Estimate of Floor Reaction Force Vector Using Foot-Pressure Sensors

Gait analysis is a systematic study of human locomotion, which can be utilized in various applications, such as rehabilitation, clinical diagnostics and sports activities. The various limitations such as cost, non-portability, long setup time, post-processing time etc., of the current gait analysis techniques have made them unfeasible for individual use. This led to an increase in research interest in developing smart insoles where wearable sensors can be employed to detect vertical ground reaction forces (vGRF) and other gait variables. Smart insoles are flexible, portable and comfortable for gait analysis, and can monitor plantar pressure frequently through embedded sensors that convert the applied pressure to an electrical signal that can be displayed and analyzed further. Several research teams are still working to improve the insoles’ features such as size, sensitivity of insoles sensors, durability, and the intelligence of insoles to monitor and control subjects’ gait by detecting various complications providing recommendation to enhance walking performance. Even though systematic sensor calibration approaches have been followed by different teams to calibrate insoles’ sensor, expensive calibration devices were used for calibration such as universal testing machines or infrared motion capture cameras equipped in motion analysis labs. This paper provides a systematic design and characterization procedure for three different pressure sensors: force-sensitive resistors (FSRs), ceramic piezoelectric sensors, and flexible piezoelectric sensors that can be used for detecting vGRF using a smart insole. A simple calibration method based on a load cell is presented as an alternative to the expensive calibration techniques. In addition, to evaluate the performance of the different sensors as a component for the smart insole, the acquired vGRF from different insoles were used to compare them. The results showed that the FSR is the most effective sensor among the three sensors for smart insole applications, whereas the piezoelectric sensors can be utilized in detecting the start and end of the gait cycle. This study will be useful for any research group in replicating the design of a customized smart insole for gait analysis.

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Associations between hoof shape and the position of the frontal plane ground reaction force vector in walking horses

New Zealand Veterinary Journal ◽

10.1080/00480169.2015.1068138 ◽

2015 ◽

Vol 64 (2) ◽

pp. 76-81 ◽

Cited By ~ 5

Author(s):

GR Colborne ◽

JE Routh ◽

KR Weir ◽

JE McKendry ◽

E Busschers

Keyword(s):

Ground Reaction Force ◽

Reaction Force ◽

Frontal Plane ◽

Force Vector

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Mechanical power output during running accelerations in wild turkeys

Journal of Experimental Biology ◽

10.1242/jeb.205.10.1485 ◽

2002 ◽

Vol 205 (10) ◽

pp. 1485-1494 ◽

Cited By ~ 29

Author(s):

Thomas J. Roberts ◽

Jeffrey A. Scales

Keyword(s):

Power Output ◽

Ground Reaction Force ◽

Center Of Mass ◽

Reaction Force ◽

Mechanical Power ◽

Force Vector ◽

Instantaneous Power ◽

Hindlimb Muscle ◽

Wild Turkeys ◽

Running Mechanics

SUMMARYWe tested the hypothesis that the hindlimb muscles of wild turkeys(Meleagris gallopavo) can produce maximal power during running accelerations. The mechanical power developed during single running steps was calculated from force-plate and high-speed video measurements as turkeys accelerated over a trackway. Steady-speed running steps and accelerations were compared to determine how turkeys alter their running mechanics from a low-power to a high-power gait. During maximal accelerations, turkeys eliminated two features of running mechanics that are characteristic of steady-speed running: (i) they produced purely propulsive horizontal ground reaction forces, with no braking forces, and (ii) they produced purely positive work during stance, with no decrease in the mechanical energy of the body during the step. The braking and propulsive forces ordinarily developed during steady-speed running are important for balance because they align the ground reaction force vector with the center of mass. Increases in acceleration in turkeys correlated with decreases in the angle of limb protraction at toe-down and increases in the angle of limb retraction at toe-off. These kinematic changes allow turkeys to maintain the alignment of the center of mass and ground reaction force vector during accelerations when large propulsive forces result in a forward-directed ground reaction force. During the highest accelerations, turkeys produced exclusively positive mechanical power. The measured power output during acceleration divided by the total hindlimb muscle mass yielded estimates of peak instantaneous power output in excess of 400 W kg-1 hindlimb muscle mass. This value exceeds estimates of peak instantaneous power output of turkey muscle fibers. The mean power developed during the entire stance phase increased from approximately zero during steady-speed runs to more than 150 W kg-1muscle during the highest accelerations. The high power outputs observed during accelerations suggest that elastic energy storage and recovery may redistribute muscle power during acceleration. Elastic mechanisms may expand the functional range of muscle contractile elements in running animals by allowing muscles to vary their mechanical function from force-producing struts during steady-speed running to power-producing motors during acceleration.

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Archery Form Guidance System Using Acceleration Sensors and Foot Pressure Sensors

Communications in Computer and Information Science - HCI International 2020 - Posters ◽

10.1007/978-3-030-50729-9_28 ◽

2020 ◽

pp. 199-203

Author(s):

Ibuki Meguro ◽

Eiichi Hayakawa

Keyword(s):

Pressure Sensors ◽

Guidance System ◽

Foot Pressure ◽

Acceleration Sensors

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Variation of medial and lateral plateau loads at the knee joint with different lever arms of the ground reaction force vector

Journal of Biomechanics ◽

10.1016/0021-9290(89)90343-6 ◽

1989 ◽

Vol 22 (10) ◽

pp. 1044

Author(s):

Håkan Lanshammar

Keyword(s):

Knee Joint ◽

Ground Reaction Force ◽

Reaction Force ◽

Force Vector ◽

Lateral Plateau

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A New Lower Extremity Modeling of Human Body With Variable Feet Links

10.1115/imece2000-2280 ◽

2000 ◽

Author(s):

Nader Arafati ◽

Jean Yves Lazennec ◽

Roger Ohayon

Keyword(s):

Ground Reaction Force ◽

Sagittal Plane ◽

Reaction Force ◽

Human Movement ◽

Knee Joints ◽

Foot Pressure ◽

Ankle Joints ◽

Reaction Forces ◽

Human Movement Modeling ◽

Force Vectors

Abstract Human movement modeling has been the object of much research for the past 30 years. In these models the position of foot link was fixed on the ground. We propose to model the feet links as variable, since the position of foot pressure center changes from heel to toes. The ground reaction forces could also be analyzed in real time. We examined this model for some static postures. In standing anatomical position, the maximum articular forces are localized in hip and knee joints. In sagittal plane, the ground reaction force vectors are positioned nearly under ankle joints. The pathological postures like body with pes cavus or with global spine kyphosis increase the articular and muscular forces. In these cases, the position of ground reaction force vectors is moved toward the toes.

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Associations between ground reaction force waveforms and sprint start performance

International Journal of Sports Science & Coaching ◽

10.1177/1747954119874887 ◽

2019 ◽

Vol 14 (5) ◽

pp. 658-666 ◽

Cited By ~ 2

Author(s):

Steffi L Colyer ◽

Philip Graham-Smith ◽

Aki IT Salo

Keyword(s):

Reaction Force ◽

Statistical Parametric Mapping ◽

Force Production ◽

Mass Motion ◽

Ground Reaction Forces ◽

Centre Of Mass ◽

Specific Training ◽

Force Vector ◽

Reaction Forces ◽

External Power

Ground reaction forces produced on the blocks determine an athlete’s centre of mass motion during the sprint start, which is crucial to sprint performance. This study aimed to understand how force waveforms are associated with better sprint start performance. Fifty-seven sprinters (from junior to world elite) performed a series of block starts during which the ground reaction forces produced by the legs and arms were separately measured. Statistical parametric mapping (linear regression) revealed specific phases of these waveforms where forces were associated with average horizontal external power. Better performances were achieved by producing higher forces and directing the force vector more horizontally during the initial parts of the block phase (17–34% and 5–37%, respectively). During the mid-push (around the time of rear block exit: ∼54% of the block push), magnitudes of front block force differentiated performers, but orientation did not. Consequently, the ability to sustain high forces during the transition from bilateral to unilateral pushing was a performance-differentiating factor. Better athletes also exhibited a higher ratio of forces on the front block in the latter parts of unilateral pushing (81–92% of the block push), which seemed to allow these athletes to exit the blocks with lower centre of mass projection angles. Training should reflect these kinetic requirements, but also include technique-based aspects to increase both force production and orientation capacities. Specific training focused on enhancing anteroposterior force production during the transition between double- to single-leg propulsion could be beneficial for overall sprint start performance.

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