Inertial Sensor-Based Centripetal Acceleration as a Correlate for Lateral Margin of Stability During Walking and Turning

AbstractThere is growing interest in using inertial sensors to continuously monitor gait during free-living mobility. Inertial sensors can provide many gait measures, but they struggle to capture the spatial stability of the center-of-mass due to limitations estimating sensor-to-sensor distance. While the margin of stability (MoS) is an established outcome describing the instantaneous mechanical stability of gait relating to fall-risk, methods to estimate the MoS from inertial sensors have been lacking. Here, we developed and tested a framework, based on centripetal acceleration, to determine a correlate for the lateral MoS using inertial sensors during walking with or without turning. Using three synchronized sensors located bilaterally on the feet and lumbar spine, the average centripetal acceleration over the subsequent step can be used as a correlate for lateral MoS. Relying only on a single sensor on the lumbar spine yielded similar results if the stance foot can be determined from other means. Additionally, the centripetal acceleration correlate of lateral MoS demonstrates clear differences between walking and turning, inside and outside turning limbs, and speed. While limitations and assumptions need to be considered when implemented in practice, this method presents a novel correlate for the lateral MoS during walking and turning using inertial sensors, although further validation is required for other activities and populations.

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Medial-lateral margin of stability for the comparison of two bone-anchored prostheses – a case study

Computer Methods in Biomechanics & Biomedical Engineering ◽

10.1080/10255842.2020.1714244 ◽

2019 ◽

Vol 22 (sup1) ◽

pp. S212-S213

Author(s):

V. Gibeaux ◽

A. Naaim ◽

T. Robert ◽

L. Frossard ◽

R. Dumas

Keyword(s):

Lateral Margin ◽

Margin Of Stability

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An investigation of the spatio-temporal parameters of gait and margins of stability throughout adulthood

Journal of The Royal Society Interface ◽

10.1098/rsif.2020.0194 ◽

2020 ◽

Vol 17 (166) ◽

pp. 20200194

Author(s):

Nolan Herssens ◽

Tamaya van Criekinge ◽

Wim Saeys ◽

Steven Truijen ◽

Luc Vereeck ◽

...

Keyword(s):

Three Dimensional ◽

Lateral Margin ◽

Leg Length ◽

Temporal Characteristics ◽

Margin Of Stability ◽

Temporal Parameters ◽

Age Related ◽

Support Domain ◽

Spatio Temporal ◽

Base Of Support

Age-related changes in the way of walking may induce changes in dynamic stability. Therefore, the relationship between age, spatio-temporal characteristics and margins of stability was examined. One hundred and five healthy adults aged between 20 and 89 years old were analysed on spatio-temporal characteristics and margins of stability using three-dimensional motion analysis. Subjects walked barefoot over a 12-m-long walkway at their preferred walking speed. Covariance among gait characteristics was reduced using a factor analysis, identifying domains of gait. The influence of age, gender, body mass index (BMI) and leg length on domains of gait and margins of stability was investigated using linear mixed models. A stepwise linear regression identified domains of gait predicting the variance in margins of stability. Four domains of gait explaining 74.17% of the variance were identified. Age had a significant influence on the medio-lateral margin of stability and the ‘variability', ‘pace' and ‘base of support' domain. BMI significantly influenced the medio-lateral margin of stability; gender and leg length had no influence on either of the margins of stability. The ‘base of support’ domain predicted 26% of the variance in the medio-lateral margin of stability. When considering the margins of stability, especially when comparing multiple groups, age, BMI and spatio-temporal parameters should be taken into account.

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Ambulatory Assessment of the Dynamic Margin of Stability Using an Inertial Sensor Network

Sensors ◽

10.3390/s19194117 ◽

2019 ◽

Vol 19 (19) ◽

pp. 4117 ◽

Cited By ~ 2

Author(s):

Michelangelo Guaitolini ◽

Federica Aprigliano ◽

Andrea Mannini ◽

Silvestro Micera ◽

Vito Monaco ◽

...

Keyword(s):

Balance Control ◽

Inertial Sensor ◽

Center Of Mass ◽

The Body ◽

Lower Limbs ◽

Measurement Unit ◽

Margin Of Stability ◽

Walking Velocity ◽

Body Center ◽

Base Of Support

Loss of stability is a precursor to falling and therefore represents a leading cause of injury, especially in fragile people. Thus, dynamic stability during activities of daily living (ADLs) needs to be considered to assess balance control and fall risk. The dynamic margin of stability (MOS) is often used as an indicator of how the body center of mass is located and moves relative to the base of support. In this work, we propose a magneto-inertial measurement unit (MIMU)-based method to assess the MOS of a gait. Six young healthy subjects were asked to walk on a treadmill at different velocities while wearing MIMUs on their lower limbs and pelvis. We then assessed the MOS by computing the lower body displacement with respect to the leading inverse kinematics approach. The results were compared with those obtained using a camera-based system in terms of root mean square deviation (RMSD) and correlation coefficient (ρ). We obtained a RMSD of ≤1.80 cm and ρ ≥ 0.85 for each walking velocity. The findings revealed that our method is comparable to camera-based systems in terms of accuracy, suggesting that it may represent a strategy to assess stability during ADLs in unstructured environments.

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Vision-Based Assessment of Gait Features Associated With Falls in People With Dementia

The Journals of Gerontology Series A ◽

10.1093/gerona/glz187 ◽

2019 ◽

Vol 75 (6) ◽

pp. 1148-1153 ◽

Cited By ~ 6

Author(s):

Sina Mehdizadeh ◽

Elham Dolatabadi ◽

Kimberley-Dale Ng ◽

Avril Mansfield ◽

Alastair Flint ◽

...

Keyword(s):

Baseline Period ◽

Demographic Variables ◽

Lateral Margin ◽

Time Variability ◽

Period Range ◽

Gait Stability ◽

Margin Of Stability ◽

People With Dementia ◽

Gait Features ◽

Important Marker

Abstract Background Gait impairments contribute to falls in people with dementia. In this study, we used a vision-based system to record episodes of walking over a 2-week period as participants moved naturally around their environment, and from these calculated spatiotemporal, stability, symmetry, and acceleration gait features. The aim of this study was to determine whether features of gait extracted from a vision-based system are associated with falls, and which of these features are most strongly associated with falling. Methods Fifty-two people with dementia admitted to a specialized dementia unit participated in this study. Thirty different features describing baseline gait were extracted from Kinect recordings of natural gait over a 2-week period. Baseline clinical and demographic measures were collected, and falls were tracked throughout the participants’ admission. Results A total of 1,744 gait episodes were recorded (mean 33.5 ± 23.0 per participant) over a 2-week baseline period. There were a total of 78 falls during the study period (range 0–10). In single variable analyses, the estimated lateral margin of stability, step width, and step time variability were significantly associated with the number of falls during admission. In a multivariate model controlling for clinical and demographic variables, the estimated lateral margin of stability (p = .01) was remained associated with number of falls. Conclusions Information about gait can be extracted from vision-based recordings of natural walking. In particular, the lateral margin of stability, a measure of lateral gait stability, is an important marker of short-term falls risk.

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