A Principal Components Analysis Approach to Quantifying Foot Clearance and Foot Clearance Variability

in Journal of Applied Biomechanics
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Low foot clearance and high variability may be related to falls risk. Foot clearance is often defined as the local minimum in toe height during swing; however, not all strides have this local minimum. The primary purpose of this study was to identify a nondiscrete measure of foot clearance during all strides, and compare discrete and nondiscrete measures in ability to rank individuals on foot clearance and variability. Thirty-five participants (young adults [n = 10], older fallers [n = 10], older nonfallers [n = 10], and stroke survivors [n = 5]) walked overground while lower extremity 3D kinematics were recorded. Principal components analysis (PCA) of the toe height waveform yielded representation of toe height when it was closest to the ground. Spearman’s rank order correlation assessed the association of foot clearance and variability between PCA and discrete variables, including the local minimum. PCA had significant (P < .05) moderate or strong associations with discrete measures of foot clearance and variability. An approximation of the discrete local minimum had a weak association with PCA and other discrete measures of foot clearance. A PCA approach to quantifying foot clearance can be used to identify the behavioral components of toe height when it is closest to the ground, even for strides without a local minimum.

Benson, Cobb, Keenan, Luo, and O’Connor are with the University of Wisconsin-Milwaukee, Milwaukee, WI, USA. Benson is also with the University of Calgary, Calgary, Canada. Hyngstrom is with Marquette University, Milwaukee, WI, USA.

Benson (lauren.benson@ucalgary.ca) is corresponding author.
  • 1.

    Robinovitch SN, Feldman F, Yang Y, et al. Video capture of the circumstances of falls in elderly people residing in long-term care: an observational study. Lancet. 2013;381(9860):47–54. PubMed ID: 23083889 doi:10.1016/S0140-6736(12)61263-X

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 2.

    Begg RK, Best R, Dell’Oro L, Taylor S. Minimum foot clearance during walking: strategies for the minimisation of trip-related falls. Gait Posture. 2007;25(2):191–198. PubMed ID: 16678418 doi:10.1016/j.gaitpost.2006.03.008

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 3.

    Nagano H, James L, Sparrow WA, Begg RK. Effects of walking-induced fatigue on gait function and tripping risks in older adults. J Neuroeng Rehabil. 2014;11:155. PubMed ID: 25399324 doi:10.1186/1743-0003-11-155

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 4.

    Moosabhoy MA, Gard SA. Methodology for determining the sensitivity of swing leg toe clearance and leg length to swing leg joint angles during gait. Gait Posture. 2006;24(4):493–501. PubMed ID: 16439130 doi:10.1016/j.gaitpost.2005.12.004

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 5.

    Santhiranayagam BK, Lai DTH, Sparrow WA, Begg RK. Minimum toe clearance events in divided attention treadmill walking in older and young adults: a cross-sectional study. J Neuroeng Rehabil. 2015;12:58. PubMed ID: 26162824 doi:10.1186/s12984-015-0052-2

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 6.

    Little VL, McGuirk TE, Patten C. Impaired limb shortening following stroke: what’s in a name? PLoS ONE. 2014;9(10):110140. PubMed ID: 25329317 doi:10.1371/journal.pone.0110140

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 7.

    Santhiranayagam BK, Sparrow WA, Lai DTH, Begg RK. Non-MTC gait cycles: an adaptive toe trajectory control strategy in older adults. Gait Posture. 2017;53(suppl C):73–79. PubMed ID: 28113075 doi:10.1016/j.gaitpost.2016.11.044

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 8.

    Schulz BW. Minimum toe clearance adaptations to floor surface irregularity and gait speed. J Biomech. 2011;44(7):1277–1284. PubMed ID: 21354576 doi:10.1016/j.jbiomech.2011.02.010

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 9.

    Winter DA. Foot trajectory in human gait—a precise and multifactorial motor control task. Phys Ther. 1992;72(1):45–53. PubMed ID: 1728048 doi:10.1093/ptj/72.1.45

  • 10.

    De Asha AR, Buckley JG. The effects of walking speed on minimum toe clearance and on the temporal relationship between minimum clearance and peak swing-foot velocity in unilateral trans-tibial amputees. Prosthet Orthot Int. 2015;39(2):120–125. PubMed ID: 24469428 doi:10.1177/0309364613515493

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 11.

    Nagano H, Begg RK, Sparrow WA, Taylor S. Ageing and limb dominance effects on foot-ground clearance during treadmill and overground walking. Clin Biomech. 2011;26(9):962–968. PubMed ID: 21719169 doi:10.1016/j.clinbiomech.2011.05.013

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 12.

    Barrett RS, Mills PM, Begg RK. A systematic review of the effect of ageing and falls history on minimum foot clearance characteristics during level walking. Gait Posture. 2010;32(4):429–435. PubMed ID: 20692163 doi:10.1016/j.gaitpost.2010.07.010

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 13.

    Begg RK, Tirosh O, Said CM, et al. Gait training with real-time augmented toe-ground clearance information decreases tripping risk in older adults and a person with chronic stroke. Front Hum Neurosci. 2014;8:243. PubMed ID: 24847234 doi:10.3389/fnhum.2014.00243

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 14.

    Khandoker AH, Taylor SB, Karmakar CK, Begg RK, Palaniswami M. Investigating scale invariant dynamics in minimum toe clearance variability of the young and elderly during treadmill walking. IEEE Trans Neural Syst Rehabil Eng. 2008;16(4):380–389. PubMed ID: 18713677 doi:10.1109/TNSRE.2008.925071

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 15.

    Byju AG, Nussbaum MA, Madigan ML. Alternative measures of toe trajectory more accurately predict the probability of tripping than minimum toe clearance. J Biomech. 2016;49(16):4016–4021. PubMed ID: 27825600 doi:10.1016/j.jbiomech.2016.10.045

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 16.

    Schulz BW. A new measure of trip risk integrating minimum foot clearance and dynamic stability across the swing phase of gait. J Biomech. 2017;55:107–112. PubMed ID: 28302314 doi:10.1016/j.jbiomech.2017.02.024

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 17.

    Daffertshofer A, Lamoth CJC, Meijer OG, Beek PJ. PCA in studying coordination and variability: a tutorial. Clin Biomech. 2004;19(4):415–428. PubMed ID: 15109763 doi:10.1016/j.clinbiomech.2004.01.005

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 18.

    Senden R, Savelberg HH, Grimm B, Heyligers IC, Meijer K. Accelerometry-based gait analysis, an additional objective approach to screen subjects at risk for falling. Gait Posture. 2012;36(2):296–300. PubMed ID: 22512847 doi:10.1016/j.gaitpost.2012.03.015

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 19.

    Sullivan KJ, Tilson JK, Cen SY, et al. Fugl-meyer assessment of sensorimotor function after stroke: standardized training procedure for clinical practice and clinical trials. Stroke. 2011;42(2):427–432. PubMed ID: 21164120 doi:10.1161/STROKEAHA.110.592766

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 20.

    Savin DN, Morton SM, Whitall J. Generalization of improved step length symmetry from treadmill to overground walking in persons with stroke and hemiparesis. Clin Neurophysiol. 2014;125(5):1012–1020. PubMed ID: 24286858 doi:10.1016/j.clinph.2013.10.044

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 21.

    Weinhandl JT, O’Connor KM. Assessment of a greater trochanter-based method of locating the hip joint center. J Biomech. 2010;43(13):2633–2636. PubMed ID: 20605153 doi:10.1016/j.jbiomech.2010.05.023

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 22.

    Borg G. Perceived exertion as an indicator of somatic stress. Scand J Rehabil Med. 1970;2(2):92–98. PubMed ID: 5523831

  • 23.

    Zeni JA Jr, Richards JG, Higginson JS. Two simple methods for determining gait events during treadmill and overground walking using kinematic data. Gait Posture. 2008;27(4)710–714. PubMed ID: 17723303 doi:10.1016/j.gaitpost.2007.07.007

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 24.

    Brandon SCE, Graham RB, Almosnino S, Sadler EM, Stevenson JM, Deluzio KJ. Interpreting principal components in biomechanics: representative extremes and single component reconstruction. J Electromyogr Kinesiol. 2013;23(6):1304–1310. PubMed ID: 24209874 doi:10.1016/j.jelekin.2013.09.010

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 25.

    Mills PM, Barrett RS, Morrison S. Toe clearance variability during walking in young and elderly men. Gait Posture. 2008;28(1):101–107. PubMed ID: 18093833 doi:10.1016/j.gaitpost.2007.10.006

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 26.

    Thies SB, Jones RK, Kenney LPJ, Howard D, Baker R. Effects of ramp negotiation, paving type and shoe sole geometry on toe clearance in young adults. J Biomech. 2011;44(15):2679–2684. PubMed ID: 21893316 doi:10.1016/j.jbiomech.2011.07.027

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 27.

    Loverro KL, Mueske NM, Hamel KA. Location of minimum foot clearance on the shoe and with respect to the obstacle changes with locomotor task. J Biomech. 2013;46(11):1842–1850. PubMed ID: 23747230 doi:10.1016/j.jbiomech.2013.05.002

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
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