.95 (0.01); p < .001 relative to other body parts), and least often to the head (0.35 (0.01)). Conversely, injury occurred most often to the head (p < .001 relative to other body parts). The probability of injury when impacts occurred was 0.40 (0.01) for the head, and 0.11 or less for all other body parts.ConclusionOur results help to explain why most falls by older adults in LTC do not cause serious injury: residents land on body parts that are the most resilient to injury. The high susceptibility of the head to injury reinforces the need to enhance upper limb protective responses for fall arrest. The dominant role of direct impact as the mechanism of injury supports approaches to attenuate impact forces through strategies like protective clothing and compliant flooring.

Low-impact (compliant) flooring and staff injuries

Introduction Low impact flooring (LIF) has shown potential for reducing fall-related injuries for older people in residential care or hospital environments. However, the increased rolling resistance when moving equipment on these floors has raised concerns that staff injuries may increase. Methods LIF was trialled on one Older Persons Health ward for 2.5 years. Reported staff injuries were monitored during and following the trial. Numbers of staff injured on the LIF ward were compared with three other similar and adjacent OPH wards without LIF for the duration of the trial (‘concurrent control’ evaluation). At the trial conclusion the LIF ward moved to a different hospital that had standard flooring. This enabled a further ‘during and after’ evaluation where numbers of staff injured from the LIF ward during the trial were compared with those reported afterwards by the same ward staff without LIF. Results There was no difference in the numbers of staff injured in the LIF ward compared with the concurrent control wards (28 LIF vs 30 control; p = 0.44). The number of staff with injuries in the LIF ward also did not significantly alter when those staff moved to a new ward without LIF (45 after vs 28 before; p = 0.11). Conclusion There was no change in the numbers of staff with injuries during the LIF trial in an Older Persons Health ward. This small study suggests LIF appears safe for both patients and staff. Implications for rehabilitation Falls in hospital are common with patient injuries occurring in approximately 20-30% of falls. Low impact (compliant) flooring may reduce fall-related injuries in hospitals and residential care. Low impact flooring has an increased rolling resistance, which has the potential to increase staff injuries when moving equipment. This study found no change in the number of staff injured during a low impact flooring trial providing some reassurance that these floors are safe for staff.

The Flooring for Injury Prevention (FLIP) Study of compliant flooring for the prevention of fall-related injuries in long-term care: A randomized trial.

BackgroundFall-related injuries exert an enormous health burden on older adults in long-term care (LTC). Softer landing surfaces, such as those provided by low-stiffness “compliant” flooring, may prevent fall-related injuries by decreasing the forces applied to the body during fall impact. Our primary objective was to assess the clinical effectiveness of compliant flooring at preventing serious fall-related injuries among LTC residents.Methods and findingsThe Flooring for Injury Prevention (FLIP) Study was a 4-year, randomized superiority trial in 150 single-occupancy resident rooms at a single Canadian LTC site. In April 2013, resident rooms were block randomized (1:1) to installation of intervention compliant flooring (2.54 cm SmartCells) or rigid control flooring (2.54 cm plywood) covered with identical hospital-grade vinyl. The primary outcome was serious fall-related injury over 4 years that required an emergency department visit or hospital admission and a treatment procedure or diagnostic evaluation in hospital. Secondary outcomes included minor fall-related injury, any fall-related injury, falls, and fracture. Outcomes were ascertained by blinded assessors between September 1, 2013 and August 31, 2017 and analyzed by intention to treat. Adverse outcomes were not assessed. During follow-up, 184 residents occupied 74 intervention rooms, and 173 residents occupied 76 control rooms. Residents were 64.3% female with mean (SD) baseline age 81.7 (9.5) years (range 51.1 to 104.6 years), body mass index 25.9 (7.7) kg/m2, and follow-up 1.64 (1.39) years. 1,907 falls were reported; 23 intervention residents experienced 38 serious injuries (from 29 falls in 22 rooms), while 23 control residents experienced 47 serious injuries (from 34 falls in 23 rooms). Compliant flooring did not affect odds of ≥1 serious fall-related injury (12.5% intervention versus 13.3% control, odds ratio [OR]: 0.98, 95% CI: 0.52 to 1.84, p = 0.950) or ≥2 serious fall-related injuries (5.4% versus 7.5%, OR: 0.74, 95% CI: 0.31 to 1.75, p = 0.500). Compliant flooring did not affect rate of serious fall-related injuries (0.362 versus 0.422 per 1,000 bed nights, rate ratio [RR]: 1.04, 95% CI: 0.45 to 2.39, p = 0.925; 0.038 versus 0.053 per fall, RR: 0.81, 95% CI: 0.38 to 1.71, p = 0.560), rate of falls with ≥1 serious fall-related injury (0.276 versus 0.303 per 1,000 bed nights, RR: 0.97, 95% CI: 0.52 to 1.79, p = 0.920), or time to first serious fall-related injury (0.237 versus 0.257, hazard ratio [HR]: 0.92, 95% CI: 0.52 to 1.62, p = 0.760). Compliant flooring did not affect any secondary outcome in this study. Study limitations included the following: findings were specific to 2.54 cm SmartCells compliant flooring installed in LTC resident rooms, standard fall and injury prevention interventions were in use throughout the study and may have influenced the observed effect of compliant flooring, and challenges with concussion detection in LTC residents may have prevented estimation of the effect of compliant flooring on fall-related concussions.ConclusionsIn contrast to results from previous retrospective and nonrandomized studies, this study found that compliant flooring underneath hospital-grade vinyl was not effective at preventing serious fall-related injuries in LTC. Future studies are needed to identify effective methods for preventing fall-related injuries in LTC.Trial registrationClinicalTrials.gov: NCT01618786

Effects of Compliant Flooring on Dynamic Balance and Gait Characteristics of Community-dwelling Older Persons.

Compliant flooring while providing the impact force attenuation in the event of falls, its low stiffness characteristic might impair balance and gait which consequently resulted in an increase in the risk of falling. To investigate the effects of compliant flooring on dynamic balance and gait performance of older adults under challenging conditions. A cross-sectional designed with repeated measured. Thirty five community-dwelling older adults (mean age 74.91 ± 6.51 yrs) participated in this study. Modified Dynamic Gait Index (mDGI) and Timed Up and Go (TUG) were used to assess dynamic balance. Spatio-temporal gait parameters were measured under comfortable and maximal speed. All tests were administered on the vinyl and compliant flooring in random order. The time taken to complete TUG and the mDGI scores were similar between the two flooring types (p ≥ 0.05). Overall, gait characteristics were comparable when walking on the compliant and vinyl flooring for both speeds except for swing time, step time, and cadence. The present study demonstrated that compliant flooring did not significantly affect dynamic balance and had minimal effects on gait characteristics. The compliant flooring appears to be safe for installing in self-ambulating older adult's home.

Comparison of impact energy absorbance by various combinations of hip protector and flooring material

Background: Understanding the nature of blunt force trauma and the energies involved is key to their effective attenuation. This study compares and analyzes the energy absorbance of various combinations of hip protectors and flooring materials to identify fracture prevention design variables. Methods: Testing was performed using a dynamic impact rig instrumented with linear encoders and a piezoelectric impact load cell, which allows for high rate of force and displacement measurements to be achieved during impact. Results show the effects of deceleration rate on peak load and measurably define the impact patterns for a range of protective materials, with compliant flooring and hip protectors reducing impact forces below the suggested fracture threshold (3742N). Results: The force reduction provided by a hip protector depends on the type of flooring and is greatest for falls onto carpet with a foam underlay. A combination of soft-shell protector with carpet and underlay showed the highest force attenuation (68%). Conclusions: The study showed that the effective selection and implementation of hip protectors in homes and care facilities must include the consideration of flooring type. The identification of peak deceleration rates also will inform the future development of multi-material protective aids.

A quasi-experimental evaluation of compliant flooring in a residential care setting.

BackgroundFall injuries affect the lives of older people to a substantial degree. This quasi-experimental observational study investigates the potential fall injury reducing effect of a compliant flooring in a residential care setting.MethodsThe allocation of the compliant flooring was non-random. Data on fall-events and individual characteristics were collected in a residential care unit during a period of 68 months. The primary outcome was the fall injury rate per fall, and a logistic regression analysis was used to test for the effect of complaint flooring. Falls per 1000 bed days was the secondary outcome, used to measure the difference in fall risk on compliant flooring versus regular flooring.ResultsThe event dataset is an unbalanced panel with repeated observations on 114 individuals, with 70% women. The mean age was 84.9 years of age, the average Body Mass Index (BMI) was 24.7, and there was a mean of 6.57 (SD: 15.28) falls per individual. The unadjusted effect estimate showed a non-significant relative risk injury reduction of 29% per fall (RR 0.71 [95% CI: 0.46–1.09]) compared to regular flooring. Re-estimating, excluding identified outliers, showed an injury risk reduction of 63% (RR 0.37 [95% CI: 0.25–0.54]). Falls per 1000 bed days showed that individuals living in apartments with compliant flooring had a fall rate of 5.3 per 1000 bed days compared to a fall rate of 8.4 per 1000 bed days among individuals living in regular apartments. This corresponds to an incidence rate ratio (IRR) of 0.63 (95% exact Poisson CI: 0.50–0.80).ConclusionThe results of this non-randomized study indicate that compliant flooring has the potential to reduce the risk of fall injury without increasing the fall risk among older people in a Swedish residential care setting.

Hand forces exerted by long-term care staff when pushing wheelchairs on compliant and non-compliant flooring

Purpose-designed compliant flooring and carpeting have been promoted as a means for reducing fall-related injuries in high-risk environments, such as long-term care. However, it is not known whether these surfaces influence the forces that long-term care staff exert when pushing residents in wheelchairs. We studied 14 direct-care staff who pushed a loaded wheelchair instrumented with a triaxial load cell to test the effects on hand force of flooring overlay (vinyl versus carpet) and flooring subfloor (concrete versus compliant rubber [brand: SmartCells]). During straight-line pushing, carpet overlay increased initial and sustained hand forces compared to vinyl overlay by 22–49% over a concrete subfloor and by 8–20% over a compliant subfloor. Compliant subflooring increased initial and sustained hand forces compared to concrete subflooring by 18–31% when under a vinyl overlay. In contrast, compliant flooring caused no change in initial or sustained hand forces compared to concrete subflooring when under a carpet overlay.

Perceptions about Compliant Flooring from Senior Managers in Long-Term Care

ABSTRACTThis study explored barriers and facilitators to adoption of compliant flooring as a fall injury prevention strategy within long-term care from the perspective of 18 long-term care senior managers. In-depth interviews were recorded, transcribed, and analyzed using the Framework Method. The most important organizational facilitators to adoption were potential for injury prevention and long-term care staff's openness to change. The most important organizational barriers to adoption were negative effects to long-term care staff and financial considerations (i.e., cost and lack of funding). The most important general organizational considerations were uncertainties about clinical effectiveness, effects on long-term care staff, and flooring performance. Overall, compliant flooring was viewed positively for long-term care. The findings also suggest an opportunity for knowledge translation to inform long-term care senior managers about the existing evidence on compliant flooring.

There is more to life than risk avoidance – elderly people’s experiences of falls, fall-injuries and compliant flooring

ABSTRACTPurpose: Falls are the most common cause of injury in all ages and are especially difficult to prevent among residential care residents. Compliant flooring that absorbs energy generated within the fall, has been proposed as a measure to prevent fall-injury, however little is known regarding the implementation aspects in clinical settings. The aim of this study is to explore the experiences of falls, the risk of fall-injury, prevention in general and specifically compliant flooring as an injury preventative measure amongst frail elderly people living in a residential care facility with compliant flooring. Through this, generate a theory that further explains the underlying barriers of active prevention amongst elderly people.Method: We used the grounded theory method and conducted semi-structured in-depth interviews with eight elderly people in residential care (data collected between February and December 2017).Results: The identified categories were Falling as a part of life, Fearing the consequences and A wish to prevent falls and injuries. Through the results it was clear that There is more to life than risk avoidance, permeated the interviews, therefore forming the grounded theory. The interviewees viewed falls as something common and normal, and were uninterested in focusing on the risk of falls. Although they wanted to prevent falls, it was often difficult to integrate preventative measures into their everyday life. They embraced the idea of an injury-reducing compliant flooring, however their main interests lay elsewhere, preferring to focus on social interaction and issues concerning daily activities.Conclusions: The theory generated in this paper proposes explanations on the obstacles of implementing fall prevention measures in an elderly frail population. The findings give insights as to why interest and compliance for active fall prevention measures are low. We conclude that complaint flooring, from the perspective of the residents, can work well in residential care.

Feasibility of Compliant Flooring in Long-Term Care: Results from a Stakeholder Symposium.

Compliant flooring aims to prevent fall-related injuries among high-risk older adults in long-term care, but uptake of compliant flooring in this setting is limited. We hosted a one-day stakeholder symposium to identify advantages and disadvantages of implementing compliant flooring in long-term care and the most pressing directions for future research from the perspective of key stakeholders. Twenty-three stakeholders representing health care, industry, and research attended the symposium. Attendees believed the most important advantages of compliant flooring were reducing injuries in residents who have fallen, potential benefits to care staff, and potential increases in quality of life for residents. Attendees perceived the most significant disadvantages of compliant flooring were financial considerations, lack of research evidence, and challenges with installation. Attendees indicated a need for additional research on cost-effectiveness and clinical effectiveness. While stakeholders perceived compliant flooring to add value to long-term care, there are significant informational and financial barriers to uptake.

Compliant flooring to prevent fall-related injuries in older adults: A scoping review of biomechanical efficacy, clinical effectiveness, cost-effectiveness, and workplace safety.

BackgroundCompliant flooring, broadly defined as flooring systems or floor coverings with some level of shock absorbency, may reduce the incidence and severity of fall-related injuries in older adults; however, a lack of synthesized evidence may be limiting widespread uptake.MethodsInformed by the Arksey and O’Malley framework and guided by a Research Advisory Panel of knowledge users, we conducted a scoping review to answer: what is presented about the biomechanical efficacy, clinical effectiveness, cost-effectiveness, and workplace safety associated with compliant flooring systems that aim to prevent fall-related injuries in healthcare settings? We searched academic and grey literature databases. Any record that discussed a compliant flooring system and at least one of biomechanical efficacy, clinical effectiveness, cost-effectiveness, or workplace safety was eligible for inclusion. Two independent reviewers screened and abstracted records, charted data, and summarized results.ResultsAfter screening 3611 titles and abstracts and 166 full-text articles, we included 84 records plus 56 companion (supplementary) reports. Biomechanical efficacy records (n = 50) demonstrate compliant flooring can reduce fall-related impact forces with minimal effects on standing and walking balance. Clinical effectiveness records (n = 20) suggest that compliant flooring may reduce injuries, but may increase risk for falls. Preliminary evidence suggests that compliant flooring may be a cost-effective strategy (n = 12), but may also result in increased physical demands for healthcare workers (n = 17).ConclusionsIn summary, compliant flooring is a promising strategy for preventing fall-related injuries from a biomechanical perspective. Additional research is warranted to confirm whether compliant flooring (i) prevents fall-related injuries in real-world settings, (ii) is a cost-effective intervention strategy, and (iii) can be installed without negatively impacting workplace safety. Avenues for future research are provided, which will help to determine whether compliant flooring is recommended in healthcare environments.

Compliant flooring to prevent fall-related injuries: a scoping review protocol

IntroductionFall-related injuries can have serious consequences for older adults, including increased risk of dependence in daily activities and mortality. Compliant flooring is a passive intervention that may reduce the incidence...

External Hand Forces Exerted by Long-Term Care Staff to Push Floor-Based Lifts: Effects of Flooring System and Resident Weight.

The aim of this study was to investigate the effects of flooring type and resident weight on external hand forces required to push floor-based lifts in long-term care (LTC). Novel compliant flooring is designed to reduce fall-related injuries among LTC residents but may increase forces required for staff to perform pushing tasks. A motorized lift may offset the effect of flooring on push forces. Fourteen female LTC staff performed straight-line pushes with two floor-based lifts (conventional, motor driven) loaded with passengers of average and 90th-percentile resident weights over four flooring systems (concrete+vinyl, compliant+vinyl, concrete+carpet, compliant+carpet). Initial and sustained push forces were measured by a handlebar-mounted triaxial load cell and compared to participant-specific tolerance limits. Participants rated pushing difficulty. Novel compliant flooring increased initial and sustained push forces and subjective ratings compared to concrete flooring. Compared to the conventional lift, the motor-driven lift substantially reduced initial and sustained push forces and perceived difficulty of pushing for all four floors and both resident weights. Participants exerted forces above published tolerance limits only when using the conventional lift on the carpet conditions (concrete+carpet, compliant+carpet). With the motor-driven lift only, resident weight did not affect push forces. Novel compliant flooring increased linear push forces generated by LTC staff using floor-based lifts, but forces did not exceed tolerance limits when pushing over compliant+vinyl. The motor-driven lift substantially reduced push forces compared to the conventional lift. Results may help to address risk of work-related musculoskeletal injury, especially in locations with novel compliant flooring.

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

BackgroundA promising strategy for reducing the incidence and severity of fall-related injuries in long-term care (LTC) is to decrease the ground surface stiffness, and the subsequent forces applied to the...

Effects of Compliant Flooring Systems and Resident Weight on Hand Forces When Pushing Floor-Based Lifts and Wheelchairs among Long-Term Care Staff

Preliminary clinical findings suggest that compliant flooring may reduce the incidence and severity of fall- related injuries in long-term care (Knoefel et al., 2013) and acute-care settings (Drahota et al., 2013). However, there is concern that manoeuvring wheeled equipment on compliant flooring could expose care staff to potentially harmful pushing forces (Drahota et al., 2013; Wynn et al., 2011). We measured the external resultant hand forces (initial and sustained) required for female direct care staff to push two floor - based lifts (conventional manual and motor-driven) (n=14) or a wheelchair (n=14), loaded with passengers of average (67 kg) and ninetieth percentile (90 kg) resident weights, over four flooring systems: concrete + vinyl, compliant (1” SmartCells) + vinyl, concrete + carpet, and compliant + carpet. We observed an interaction between lift type and floor system for initial (p &lt; 0.001) and sustained (p &lt; 0.001) forces. Independent of resident weight, mean forces were lower for the motor-driven lift than the conventional lift on all flooring conditions (by 34.8 – 74.4 N for initial forces and by 14.1 – 64.5 N for sustained forces). With the vinyl overlay, initial forces were higher on compliant than concrete subflooring when using the conventional lift (mean difference = 44.7 N, 47.7% increase, p &lt; 0.001) and motor-driven lift (29.8 N, 45.8% increase, p &lt; 0.001). Similarly, with the vinyl overlay, sustained resultant forces were higher on compliant subflooring than concrete subflooring when using the conventional lift (39.0 N, 88.2% increase, p &lt; 0.001) and motor-driven lift (9.7 N, 29.0% increase, p &lt; 0.001). With the carpet overlay, the differences between compliant and concrete subfloors were less pronounced than with the vinyl overlay for the conventional lift (Finitial: 23.0 N higher, 14.9% increase, p &lt; 0.001; Fsustained: 15.6 N higher, 18.7% increase, p &lt; 0.001) and absent when using the motor-driven lift (Finitial: p = 0.975; Fsustained: p = 0.999). We also observed an interaction between resident weight and lift type for initial (p = 0.004) and sustained forces (p &lt; 0.001). Independent of flooring system, Finitial was 18.6 N higher (13.5% increase, p &lt; 0.001) and Fsustained was 11.7 N higher (14.3% increase, p &lt; 0.001) for the ninetieth percentile weight than the average weight for the conventional lift. In contrast, there were no differences in Finitial (p = 0.200) and Fsustained (p = 0.100) between the average and ninetieth percentile weight conditions for the motor-driven lift. Similar trends were observed when participants pushed the wheelchair. In summary, this study found that compliant subflooring increased the external hand forces required for female direct care staff to push floor -based lifts and wheelchairs compared to concrete subflooring, and these increases in force were greater when pushing over vinyl than carpet overlay. This study also demonstrated that a motor-driven lift substantially reduced push forces compared to a conventional manual lift. Thus, motor-driven lifts may help to prevent work- related musculoskeletal injuries in long-term care facilities, especially in facilities with compliant flooring.

Lower limb kinematic variability in dancers performing drop landings onto floor surfaces with varied mechanical properties

Elite dancers perform highly skilled and consistent movements. These movements require effective regulation of the intrinsic and extrinsic forces acting within and on the body. Customized, compliant floors typically used in dance are assumed to enhance dance performance and reduce injury risk by dampening ground reaction forces during tasks such as landings. As floor compliance can affect the extrinsic forces applied to the body, secondary effects of floor properties may be observed in the movement consistency or kinematic variability exhibited during dance performance. The aim of this study was to investigate the effects of floor mechanical properties on lower extremity kinematic variability in dancers performing landing tasks. A vector coding technique was used to analyze sagittal plane knee and ankle joint kinematic variability, in a cohort of 12 pre-professional dancers, through discrete phases of drop landings from a height of 0.2m. No effect on kinematic variability was observed between floors, indicating that dancers could accommodate the changing extrinsic floor conditions. Future research may consider repeat analysis under more dynamic task constraints with a less experienced cohort. However, knee/ankle joint kinematic variability was observed to increase late in the landing phase which was predominantly comprised of knee flexion coupled with the terminal range of ankle dorsiflexion. These findings may be the result of greater neural input late in the landing phase as opposed to the suggested passive mechanical interaction of the foot and ankle complex at initial contact with a floor. Analysis of joint coordination in discrete movement phases may be of benefit in identifying intrinsic sources of variability in dynamic tasks that involve multiple movement phases.