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arxiv: 1906.08670 · v1 · pith:TUGFWL5Dnew · submitted 2019-06-20 · 💻 cs.HC

A Mixed VR and Physical Framework to Evaluate Impacts of Virtual Legs and Elevated Narrow Working Space on Construction Workers Gait Pattern

Mahmoud Habibnezhad , Jay Puckett , Mohammad Sadra Fardhosseini , Lucky Agung Pratama This is my paper

Pith reviewed 2026-05-25 19:25 UTC · model grok-4.3

classification 💻 cs.HC
keywords virtual realitygait analysisconstruction safetyelevated surfacespostural stabilityvirtual legsheight exposurenatural walking
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The pith

Virtual height exposure shortens stride length and lengthens gait duration in a mixed VR-physical setup for construction workers.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper creates a VR framework allowing safe study of gait changes when workers navigate elevated narrow spaces, using natural walking instead of treadmills and adding virtual legs to the avatar for greater presence. Twelve adults walked a virtual loop at ground level and at the 17th floor of an unfinished structure. Quantitative comparison showed shorter strides and longer gait times under height exposure, with the virtual legs model further shortening strides even at ground level. The work positions this platform as a foundation for future VR-based height safety research in construction.

Core claim

Quantitative gait comparison revealed that exposure to virtual height at the 17th floor decreased participants' stride length and increased gait duration relative to ground level; at ground level the enhanced model with virtual legs also reduced average stride length and height.

What carries the argument

Mixed VR-physical framework using an enhanced first-person character model with virtual legs and natural walking locomotion on a physical loop path to simulate elevated narrow working spaces.

If this is right

  • Height exposure reliably alters gait toward shorter strides and slower timing, indicating increased instability risk.
  • Including virtual legs improves the model's effect on ground-level gait parameters, supporting its use for realism.
  • The platform enables repeatable, safe testing of height-related postural changes without physical site hazards.
  • Results provide baseline data for extending VR gait analysis to other construction safety scenarios.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The same mixed setup could test gait under added variables such as carrying loads or uneven virtual surfaces.
  • If real-world validation holds, VR could replace some on-site training for elevated work.
  • Physical elements like platform tilt or wind simulation could be layered in to increase fidelity.

Load-bearing premise

The VR environment with virtual legs produces gait and postural responses that match those in real elevated narrow construction sites rather than VR-specific effects.

What would settle it

A side-by-side measurement of stride length and gait duration for the same participants performing the identical narrow-path walking task on an actual elevated scaffold or beam at height versus in the VR setup.

read the original abstract

It is difficult to conduct training and evaluate workers' postural performance by using the actual job site environment due to safety concerns. Virtual reality (VR) provides an alternative to create immersive working environments without significant safety concerns. Working on elevated surfaces is a dangerous scenario, which may lead to gait and postural instability and, consequently, a serious fall. Previous studies showed that VR is a promising tool for measuring the impact of height on the postural sway. However, most of these studies used the treadmill as the walking locomotion apparatus in a virtual environment (VE). This paper was focused on natural walking locomotion to reduce the inherent postural perturbations of VR devices. To investigate the impact of virtual height on gait characteristics and keep the level of realism and feeling of presence at their highest, we enhanced the first-person-character model with "virtual legs". Afterward, we investigated its effect on the gait parameters of the participants with and without the presence of height. To that end, twelve healthy adults were asked to walk on a virtual loop path once at the ground level and once at the 17th floor of an unfinished structure. By quantitatively comparing the participants' gait pattern results, we observed a decrease in the stride length and increase in the gait duration of the participants exposed to height. At the ground level, the use of the enhanced model reduced participants' average stride length and height. The results of this study help us understand users' behaviors when they were exposed to elevated surfaces and establish a firm ground for gait stability analysis for the future height-related VR studies. We expect this developed VR platform can generate reliable results of VR application in more construction safety studies.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

3 major / 2 minor

Summary. The paper presents a mixed VR-physical framework using natural walking locomotion and an enhanced first-person avatar with virtual legs to study gait changes in simulated elevated narrow workspaces. Twelve participants walked a virtual loop at ground level and at simulated 17th-floor height; the authors report shorter stride length and longer gait duration under height exposure, plus reduced stride length/height from the virtual-legs model at ground level. The work aims to support safer VR-based construction safety training by quantifying height-induced gait instability.

Significance. If the reported gait shifts can be statistically validated and shown to generalize beyond VR artifacts, the platform would offer a practical, low-risk method for studying postural responses in high-fall-risk scenarios, extending prior VR postural-sway work to natural locomotion. The use of natural walking rather than treadmill locomotion is a methodological strength that could improve ecological validity for construction applications.

major comments (3)
  1. [Abstract] Abstract and Results: directional claims of decreased stride length and increased gait duration under height exposure are stated without any statistical tests, p-values, confidence intervals, or error bars, so the central empirical observation cannot be evaluated for reliability or effect size.
  2. [Methods] Methods: gait-parameter extraction (stride length, duration, height) is described only at a high level; no hardware details, tracking calibration, stride-detection algorithm, or data-processing pipeline are supplied, preventing replication or assessment of measurement validity.
  3. [Experimental Procedure] Experimental design: the study compares only ground-level VR versus height VR; without a matched physical elevated narrow-platform baseline (with harness), observed gait changes cannot be confidently attributed to height rather than VR-specific factors such as reduced FOV, locomotion mismatch, or virtual-leg rendering, directly weakening the claim that results are representative of real elevated workspaces.
minor comments (2)
  1. [Participants] Participant section lacks explicit inclusion/exclusion criteria and demographic summary table, which is standard for human-subject gait studies.
  2. [Virtual Environment] The virtual loop path geometry and turning radii are not illustrated or quantified, making it difficult to interpret stride-length changes on curved segments.

Simulated Author's Rebuttal

3 responses · 0 unresolved

We thank the referee for the constructive comments on statistical reporting, methods transparency, and experimental design. We address each point below and will revise the manuscript to improve clarity and rigor while preserving the core contribution of a natural-walking VR platform for height-related gait research.

read point-by-point responses

  1. Referee: [Abstract] Abstract and Results: directional claims of decreased stride length and increased gait duration under height exposure are stated without any statistical tests, p-values, confidence intervals, or error bars, so the central empirical observation cannot be evaluated for reliability or effect size.

    Authors: We agree that the absence of statistical tests prevents proper evaluation of the reported gait changes. In the revised manuscript we will add paired t-tests (or non-parametric equivalents) with p-values, effect sizes, and confidence intervals for stride length and gait duration comparisons between ground-level and height conditions, both in the abstract and results section. Error bars will also be included in any figures. revision: yes

  2. Referee: [Methods] Methods: gait-parameter extraction (stride length, duration, height) is described only at a high level; no hardware details, tracking calibration, stride-detection algorithm, or data-processing pipeline are supplied, preventing replication or assessment of measurement validity.

    Authors: We acknowledge the methods section is insufficiently detailed. The revised version will expand this section to specify the VR hardware (headset model, tracking system), calibration procedures, the exact algorithm used to detect heel-strike events from position data, and the full data-processing pipeline including filtering and stride segmentation criteria. revision: yes

  3. Referee: [Experimental Procedure] Experimental design: the study compares only ground-level VR versus height VR; without a matched physical elevated narrow-platform baseline (with harness), observed gait changes cannot be confidently attributed to height rather than VR-specific factors such as reduced FOV, locomotion mismatch, or virtual-leg rendering, directly weakening the claim that results are representative of real elevated workspaces.

    Authors: The experimental design intentionally isolates the effect of simulated height within an otherwise identical VR setup (same locomotion method, same virtual legs, same narrow path geometry) to examine VR-induced responses relevant to safety training. We agree, however, that without a matched physical elevated-platform condition the changes cannot be unambiguously attributed to height perception alone versus VR artifacts. In revision we will (a) explicitly state this limitation in the discussion, (b) temper claims about direct representativeness of real elevated workspaces, and (c) note that the platform is intended as a low-risk proxy rather than a perfect substitute for physical testing. revision: partial

Circularity Check

0 steps flagged

No circularity: purely empirical user study with direct measurements only

full rationale

The paper reports results from a controlled user study in which 12 participants walked a virtual loop path at ground level and at simulated height, with gait parameters (stride length, duration) measured directly via motion capture. All reported observations (decrease in stride length and increase in gait duration at height; effect of virtual legs at ground level) are statistical summaries of collected data. No equations, derivations, fitted parameters, predictions, uniqueness theorems, or ansatzes appear anywhere in the manuscript. No self-citations are invoked to justify any load-bearing premise. The study is self-contained against its own empirical benchmarks and contains no derivation chain that could reduce to its inputs by construction.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

Empirical human-subjects study with no mathematical model, free parameters, or invented physical entities; relies on the standard domain assumption that VR gait responses generalize to real elevated conditions.

axioms (1)
  • domain assumption VR simulation with virtual legs produces gait responses representative of real elevated narrow working spaces
    Central to interpreting observed stride and duration changes as safety-relevant rather than VR artifacts.

pith-pipeline@v0.9.0 · 5848 in / 1223 out tokens · 32130 ms · 2026-05-25T19:25:27.651609+00:00 · methodology

discussion (0)

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Reference graph

Works this paper leans on

40 extracted references · 40 canonical work pages

  1. [1]

    https://data.bls.gov/timeseries/FWU00X4XXX XX8EN00 (accessed January 10, 2019)

    Bureau of Labor Sta tistics Data, (2018). https://data.bls.gov/timeseries/FWU00X4XXX XX8EN00 (accessed January 10, 2019)

    work page 2018

  2. [2]

    Hsiao, P

    H. Hsiao, P. Simeonov, Preventing falls from roofs: a critical review, Ergonomics. 44 (2001) 537–561. doi:10.1080/00140130110034480

    work page doi:10.1080/00140130110034480 2001

  3. [3]

    Boffino, C.S

    C.C. Boffino, C.S. Cardoso de Sa, C. Gorenstein, R.G. Brown, L.F.H. Basile, R.T. Ramos, Fear of heights: Cognitive performance and postural control, Eur. Arch. Psychiatry Clin. Neurosci. 259 (2009) 114 –119. doi:10.1007/s00406 -008- 0843-6

    work page doi:10.1007/s00406 2009

  4. [4]

    Keshner, Virtual reality and physical rehabilitation: a new toy or a new research and rehabilitation tool?, J

    E. Keshner, Virtual reality and physical rehabilitation: a new toy or a new research and rehabilitation tool?, J. Neuroeng. Rehabil. 1 (2004) 8. doi:10.1186/1743-0003-1-8

    work page doi:10.1186/1743-0003-1-8 2004

  5. [5]

    Burdea, P

    G. Burdea, P. Coiffet, Virtual reality technology, J. Wiley -Interscience, 20 03. goo.gl/W5x41J (accessed July 26, 2017)

    work page 2017

  6. [6]

    Mujber, T

    T.S. Mujber, T. Szecsi, M.S.J. Hashmi, Virtual reality applications in manufacturing process simulation, J. Mater. Process. Technol. 155 –156 (2004) 1834 –1838. doi:10.1016/j.jmatprotec.2004.04.401

    work page doi:10.1016/j.jmatprotec.2004.04.401 2004

  7. [7]

    Horlings, M.G

    C.G.C. Horlings, M.G. Carpenter, U.M. Küng, F. Honegger, B. Wiederhold, J.H.J. Allum, Influence of virtual reality on postural stability during movements of quiet stance, Neurosci. Lett. 451 (2009) 227 –231. doi:10.1016/j.neulet.2008.12.057

    work page doi:10.1016/j.neulet.2008.12.057 2009

  8. [8]

    Cleworth, B.C

    T.W. Cleworth, B.C. Horslen, M.G. C arpenter, Influence of real and virtual heights on standing balance, Gait Posture. 36 (2012) 172 –176. doi:10.1016/j.gaitpost.2012.02.010

    work page doi:10.1016/j.gaitpost.2012.02.010 2012

  9. [9]

    Greffou, A

    S. Greffou, A. Bertone, J. -M. Hanssens, J. Faubert, Development of visually driven postural reactivity: a fully immersive virtual reality study., J. Vis. 8 (2008) 15.1-10. doi:10.1167/8.6.426

    work page doi:10.1167/8.6.426 2008

  10. [10]

    Mirelman, I

    A. Mirelman, I. Maidan, T. Herman, J.E. Deutsch, N. Giladi, J.M. Hausdorff, Virtual reality for gait training: Can it induce motor learning to enhance complex walking and r educe fall risk in patients with Parkinson’s disease?, Journals Gerontol. - Ser. A Biol. Sci. Med. Sci. 66 A (2011) 234–240. 36th International Symposium on Automation and Robotics in ...

    work page doi:10.1093/gerona/glq201 2011

  11. [11]

    Tossavainen, M

    T. Tossavainen, M. Juhola, I. Pyykkö, H. Aalto, E. Toppila, Virtual reality stimuli for force platform posturography, Stud. Health Technol. Inform. 90 (2002) 78 –82. doi:10.3233/978 -1- 60750-934-9-78

    work page doi:10.3233/978 2002

  12. [12]

    Wallach, M

    H.S. Wallach, M. Bar -Zvi, Virtual -reality- assisted treatment of flight phobia, Isr. J. Psychiatry Relat. Sci. 44 (2007) 29–32

    work page 2007

  13. [13]

    Abdelhamid, J

    T. Abdelhamid, J. E verett, Identify Root Causes of Construction Accidents, J. Constr. Eng. Manag. 126 (2000) 52 –60. doi:10.1061/(ASCE)0733-9364(2000)126:1(52)

    work page doi:10.1061/(asce)0733-9364(2000)126:1(52 2000

  14. [14]

    Bobick, Falls through Roof and Floor Openings and Surfaces, Including Skylights: 1992–2000, J

    T.G. Bobick, Falls through Roof and Floor Openings and Surfaces, Including Skylights: 1992–2000, J. Constr. En g. Manag. 130 (2004) 895–907. doi:10.1061/(ASCE)0733 - 9364(2004)130:6(895)

    work page doi:10.1061/(asce)0733 1992

  15. [15]

    Hinze, J

    J. Hinze, J. Gambatese, Factors That Influence Safety Performance of Specialty Contractors, J. Constr. Eng. Manag. 129 (2003) 159 –164. doi:10.1061/(ASCE)0733- 9364(2003)129:2(159)

    work page doi:10.1061/(asce)0733- 2003

  16. [16]

    Y. Kang, S. Siddiqui, S.J. Suk, S. Chi, C. Kim, Trends of Fall Accidents in the U.S. Construction Industry, J. Constr. Eng. Manag. 143 (2017) 04017043. doi:10.1061/(ASCE)CO.1943 - 7862.0001332

    work page doi:10.1061/(asce)co.1943 2017

  17. [17]

    Parsons, T

    T. Parsons, T. Pizatella, Safety analysis of high risk activities within the roofing industry., NTIS, SPRINGFIELD, VA(USA). 1984. (1984). goo.gl/Jt7t6v (accessed July 27, 2017)

    work page 1984

  18. [18]

    K. Hu, H. Rahmandad, T. Smith‐Jackson, W. Winchester, Factors influencing the risk of falls in the construction industry: a review of the evidence, Constr. Manag. Econ. 29 (2011) 397 –

    work page 2011

  19. [19]

    doi:10.1080/01446193.2011.558104

    work page doi:10.1080/01446193.2011.558104 2011

  20. [20]

    Sinitksi, K

    E.H. Sinitksi, K. Terry, J.M. Wilken, J.B. Dingwell, Effects of perturbation magnitude on dynamic stability when walking in destabilizing environments, J. Biomech. 45 (2012) 2084–2091. doi:10.1016/j.jbiomech.2012.05.039

    work page doi:10.1016/j.jbiomech.2012.05.039 2012

  21. [21]

    Paillard, F

    T. Paillard, F. Noé, Effect of expertise and visual contribution on postural control in soccer, Scand. J. Med. Sci. Sport. 16 (2006) 345 –348. doi:10.1111/j.1600-0838.2005.00502.x

    work page doi:10.1111/j.1600-0838.2005.00502.x 2006

  22. [22]

    Faubert, R

    J. Faubert, R. Allard, Effect of visual distortion on postural balance in a full immersion stereoscopic environment, in: A.J. Woods, J.O. Merritt, S.A. Benton, M.T. Bolas (Eds.), Proc. SPIE, Vol. 5291, p. 491 -500 (2004)., 2004: pp. 491–500. doi:10.1117/12.527017

    work page doi:10.1117/12.527017 2004

  23. [23]

    Minshew, K

    N.J. Minshew, K. Sung, B.L. Jones, J.M. Furman, Underdevelopment of the postural control system in autism., Neurology. 63 (2004) 2056 – 61. http://www.ncbi.nlm.nih.gov/pubmed/15596750 (accessed July 27, 2017)

    work page arXiv 2004

  24. [24]

    Jebelli, C.R

    H. Jebelli, C.R. Ahn, T.L. Stentz, Fall risk analysis of construction workers using inertial measurement units: Validating the usefulness of the postural stability metrics in construction, Saf. Sci. 84 (2016) 161 –170. doi:10.1016/j.ssci.2015.12.012

    work page doi:10.1016/j.ssci.2015.12.012 2016

  25. [25]

    England, K.P

    S.A. England, K.P. Granata, The influence of gait speed on local dynamic stability of walking, Gait Posture. 25 (2007) 172 –178. doi:10.1016/j.gaitpost.2006.03.003

    work page doi:10.1016/j.gaitpost.2006.03.003 2007

  26. [26]

    Qu, Effects of cognitive and physical loads on local dynamic stability during gait, Appl

    X. Qu, Effects of cognitive and physical loads on local dynamic stability during gait, Appl. Ergon. 44 (2013) 455 –458. doi:10.1016/j.apergo.2012.10.018

    work page doi:10.1016/j.apergo.2012.10.018 2013

  27. [27]

    Rosenstein MT, Collins JJ, A practical method for calculating largest Lyapunov exponents from small data sets, Phys D

    D.L.C. Rosenstein MT, Collins JJ, A practical method for calculating largest Lyapunov exponents from small data sets, Phys D. 65 (1993) 117–134

    work page 1993

  28. [28]

    McAndrew, J.B

    P.M. McAndrew, J.B. Dingwell, J.M. Wilken, Walking variability during continuous pseudo - random oscillations of the support surface and visual field, J. Biomech. 43 (2010) 1470 –1475. doi:10.1016/j.jbiomech.2010.02.003

    work page doi:10.1016/j.jbiomech.2010.02.003 2010

  29. [29]

    Rothbaum, L.F

    B.O. Rothbaum, L.F. Hodges, R. Kooper, D. Opdyke, J.S. Williford, N. North, Effectiveness of com puter generated (virtual reality) graded exposure in the treatment of acrophobia, Am. J. Psychiatry. 152 (1995) 626 –628. doi:10.1176/ajp.152.4.626

    work page doi:10.1176/ajp.152.4.626 1995

  30. [30]

    Brandt, F

    T. Brandt, F. Arnold, W. Bles, T.S. Kapteyn, The mechanism of physiological height vertigo. I. Theoretical approach and psychophysics., Acta Otolaryngol. 89 (1980) 513–23

    work page 1980

  31. [31]

    Regenbrecht, T.W

    H.T. Regenbrecht, T.W. Schubert, F. Friedmann, Measuring the Sense of Presence and its Relations to Fear of Heights in Virtual Environments, Int. J. Hum. Comput. Interact. 10 (1998) 233–249. http://www.igroup.org/schubert/papers/regenbre cht_schubert_friedmann_ijhci98.pdf (accessed December 29, 2018)

    work page 1998

  32. [32]

    D.D. Espy, F. Yang, T. Bhatt, Y. -C. Pai, 36th International Symposium on Automation and Robotics in Construction (ISARC 2019) Independent influence of gait speed and step length on stability and fall risk., Gait Posture. 32 (2010) 378 –82. doi:10.1016/j.gaitpost.2010.06.013

    work page doi:10.1016/j.gaitpost.2010.06.013 2019

  33. [33]

    Ayoubi, C.P

    F. Ayoubi, C.P. Launay, A. Kabeshova, B. Fantino, C. Annweiler, O. Beauchet, The influence of fear of falling on gait variability: results from a large elderly population -based cross-sectional study., J. Neuroeng. Rehabil. 11 (2014) 128. doi:10.1186/1743-0003-11-128

    work page doi:10.1186/1743-0003-11-128 2014

  34. [34]

    Chamberlin, B.D

    M.E. Chamberlin, B.D. Fulwider, S.L. Sanders, J.M. Medeiros, Does Fear of Falling Influence Spatial and Temporal Gait Parameters in Elderly Persons Beyond Changes Associated W ith Normal Aging?, 2005. https://core.ac.uk/download/pdf/85214868.pdf (accessed December 30, 2018)

    work page arXiv 2005

  35. [35]

    M.A. (Nort. C.S.U. Sheik_Nainar, D.C.S.U. Kaber B., The Utility of a Virtual Reality Locomotion Interface for Studying Gait Behavior, Hum. Factors. 4 ( 2007) 696 –709. doi:10.1518/001872007X215773

    work page doi:10.1518/001872007x215773 2007

  36. [36]

    Schniepp, G

    R. Schniepp, G. Kugler, M. Wuehr, M. Eckl, D. Huppert, S. Huth, C. Pradhan, K. Jahn, T. Brandt, J. Wagner, J. Kline, T.M. Lau, Quantification of gait changes in subjects with visual height intolerance when exposed to heights, Front. Hum. Neurosci. 8 (2014). doi:10.3389/fnhum.2014.00963

    work page doi:10.3389/fnhum.2014.00963 2014

  37. [37]

    Habibnezhad, S

    M. Habibnezhad, S. Fardhosseini, A.M. Vahed, B. Esmaeili, M.D. Dodd, The Relationship between Construction Workers’ Risk Perception and Eye Movement in Hazard Identifica tion, in: Constr. Res. Congr. 2016 Old New Constr. Technol. Converg. Hist. San Juan - Proc. 2016 Constr. Res. Congr. CRC 2016, 2016. doi:10.1061/9780784479827.297

    work page doi:10.1061/9780784479827.297 2016

  38. [38]

    Boheir, S

    S. Boheir, S. Hasanzadeh, B. Esmaeili, M.D. Dodd, S. Fardhosseini, MEASURING CONSTRUCTION WORKERS’ ATTENTION USING EYETRACKING TECHNOLOGY, in: 5th Int. Constr. Spec. Conf., Univ. of British Columbia, Vancouver, 2015. https://www.researchgate.net/publication/28851 6371 (accessed March 21, 2019)

    work page 2015

  39. [39]

    Habibnezhad, B

    M. Habibnezhad, B. Esmaeili, The Influence of Individual Cultural Values on Construction Workers’ Risk Perception, 52nd ASC Annu. Int. Conf. Proc. (2016). http://ascpro.ascweb.org/chair/paper/CPRT2110 02016.pdf (accessed October 30, 2017)

    work page 2016

  40. [40]

    Fardhosseini, B

    M.S. Fardhosseini, B. Esmaeili, The Impact of the Legal ization of Recreational Marijuana on Construction Safety, in: Constr. Res. Congr. 2016, American Society of Civil Engineers, Reston, VA, 2016: pp. 2972 –2983. doi:10.1061/9780784479827.296

    work page doi:10.1061/9780784479827.296 2016