scholarly journals Effects of Velocity and Weight Support on Ground Reaction Forces and Metabolic Power during Running

2008 ◽  
Vol 24 (3) ◽  
pp. 288-297 ◽  
Author(s):  
Alena M. Grabowski ◽  
Rodger Kram
Keyword(s):  
Body Weight ◽  
Normal Weight ◽  
Treadmill Running ◽  
Ground Reaction Forces ◽  
Metabolic Power ◽  
Data Set ◽  
Weight Support ◽  
Scientific Goal ◽  
Reaction Forces ◽  
Support Body Weight

The biomechanical and metabolic demands of human running are distinctly affected by velocity and body weight. As runners increase velocity, ground reaction forces (GRF) increase, which may increase the risk of an overuse injury, and more metabolic power is required to produce greater rates of muscular force generation. Running with weight support attenuates GRFs, but demands less metabolic power than normal weight running. We used a recently developed device (G-trainer) that uses positive air pressure around the lower body to support body weight during treadmill running. Our scientific goal was to quantify the separate and combined effects of running velocity and weight support on GRFs and metabolic power. After obtaining this basic data set, we identified velocity and weight support combinations that resulted in different peak GRFs, yet demanded the same metabolic power. Ideal combinations of velocity and weight could potentially reduce biomechanical risks by attenuating peak GRFs while maintaining aerobic and neuromuscular benefits. Indeed, we found many combinations that decreased peak vertical GRFs yet demanded the same metabolic power as running slower at normal weight. This approach of manipulating velocity and weight during running may prove effective as a training and/or rehabilitation strategy.

scholarly journals Metabolic cost of generating horizontal forces during human running

1999 ◽  
Vol 86 (5) ◽  
pp. 1657-1662 ◽  
Author(s):  
Young-Hui Chang ◽  
Rodger Kram
Keyword(s):  
Body Weight ◽  
Oxygen Consumption ◽  
Metabolic Cost ◽  
Ground Reaction Forces ◽  
Vertical Force ◽  
Order Of Magnitude ◽  
Reaction Forces ◽  
The Cost ◽  
Support Body Weight ◽  
Human Running

Previous studies have suggested that generating vertical force on the ground to support body weight (BWt) is the major determinant of the metabolic cost of running. Because horizontal forces exerted on the ground are often an order of magnitude smaller than vertical forces, some have reasoned that they have negligible cost. Using applied horizontal forces (AHF; negative is impeding, positive is aiding) equal to −6, −3, 0, +3, +6, +9, +12, and +15% of BWt, we estimated the cost of generating horizontal forces while subjects were running at 3.3 m/s. We measured rates of oxygen consumption (V˙o 2) for eight subjects. We then used a force-measuring treadmill to measure ground reaction forces from another eight subjects. With an AHF of −6% BWt,V˙o 2 increased 30% compared with normal running, presumably because of the extra work involved. With an AHF of +15% BWt, the subjects exerted ∼70% less propulsive impulse and exhibited a 33% reduction inV˙o 2. Our data suggest that generating horizontal propulsive forces constitutes more than one-third of the total metabolic cost of normal running.

scholarly journals Mechanical evidence that flamingos can support their body on one leg with little active muscular force

2017 ◽  
Vol 13 (5) ◽  
pp. 20160948 ◽  
Author(s):  
Young-Hui Chang ◽  
Lena H. Ting
Keyword(s):  
Body Weight ◽  
Joint Torque ◽  
Body Sway ◽  
Active Muscle ◽  
Reduced Body ◽  
Weight Support ◽  
Energetic Expenditure ◽  
Distal Joint ◽  
Support Body Weight ◽  
Muscle Contractile

Flamingos (Phoenicopteridae) often stand and sleep on one leg for long periods, but it is unknown how much active muscle contractile force they use for the mechanical demands of standing on one leg: body weight support and maintaining balance. First, we demonstrated that flamingo cadavers could passively support body weight on one leg without any muscle activity while adopting a stable, unchanging, joint posture resembling that seen in live flamingos. By contrast, the cadaveric flamingo could not be stably held in a two-legged pose, suggesting a greater necessity for active muscle force to stabilize two-legged versus one-legged postures. Our results suggest that flamingos engage a passively engaged gravitational stay apparatus (proximally located) for weight support during one-legged standing. Second, we discovered that live flamingos standing on one leg have markedly reduced body sway during quiescent versus alert behaviours, with the point of force application directly under the distal joint, reducing the need for muscular joint torque. Taken together, our results highlight the possibility that flamingos stand for long durations on one leg without exacting high muscular forces and, thus, with little energetic expenditure.

scholarly journals Machine Learning-Based Estimation of Ground Reaction Forces and Knee Joint Kinetics from Inertial Sensors While Performing a Vertical Drop Jump

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7709
Author(s):  
Serena Cerfoglio ◽  
Manuela Galli ◽  
Marco Tarabini ◽  
Filippo Bertozzi ◽  
Chiarella Sforza ◽  
...  
Keyword(s):  
Neural Network ◽  
Machine Learning ◽  
Knee Joint ◽  
Field Analysis ◽  
Ground Reaction Forces ◽  
Drop Jump ◽  
Joint Moments ◽  
Data Set ◽  
Joint Kinetics ◽  
Reaction Forces

Nowadays, the use of wearable inertial-based systems together with machine learning methods opens new pathways to assess athletes’ performance. In this paper, we developed a neural network-based approach for the estimation of the Ground Reaction Forces (GRFs) and the three-dimensional knee joint moments during the first landing phase of the Vertical Drop Jump. Data were simultaneously recorded from three commercial inertial units and an optoelectronic system during the execution of 112 jumps performed by 11 healthy participants. Data were processed and sorted to obtain a time-matched dataset, and a non-linear autoregressive with external input neural network was implemented in Matlab. The network was trained through a train-test split technique, and performance was evaluated in terms of Root Mean Square Error (RMSE). The network was able to estimate the time course of GRFs and joint moments with a mean RMSE of 0.02 N/kg and 0.04 N·m/kg, respectively. Despite the comparatively restricted data set and slight boundary errors, the results supported the use of the developed method to estimate joint kinetics, opening a new perspective for the development of an in-field analysis method.

Mechanisms of Gait Adaptation in Overweight Pregnant Women

2020 ◽  
Vol 110 (4) ◽  
Author(s):  
Jolanta Pauk ◽  
Dagna Swinarska ◽  
Kristina Daunoraviciene
Keyword(s):  
Pregnant Women ◽  
Plantar Pressure ◽  
Normal Weight ◽  
Ground Reaction Forces ◽  
Third Trimester ◽  
Gait Adaptation ◽  
The Third ◽  
Plantar Pressure Distribution ◽  
Gait Parameters ◽  
Reaction Forces

Background Pregnancy is a period when a woman's body undergoes changes. The purpose of this study was to analyze the mechanisms of gait adaptation in overweight pregnant women regarding spatiotemporal gait parameters, ground reaction forces, and plantar pressure distribution. Methods The tests were performed in 29 normal-weight pregnant women and 26 pregnant women who were overweight before pregnancy. The measurements included spatiotemporal gait parameters, in-shoe plantar pressure distribution, and ground reaction forces during gestation. Results The results indicate that both normal-weight and overweight pregnant women make use of the same spatiotemporal gait parameters to increase body stability and safety of movement during pregnancy. The double-step duration in the third trimester of pregnancy was higher in normal-weight and overweight pregnant women compared with in the first trimester (P < .05). A significant change in pressure amplitude was found under all anatomical parts of the foot in the third trimester (P < .05). The results also suggest a higher increase in the maximum amplitude of force in overweight pregnant women in the third trimester compared with the normal-weight group. Conclusions This study suggests that both normal-weight and overweight pregnant women use different mechanisms of gait adaptation during pregnancy. In practice, understanding the biomechanical changes in women's gait can protect the musculoskeletal system during gestation.

scholarly journals Using Ground Reaction Forces To Predict Fatigue In Treadmill Running: A Machine Learning Approach

2021 ◽  
Author(s):  
Sérgio Baldo Junior ◽  
Thiago Faria dos Santos ◽  
Renato Tinós ◽  
Paulo Roberto Pereira Santiago
Keyword(s):  
Machine Learning ◽  
High Performance ◽  
Good Accuracy ◽  
Low Cost ◽  
Treadmill Running ◽  
Ground Reaction Forces ◽  
Machine Learning Methods ◽  
Machine Learning Approach ◽  
Reaction Forces ◽  
Interesting Alternative

Abstract The analysis of running patterns, especially those associated with fatigue, can help specialists in designing more efficient workouts and preventing injuries in high-performance sports. However, classifying running patterns is not trivial for humans. An interesting alternative is to use Machine Learning methods, such as Artificial Neural Networks (ANNs), to classify running patterns. In this work, ground reaction forces are measured by sensors coupled to the base of a low-cost open-source treadmill. ANNs are used to classify the force signals and to indicate the occurrence of fatigue. Different features, extracted from the force signals, are proposed and investigated. A Genetic Algorithm (GA) is used to select the best features. The experimental results indicate that the ANN is able to classify the running patterns with good accuracy. In addition, some features selected by the GA provide important information regarding the identification of fatigue in treadmill running.

scholarly journals A data set with kinematic and ground reaction forces of human balance

2017 ◽  
Author(s):  
Damiana A dos Santos ◽  
Claudiane A Fukuchi ◽  
Reginaldo K Fukuchi ◽  
Marcos Duarte
Keyword(s):  
Center Of Pressure ◽  
Reaction Force ◽  
Kinematic Model ◽  
Three Dimensional ◽  
Force Platform ◽  
Whole Body ◽  
Ground Reaction Forces ◽  
Data Set ◽  
Public Data ◽  
Reaction Forces

This article describes a public data set with the three-dimensional kinematics of the whole body and the ground reaction forces (with a dual force platform setup) of subjects standing still for 60 s in different conditions, in which the vision and the standing surface were manipulated. Twenty-seven young subjects and 22 old subjects were evaluated. The data set comprises a file with metadata plus 1,813 files with the ground reaction force (GRF) and kinematics data for the 49 subjects (three files for each of the 12 trials plus one file for each subject). The file with metadata has information about each subject’s sociocultural, demographic, and health characteristics. The files with the GRF have the data from each force platform and from the resultant GRF (including the center of pressure data). The files with the kinematics have the three-dimensional position of the 42 markers used for the kinematic model of the whole body and the 73 calculated angles. In this text, we illustrate how to access, analyze, and visualize the data set. All the data is available at Figshare (DOI: 10.6084/m9.figshare.4525082 ), and a companion Jupyter Notebook (available at https://github.com/demotu/datasets ) presents the programming code to generate analyses and other examples.

scholarly journals A data set with kinematic and ground reaction forces of human balance

2017 ◽  
Author(s):  
Damiana A dos Santos ◽  
Claudiane A Fukuchi ◽  
Reginaldo K Fukuchi ◽  
Marcos Duarte
Keyword(s):  
Center Of Pressure ◽  
Reaction Force ◽  
Kinematic Model ◽  
Three Dimensional ◽  
Force Platform ◽  
Whole Body ◽  
Ground Reaction Forces ◽  
Data Set ◽  
Public Data ◽  
Reaction Forces

This article describes a public data set with the three-dimensional kinematics of the whole body and the ground reaction forces (with a dual force platform setup) of subjects standing still for 60 s in different conditions, in which the vision and the standing surface were manipulated. Twenty-seven young subjects and 22 old subjects were evaluated. The data set comprises a file with metadata plus 1,813 files with the ground reaction force (GRF) and kinematics data for the 49 subjects (three files for each of the 12 trials plus one file for each subject). The file with metadata has information about each subject’s sociocultural, demographic, and health characteristics. The files with the GRF have the data from each force platform and from the resultant GRF (including the center of pressure data). The files with the kinematics have the three-dimensional position of the 42 markers used for the kinematic model of the whole body and the 73 calculated angles. In this text, we illustrate how to access, analyze, and visualize the data set. All the data is available at Figshare (DOI: 10.6084/m9.figshare.4525082 ), and a companion Jupyter Notebook (available at https://github.com/demotu/datasets ) presents the programming code to generate analyses and other examples.

Acceleration and balance in trotting dogs

1999 ◽  
Vol 202 (24) ◽  
pp. 3565-3573 ◽  
Author(s):  
D.V. Lee ◽  
J.E. Bertram ◽  
R.J. Todhunter
Keyword(s):  
Body Weight ◽  
Steady State ◽  
The Body ◽  
Ground Reaction Forces ◽  
Pitching Moment ◽  
Acceleration And Deceleration ◽  
Reaction Forces ◽  
Force Time

During quadrupedal trotting, diagonal pairs of limbs are set down in unison and exert forces on the ground simultaneously. Ground-reaction forces on individual limbs of trotting dogs were measured separately using a series of four force platforms. Vertical and fore-aft impulses were determined for each limb from the force/time recordings. When mean fore-aft acceleration of the body was zero in a given trotting step (steady state), the fraction of vertical impulse on the forelimb was equal to the fraction of body weight supported by the forelimbs during standing (approximately 60 %). When dogs accelerated or decelerated during a trotting step, the vertical impulse was redistributed to the hindlimb or forelimb, respectively. This redistribution of the vertical impulse is due to a moment exerted about the pitch axis of the body by fore-aft accelerating and decelerating forces. Vertical forces exerted by the forelimb and hindlimb resist this pitching moment, providing stability during fore-aft acceleration and deceleration.

scholarly journals Motor Strategies Used by Rats Spinalized at Birth to Maintain Stance in Response to Imposed Perturbations

2007 ◽  
Vol 97 (4) ◽  
pp. 2663-2675 ◽  
Author(s):  
Simon F. Giszter ◽  
Michelle R. Davies ◽  
Virginia Graziani
Keyword(s):  
Body Weight ◽  
Principal Axis ◽  
Center Of Pressure ◽  
Whole Body ◽  
Ground Reaction Forces ◽  
Quiet Stance ◽  
Reaction Forces ◽  
Pattern Generators ◽  
Motor Strategies ◽  
Intact Rats

Some rats spinalized P1/P2 achieve autonomous weight-supported locomotion and quiet stance as adults. We used force platforms and robot-applied perturbations to test such spinalized rats ( n = 6) that exhibited both weight-supporting locomotion and stance, and also normal rats ( n = 8). Ground reaction forces in individual limbs and the animals' center of pressure were examined. In normal rats, both forelimbs and hindlimbs participated actively to control horizontal components of ground reaction forces. Rostral perturbations increased forelimb ground reaction forces and caudal perturbations increased hindlimb ground reaction forces. Operate rats carried 60% body weight on the forelimbs and had a more rostral center of pressure placement. The pattern in normal rats was to carry significantly more weight on the hindlimbs in quiet stance (roughly 60%). The strategy of operate rats to compensate for perturbations was entirely in forelimbs; as a result, the hindlimbs were largely isolated from the perturbation. Stiffness magnitude of the whole body was measured: its magnitude was hourglass shaped, with the principal axis oriented rostrocaudally. Operate rats were significantly less stiff—only 60–75% of normal rats' stiffness. The injured rats adopt a stance strategy that isolates the hindlimbs from perturbation and may thus prevent hindlimb loadings. Such loadings could initiate reflex stepping, which we observed. This might activate lumbar pattern generators used in their locomotion. Adult spinalized rats never achieve independent hindlimb weight-supported stance. The stance strategy of the P1 spinalized rats differed strongly from the behavior of intact rats and may be difficult for rats spinalized as adults to master.

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