The interaction between load and coupling during dynamic manual materials handling tasks

1998 ◽  
Vol 1 (1) ◽  
pp. 3-11
Author(s):  
Gary A. Mirka ◽  
Ann Baker ◽  
Angela Harrison ◽  
Dan Kelaher
Keyword(s):  
Coupling Condition ◽  
Materials Handling ◽  
Manual Materials Handling ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Low Levels ◽  
Vertical Ground Reaction Forces ◽  
The Impact ◽  
Dynamic Moment

The purpose of this research was to determine the impact of coupling and load magnitude on trunk dynamics during lifting activities. Subjects lifted a box that simulated three levels of coupling: good, fair and poor and seven levels of mass: ranging from 4.5-31.5 kg. The dependent variables were the peak dynamic moment generated about the lumbosacral joint and the peak vertical ground reaction forces produced during the lift. The results show that at low levels of box mass there are no significant differences in trunk dynamics and resulting peak dynamic moment across the different coupling conditions. However, when loads greater than 13.5 kg were lifted, a change in the normal dynamics of the lifting motion was noted, but only in the poor coupling condition, indicating an interaction between load and coupling. The results of this study indicate that the role of coupling under dynamic lifting conditions has both a perceptual and biomechanical basis that need to be considered when designing manual materials handling tasks.

The role of compliance in mammalian running gaits

1985 ◽  
Vol 115 (1) ◽  
pp. 263-282 ◽  
Author(s):  
T. A. McMahon
Keyword(s):  
Ground Reaction Forces ◽  
Metabolic Power ◽  
High Speeds ◽  
Compliant Surfaces ◽  
Reaction Forces ◽  
Spring System ◽  
Vertical Ground ◽  
Mass Spring ◽  
Vertical Ground Reaction Forces

The running gaits used by both bipedal and quadrupedal animals are reviewed and contrasted. At high speeds, bipeds use both ordinary running, in which the legs move opposite one another, and hopping. Quadrupeds generally use the trot or its variations at moderate speeds, and first the canter and then the gallop as speed increases. Running in both bipeds and quadrupeds generally involves at least one aerial phase per stride cycle, but certain perturbations to running including running in circles, running under enhanced gravity, running on compliant surfaces and running with increased knee flexion (Groucho running) can reduce the aerial phase, even to zero. A conceptual model of running based on the idea that an animal rebounds from the ground like a resonant mass-spring system may be used to compare the various gaits. The model makes specific predictions which show that galloping is generally faster than cantering, pronking or trotting, and requires lower peak vertical forces on the legs while also giving a smoother ride. Even so, trotting might be preferred to galloping at low and moderate speeds for the same reason that normal running is preferred to Groucho running-the more compliant gait offers a smoother ride and lower vertical ground-reaction forces on the feet, but this can only be obtained at a high cost of increased metabolic power.

scholarly journals A Robust Methodology for the Reconstruction of the Vertical Pedestrian-Induced Load from the Registered Body Motion

Vibration ◽  
2018 ◽  
Vol 1 (2) ◽  
pp. 250-268 ◽  
Author(s):  
Katrien Van Nimmen ◽  
Guoping Zhao ◽  
André Seyfarth ◽  
Peter Van den Broeck
Keyword(s):  
Soft Tissue ◽  
Low Cost ◽  
Single Step ◽  
The Body ◽  
Body Motion ◽  
Ground Reaction Forces ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Vertical Ground Reaction Forces ◽  
The Impact

This paper proposes a methodology to reconstruct the vertical GRFs from the registered body motion that is reasonably robust against measurement noise. The vertical GRFs are reconstructed from the experimentally identified time-variant pacing rate and a generalised single-step load model available in the literature. The proposed methodology only requires accurately capturing the body motion within the frequency range 1–10 Hz and does not rely on the exact magnitude of the registered signal. The methodology can therefore also be applied when low-cost sensors are used and to minimize the impact of soft-tissue artefacts. In addition, the proposed procedure can be applied regardless of the position of the sensor on the human body, as long as the recorded body motion allows for identifying the time of a nominally identical event in successive walking cycles. The methodology is illustrated by a numerical example and applied to an experimental dataset where the ground reaction forces and the body motion were registered simultaneously. The results show that the proposed methodology allows for arriving at a good estimate of the vertical ground reaction forces. When the impact of soft-tissue artefacts is low, a comparable estimate can be obtained using Newton’s second law of motion.

scholarly journals Joint angle estimation with wavelet neural networks

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saaveethya Sivakumar ◽  
Alpha Agape Gopalai ◽  
King Hann Lim ◽  
Darwin Gouwanda ◽  
Sunita Chauhan
Keyword(s):  
Gait Analysis ◽  
Real Time ◽  
Monitoring Applications ◽  
Reaction Forces ◽  
Multiple Sensor ◽  
Vertical Ground ◽  
Overall Performance ◽  
Gait Monitoring ◽  
Vertical Ground Reaction Forces ◽  
And Control

AbstractThis paper presents a wavelet neural network (WNN) based method to reduce reliance on wearable kinematic sensors in gait analysis. Wearable kinematic sensors hinder real-time outdoor gait monitoring applications due to drawbacks caused by multiple sensor placements and sensor offset errors. The proposed WNN method uses vertical Ground Reaction Forces (vGRFs) measured from foot kinetic sensors as inputs to estimate ankle, knee, and hip joint angles. Salient vGRF inputs are extracted from primary gait event intervals. These selected gait inputs facilitate future integration with smart insoles for real-time outdoor gait studies. The proposed concept potentially reduces the number of body-mounted kinematics sensors used in gait analysis applications, hence leading to a simplified sensor placement and control circuitry without deteriorating the overall performance.

scholarly journals Hindlimb muscular activity, kinetics and kinematics of cats jumping to their maximum achievable heights

1981 ◽  
Vol 91 (1) ◽  
pp. 73-86 ◽  
Author(s):  
F. E. Zajac ◽  
M. R. Zomlefer ◽  
W. S. Levine
Keyword(s):  
Vertical Jump ◽  
Muscular Activity ◽  
Dynamic State ◽  
Extensor Muscles ◽  
Ankle Joints ◽  
Flexor Muscles ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Vertical Ground Reaction Forces ◽  
Propulsion Phase

Cats were trained to jump from a force platform to their maximum achievable heights. Vertical ground reaction forces developed by individual hindlimbs showed that the propulsion phase consists of two epochs. During the initial “preparatory phase' the cat can traverse many different paths. Irrespective of the path traversed, however, the cat always attains the same position, velocity and momentum at the end of this phase. Starting from this dynamic state the cat during the subsequent “launching phase' (about 150 ms long) generates significant propulsion as its hindlimbs develop force with identical, stereotypic profiles. Cinematographic data, electromyographic data, and computed torques about the hip, knee and ankle joints indicate that during the jump proximal extensor musculature is activated before distal musculature. During terminal experiments when the hindlimb was set at positions corresponding to those in the jump, isometric torques produced by tetanic stimulation of groups of extensor and flexor muscles were compared with computed torques developed by the same cat during previous jumps. These comparisons suggest that extensor muscles of the hindlimb are fully activated during the maximal vertical jump.

scholarly journals Hip and Knee Kinematics and Kinetics During Landing Tasks After Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-Analysis

2018 ◽  
Vol 53 (2) ◽  
pp. 144-159 ◽  
Author(s):  
Adam S. Lepley ◽  
Christopher M. Kuenze
Keyword(s):  
Ligament Reconstruction ◽  
Cruciate Ligament ◽  
Meta Analysis ◽  
Knee Extension ◽  
Injured Limb ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Anterior Cruciate ◽  
Vertical Ground Reaction Forces ◽  
Kinematics And Kinetics

Objective:  To evaluate the current evidence concerning kinematic and kinetic strategies adopted during dynamic landing tasks by patients with anterior cruciate ligament reconstruction (ACLR). Data Sources:  PubMed, Web of Science. Study Selection:  Original research articles that evaluated kinematics or kinetics (or both) during a landing task in those with a history of ACLR were included. Data Extraction:  Methodologic quality was assessed using the modified Downs and Black checklist. Means and standard deviations for knee or hip (or both) kinematics and kinetics were used to calculate Cohen d effect sizes and corresponding 95% confidence intervals between the injured limb of ACLR participants and contralateral or healthy matched limbs. Data were further stratified by landing tasks, either double- or single-limb landing. A random-effects–model meta-analysis was used to calculate pooled effect sizes and 95% confidence intervals. Data Synthesis:  The involved limbs of ACLR patients demonstrated clinically and significantly lower knee-extension moments during double-legged landing compared with healthy contralateral limbs and healthy control limbs (Cohen d range = −0.81 to −1.23) and decreased vertical ground reaction forces when compared with healthy controls, regardless of task (Cohen d range = −0.39 to −1.75). Conclusions:  During single- and double-legged landing tasks, individuals with ACLR demonstrated meaningful reductions in injured-limb knee-extension moments and vertical ground reaction forces. These findings indicate potential unloading of the injured limb after ACLR, which may have significant implications for secondary ACL injury and long-term joint health.

Comparison of overground and treadmill vertical ground reaction forces

1995 ◽  
Vol 3 (2) ◽  
pp. 86
Author(s):  
H.John Yack ◽  
Carole Tucker ◽  
Scott C White Heather Collins
Keyword(s):  
Ground Reaction Forces ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Vertical Ground Reaction Forces

Effects of partial immersion in water on vertical ground reaction forces and weight distribution in dogs

2010 ◽  
Vol 71 (12) ◽  
pp. 1413-1416 ◽  
Author(s):  
David Levine ◽  
Denis J. Marcellin-Little ◽  
Darryl L. Millis ◽  
Verena Tragauer ◽  
Jason A. Osborne
Keyword(s):  
Weight Distribution ◽  
Ground Reaction Forces ◽  
Partial Immersion ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Vertical Ground Reaction Forces

The role of implicit learning in logo substitution

2019 ◽  
Vol 36 (5) ◽  
pp. 610-619 ◽  
Author(s):  
Rafal Ohme ◽  
Christo Boshoff
Keyword(s):  
Implicit Learning ◽  
Experimental Studies ◽  
Target Market ◽  
Human Beings ◽  
Content Type ◽  
Quasi Experimental ◽  
Low Levels ◽  
The Impact ◽  
A Company

Purpose Some marketers have challenged psychologists’ contention that human beings can only learn by using conscious effort. They argue that advertising can be effective at low levels of (or even no) attention. Also, despite the absence of (or low levels of) consciousness, these subconscious responses can be linked to brands. The purpose of this study is to investigate the impact of implicit learning in the context of logo substitution – an image that may not look like the original logo, and may not even be consciously associated with the original brand or its logo. Design/methodology/approach Data were collected by means of two quasi-experimental studies. Findings The results suggest that, thanks to implicit learning, logo substitution can be effective. Research limitations/implications One limitation was that data were collected from two relatively small convenience samples. Practical implications Logo substitution can be of value when a company faces a situation when advertising is banned or restricted, when the target market is saturated with marketing stimuli (clutter) and when there is a risk that aggressive advertising can lead to psychological reactance. The purpose of logo substitution would then be to unobtrusively activate mental representations closely related to the original logo. Originality/value The central contribution of this study is that it demonstrates how the principles of implicit social cognition, implicit learning and logo substitution can be used by marketers to overcome the undesirable and even adverse advertising circumstances they sometimes face.

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