To see the other types of publications on this topic, follow the link: Joint-Reaction Forces.
Dissertations / Theses on the topic 'Joint-Reaction Forces'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 20 dissertations / theses for your research on the topic 'Joint-Reaction Forces.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Allen, James Brandon. "Estimating Uncertainties in the Joint Reaction Forces of Construction Machinery." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/33046.
Full textAbstract:
In this study we investigate the propagation of uncertainties in the input forces through a mechanical system. The system of interest was a wheel loader, but the methodology developed can be applied to any multibody systems. The modeling technique implemented focused on efficiently modeling stochastic systems for which the equations of motion are not available. The analysis targeted the reaction forces in joints of interest.
The modeling approach developed in this thesis builds a foundation for determining the uncertainties in a Caterpillar 980G II wheel loader. The study begins with constructing a simple multibody deterministic system. This simple mechanism is modeled using differential algebraic equations in Matlab. Next, the model is compared with the CAD model constructed in ProMechanica. The stochastic model of the simple mechanism is then developed using a Monte Carlo approach and a Linear/Quadratic transformation method. The Collocation Method was developed for the simple case study for both Matlab and ProMechanica models.
Thus, after the Collocation Method was validated on the simple case study, the method was applied to the full 980G II wheel loader in the CAD model in ProMechanica.
This study developed and implemented an efficient computational method to propagate computational method to propagate uncertainties through â black-boxâ models of mechanical systems. The method was also proved to be reliable and easier to implement than traditional methods.
Master of Science
2
Chinworth, Susan A. (Susan Annette). "Ground Reaction Forces and Ankle and Knee Moments During Rope Skipping." Thesis, University of North Texas, 1989. https://digital.library.unt.edu/ark:/67531/metadc501047/.
Full textAbstract:
Ground reaction force (GRF) data collected and synchronized with film data to determine peak GRF and calculate moments about ankle and knee during rope skipping. Two, five minute conditions were analyzed for 10 subjects. Condition 1 was set rate and style. Condition 2 was subjects' own rate and style. Means and standard deviations were reported for peak GRF, ankle and knee moments. One way ANOVAs reported no significant difference between conditions for variables measured. Efficiency and nature of well phased impacts during rope skipping may be determined by combination of GRF, similarities in magnitude and direction of joint moments, and sequencing of segmental movements. Technique and even distribution of force across articulations appear more important than magnitudes of force produced by given styles.
3
Pashak, Riley. "Susceptibility to Ankle Sprain Injury between Dominant and Non-Dominant Leg During Jump Landings." UKnowledge, 2019. https://uknowledge.uky.edu/khp_etds/66.
Full textAbstract:
Ankle sprains are one of the most common injuries within athletics in the United States with approximately one-million student athletes experiencing ankle sprains each year. Studies argue excessive or rapid ankle inversion occurring from jump landings may cause ankle sprains. Also, the effect of limb dominance on risk of ankle sprain is not well documented.
The aim of this study was to determine if there is an affect of leg dominance on landing mechanism of the ankle joint that predisposes either ankle joint to greater risk of ankle sprain.
Twelve recreationally active subjects were recruited and completed four maximal vertical jumps. Ground reaction force, marker position data and maximal vertical jump height were collected using two Bertec Force plates, a 10-camera motion capture system, and a Vertec Vertical Jump Trainer, respectively. Cortex and Visual3D software programs were used to process the motion capture data and to calculate peak vertical ground reaction forces(vGRF), loading rate, and ankle joint moments. There were no statistically significant differences in ankle joint moment or loading rate between limbs, but peak vGRF were significantly higher (p < 0.05) in the non-dominant ankle. The results suggest the non-dominant ankle displays higher injury potential, as the non-dominant leg accumulates a larger peak landing force.
4
Wikstrom, Erik A. "Functional vs isokinetic fatigue protocol effects on time to stabilization, peak vertical ground reaction forces, and joint kinematics in jump landing /." [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0000825.
Full text
5
Wahid, Ammar. "Influence of kinematics on the calculation of hip joint reaction forces in patients with symptomatic leg length inequality following total hip replacement." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/16065/.
Full textAbstract:
Up to 10% of patients following Total Hip Replacement (THR) are symptomatic for a Leg Length Inequality (LLI), commonly being up to 20mm longer on the operated side. With 100,000 patients undergoing THR in 2015, 8.7% of all errors in the NHS being attributed to an LLI and malpractice claims being frequent, understanding why certain patients are symptomatic whilst others remain asymptomatic is of great importance. Anthropometric and demographic measurements together with gait analysis results were compared between a group of 26 symptomatic LLI patients following THR, 14 asymptomatic THR patients and 38 healthy individuals using Plug-in-Gait. Statistically significant results were found for height, with LLI patients generally being 6% shorter than their THR counterparts. Gait analysis results using Visual3D and AnyBody found LLI patients demonstrated reductions in peak joint forces, ground reaction forces, moments and knee flexion relative to the THR and healthy group. This was linked to LLI patients walking 20% and 59% slower than their THR and healthy counterparts respectively. Wear analysis found that LLI patients had 9% greater sliding distances than THR patients per stride together with more unidirectional motion paths. A thorough critique of Plug-in-Gait found the clinical results were generally reliable. Further sensitivity analyses however highlighted the weaknesses of the model if used improperly, with a 45mm error in lateral thigh marker positioning leading to a 10% change in hip flexion angle. The choice of hip joint centre regression equation, errors in joint width measurement and the use of CAST over PiG were also found to have a profound effect on kinematic results. It was concluded that LLI patients were symptomatic due to a combination of a greater LLI magnitude to height ratio, leading to greater pelvic obliquity in smaller individuals, and weakened muscles/soft tissues at the hip causing an asymmetric gait.
6
Bader, Joseph Scott. "DISTAL RADIOULNAR JOINT BIOMECHANICS AND FOREARM MUSCLE ACTIVITY." UKnowledge, 2011. http://uknowledge.uky.edu/gradschool_diss/825.
Full textAbstract:
Optimal management of fractures, post-traumatic arthritis and instability of the distal radioulnar joint (DRUJ) requires an understanding of the forces existing across this joint as a function of the activities of daily living. However, such knowledge is currently incomplete. The goal of this research was to quantify the loads that occur at the DRUJ during forearm rotation and to determine the effect that individual muscles have on those loads.
Human and cadaver studies were used to analyze the shear (A-P), transverse (M-L) and resultant forces at the DRUJ and to determine the role that 15 individual muscles had on those forces. Data for scaling the muscles forces came from EMG analysis measuring muscle activity at nine positions of forearm rotation in volunteers during isometric pronation and supination. Muscle orientations were determined from the marked muscle origin and insertion locations of nine cadaveric arms at various stages of forearm rotation. The roles that individual muscles played in DRUJ loading were analyzed by removing the muscle of interest from the analysis and comparing the results.
The EMG portion of this study found that the pronator quadratus, pronator teres, brachioradialis, flexor carpi radialis and palmaris longus contribute significantly to forearm pronation. The supinator, biceps brachii, and abductor pollicis longus were found to contribute significantly to supination.
The results of the DRUJ analysis affirm that large transverse forces pass from the radius to the ulnar head at all positions of forearm rotation during pronation and supination (57.5N-181.4N). Shear forces exist at the DRUJ that act to pull the radius away from the ulna in the AP direction and are large enough to merit consideration when examining potential treatment options (7.9N-99.5N).
Individual muscle analysis found that the extensor carpi radialis brevis, extensor pollicis longus, extensor carpi ulnaris, extensor indicis and palmaris longus had minimal effect on DRUJ loading. Other than the primary forearm rotators (pronator quadratus, pronator teres, supinator, biceps brachii), the muscles that exhibited the largest influence on DRUJ loading were the abductor pollicis longus, brachialis, brachioradialis, extensor carpi ulnaris, flexor carpi radialis, and flexor carpi ulnaris.
7
Patergnani, Matteo. ""Influence of lower-limb joint models on subject-specific musculoskeletal model predictions during gait" ( "modelli muscoloscheletrici personalizzati dell'arto inferiore: Analisi dell'effetto della modellazione dei giunti sulla predizione dei carichi agenti sul sistema scheletrico durante il cammino")." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amslaurea.unibo.it/6439/.
Full textAbstract:
The aim of the present thesis was to investigate the influence of lower-limb joint models on musculoskeletal model predictions during gait.
We started our analysis by using a baseline model, i.e., the state-of-the-art lower-limb model (spherical joint at the hip and hinge joints at the knee and ankle) created from MRI of a healthy subject in the Medical Technology Laboratory of the Rizzoli Orthopaedic Institute. We varied the models of knee and ankle joints, including: knee- and ankle joints with mean instantaneous axis of rotation, universal joint at the ankle, scaled-generic-derived planar knee, subject-specific planar knee model, subject-specific planar ankle model, spherical knee, spherical ankle. The joint model combinations corresponding to 10 musculoskeletal models were implemented into a typical inverse dynamics problem, including inverse kinematics, inverse dynamics, static optimization and joint reaction analysis algorithms solved using the OpenSim software to calculate joint angles, joint moments, muscle forces and activations, joint reaction forces during 5 walking trials. The predicted muscle activations were qualitatively compared to experimental EMG, to evaluate the accuracy of model predictions.
Planar joint at the knee, universal joint at the ankle and spherical joints at the knee and at the ankle produced appreciable variations in model predictions during gait trials. The planar knee joint model reduced the discrepancy between the predicted activation of the Rectus Femoris and the EMG (with respect to the baseline model), and the reduced peak knee reaction force was considered more accurate. The use of the universal joint, with the introduction of the subtalar joint, worsened the muscle activation agreement with the EMG, and increased ankle and knee reaction forces were predicted. The spherical joints, in particular at the knee, worsened the muscle activation agreement with the EMG. A substantial increase of joint reaction forces at all joints was predicted despite of the good agreement in joint kinematics with those of the baseline model. The introduction of the universal joint had a negative effect on the model predictions. The cause of this discrepancy is likely to be found in the definition of the subtalar joint and thus, in the particular subject’s anthropometry, used to create the model and define the joint pose.
We concluded that the implementation of complex joint models do not have marked effects on the joint reaction forces during gait. Computed results were similar in magnitude and in pattern to those reported in literature. Nonetheless, the introduction of planar joint model at the knee had positive effect upon the predictions, while the use of spherical joint at the knee and/or at the ankle is absolutely unadvisable, because it predicted unrealistic joint reaction forces.
8
Standifird, Tyler W. "Lower Extremity Joint Moments During the Active Peak Vertical Ground Reaction Force in Three Different Running Conditions." BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/2982.
Full textAbstract:
The purpose of this study was to compare joint moments during the active peak vertical ground reaction force (PVGRF) when running in three conditions. Twenty-five subjects, sixteen male and nine female, were measured using 3-dimensional motion analysis while running barefoot, in Vibram FiveFingers® (VF®) minimalist running shoes and in traditional running shoes at a 7-minute-mile pace (3.84 m/s). Joint moment differences were calculated and compared using a mixed model analysis of variance. Results showed the VF® was effective at mimicking both the kinetic and kinematic attributes of barefoot running. The only significant difference found when comparing barefoot and VF® running was in the ankle angle (p < .005). All other variables in the lower extremity were the same for the two conditions. Though the subjects in our study had no previous experience with VF® (or barefoot) running they were able to closely mimic barefoot running upon initial running trials. Joint moments at the ankle were higher for barefoot and VF® running (p < .001) when compared with shod running. This may potentially lead to a greater risk of injury at the ankle joint when running barefoot or in VF®. The hip joint moments were only different when comparing the barefoot condition to the shod condition (p=.002), with the barefoot condition higher than shod running. The knee joint moment was smaller during the VF® and barefoot conditions when compared with shod running (p < .001) and may lead to a decrease in injury rates at the knee. Though a reduction in moments of the lower extremity may lead to a decrease of injury at the corresponding joint, it is important to consider the adaptations that take place as a result of varying stresses. According to Wolff's law, bone and surrounding tissue will adapt to the loads it is placed under. Taking this into consideration, it is important to remember that lower moments may lead to weaker bones and surrounding tissues and without compensation for these reduced loads, injury rates may remain the same over time.
9
Lima, Gustavo Freitas de. "Desenvolvimento de um sistema para monitoramento de variáveis da marcha e controle de EENM na marcha." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/18/18151/tde-15102008-140110/.
Full textAbstract:
A lesão medular pode prejudicar a marcha de um indivíduo. Para estes casos, uma técnica de reabilitação que tem se tornado mais popular é a Estimulação Elétrica Neuro Muscular (EENM). Na marcha assistida por EENM tradicional, o controle da estimulação é realizado utilizando-se acionamento manual, um fato que ajuda a torná-la distante da marcha saudável. Este trabalho propõe um sistema que monitora variáveis da marcha - ângulos da articulação do joelho, e forças de reação do solo (retropé e antepé) - e as utiliza como entradas para uma rede neural artificial (RNA), a fim de poder controlar automaticamente a EENM na marcha. Os transdutores utilizados para medir ângulos foram eletrogoniômetros, montados nos membros inferiores do indivíduo utilizando tiras de velcro. Para medição das forças, os transdutores utilizados foram células de carga construídas com strain gages, montadas em sandálias instrumentadas. Os métodos para construção do hardware de aquisição de dados (transdutores e interface) e do software estão descritos, bem como os métodos de calibração dos transdutores. Todos os transdutores apresentaram comportamento linear. Testes iniciais foram realizados, utilizando primeiramente um indivíduo saudável, e depois dois pacientes que normalmente realizam treinamento de marcha com suspensão de peso (assistida por EENM ou não). Os resultados mostraram que o módulo de monitoramento permite gravar os dados coletados, e realizar comparações entre padrões de marcha de diferentes indivíduos, bem como diferentes estágios de reabilitação para um mesmo indivíduo. O treinamento da RNA para o indivíduo saudável apresentou uma taxa de acerto próxima de 90%, e para os pacientes lesados medulares a taxa foi de cerca de 80%. O módulo de controle apresentou resultados promissores nos testes práticos realizados, com respostas rápidas e corretas para o indivíduo saudável. Sugestões para trabalhos futuros foram dadas, para que testes práticos de controle possam ser realizados utilizando pacientes lesados medulares.Spinal cord injury (SCI) may impair an individual\'s gait. For these cases, a rehabilitation technique that has become more popular is functional electrical stimulation (FES). On traditional FES-assisted gait, the stimulation control is performed with manual triggering, a fact that helps make it distant from healthy gait. This work proposes a system that monitors gait variables - knee joint angles, and ground reaction forces (rearfoot and forefoot) - and uses them as inputs for an Artificial Neural Network (ANN), in order to be able to automatically control gait FES. The transducers used for angle measurement were electrogoniometers, mounted on the individuals lower limbs using Velcro straps. For force measurement, the transducers used were load cells built with strain gages, mounted on instrumented sandals. The methods for building the data acquisition hardware (transducers and interface) and software are described, along with the transducer calibration methods. All transducers presented linear behavior. Initial tests were performed, using first a healthy individual, and then a couple of patients that normally undergo suspended gait raining (FES-assisted or not). The results showed that the monitoring module allows recording the data collected, and making comparison between different individuals\' gait patterns, as well as different rehabilitation stages for the same individual. The ANN training for the healthy individual presented an accuracy rate close to 90%, and for the SCI patients the rate was about 80%. The control module showed promising results on practical tests performed, with quick and accurate responses for the healthy individual. Suggestions for future works were given, so that practical control tests can be performed using SCI patients.
10
Faraci, Vincent J. "Ground reaction force analyis [sic] of athletes with and without patellar tendinitis." Virtual Press, 1997. http://liblink.bsu.edu/uhtbin/catkey/1048384.
Full textAbstract:
The purpose of this study was to examine differences in drop landing ground reaction forces between athletes with and without patellar tendinitis. Subjects included 30 recreational athletes, 15 with patellar tendinitis and 15 without. Subjects with patellar tendinitis were tested twice, before (PTI) and after (PTF) rehabilitation. The non-patellar tendinitis (NPT) group was tested once. Subjects performed three trials of a drop landing from a height of 40 cm onto the force plate. Video data was collected to determine the deepest angle of knee flexion during landing. Statistical analysis using ANOVA revealed significant differences in maximum vertical force for the initial peak, post hoc analysis revealed differences between PTI and NPT groups aswell as between PTF and NPT groups. Results indicate athletes with patellar tendinitis exhibit higher initial peak 1 VGRF than athletes without patellar tendinitis. Results indicate that athletes who consistently land with elevated peak 1 ground reaction force are more likely to develop patellar tendinitis.School of Physical Education
11
Hungenahalli, Shivanna Bharath. "Musculoskeletal Modeling of Ballet." Thesis, Linköpings universitet, Mekanik och hållfasthetslära, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-171924.
Full textAbstract:
This thesis work comprises the working and simulation procedures being involved in simulating motion capture data in AnyBody Modeling System. The motion capture data used in this thesis are ballet movements from dancers of Östgöta ballet and dance academy. The ballet movements taken into consideration are the arabesque on demi-pointe and pirouette. The arabesque on demi-pointe was performed by two dancers but the pirouette is performed by only one dancer. The method involved recording ballet movements by placing markers on the dancer's body and using this motion capture data as input to AnyBody Modeling System to create a musculoskeletal simulation. The musculoskeletal modeling involved creating a very own Qualisys marker protocol for the markers placed on the ballet dancers. Then implementing the marker protocol onto a human model in AnyBody Modeling System by making use of the AnyBody Managed Modeling Repository (TM) and obtain the kinematics from the motion capture. To best fit the human model to the dancer's anthropometry, scaling of the human model is done, environmental conditions such as the force plates are provided. An optimization algorithm is conducted for the marker positions to best fit the dancer's anthropometry by running parameter identification. From the kinematics of the motion capture data, we simulate the inverse dynamics in AnyBody Modeling System. The simulations explain a lot of parameters that describe the ballet dancers. Results such as the center of mass, the center of pressure, muscle activation, topple angle are presented and discussed. Moreover, we compare the models of the dancers and draw conclusions about body balance, effort level, and muscles activated during the ballet movements.
12
McCarren, Gillian A. "The Impact of Dual Task Shooting on Knee Kinematics and Kinetics." Ohio University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1556214323893082.
Full text
13
Grøtner, Katrine, and Huy Hoang Pham. "Kinetik ved løb med dagligdagsprotese og løbespecifikprotese hos transtibial amputerede: Et cross-sectional studie." Thesis, Hälsohögskolan, Jönköping University, HHJ, Avd. för rehabilitering, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-49495.
Full textAbstract:
Formål: Formålet med studiet er at undersøge hvordan løb med en dagligdagsprotese og en løbespecifikprotese påvirker kinetik i nedre ekstremiteter hos mennesker med en transtibial-amputation. Metode: Kinetisk data blev indsamlet ved løbetests, med begge proteser, med et motion capture system og kraftplader i et klinisk ganganalyse lab i Göteborg, Sverige. Deltagere(n=2) udførte løbetests i selvvalgt hastighed, iført refleksive markører. Vertikal GRF, fod progressions vinkel, adducerende/abducerende hofte- og knæmoment udvalgt til videre databehandling. Resultat: Forskelle i hofte- og knæ adduktions moment og fod progressions vinkel blev observeret mellem de to protesetyper. Momenterne var mindre, når deltagerne løb med den løbespecifikke protese. Forskelle på den amputerede side og den kontralaterale side noteredes ved alle parametre uanset protesetype. Den kontralaterale side havde forøgede værdier sammenlignet med den amputerede side. Konklusion: Grundet forsøgets størrelse kan vi ikke konkludere, at individer med unilateral amputation i nedre ekstremitet absorberer belastning bedre, når de løber med en løbespecifikprotese fremfor en dagligdagsprotese.Aim: The aim of this study was to investigate how running with a daily-use prosthesis and a running specific prosthesis affects kinetics in the lower extremities when it comes to people with a transtibial amputation. Method: Kinetic data was collected through running tests, using both type of prosthesis, with a motion capture system and force plates in a clinical gait lab in Gothenburg, Sweden. Participants (n=2) executed the running tests in a self-selected speed, while wearing reflective markers. Vertical ground reaction force, foot progression angle, hip- and knee moment were selected for data processing. Results: Differences in hip- and knee adduction moment and foot progression angle were observed between the two types of prostheses. Moments were smaller when participants ran with running-specific prosthesis. Dissimilarity for the amputated side and the contralateral side were noted for all parameters regardless of type of prosthesis. The contralateral side had increased values compared to the amputated side. Conclusion: Because of the sample size we cannot conclude that individuals with a unilateral lower body amputation absorb load more efficiently when running with a running-specific prosthesis rather than a daily-use prosthesis.
14
Cotter, Joshua Allan. "The Effect of Squat Load and Depth on Patellofemoral Joint Kinetics." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1243606700.
Full text
15
Boldt, Daryl E. "A descriptive analysis of the joint reaction forces and the ground reaction forces in the lower limb during the landing of a triple toe loop." 1994. http://hdl.handle.net/1993/17832.
Full text
16
Ismail, Karim K. "Hip joint forces in individuals with femoroacetabular impingement syndrome." Thesis, 2021. https://hdl.handle.net/2144/42610.
Full textAbstract:
Femoroacetabular impingement syndrome (FAIS) is a disorder characterized by
specific morphology of the femur and/or acetabulum, which may lead to hip pain during
gait. Compared to individuals without pain, people with FAIS walk with more anterior
pelvic tilt, and their pain may result from excessive anteriorly-directed hip joint forces.
Previous approaches using musculoskeletal modelling to calculate joint forces, however,
may inaccurately assume that each individual stands in an entirely neutral position when
determining static joint angles. Consequently, information on parameters that affect joint
forces (such as pelvic tilt) is lost in kinematic data used to estimate joint loading. To
observe the effect of computationally altered pelvic tilt on joint forces, gait data of six
healthy individuals were processed using Vicon and Visual3D. Each participant’s pelvic
tilt was adjusted by ±5 degrees and ±10 degrees of tilt at all time points. Five analyses
were performed per individual: no change in tilt, two posterior (positive) tilts, and two
anterior (negative) tilts. The resulting data were imported into OpenSim to estimate
forces from the femur onto the acetabulum in the anterior, superior, and medial
directions. Data for each participant were normalized for gait cycle and body weight in
MATLAB. Statistical parametric mapping software was used to determine if the
differences in joint loads were significant. A more anterior pelvic tilt led to a reduction in
anteriorly-directed joint forces, and an increase in the superior and medial directions.
Based on these results, each individual’s pelvic tilt (obtained from their stationary
kinematic data) was accounted for when modeling FAIS and healthy individuals. Using
the same methods as above, the hip joint forces of 22 people with FAIS were compared
to those of 22 healthy individuals as both groups walked at a prescribed speed. Although
there were reductions in joint forces in both FAIS limbs compared to those of the control
group, the differences were not significant, possibly due to the high variability of joint
forces. Despite the significant effects of pelvic tilt on hip joint force, other underlying
assumptions need to be addressed in musculoskeletal modeling software in order to
compare different conditions, such as the use of the same generic model despite
differences in sex and hip morphology. Future studies comparing pathological and
healthy joint loads can inform researchers on gait alteration strategies and the design of
assistive devices to manage the symptoms and onset of conditions such as FAIS.2022-05-15T00:00:00Z
17
Slot, Tegan. "Occupational Biomechanics of Tree-Planters: A study of musculoskeletal symptoms, posture and joint reaction forces in Ontario tree-planters." Thesis, 2010. http://hdl.handle.net/1974/5534.
Full textAbstract:
Tree-planters are likely to suffer from musculoskeletal injuries during their short work season. The objective of this research is to identify the biomechanical mechanisms that contribute to these injuries with an overall goal of reducing injury frequency and severity.
Pre- and post-season discomfort questionnaires were administered to workers in two tree-planting camps to identify areas of the body most prone to injury. Musculoskeletal pain and discomfort were significantly higher post season. Greatest pain and discomfort were reported in the feet, wrists and back, while the highest frequency of pain was reported in the back.
Upper body and trunk postures were recorded during the tree-planting task in the field using digital video and inclinometers. Results indicated that deep trunk flexion occurred over 2600 times per day and workers spent at least half of their workday in trunk flexion greater than 45 degrees. Although results provide useful insight into injury mechanisms, postural data were two dimensional.
Inertial motion sensors were used in a second field study the following season to examine differences in three-dimensional upper limb and trunk relative joint angles during commonly used tree seedling unloading methods. Results showed trunk rotation up to 50 degrees combined with deep trunk flexion during parts of the task. Trunk flexion and rotation were significantly less when the tree seedling load was distributed asymmetrically as compared to symmetrically.
Joint reaction forces in the lower body and trunk during the same unloading methods was examined during a simulated planting task in a lab environment. Greatest joint reaction forces and non-neutral postures occurred when the tree was inserted into the ground. Right-loaded planting bags resulted in more substantial differences in posture and joint reaction forces than either left-loaded or even-loaded bags. Axial forces were greater in the right leg than the left throughout the task, regardless of loading condition.
In conclusion, underlying biomechanical mechanisms for injury during tree-planting seem to be a combination of awkward postures (particularly the trunk), repetitive motions, and carrying of heavy loads. Different seedling unloading strategies did not result in substantial overall differences in posture or joint reaction forces.Thesis (Ph.D, Kinesiology & Health Studies) -- Queen's University, 2010-04-14 10:02:32.385
18
Ventura, Jessica Dawn. "Experimental analysis and computational simulation of unilateral transtibial amputee walking to evaluate prosthetic device design characteristics and amputee gait mechanics." Thesis, 2010. http://hdl.handle.net/2152/ETD-UT-2010-05-786.
Full textAbstract:
Over one million amputees are living in the United States with major lower limb loss (Ziegler-Graham et al. 2008). Lower limb amputation leads to the functional loss of the ankle plantar flexor muscles, which are important contributors to body support, forward propulsion, and leg swing initiation during walking (Neptune et al. 2001; Liu et al. 2006). Effective prosthetic component design is essential for successful rehabilitation of amputees to return to an active lifestyle by partially replacing the functional role of the ankle muscles. The series of experimental and computer simulation studies presented in this research showed that design characteristics of energy storage and return prosthetic ankles, specifically the elastic stiffness, significantly influence residual and intact leg ground reaction forces, knee joint moments, and muscle activity, thus affecting muscle output. These findings highlight the importance of proper prosthetic foot stiffness prescription for amputees to assure effective rehabilitation outcomes. The research also showed that the ankle muscles serve to stabilize the body during turning the center of mass. When amputees turn while supported by their prosthetic components, they rely more on gravity to redirect the center of mass than active muscle generation. This mechanism increases the risks of falling and identifies a need for prosthetic components and rehabilitation focused on increasing amputee stability during turning. A proper understanding of the effects of prosthetic components on amputee walking mechanics is critical to decreasing complications and risks that are prevalent among lower-limb amputees. The presented research is an important step towards reaching this goal.text
19
Su, Jin Cheng, and 蘇金城. "Modeling and analysis of the joint reaction force on the double-flexible links system." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/36929059159385340478.
Full text
20
Shih, Szu-Ming, and 史世民. "Using the Artificial Neural Network to Predict the Joint Torque of Lower Limbs during Two Kinds of Vertical Jump through the Parameters of Ground Reaction Force." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/83509241898515623968.
Full textAbstract:
碩士國立體育學院
運動科學研究所
92
The test of vertical jump was often used for assessing the athlete’s muscular ability of lower limbs. However, ground reaction force (GRF) could only show the power level of lower limbs during vertical jump, it couldn’t reflect the controlling situation of every lower limbs’ joint and muscle. The purpose of this study was to construct an artificial neural network (ANN) model which could predict the joint torque of lower limbs through the relevant parameters of GRF during 2 kinds of vertical jump, instead of the calculation of inverse dynamics. This study used the experiment data of 10 male players (age: 20.10 ±1.91 yrs ; height: 179.34 ±4.25 cm ; weight: 69.58 ±3.91 kgw). The input parameters of this model were time%, GRF, vertical displacement, speed, and power; the output parameters of this model were all joint torque of lower limbs. Finally “5-10-3 model” was found to be an optimum model (input layer had 5 artificial neurons; there’s 1 hidden layer, and it had 10 artificial neurons; output layer had 3 artificial neurons). In this study, every mean root-of-mean-square was under 0.05, and every correlation coefficient was above 0.95. Moreover, this model worked well when it predicted the extreme value of joint torque and the impulse of angle. Therefore, this result showed that the method should be feasible to predict the joint torque of lower limbs through the relevant parameters of GRF by this ANN model. Nevertheless, since the subjects in original experiment were all young male players, it was a must taking into consideration the characteristics of subjects while promoting the result of this study.