scholarly journals Conceptual Design of a Compliant Hip Orthosis for Trendelenburg Gait

2021 ◽  
Author(s):  
P. Vugts ◽  
J. Rommers ◽  
Bram T. Sterke ◽  
J. L. Herder
Keyword(s):  
Theoretical Analysis ◽  
Conceptual Design ◽  
Hip Joint ◽  
Human Body ◽  
Stiffness Ratio ◽  
Gait Disorder ◽  
Shear Forces ◽  
High Stiffness ◽  
Flexion Extension ◽  
Hip Abduction

Abstract Weakness of the hip abduction muscles can result in a gait disorder named Trendelenburg gait, which can lead to problems in the hip joint, knees, and ankles. In this paper, the conceptual design of a compliant hip orthosis to prevent Trendelenburg gait is presented. A theoretical analysis and measurements on a technical prototype show a high stiffness ratio between adduction and flexion-extension of the leg, and minimal shear forces from the orthosis on the human body while staying close to the human body.

scholarly journals Reliability of a New Portable Dynamometer for Assessing Hip and Lower Limb Strength

2021 ◽  
Vol 11 (8) ◽  
pp. 3391
Author(s):  
Jan Marušič ◽  
Goran Marković ◽  
Nejc Šarabon
Keyword(s):  
Lower Limb ◽  
External Rotation ◽  
Peak Torque ◽  
Knee Extension ◽  
Lower Limb Muscles ◽  
Lower Limb Strength ◽  
Flexion Extension ◽  
Strength Tests ◽  
Hip Abduction ◽  
Maximal Peak

The purpose of this study was to evaluate intra- and inter-session reliability of the new, portable, and externally fixated dynamometer called MuscleBoard® for assessing the strength of hip and lower limb muscles. Hip abduction, adduction, flexion, extension, internal and external rotation, knee extension, ankle plantarflexion, and Nordic hamstring exercise strength were measured in three sessions (three sets of three repetitions for each test) on 24 healthy and recreationally active participants. Average and maximal value of normalized peak torque (Nm/kg) from three repetitions in each set and agonist:antagonist ratios (%) were statistically analyzed; the coefficient of variation and intra-class correlation coefficient (ICC2,k) were calculated to assess absolute and relative reliability, respectively. Overall, the results display high to excellent intra- and inter-session reliability with low to acceptable within-individual variation for average and maximal peak torques in all bilateral strength tests, while the reliability of unilateral strength tests was moderate to good. Our findings indicate that using the MuscleBoard® dynamometer can be a reliable device for assessing and monitoring bilateral and certain unilateral hip and lower limb muscle strength, while some unilateral strength tests require some refinement and more extensive familiarization.

Hip and ankle strength and range of motion in female soccer players with dynamic knee valgus

2021 ◽  
pp. 1-6
Author(s):  
Young Jin Jo ◽  
Young Kyun Kim
Keyword(s):  
Range Of Motion ◽  
Female Athletes ◽  
External Rotation ◽  
Preventive Measure ◽  
Control Group ◽  
Knee Valgus ◽  
Strength Ratio ◽  
Flexion Extension ◽  
Hip Abduction ◽  
Single Leg Squat

BACKGROUND: Dynamic knee valgus (DKV) is a known risk factor for acute and chronic knee injuries and is more frequently diagnosed in females. A real-time single-leg squat test (SLST) could screen for DKV to prevent injuries. OBJECTIVE: To compare the differences in lower extremity strength and range of motion (ROM) in female soccer athletes with and without DKV during an SLST. METHODS: Eighteen subjects with DKV (DKV group) and 18 subjects without DKV (control group) during a single-leg squat were included. Hip strength (flexion, extension, abduction, adduction, internal rotation, and external rotation) was measured with a hand-held dynamometer. Hip ROM (internal and external rotation), and ankle ROM (dorsiflexion with the knee flexed and extended) were measured. Independent t-test was used to compare the averages of the groups. RESULTS: There were significant differences in hip abduction to adduction strength ratio (DKV: 1.48 ± 0.3, control: 1.22 ± 0.26, p< 0.01) and ankle dorsiflexion with knee flexed (DKV: 17.22 ± 6.82, control: 21.22 ± 4.55, p< 0.05) and extended (DKV: 10.14 ± 4.23, control: 14.75 ± 3.40, p< 0.001) between the groups. CONCLUSION: The hip abduction to adduction strength ratio and gastrocnemius and soleus flexibility may be associated factors in dynamic knee valgus and therefore should be assessed and treated, if indicated, as a possible preventive measure in female athletes with this variation.

AN ALGORITHM TO CALCULATE THE COMPONENTS OF ALL MUSCLE FORCES DURING EACH PHASES OF THE GAIT CYCLE, FOR THE PELVIC-FEMUR COMPLEX

2005 ◽  
Vol 05 (04) ◽  
pp. 539-548 ◽  
Author(s):  
SANTANU MAJUMDER ◽  
AMIT ROYCHOWDHURY ◽  
SUBRATA PAL
Keyword(s):  
Finite Element ◽  
Hip Joint ◽  
Computational Models ◽  
Gait Cycle ◽  
Muscle Force ◽  
Fe Analysis ◽  
Muscle Forces ◽  
Force Magnitude ◽  
Flexion Extension ◽  
Force Components

With the help of finite element (FE) computational models of femur, pelvis or hip joint to perform quasi-static stress analysis during the entire gait cycle, muscle force components (X, Y, Z) acting on the hip joint and pelvis are to be known. Most of the investigators have presented only the net muscle force magnitude during gait. However, for the FE software, either muscle force components (X, Y, Z) or three angles for the muscle line of action are required as input. No published algorithm (with flowchart) is readily available to calculate the required muscle force components for FE analysis. As the femur rotates about the hip center during gait, the lines of action for 27 muscle forces are also variable. To find out the variable lines of action and muscle force components (X, Y, Z) with directions, an algorithm was developed and presented here with detailed flowchart. We considered the varying angles of adduction/abduction, flexion/extension during gait. This computer program, obtainable from the first author, is able to calculate the muscle force components (X, Y, Z) as output, if the net magnitude of muscle force, hip joint orientations during gait and muscle origin and insertion coordinates are provided as input.

Detection of Human Body Motion Based on Electrostatic Measurements in the Indoor Environment

2011 ◽  
Vol 480-481 ◽  
pp. 1329-1334
Author(s):  
Wei Zheng ◽  
Zhan Zhong Cui
Keyword(s):  
Theoretical Analysis ◽  
Real Time ◽  
Human Body ◽  
Motion Detection ◽  
Average Velocity ◽  
Indoor Environment ◽  
Detection Method ◽  
Body Motion ◽  
The Real ◽  
Multiple Electrodes

An effective non-contact electrostatic detection method is used for human body motion detection. Theoretical analysis and pratical experiments are carried out to prove that this method is effective in the field of human body monitoring, in which a model for human body induced potential by stepping has been proposed. Furthermore, experiment results also prove that it’s feasible to measure the average velocity and route of human body motion by multiple electrodes array. What’s more the real-time velocity and direction of human body motion can be determined by orthogonal electrostatic detector array, and the real-time velocity and direction of human body motion can be obtained within the range of 2 meters.

scholarly journals Physiological Gait versus Gait in VR on Multidirectional Treadmill—Comparative Analysis

Medicina ◽  
2019 ◽  
Vol 55 (9) ◽  
pp. 517 ◽  
Author(s):  
Katarzyna Jochymczyk-Woźniak ◽  
Katarzyna Nowakowska ◽  
Jacek Polechoński ◽  
Sandra Sładczyk ◽  
Robert Michnik
Keyword(s):  
Comparative Analysis ◽  
Knee Joint ◽  
Hip Joint ◽  
Pelvic Tilt ◽  
Plantar Flexion ◽  
Center Of Mass ◽  
The Body ◽  
Joint Rotation ◽  
Active Motion ◽  
Flexion Extension

Background and objectives: Virtual reality (VR) is increasingly often finding applications in physiotherapy and health promotion. Recent years have seen the use of advanced technologies in the promotion of physical activity (PA) in society. New simulators, e.g., treadmills, enable the performance of PA (e.g., locomotive movements) in VR (artificially created virtual world). The question of how such movements are similar to natural forms of human locomotion (march, run) inspired the comparative analysis of physiological gait and gait in VR on a multidirectional Omni treadmill. Materials and Methods: The tests involved the use of the BTS Smart system for the triplanar analysis of motion. The test involved 10 healthy females aged 20–24 (weight: 52 ± 3.1 kg, height 162 ± 5.4 cm). Measurements were performed at two stages. The first stage involved the standard assessment of physiological gait, whereas the second was focused on gait forced by the Omni treadmill. The following gait parameters were analyzed: Flexion-extension in the ankle, knee joint and hip joint, rotation in the hip joint and knee joint, foot progression, adduction-abduction in the knee joint and hip joint, pelvic obliquity, pelvic tilt, pelvic rotation as well as energy expenditure and the movement of the body center of mass. Results: The analysis of the test results revealed the existence of differences in the kinematics of physical gait and gait on the treadmill. The greatest differences were recorded in relation to the dorsal-plantar flexion in the ankle, the foot progression, the rotation of the knee joint, pelvic tilt and rotation. In addition, the gait on the treadmill is characterized by the longer duration of the stance phase and reduced ranges of the following movements: Flexion-extension in the ankle, knee joint and hip joint, adduction-abduction in the hip joint as well as rotation in the ankle and hip joint. The values of potential, kinetic and total energy recorded in relation to forced gait are significantly lower than those of physiological gait. Conclusions: Because of the fact that the parameters of gait on the Omni platform vary significantly from the parameters of physical gait, the application of the Omni treadmill in the re-education of gait during rehabilitation should be treated with considerable care. Nonetheless, the treadmill has adequate potential to become a safe simulator enabling active motion in VR using locomotive movements.

scholarly journals A bistable structural element

2008 ◽  
Vol 222 (11) ◽  
pp. 2045-2051 ◽  
Author(s):  
T Schioler ◽  
S Pellegrino
Keyword(s):  
Theoretical Analysis ◽  
Analytical Model ◽  
Mechanical Behaviour ◽  
The Other ◽  
Experimental Measurements ◽  
Structural Element ◽  
High Stiffness ◽  
Revolute Joints ◽  
Prototype Structure ◽  
Good Agreement

This article presents a novel bistable structural element that has high stiffness in stable configurations, but requires only a small amount of energy to be switched from one configuration to the other. The element is based on a planar linkage of four bars connected by revolute joints, braced by tape-spring diagonals. A description of the concept is presented, along with a detailed theoretical analysis of its mechanical behaviour. Experimental measurements obtained from a prototype structure are found to be in very good agreement with the predictions from this analytical model.

scholarly journals Can the Open Stance Forehand Increase the Risk of Hip Injuries in Tennis Players?

2020 ◽  
Vol 8 (12) ◽  
pp. 232596712096629
Author(s):  
Caroline Martin ◽  
Anthony Sorel ◽  
Pierre Touzard ◽  
Benoit Bideau ◽  
Ronan Gaborit ◽  
...  
Keyword(s):  
Hip Joint ◽  
Inverse Dynamics ◽  
External Rotation ◽  
Tennis Players ◽  
Flexion Extension ◽  
Hip Injuries ◽  
Hip Motion ◽  
Hip Kinematics ◽  
The Right ◽  
Hip Flexion

Background: The open stance forehand has been hypothesized by tennis experts (coaches, scientists, and clinicians) to be more traumatic than the neutral stance forehand as regards hip injuries in tennis. However, the influence of the forehand stance (open or neutral) on hip kinematics and loading has not been assessed. Purpose: To compare the kinematics and kinetics at the hip joint during 3 common forehand stances (attacking neutral stance [ANS], attacking open stance [AOS], defensive open stance [DOS]) in advanced tennis players to determine whether the open stance forehand induces higher hip loading. Study Design: Descriptive laboratory study. Methods: The ANS, AOS, and DOS forehand strokes of 8 advanced right-handed tennis players were recorded with an optoelectronic motion capture system. The flexion-extension, abduction-adduction, and external-internal rotation angles as well as intersegmental forces and torques of the right hip were calculated using inverse dynamics. Results: The DOS demonstrated significantly higher values than both the ANS and AOS for anterior ( P < .001), medial ( P < .001), and distractive ( P < .001) forces as well as extension ( P = .004), abduction ( P < .001), and external rotation ( P < .001) torques. The AOS showed higher distractive forces than the ANS ( P = .048). The DOS showed more extreme angles of hip flexion ( P < .001), abduction ( P < .001), and external rotation ( P = .010). Conclusion: The findings of this study imply that the DOS increased hip joint angles and loading, thus potentially increasing the risk of hip overuse injuries. The DOS-induced hip motion could put players at a higher risk of posterior-superior hip impingement compared with the ANS and AOS. Clinical Relevance: Coaches and clinicians with players who have experienced hip pain or sustained injuries should encourage them to use a more neutral stance and develop a more aggressive playing style to avoid the DOS, during which hip motion and loading are more extreme.

Finite element modeling and simulation of hip joints in elderly women: for development of protective clothing against fracture

2020 ◽  
Vol 32 (5) ◽  
pp. 661-675
Author(s):  
Jinhee Park ◽  
Yun Ja Nam
Keyword(s):  
Finite Element ◽  
Hip Joint ◽  
Human Body ◽  
Protective Clothing ◽  
Elderly Women ◽  
Hip Joints ◽  
Cross Sectional ◽  
Content Type ◽  
Protective Devices ◽  
Joint Fracture

PurposeFracture experiments on real human bodies to examine the protected positions and protective devices for the development of protective clothing to manage fractures is exceedingly difficult. Thus, the experimental design will have limitations, more of which are imposed if subjects are elderly people. To circumvent these limitations, this study proposes a finite element model of the hip joint in elderly women with virtual impact simulations that can replace actual fall and impact tests, and examine the positions and characteristics of fractures resulting from taking a fall.Design/methodology/approachThe hip joints were modeled after the average horizontal surface size and cross-sectional shapes of the lower extremities (waist to knee) in 439 elderly Korean women in that age group. The model was composed of bones, cartilages, and soft tissue.FindingsThe fracture was examined by comparing the maximum stress on the hip joint by applying a point force to its adjacent surface. The vulnerable part in the hip joint neck with a high risk of fracture risk on an impact could be determined and used to set the protective device attachment position.Originality/valueIt is significant that this study has developed a partial model of the human body that can be used for a relatively simple simulation by minimizing the highly complex human body as much as possible. Furthermore, the model is easily applicable to the designing of protected positions and protective devices for the development of special clothing, for hip joint fracture prevention.

scholarly journals Optimal Level of Assistance and Weight of Hip-joint Wearable Robot Considering Influences to the Human Body

2019 ◽  
Vol 52 (22) ◽  
pp. 13-18
Author(s):  
Yoosuk Kim ◽  
Sungwon Shin ◽  
Kyoungchul Kong ◽  
Dyhyun Han
Keyword(s):  
Hip Joint ◽  
Human Body ◽  
Optimal Level ◽  
Wearable Robot

scholarly journals Materials for Hip Prostheses: A Review of Wear and Loading Considerations

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 495 ◽  
Author(s):  
Massimiliano Merola ◽  
Saverio Affatato
Keyword(s):  
Wear Rate ◽  
Hip Joint ◽  
Human Body ◽  
Material Behavior ◽  
Hip Implants ◽  
Hip Prostheses ◽  
Replacement Surgery ◽  
Current State ◽  
Frictional Forces ◽  
Key Aspects

Replacement surgery of hip joint consists of the substitution of the joint with an implant able to recreate the articulation functionality. This article aims to review the current state of the art of the biomaterials used for hip implants. Hip implants can be realized with different combination of materials, such as metals, ceramics and polymers. In this review, we analyze, from international literature, the specific characteristics required for biomaterials used in hip joint arthroplasty, i.e., being biocompatible, resisting heavy stress, opposing low frictional forces to sliding and having a low wear rate. A commentary on the evolution and actual existing hip prostheses is proposed. We analyzed the scientific literature, collecting information on the material behavior and the human-body response to it. Particular attention has been given to the tribological behavior of the biomaterials, as friction and wear have been key aspects to improve as hip implants evolve. After more than 50 years of evolution, in term of designs and materials, the actual wear rate of the most common implants is low, allowing us to sensibly reduce the risk related to the widespread debris distribution in the human body.

Sign in / Sign up

Export Citation Format

Share Document