Foot displacement but not velocity predicts the outcome of a slip induced in young subjects while walking

Brady, Rachael; Pavol, Michael J.; Owings, Tammy M.; Grabiner, Mark D.

doi:10.1016/s0021-9290(00)00037-3

Cited by 126 publications

(119 citation statements)

References 9 publications

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“…These slipping experiments indicated that a slip was likely to result in a fall if the sliding exceeded 0.1 m in distance or 0.5 m s −1 in velocity. A recent study by Brady et al (2000) suggested that foot displacement rather than the velocity of the slipping foot would predict the outcome of a slip, and that the threshold values for fall avoidance may be higher than previously thought. Roughly 75% of the subjects in these bare foot slipping experiments over an oily vinyl surface were able to recover balance, when the slip distance was 0.2 m and the slipping foot velocity was 1.1 m s −1 (cf.…”

Section: Biomechanically-oriented Approachesmentioning

confidence: 92%

“…Obviously, an increasingly safer situation from the point of view of balance recovery would follow. On the contrary, if the critical values (s = 0.2 m and v = 1.1 m s −1 ) for slip distance and velocity suggested by Brady et al (2000) would be applied in this equation, then the minimum coefficient of friction in the interface would need to be about 0.3 for a fall recovery.…”

Section: Critical Slip Distancementioning

confidence: 99%

“…Pai and Patton (1997) and Pai and Iqbal (1999) used an inverted pendulum model with a foot segment to simulate centre of mass velocity-position constraints and movement termination for balance recovery. In fact, recent studies suggest that in addition to foot displacement during slipping (Brady et al 2000), the movement of the body's centre of mass over the base of support plays a significant role in slip recovery and fall termination (Pai and Patton 1997, Pai and Iqbal 1999, You et al 2001.…”

Section: Differentiation Between Slipping and Fallingmentioning

confidence: 99%

“…The output estimates have comprised, among others, perceived sense of slip and slip distance evaluations, slipperiness ratings, heel velocity measurements, heel and trunk acceleration and postural instability measurements, and falling frequency estimations , Leamon and Son 1989, Myung et al 1993, Cohen and Cohen 1994a, b, Hirvonen et al 1994, Chiou et al 2000. Other approaches have focused on kinematics (spatial movement of the body) and kinetics (ground reaction forces, utilized and required friction) of slipping and falling (Strandberg and Lanshammar 1981, Morach 1993, Redfern and Rhoades 1996, Hanson et al 1999, Brady et al 2000, You et al 2001 or electromyographic (EMG) activity of compensatory muscle responses during simulated slipping (Tang et al 1998). …”

Section: Introductionmentioning

confidence: 99%

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Human-centred approaches in slipperiness measurement

Grönqvist¹,

Abeysekera²,

Gard³

et al. 2001

Ergonomics

111

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A number of human-centred methodologies-subjective, objective, and combined-are used for slipperiness measurement. They comprise a variety of approaches from biomechanically-oriented experiments to psychophysical tests and subjective evaluations. The objective of this paper is to review some of the research done in the field, including such topics as awareness and perception of slipperiness, postural and balance control, rating scales for balance, adaptation to slippery conditions, measurement of unexpected movements, kinematics of slipping, and protective movements during falling. The role of human factors in slips and falls will be discussed. Strengths and weaknesses of human-centred approaches in relation to mechanical slip test methodologies are considered. Current friction-based criteria and thresholds for walking without slipping are reviewed for a number of work tasks. These include activities such as walking on a level or an inclined surface, running, stopping and jumping, as well as stair ascent and descent, manual exertion (pushing and pulling, load carrying, lifting) and particular concerns of the elderly and mobility disabled persons. Some future directions for slipperiness measurement and research in the field of slips and falls are outlined. Human-centred approaches for slipperiness measurement do have many applications. First, they are utilized to develop research hypotheses and models to predict workplace risks caused by slipping. Second, they are important alternatives to apparatus-based friction measurements and are used to validate such methodologies. Third, they are used as practical tools for evaluating and monitoring slip resistance properties of foot wear, anti-skid devices and floor surfaces.

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Section: Biomechanically-oriented Approachesmentioning

confidence: 92%

Section: Critical Slip Distancementioning

confidence: 99%

Section: Differentiation Between Slipping and Fallingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Human-centred approaches in slipperiness measurement

Grönqvist¹,

Abeysekera²,

Gard³

et al. 2001

Ergonomics

111

View full text Add to dashboard Cite

show abstract

“…To this purpose, quantitative kinematic measurements such as joint angular rotations, are generally accomplished by means of devices (i.e. markers or electrogoniometries) applied on the subject during the movement execution [3][4] [5]. These systems are particularly accurate and widely accepted by the medical community.…”

Section: Introductionmentioning

confidence: 99%

2D Markerless Gait Analysis

2009

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Abstract-We present a 2D gait analysis system which is completely markerless and extracts kinematic information by analyzing video sequences obtained from an RGB video camera. These properties make the proposed approach particularly suitable in medical contexts where visual gait observation is still a recognised procedure or the invasiveness and high costs of marker-based systems can not be afforded.

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Control of dynamic stability during gait termination on a slippery surface in Parkinson's disease

et al. 2008

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Parkinson’s disease (PD) causes instability and difficulty adapting behaviour. To examine the effects of PD on adaptation to repeated, cued gait termination (GT) on a slippery surface, an unexpected slip perturbation during GT was followed by stops on a slippery surface under two conditions: planned over multiple steps and cued one step prior to GT. Measurements of feedforward and feedback-based responses were compared for group (PD versus control) and trial to determine 1) how PD affects the ability to integrate adaptive feedforward and feedback-based strategies to stopping on a slippery surface, 2) if adaptations can be maintained when the slippery stop is required within one step, and 3) if adaptations are not maintained, can behaviour be readapted with repeated exposure. Similar to controls, the PD group was able to adapt and integrate feedforward and feedback-based components of GT to increase stability under both stop conditions. Feedforward adaptations included a shorter, wider step, and a smaller anterior-posterior and larger lateral stability margin. Feedback-based adaptations included a longer, wider subsequent step. When cued to stop within one step, both groups maintained most of these adaptations: Foot angle at contact increased in the first cued stop but re-adapted with practice. PD did not affect the ability to adapt to gait termination on a slippery surface over multiple steps or within one step.

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Foot displacement but not velocity predicts the outcome of a slip induced in young subjects while walking

Cited by 126 publications

References 9 publications

Human-centred approaches in slipperiness measurement

Human-centred approaches in slipperiness measurement

2D Markerless Gait Analysis

Control of dynamic stability during gait termination on a slippery surface in Parkinson's disease

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