Slip and fall accidents are a major and growing source of occupational injuries. Increasing the available coefficient of friction (ACOF) between the shoe and floor surface is an effective method for reducing slipping risk. A significant need exists for portable, cost-effective shoe-floor ACOF testing equipment that is valid for predicting slip risk. Filling this need is likely to increase the use of rigorous slip-testing in the field, customizing footwear programs to a specific workplace, and selecting the most effective footwear or flooring intervention. The overall objective of this SBIR Phase II (R44) research study is to develop a portable ACOF testing device that predicts whether a person is likely to slip with sensitivity and specificity. The feasibility of this approach is supported by preliminary development of a biofidelic slip-testing device. The potential for our approach to improve the validity of slip-testing is supported by preliminary data that found that current testing methods do not reflect the kinematics of slipping and that the under-shoe testing condition are critical to the tester's ability to predict slips. The proposed research will be accomplished with four aims:
Aim 1 : Identify a set of testing conditions (force, sliding speed and shoe-floor angle profiles) that best predict slip events;
Aim 2 : Develop a slip-tester that is portable, inexpensive and biofidelic;
Aim 3 : Quantify reproducibility and repeatability of the device using an interlaboratory study;
and Aim 4 : Validate the ability of the portable testing device to predict slipping events.
Aim 1 will use previously-collected human slipping data and the biofidelic slip-tester to identify testing kinematics and kinetics that best predict slips.
Aim 2 will create a portable device that uses kinematic linkage systems to achieve the testing conditions identified in Aim 1 using stepper motors and calculates ACOF based on forces measured with a load cell.
Aim 2 will also include a hypothesis (H2.1) that the developed device will yield ACOF values that are well correlated with the biofidelic slip-testing device developed in Phase 1.
Aim 3 will perform a multiple site interlaboratory study to quantify repeatability of the device and reproducibility across operators and devices.
Aim 3 will include a hypothesis (H3.1) that differences in ACOF values will not be observed across operators and devices.
Aim 4 will quantify the validity of the device for prospectively predicting human slip propensity based on ACOF data collected with the device.
Aim 4 includes a hypothesis (H4.1) that the device will predict slipping risk. This proposed research is expected to lead to a state-of-the art device that will promote interventions that reduce accidental injuries due to slipping. Commercializing this innovation will position Crossroads Consulting, LLC to reach new markets for both laboratory and field slip-testing, targeting safety and occupational health consultants, smaller shoe and flooring manufactures, as well as the research community. As a result, Crossroads Consulting, LLC is anticipated to grow in size and revenues through product sales and service agreements.!
Slip and fall accidents are a significant source injuries and fatalities for all age groups. Valid measurements of ACOF between shoes and flooring surfaces is essential to identify circumstances in need of intervention and identifying the optimal intervention. The purpose of this research is to develop a portable, valid and cost- effective design for measuring shoe-floor ACOF.
Iraqi, Arian; Cham, Rakié; Redfern, Mark S et al. (2018) Kinematics and kinetics of the shoe during human slips. J Biomech 74:57-63 |
Iraqi, Arian; Cham, Rakié; Redfern, Mark S et al. (2018) Coefficient of friction testing parameters influence the prediction of human slips. Appl Ergon 70:118-126 |