scholarly journals Effects of Gait Speed of Femoroacetabular Joint Forces

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Joshua T. Weinhandl ◽  
Bobbie S. Irmischer ◽  
Zachary A. Sievert
Keyword(s):  
Hip Joint ◽  
Gait Speed ◽  
Gait Cycle ◽  
Musculoskeletal Modeling ◽  
Joint Loading ◽  
Joint Force ◽  
Joint Forces ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Vertical Ground Reaction Forces

Alterations in hip joint loading have been associated with diseases such as arthritis and osteoporosis. Understanding the relationship between gait speed and hip joint loading in healthy hips may illuminate changes in gait mechanics as walking speed deviates from preferred. The purpose of this study was to quantify hip joint loading during the gait cycle and identify differences with varying speed using musculoskeletal modeling. Ten, healthy, physically active individuals performed walking trials at their preferred speed, 10% faster, and 10% slower. Kinematic, kinetic, and electromyographic data were collected and used to estimate hip joint force via a musculoskeletal model. Vertical ground reaction forces, hip joint force planar components, and the resultant hip joint force were compared between speeds. There were significant increases in vertical ground reaction forces and hip joint forces as walking speed increased. Furthermore, the musculoskeletal modeling approach employed yielded hip joint forces that were comparable to previous simulation studies and in vivo measurements and was able to detect changes in hip loading due to small deviations in gait speed. Applying this approach to pathological and aging populations could identify specific areas within the gait cycle where force discrepancies may occur which could help focus management of care.

Musculoskeletal Modeling of Acetabular Dysplasia-Kinematics, Muscle and Joint Reaction Forces

2010 ◽  
Author(s):  
Michael D. Harris ◽  
Ryan S. Davis ◽  
Bruce A. MacWilliams ◽  
Christopher L. Peters ◽  
Andrew E. Anderson
Keyword(s):  
Hip Joint ◽  
Acetabular Dysplasia ◽  
Joint Kinematics ◽  
Developmental Dysplasia ◽  
Musculoskeletal Modeling ◽  
Muscle Forces ◽  
Joint Force ◽  
Joint Reaction Forces ◽  
Reaction Forces ◽  
Joint Reaction

Anatomical pathologies of the hip, such as developmental dysplasia are a common cause of hip pain in the young adult. While it is generally accepted that cartilaginous lesions and tears to the acetabular labrum initiate pain, muscle compensation/weakness may also contribute, especially for patients who do not have evidence of soft-tissue damage. Musculoskeletal models provide estimates of muscle forces as well as the equivalent force that acts upon the joint. Force data can then be compared to any observed differences in joint kinematics, thereby improving the interpretability of data from traditional gait studies. While a few studies have reported alterations in hip joint kinematics due to acetabular dysplasia, to our knowledge, muscle force differences have not been estimated [1, 2]. The purpose of this study was to couple traditional gait analysis with musculoskeletal modeling to compare hip joint kinematics, muscle forces, and joint reaction forces between subjects with acetabular dysplasia and normal controls.

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.

A Robotic Cadaveric Flatfoot Analysis of Stance Phase

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
Lyle T. Jackson ◽  
Patrick M. Aubin ◽  
Matthew S. Cowley ◽  
Bruce J. Sangeorzan ◽  
William R. Ledoux
Keyword(s):  
Surgical Treatment ◽  
Degrees Of Freedom ◽  
Stance Phase ◽  
Gait Cycle ◽  
Ground Reaction Forces ◽  
Pes Planus ◽  
Reaction Forces ◽  
Vertical Ground

The symptomatic flatfoot deformity (pes planus with peri-talar subluxation) can be a debilitating condition. Cadaveric flatfoot models have been employed to study the etiology of the deformity, as well as invasive and noninvasive surgical treatment strategies, by evaluating bone positions. Prior cadaveric flatfoot simulators, however, have not leveraged industrial robotic technologies, which provide several advantages as compared with the previously developed custom fabricated devices. Utilizing a robotic device allows the researcher to experimentally evaluate the flatfoot model at many static instants in the gait cycle, compared with most studies, which model only one to a maximum of three instances. Furthermore, the cadaveric tibia can be statically positioned with more degrees of freedom and with a greater accuracy, and then a custom device typically allows. We created a six degree of freedom robotic cadaveric simulator and used it with a flatfoot model to quantify static bone positions at ten discrete instants over the stance phase of gait. In vivo tibial gait kinematics and ground reaction forces were averaged from ten flatfoot subjects. A fresh frozen cadaveric lower limb was dissected and mounted in the robotic gait simulator (RGS). Biomechanically realistic extrinsic tendon forces, tibial kinematics, and vertical ground reaction forces were applied to the limb. In vitro bone angular position of the tibia, calcaneus, talus, navicular, medial cuneiform, and first metatarsal were recorded between 0% and 90% of stance phase at discrete 10% increments using a retroreflective six-camera motion analysis system. The foot was conditioned flat through ligament attenuation and axial cyclic loading. Post-flat testing was repeated to study the pes planus deformity. Comparison was then made between the pre-flat and post-flat conditions. The RGS was able to recreate ten gait positions of the in vivo pes planus subjects in static increments. The in vitro vertical ground reaction force was within ±1 standard deviation (SD) of the in vivo data. The in vitro sagittal, coronal, and transverse plane tibial kinematics were almost entirely within ±1 SD of the in vivo data. The model showed changes consistent with the flexible flatfoot pathology including the collapse of the medial arch and abduction of the forefoot, despite unexpected hindfoot inversion. Unlike previous static flatfoot models that use simplified tibial degrees of freedom to characterize only the midpoint of the stance phase or at most three gait positions, our simulator represented the stance phase of gait with ten discrete positions and with six tibial degrees of freedom. This system has the potential to replicate foot function to permit both noninvasive and surgical treatment evaluations throughout the stance phase of gait, perhaps eliciting unknown advantages or disadvantages of these treatments at other points in the gait cycle.

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
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