Assessing the effects of slippery steel beam coatings to ironworkers' gait stability.

Since ironworkers walk and perform their tasks on steel beams, identifying the effects of slippery steel beam surfaces on ironworkers' gait stability-which can be related to safety risk-is critical. However, there is no accepted or validated standard for measuring the slipperiness of coated steel beams, which makes evaluating and controlling for slipperiness a challenge. In this context, this study investigated the effect of the slipperiness of steel beam coatings on ironworkers' gait stability. Accordingly, to identify the relationships between coefficient of friction, perceived slipperiness, and gait stability-represented as the Maximum Lyaponuv exponent (Max LE)-an experiment was conducted with eight different surfaces and sixteen subjects with varying experience as ironworkers. The experiment's results indicate that the slipperiness of the various surfaces greatly affect ironworkers' gait stability while they walk on coated steel beam surfaces. In detail, the Max LE of two subject groups-experienced and inexperienced ironworkers-highly correlated with both the dynamic coefficient of friction values measured by following ANSI B101.3 and with the subjective rating scores of the inexperienced subject group. Unlike subjective rating scores-which were particularly incongruent among experienced workers-the Max LE of inexperienced and experienced subjects has a consistent pattern. This study result highlights an opportunity for using gait stability measurements to quantify and differentiate the safety risks caused by slippery coated steel beams in the future.

[1]  R E Schlegel,et al.  Coefficient of Friction and Subjective Assessment of Slippery Work Surfaces , 1992, Human factors.

[2]  K. Li.  A biomechanical study of slipping accidents with load carriage , 1991 .

[3]  H. Abarbanel,et al.  Local false nearest neighbors and dynamical dimensions from observed chaotic data. , 1993, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[4]  Y. Pai,et al.  Dynamic gait stability, clinical correlates, and prognosis of falls among community-dwelling older adults. , 2011, Archives of physical medicine and rehabilitation.

[5]  D. Ruelle,et al.  Ergodic theory of chaos and strange attractors , 1985 .

[6]  H. Menz,et al.  Rapid gait termination: effects of age, walking surfaces and footwear characteristics. , 2009, Gait & posture.

[7]  Jeffrey M. Hausdorff,et al.  Rhythmic auditory stimulation modulates gait variability in Parkinson's disease , 2007, The European journal of neuroscience.

[8]  Henry D. I. Abarbanel,et al.  Analysis of Observed Chaotic Data , 1995 .

[9]  D. Sternad,et al.  Local dynamic stability versus kinematic variability of continuous overground and treadmill walking. , 2001, Journal of biomechanical engineering.

[10]  J. Dingwell,et al.  Effects of walking speed, strength and range of motion on gait stability in healthy older adults. , 2008, Journal of biomechanics.

[11]  Quentin Ladetto,et al.  On foot navigation: continuous step calibration using both complementary recursive prediction and adaptive Kalman filtering , 2000 .

[12]  M. C. Bisi,et al.  Measures of gait stability: performance on adults and toddlers at the beginning of independent walking , 2014, Journal of NeuroEngineering and Rehabilitation.

[13]  C Basdogan,et al.  Kinematics and dynamic stability of the locomotion of post-polio patients. , 1996, Journal of biomechanical engineering.

[14]  T. Bhatt,et al.  Adaptive control of gait stability in reducing slip-related backward loss of balance , 2006, Experimental Brain Research.

[15]  George I. Turnbull,et al.  The Effect of Visual Cues on the Gait of Independently Mobile Parkinson's Disease Patients , 1991 .

[16]  M. Rosenstein,et al.  A practical method for calculating largest Lyapunov exponents from small data sets , 1993 .

[17]  R. Cham,et al.  Changes in gait when anticipating slippery floors. , 2002, Gait & Posture.

[18]  T Bhatt,et al.  Influence of gait speed on stability: recovery from anterior slips and compensatory stepping. , 2005, Gait & posture.

[19]  Mumtaz Usmen,et al.  Comparative Injury and Fatality Risk Analysis of Building Trades , 2006 .

[20]  Youlian Hong,et al.  Human walks carefully when the ground dynamic coefficient of friction drops below 0.41 , 2009 .

[21]  Wen-Ruey Chang,et al.  Gait adaptation on surfaces with different degrees of slipperiness. , 2017, Applied ergonomics.

[22]  G H Cattledge,et al.  Nonfatal occupational fall injuries in the West Virginia construction industry. , 1996, Accident; analysis and prevention.

[23]  Jimmie Hinze,et al.  Analysis of Construction Worker Fall Accidents , 2003 .

[24]  Jian Liu,et al.  Local Dynamic Stability Assessment of Motion Impaired Elderly Using Electronic Textile Pants , 2008, IEEE Transactions on Automation Science and Engineering.

[25]  Steven Di Pilla,et al.  Slip and Fall Prevention: A Practical Handbook , 2003 .

[26]  Changbum R. Ahn,et al.  Comprehensive Fall-Risk Assessment of Construction Workers Using Inertial Measurement Units: Validation of the Gait-Stability Metric to Assess the Fall Risk of Iron Workers , 2016, J. Comput. Civ. Eng..

[27]  Scott A. England,et al.  The influence of gait speed on local dynamic stability of walking. , 2007, Gait & posture.

[28]  J. Dingwell,et al.  Nonlinear time series analysis of normal and pathological human walking. , 2000, Chaos.

[29]  Chia-Fen Chi,et al.  Accident patterns and prevention measures for fatal occupational falls in the construction industry. , 2005, Applied ergonomics.

[30]  Leon O. Chua,et al.  Practical Numerical Algorithms for Chaotic Systems , 1989 .

[31]  H. Abarbanel,et al.  Determining embedding dimension for phase-space reconstruction using a geometrical construction. , 1992, Physical review. A, Atomic, molecular, and optical physics.