Experimental/Analytical Analysis of Human Locomotion Using Bondgraphs

2003 ◽  
Vol 125 (4) ◽  
pp. 490-498 ◽  
Author(s):  
Cristian Pop ◽  
Amir Khajepour ◽  
Jan P. Huissoon ◽  
Aftab E. Patla

A new vectorial bondgraph approach for modeling and simulation of human locomotion is introduced. The vectorial bondgraph is applied to an eight-segment gait model to derive the equations of motion for studying ground reaction forces (GRFs) and centers of pressure (COPs) in single and double support phases of ground and treadmill walking. A phase detection technique and accompanying transition equation is proposed with which the GRFs and COPs may be calculated for the transitions from double-to-single and single-to-double support phases. Good agreement is found between model predictions and experimental data obtained from force plate measurements. The bondgraph modeling approach is shown to be both informative and adaptable, in the sense that the model resembles the human body structure, and that modeled body segments can be easily added or removed.

2007 ◽  
Vol 23 (4) ◽  
pp. 322-329 ◽  
Author(s):  
Chip Wade ◽  
Mark S. Redfern

Locomotion over ballast surfaces provides a unique situation for investigating the biomechanics of gait. Although much research has focused on level and sloped walking on a smooth, firm surface in order to understand the common kinematic and kinetic variables associated with human locomotion, the literature currently provides few if any discussions regarding the dynamics of locomotion on surfaces that are either rocky or uneven. The purpose of this study was to investigate a method for using force plates to measure the ground reaction forces (GRFs) during gait on ballast. Ballast is a construction aggregate of unsymmetrical rock used in industry for the purpose of forming track bed on which railway ties are laid or in yards where railroad cars are stored. It is used to facilitate the drainage of water and to create even running surfaces. To construct the experimental ballast surfaces, 31.75-mm (1¼-in.) marble ballast at depths of approximately 63.5 mm (2.5 in.) or 101.6 mm (4 in.) were spread over a carpeted vinyl tile walkway specially designed for gait studies. GRF magnitudes and time histories from a force plate were collected under normal smooth surface and under both ballast surface conditions for five subjects. GRF magnitudes and time histories during smooth surface walking were similar to GRF magnitudes and time histories from the two ballast surface conditions. The data presented here demonstrate the feasibility of using a force plate system to expand the scope of biomechanical analyses of locomotion on ballast surfaces.


2006 ◽  
Vol 3 (4) ◽  
pp. 209-216 ◽  
Author(s):  
Pia Gustås ◽  
Christopher Johnston ◽  
Stig Drevemo

AbstractThe objective of the present study was to compare the hoof deceleration and ground reaction forces following impact on two different surfaces. Seven unshod Standardbreds were trotted by hand at 3.0–5.7 m s− 1 over a force plate covered by either of the two surfaces, sandpaper or a 1 cm layer of sand. Impact deceleration data were recorded from one triaxial accelerometer mounted on the fore- and hind hooves, respectively. Ground reaction force data were obtained synchronously from a force plate, sampled at 4.8 kHz. The differences between the two surfaces were studied by analysing representative deceleration and force variables for individual horses. The maximum horizontal peak deceleration and the loading rates of the vertical and the horizontal forces were significantly higher on sandpaper compared with the sand surface (P < 0.001). In addition, the initial vertical deceleration was significantly higher on sandpaper in the forelimb (P < 0.001). In conclusion, it was shown that the different qualities of the ground surface result in differences in the hoof-braking pattern, which may be of great importance for the strength of the distal horse limb also at slow speeds.


2007 ◽  
Vol 23 (3) ◽  
pp. 180-189 ◽  
Author(s):  
Niell G. Elvin ◽  
Alex A. Elvin ◽  
Steven P. Arnoczky

Modern electronics allow for the unobtrusive measurement of accelerations outside the laboratory using wireless sensor nodes. The ability to accurately measure joint accelerations under unrestricted conditions, and to correlate them with jump height and landing force, could provide important data to better understand joint mechanics subject to real-life conditions. This study investigates the correlation between peak vertical ground reaction forces, as measured by a force plate, and tibial axial accelerations during free vertical jumping. The jump heights calculated from force-plate data and accelerometer measurements are also compared. For six male subjects participating in this study, the average coefficient of determination between peak ground reaction force and peak tibial axial acceleration is found to be 0.81. The coefficient of determination between jump height calculated using force plate and accelerometer data is 0.88. Data show that the landing forces could be as high as 8 body weights of the jumper. The measured peak tibial accelerations ranged up to 42 g. Jump heights calculated from force plate and accelerometer sensors data differed by less than 2.5 cm. It is found that both impact accelerations and landing forces are only weakly correlated with jump height (the average coefficient of determination is 0.12). This study shows that unobtrusive accelerometers can be used to determine the ground reaction forces experienced in a jump landing. Whereas the device also permitted an accurate determination of jump height, there was no correlation between peak ground reaction force and jump height.


1986 ◽  
Vol 15 (1) ◽  
pp. 27-34 ◽  
Author(s):  
R Seliktar ◽  
J Mizrahi

Human locomotion studies employing cinematography and force plates have been conducted during the last five decades with the goal of producing a clinically acceptable gait evaluation technique. The bulk of information contained in the kinetic studies was the major obstacle in achieving this goal. Our aim in this work was to explore the possibility of representing some locomotor abnormalities solely by their reflection on the ground reaction force characteristics. As a first stage towards the establishment of these relationships, the gait characteristics of below-knee amputees were examined. One hundred and thirty ground force test results as obtained on twenty three below-knee amputees were analysed. Different variables such as time durations of the various phases, peak forces, impulses, rate of change of the forces, and others, were examined. The conclusions suggest that some of these variables are suitable for evaluation of gait and some, such as small perturbations superimposed on the curve, may serve as indicators of specific malfunction of the prosthetic system.


2020 ◽  
Vol 30 (89) ◽  
pp. 13-20
Author(s):  
Dimitrije Cabarkapa ◽  
Andrew Fry ◽  
Damjana Cabarkapa ◽  
Arden Rogers ◽  
Eric Mosier

Aim: The purpose of this study was to quantify ground reaction forces for some of the most commonly utilised volleyball blocking approaches and to examine their kinetic and kinematic characteristics. Basic procedures: The study was comprised of 18 healthy recreationally active women who volunteered to participate. Immediately after completion of the warm-up protocol, subjects performed 5 blocking approaches: stationary blocking approach (SBA), shuffle block to the right (SHBR), shuffle block to the left (SHBL), swing block to the right (SWBR) and swing block to the left (SWBL). In order to allow adequate recovery, each trial was randomly assigned and separated by a 1-2 minute rest interval. A uni-axial force plate with data acquisition system sampling at 1000 Hz was used to measure ground reaction forces. Main findings: SWBR and SWBL unveiled the greatest peak concentric force and rate of force development when compared to SBA, while no difference was observed when compared to SHBR and SHBL. Results: No significant differences were observed in peak landing force, impulse, and vertical jump height between any of the blocking approaches examined in this study. Conclusions: Knowing biomechanical characteristics of some of the most commonly utilised volleyball blocking approaches may help athletes to appropriately respond and quickly adjust to the opponent’s attacking position. Kinetic and kinematic variables are likely to be augmented with an advanced level of competition and can be trained and improved by properly designed and implemented strength and conditioning programmes.


2008 ◽  
Vol 21 (03) ◽  
pp. 243-249 ◽  
Author(s):  
D. Damur ◽  
T. Guerrero ◽  
M. Haessig ◽  
P. Montavon ◽  
K. Voss

Summary Objective: To assess functional outcome in dogs with cranial cruciate ligament (CrCL) disease after tibial tuberosity advancement (TTA) using force plate gait analysis, and to evaluate parameters potentially influencing outcome. Study design: Prospective clinical study. Animals: Consecutive clinical patients (n=37) with CrCL-deficient stifles (n=40). Methods: The stifle joints were examined arthroscopically prior to TTA. Meniscal release was not performed if the medial meniscus was intact. Open medial arthrotomy and partial meniscectomy were performed in the presence of meniscal tears. Vertical ground reaction forces were measured preoperatively and at follow-up examinations four to 16 months postoperatively (mean: 5.9 months). The ground reaction forces of a group of 65 healthy dogs were used for the comparison. The potential effects of clinical parameters on functional outcome were evaluated statistically. Results: Complete CrCL rupture was identified in 28 joints, and partial CrCL rupture in 12 joints. The medial meniscus was damaged in 21 stifles. Vertical ground reaction forces were significantly higher at follow-up (P<0.01), but remained significantly lower than those of control dogs (P<0.01). Complications were identified in 25% of joints, and the dogs with complications had significantly lower peak vertical forces at follow-up than the dogs without complications (P=0.04). Other clinical parameters did not influence outcome. Conclusions: Tibial tuberosity advancement significantly improved limb function in dogs with CrCL disease, but did not result in complete return to function. Complications adversely affected functional outcome. Clinical significance: A return to a function of approximately 90% of normal can be expected in dogs with CrCL disease undergoing TTA.


2012 ◽  
Vol 134 (1) ◽  
Author(s):  
M. Amine Hassini ◽  
Mihai Arghir

The traditional small perturbation method is successfully used for linear dynamic analysis of gas bearings but excludes any nonlinear study. Investigating large displacements requires the evaluation of the nonlinear aerodynamic forces in the thin film. To avoid solving the unsteady compressible thin film fluid equations, we propose a method based on the use of frequency dependent dynamic coefficients and on the rational function approximation of the resulting impedances. Calculating impedances for several eccentricities enables mapping the full dynamic behavior of the bearing. A set of ordinary differential equations is then developed by using the inverse of Laplace transform. The equations of motion of the rotor are subsequently solved numerically with local linearization at each time step. The numerical results obtained by using impedances are in good agreement with the reaction forces obtained by solving the full nonlinear transient Reynolds equation.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Amitava Halder ◽  
Chuansi Gao ◽  
Michael Miller

The effects of cooling on neuromuscular function and performance during gait are not fully examined. The purpose of this study was to investigate the effects of local cooling for 20 min in cold water at 10°C in a climate chamber also at 10°C on maximal isometric force and electromyographic (EMG) activity of the lower leg muscles. Gait ground reaction forces (GRFs) were also assessed. Sixteen healthy university students participated in the within subject design experimental study. Isometric forces of the tibialis anterior (TA) and the gastrocnemius medialis (GM) were measured using a handheld dynamometer and the EMG was recorded using surface electrodes. Ground reaction forces during gait and the required coefficient of friction (RCOF) were recorded using a force plate. There was a significantly reduced isometric maximum force in the TA muscle (P<0.001) after cooling. The mean EMG amplitude of GM muscle was increased after cooling (P<0.003), indicating that fatigue was induced. We found no significant changes in the gait GRFs and RCOF on dry and level surface. These findings may indicate that local moderate cooling 20 min of 10°C cold water, may influence maximal muscle performance without affecting activities at sub-maximal effort.


Author(s):  
Aydin Valizadeh orang ◽  
Arefeh Mokhtari Malekabadi ◽  
AmirAli Jafarnezhadgero

Background:Walking is one the common daily activities. With the beginning of middle age, weakness in the lower limb muscles can reduce the ability to walk. The use of foot orthoses reduce the load on the limbs and supports the joints during walking. The purpose of the present study was to investigate the acute effect of foot orthoses on the frequency spectrum of ground reaction forces during walking in the older adults. Methods: In this semi-experimental and laboratory study, 21 elderly (15 females and 6 males) with a mean height of 164.19±4.26 centimeters and weight of 80.04±3.50 kg, and age of 66.00±3.50 years were volunteered to participate in the study. The walking trials were done during three conditions including walking without foot orthoses, walking with small and large textured orthoses. The Bertec force plate (made in USA) with dimensions of 40 * 60 cm was used to record ground reaction forces. Results: The results of this study did not show any significant differences between walking without foot orthoses, walking with small and large textured foot orthoses for frequency of 99.5%, median frequency, frequency band and number of essential harmonics (P>0.05). However, the comfort level during wearing of large texture insole condition significantly increased compared to other conditions (P<0.05). Conclusion: The textured foot orthoses do not affect the frequency spectrum of ground reaction forces; however, it improves the comfort of the individual while walking.


2021 ◽  
Vol 6 (1) ◽  
pp. 30
Author(s):  
Tayssir Limam ◽  
Florian Vogl ◽  
William R. Taylor

The measurement of ground reaction forces (GRFs) helps in determining the role of each limb for support and propulsion in predicting muscle activities, and in determining the strain conditions experienced by bones. Measuring the GRFs in mice models is therefore a cornerstone for understanding rodent musculoskeletal and neuromotor systems, as well as for improved translation of knowledge to humans. Current force plates are too big in size to allow the measurement of forces for each paw. This limitation is mainly due to the large size of the used sensors. The goal of our study was therefore to develop a small 3D force sensor for application in rodent gait analysis. We designed a flexible and small mechanical structure (8 mm × 8 mm) to isolate force components. Using FEM simulation, we chose the area with the highest strain to fix two strain gauges for each direction. The small size of the sensor allows us to fix four of them under a plate on the mouse paw size (approximately 17 mm). According to our primary results, the force plate has a resolution of 2 mN in the vertical direction and 1 mN in the fore-aft and mediolateral directions. The construction of a runway with such a force plate will allow the measurement of GRFs and the centre of pressure of each rodent paw for different steps. Such techniques thus provide a basis for assessing functionality in mice models, towards improved translation of rodent research.


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