Pub Date : 2021-12-17DOI: 10.18122/td.1835.boisestate
G. J. Salverda
Introduction: Adopting knee adduction biomechanics during prolonged load carriage, a common military occupational activity, may increase service members knee osteoarthritis (OA) risk. Although service members reportedly increase knee adduction motions and moments during prolonged load carriage, it is unknown if either body borne load or walk duration increases velocity of knee adduction biomechanics, and subsequent knee OA risk. Varus thrust and alignment are also related to greater knee OA risk, yet it is unknown whether varus thrust and/or alignment are related to magnitude and velocity of knee adduction biomechanics during prolonged load carriage. Purpose: To determine whether body borne load and walk duration impacted magnitude and velocity of knee adduction biomechanics, or whether increases in knee adduction biomechanics are related to knee varus thrust or alignment. Methods: Seventeen participants (11 male/6 female, 23.2 ± 2.9 yrs, 1.8 ± .09 m, 71.0 ± 12.1 kg) had knee adduction biomechanics quantified while walking 1.3 m/s for 60 minutes with three body borne loads (0 kg, 15 kg, and 30 kg). Specifically, peak, average and maximum velocity, as well as time to peak, for knee adduction angle and moment, and varus thrust (first 16% of stance) were calculated at minutes 0, 30, and 60 of the load carriage task. Static knee alignment was calculated as the frontal plane knee projection angle. Statistical Analysis: Participants were defined as varus thrust (VT, n=8) or control (CON, n=9). Then, each knee adduction measurement was submitted to a repeated measures ANCOVA to test the main effect and interaction between body borne load (0 kg, 15 kg, and 30 kg), time (minutes 0, 30, and 60), and group (VT and CON), with static alignment considered a covariate. Results: A significant 3-way interaction for maximum varus thrust velocity (p=0.014), revealed the VT group exhibited greater maximum velocity at minutes 0 through 60 (p ≤ 0.038) with the 0 kg load, and minutes 0 and 60 (p ≤ 0.043) with the 15 kg load. Significant load by group interactions for magnitude (p=0.008) and average velocity (p=0.013) of varus thrust, and maximum KAA velocity (p=0.041) revealed VT participants exhibited larger and faster varus thrust and knee adduction angle than the CON group with the 0 kg and 15 kg loads (p < 0.050). Additionally, both magnitude and maximum velocity of KAM increased with the addition of load (p=0.009 and p=0.004), and walk duration increased magnitude of varus thrust (p=0.044). Static alignment was not a significant covariate for any knee adduction measure (p > 0.05). Conclusion: During prolonged load carriage participants adopted larger, faster knee adduction biomechanics, potentially increasing risk of knee OA. The VT group exhibited greater knee OA risk, and larger, faster knee adduction motions when walking with the lighter (0 kg and 15 kg) loads; while CON adopted increases in knee adduction bio
{"title":"Prolonged Load Carriage Impacts Magnitude and Velocity of Knee Adduction Biomechanics","authors":"G. J. Salverda","doi":"10.18122/td.1835.boisestate","DOIUrl":"https://doi.org/10.18122/td.1835.boisestate","url":null,"abstract":"Introduction: Adopting knee adduction biomechanics during prolonged load carriage, a common military occupational \u0000 activity, may increase service members knee osteoarthritis (OA) risk. Although service members reportedly increase knee adduction \u0000 motions and moments during prolonged load carriage, it is unknown if either body borne load or walk duration increases velocity \u0000 of knee adduction biomechanics, and subsequent knee OA risk. Varus thrust and alignment are also related to greater knee OA risk, \u0000 yet it is unknown whether varus thrust and/or alignment are related to magnitude and velocity of knee adduction biomechanics \u0000 during prolonged load carriage. Purpose: To determine whether body borne load and walk duration impacted \u0000 magnitude and velocity of knee adduction biomechanics, or whether increases in knee adduction biomechanics are related \u0000 to knee varus thrust or alignment. Methods: Seventeen participants (11 male/6 female, 23.2 ± 2.9 yrs, \u0000 1.8 ± .09 m, 71.0 ± 12.1 kg) had knee adduction biomechanics quantified while walking 1.3 m/s for 60 minutes with three \u0000 body borne loads (0 kg, 15 kg, and 30 kg). Specifically, peak, average and maximum velocity, as well as time to peak, \u0000 for knee adduction angle and moment, and varus thrust (first 16% of stance) were calculated at minutes 0, 30, and 60 \u0000 of the load carriage task. Static knee alignment was calculated as the frontal plane knee projection \u0000 angle. Statistical Analysis: Participants were defined as varus thrust (VT, n=8) or control (CON, n=9). Then, \u0000 each knee adduction measurement was submitted to a repeated measures ANCOVA to test the main effect and interaction \u0000 between body borne load (0 kg, 15 kg, and 30 kg), time (minutes 0, 30, and 60), and \u0000 group (VT and CON), with static alignment considered a covariate. Results: A significant 3-way \u0000 interaction for maximum varus thrust velocity (p=0.014), revealed the VT group exhibited greater maximum velocity at \u0000 minutes 0 through 60 (p ≤ 0.038) with the 0 kg load, and minutes 0 and 60 (p ≤ 0.043) with the 15 kg load. Significant \u0000 load by group interactions for magnitude (p=0.008) and average velocity (p=0.013) of varus thrust, and maximum KAA \u0000 velocity (p=0.041) revealed VT participants exhibited larger and faster varus thrust and knee adduction angle than \u0000 the CON group with the 0 kg and 15 kg loads (p < 0.050). Additionally, both magnitude and maximum velocity of KAM \u0000 increased with the addition of load (p=0.009 and p=0.004), and walk duration increased magnitude of varus thrust \u0000 (p=0.044). Static alignment was not a significant covariate for any knee adduction measure \u0000 (p > 0.05). Conclusion: During prolonged load carriage participants adopted larger, faster knee adduction \u0000 biomechanics, potentially increasing risk of knee OA. The VT group exhibited greater knee OA risk, and larger, faster \u0000 knee adduction motions when walking with the lighter (0 kg and 15 kg) loads; while CON adopted increases in knee \u0000 adduction bio","PeriodicalId":72381,"journal":{"name":"Biomechanics (Basel, Switzerland)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44331819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-28DOI: 10.3390/biomechanics1030028
Jair Wesley Ferreira Bueno, D. B. Coelho, Caroline Ribeiro de Souza, L. A. Teixeira
An important health-related problem of obesity is reduced stance stability, leading to increased chance of falling. In the present experiment, we aimed to compare stability in quiet and in dynamic body balance between women with morbid obesity (n = 13, body mass index [BMI] > 40 Kg/m2, mean age = 38.85 years) and with healthy body weight (lean) (n = 13; BMI < 25 Kg/m2, mean age = 37.62 years), evaluating the extent to which quiet and dynamic balance stability are associated with plantar sensibility. Quiet stance was evaluated in different visual and support base conditions. The dynamic task consisted of rhythmic flexion—extension movements at the hip and shoulder, manipulating vision availability. The plantar sensibility threshold was measured through application of monofilaments on the feet soles. The results showed that the morbidly obese, in comparison with the lean women, had higher plantar sensibility thresholds, and a reduced balance stability in quiet standing. Mediolateral stance stability on the malleable surface was strongly correlated with plantar sensibility in the obese women. Analysis of dynamic balance showed no effect of obesity and weaker correlations with plantar sensibility. Our results suggest that reduced plantar sensibility in morbidly obese women may underlie their diminished stance stability, while dynamic balance control seems to be unaffected by their reduced plantar sensibility.
{"title":"Association of Foot Sole Sensibility with Quiet and Dynamic Body Balance in Morbidly Obese Women","authors":"Jair Wesley Ferreira Bueno, D. B. Coelho, Caroline Ribeiro de Souza, L. A. Teixeira","doi":"10.3390/biomechanics1030028","DOIUrl":"https://doi.org/10.3390/biomechanics1030028","url":null,"abstract":"An important health-related problem of obesity is reduced stance stability, leading to increased chance of falling. In the present experiment, we aimed to compare stability in quiet and in dynamic body balance between women with morbid obesity (n = 13, body mass index [BMI] > 40 Kg/m2, mean age = 38.85 years) and with healthy body weight (lean) (n = 13; BMI < 25 Kg/m2, mean age = 37.62 years), evaluating the extent to which quiet and dynamic balance stability are associated with plantar sensibility. Quiet stance was evaluated in different visual and support base conditions. The dynamic task consisted of rhythmic flexion—extension movements at the hip and shoulder, manipulating vision availability. The plantar sensibility threshold was measured through application of monofilaments on the feet soles. The results showed that the morbidly obese, in comparison with the lean women, had higher plantar sensibility thresholds, and a reduced balance stability in quiet standing. Mediolateral stance stability on the malleable surface was strongly correlated with plantar sensibility in the obese women. Analysis of dynamic balance showed no effect of obesity and weaker correlations with plantar sensibility. Our results suggest that reduced plantar sensibility in morbidly obese women may underlie their diminished stance stability, while dynamic balance control seems to be unaffected by their reduced plantar sensibility.","PeriodicalId":72381,"journal":{"name":"Biomechanics (Basel, Switzerland)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43214435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-05DOI: 10.3390/biomechanics1030027
A. Lipphaus, Matthias Klimek, U. Witzel
Open-book fractures are defined as the separation of the pubic symphysis or fractures of the rami and disruption of the anterior sacroiliac, sacrotuberous, and sacrospinal ligaments. They can be stabilized by fixation of the anterior arch. However, indications and advantages of additional placement of iliosacral screws remain unknown. A CT-based model of the healthy pelvis was created and ligaments were modeled as tension springs. Range of motion of the sacroiliac joint and the pubic symphysis, and bone and implant stresses were compared for the physiological model, anterior symphyseal plating alone, and additional posterior fixation using two iliosacral screws. The range of motion of the sacroiliac joint was reduced for anterior symphyseal plating alone and further decrease was noted with additional posterior fixation. Von Mises stresses acting on the symphyseal plate were 819.7 MPa for anterior fixation only and 711.56 MPa for additional posterior fixation equivalent with a safety factor of 1.1 and 1.26, respectively. Implant stresses were highest parasymphyseal. While bone stresses exhibited a more homogeneous distribution in the model of the healthy pelvis and the model with anterior and posterior fixation, pure symphyseal plating resulted in bending at the pelvic rami. The analysis does not indicate the superiority of either anterior plating alone or additional posterior fixation. In both cases, the physiological range of motion of the sacroiliac joint is permanently limited, which should be taken into account with regard to implant removal or more flexible techniques for stabilization of the sacroiliac joint.
{"title":"Comparative Finite Element Analysis of Fixation Techniques for APC II Open-Book Injuries of the Pelvis","authors":"A. Lipphaus, Matthias Klimek, U. Witzel","doi":"10.3390/biomechanics1030027","DOIUrl":"https://doi.org/10.3390/biomechanics1030027","url":null,"abstract":"Open-book fractures are defined as the separation of the pubic symphysis or fractures of the rami and disruption of the anterior sacroiliac, sacrotuberous, and sacrospinal ligaments. They can be stabilized by fixation of the anterior arch. However, indications and advantages of additional placement of iliosacral screws remain unknown. A CT-based model of the healthy pelvis was created and ligaments were modeled as tension springs. Range of motion of the sacroiliac joint and the pubic symphysis, and bone and implant stresses were compared for the physiological model, anterior symphyseal plating alone, and additional posterior fixation using two iliosacral screws. The range of motion of the sacroiliac joint was reduced for anterior symphyseal plating alone and further decrease was noted with additional posterior fixation. Von Mises stresses acting on the symphyseal plate were 819.7 MPa for anterior fixation only and 711.56 MPa for additional posterior fixation equivalent with a safety factor of 1.1 and 1.26, respectively. Implant stresses were highest parasymphyseal. While bone stresses exhibited a more homogeneous distribution in the model of the healthy pelvis and the model with anterior and posterior fixation, pure symphyseal plating resulted in bending at the pelvic rami. The analysis does not indicate the superiority of either anterior plating alone or additional posterior fixation. In both cases, the physiological range of motion of the sacroiliac joint is permanently limited, which should be taken into account with regard to implant removal or more flexible techniques for stabilization of the sacroiliac joint.","PeriodicalId":72381,"journal":{"name":"Biomechanics (Basel, Switzerland)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43694941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In biomedical studies as well as in clinical trials, it is often useful to have a reliable measure of the force exerted by the body(eg. clenching force at the teeth or pinch force at fingertips) or on the body by external stimuli (eg. taps to elicit reflexes orlocal pressure for nociceptive stimulation). Thin-film sensors such as FlexiForce ® provide a very handy and versatile solutionfor these application, but can be easily damaged and offer poor accuracy and repeatability, being heavily affected by thesurface material they get in contact with. The aim of the study is the realization of a 3D-printed cover that completely embedsthe sensor, thus providing mechanical protection and increasing reliability of the measurement. The increasing availability of3D printers and of printing materials for medical use allows the user to shape the cover according to specific needs, with shortdeveloping time and low cost.
{"title":"Self-made 3D-printed encapsulation of thin-film transducers for reliable force measurement in biomedical applications","authors":"R. Pertusio, S. Roatta","doi":"10.31219/osf.io/5bgjq","DOIUrl":"https://doi.org/10.31219/osf.io/5bgjq","url":null,"abstract":"In biomedical studies as well as in clinical trials, it is often useful to have a reliable measure of the force exerted by the body(eg. clenching force at the teeth or pinch force at fingertips) or on the body by external stimuli (eg. taps to elicit reflexes orlocal pressure for nociceptive stimulation). Thin-film sensors such as FlexiForce ® provide a very handy and versatile solutionfor these application, but can be easily damaged and offer poor accuracy and repeatability, being heavily affected by thesurface material they get in contact with. The aim of the study is the realization of a 3D-printed cover that completely embedsthe sensor, thus providing mechanical protection and increasing reliability of the measurement. The increasing availability of3D printers and of printing materials for medical use allows the user to shape the cover according to specific needs, with shortdeveloping time and low cost.","PeriodicalId":72381,"journal":{"name":"Biomechanics (Basel, Switzerland)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41877648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-20DOI: 10.3390/biomechanics1030026
M. Wells, Feng-Chi Yang
Chronic health problems, such as neurological conditions or long-lasting diseases, impair patients’ physical and mental functions with a subsequent reduction in overall quality of life. The purpose of this systematic review was to summarize how ballroom dance is being investigated as a rehabilitative method in individuals with neurological or medical diseases. A systematic literature search was conducted in databases including MEDLINE, SPORTDiscus, and PubMed. Of 728 articles located and titles and abstracts screened, 12 studies were included in this review. Study groups included Parkinson’s disease (4 studies), multiple sclerosis (2), spinal cord injury (1), stroke (1), dementia (1), cancer (2), and diabetes (1). Ballroom dances utilized included a combination of smooth and rhythm dances. Results revealed that ballroom dance is effective in improving gait functions, balance, and quality of life among various populations living with chronic neurological or medical conditions. In addition, ballroom dance is safe and associated with a low attrition rate (7.7%). There is increasing evidence to support ballroom dance as a feasible and effective intervention for adults with chronic neurological disorders or medical diseases. Further large-scale, randomized controlled trials are needed to examine the mechanisms, effectiveness, retention, and safety of ballroom dance as a rehabilitative intervention.
{"title":"Ballroom Dance as a Form of Rehabilitation: A Systematic Review","authors":"M. Wells, Feng-Chi Yang","doi":"10.3390/biomechanics1030026","DOIUrl":"https://doi.org/10.3390/biomechanics1030026","url":null,"abstract":"Chronic health problems, such as neurological conditions or long-lasting diseases, impair patients’ physical and mental functions with a subsequent reduction in overall quality of life. The purpose of this systematic review was to summarize how ballroom dance is being investigated as a rehabilitative method in individuals with neurological or medical diseases. A systematic literature search was conducted in databases including MEDLINE, SPORTDiscus, and PubMed. Of 728 articles located and titles and abstracts screened, 12 studies were included in this review. Study groups included Parkinson’s disease (4 studies), multiple sclerosis (2), spinal cord injury (1), stroke (1), dementia (1), cancer (2), and diabetes (1). Ballroom dances utilized included a combination of smooth and rhythm dances. Results revealed that ballroom dance is effective in improving gait functions, balance, and quality of life among various populations living with chronic neurological or medical conditions. In addition, ballroom dance is safe and associated with a low attrition rate (7.7%). There is increasing evidence to support ballroom dance as a feasible and effective intervention for adults with chronic neurological disorders or medical diseases. Further large-scale, randomized controlled trials are needed to examine the mechanisms, effectiveness, retention, and safety of ballroom dance as a rehabilitative intervention.","PeriodicalId":72381,"journal":{"name":"Biomechanics (Basel, Switzerland)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47922737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-18DOI: 10.3390/biomechanics1030025
Sentong Wang, K. Hase, S. Ota
Finite element musculoskeletal (FEMS) approaches using concurrent musculoskeletal and finite element models driven by motion data such as marker-based motion trajectory can provide insight into the interactions between the knee joint secondary kinematics, contact mechanics, and muscle forces in subject-specific biomechanical investigations. However, these data-driven FEMS systems have a major disadvantage that makes them challenging to apply in clinical environments, i.e., they require expensive and inconvenient equipment for data acquisition. In this study, we developed an FEMS model of the lower limb driven solely by inertial measurement unit sensors that include the tissue geometries of the entire knee joint, and that combine modeling of 16 muscles into a single framework. The model requires only the angular velocities and accelerations measured by the sensors as input. The target outputs (knee contact mechanics, secondary kinematics, and muscle forces) are predicted from the convergence results of iterative calculations of muscle force optimization and knee contact mechanics. To evaluate its accuracy, the model was compared with in vivo experimental data during gait. The maximum contact pressure (11.3 MPa) occurred on the medial side of the cartilage at the maximum loading response. The developed framework combines measurement convenience and accurate modeling, and shows promise for clinical applications aimed at understanding subject-specific biomechanics.
{"title":"Development of a Lower Limb Finite Element Musculoskeletal Gait Simulation Framework Driven Solely by Inertial Measurement Unit Sensors","authors":"Sentong Wang, K. Hase, S. Ota","doi":"10.3390/biomechanics1030025","DOIUrl":"https://doi.org/10.3390/biomechanics1030025","url":null,"abstract":"Finite element musculoskeletal (FEMS) approaches using concurrent musculoskeletal and finite element models driven by motion data such as marker-based motion trajectory can provide insight into the interactions between the knee joint secondary kinematics, contact mechanics, and muscle forces in subject-specific biomechanical investigations. However, these data-driven FEMS systems have a major disadvantage that makes them challenging to apply in clinical environments, i.e., they require expensive and inconvenient equipment for data acquisition. In this study, we developed an FEMS model of the lower limb driven solely by inertial measurement unit sensors that include the tissue geometries of the entire knee joint, and that combine modeling of 16 muscles into a single framework. The model requires only the angular velocities and accelerations measured by the sensors as input. The target outputs (knee contact mechanics, secondary kinematics, and muscle forces) are predicted from the convergence results of iterative calculations of muscle force optimization and knee contact mechanics. To evaluate its accuracy, the model was compared with in vivo experimental data during gait. The maximum contact pressure (11.3 MPa) occurred on the medial side of the cartilage at the maximum loading response. The developed framework combines measurement convenience and accurate modeling, and shows promise for clinical applications aimed at understanding subject-specific biomechanics.","PeriodicalId":72381,"journal":{"name":"Biomechanics (Basel, Switzerland)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42397009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-15DOI: 10.3390/biomechanics1030024
T. Hortobágyi
Welcome to Neuromechanics, a section of Biomechanics published by the Multidisciplinary Digital Publishing Institute, MDPI [...]
欢迎来到《神经力学》，这是由MDPI多学科数字出版研究所出版的生物力学部分〔…〕
{"title":"Introduction to Neuromechanics, a New MDPI Open Access Section of Biomechanics","authors":"T. Hortobágyi","doi":"10.3390/biomechanics1030024","DOIUrl":"https://doi.org/10.3390/biomechanics1030024","url":null,"abstract":"Welcome to Neuromechanics, a section of Biomechanics published by the Multidisciplinary Digital Publishing Institute, MDPI [...]","PeriodicalId":72381,"journal":{"name":"Biomechanics (Basel, Switzerland)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42481225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-07DOI: 10.3390/biomechanics1020022
Blake Johnson, Scott Campbell, Naira Campbell-Kyureghyan
The liver and kidneys are the most commonly injured organs due to traumatic impact forces applied to the abdomen and pose a challenge to physicians due to a hard-to-diagnose risk of internal bleeding. A better understanding of the mechanism of injury will improve diagnosis, treatment, forensics, and other fields. Finite element modelling is a tool that can aid in this understanding, but accurate material properties are required including the strain rate dependency and the feasibility of using animal tissue properties instead of human. The elastic modulus in a probing protocol and the elastic modulus, failure stress, and failure strain in a compression protocol were found for both liver and kidney tissue from human and porcine specimens at varying strain rates. Increases in the elastic modulus were seen for both the human kidney and liver, but only for the porcine kidney, when comparing the unconfined compression and probing protocols. A strain rate dependency was found for both the liver and kidney properties and was observed to have a larger saturation effect at higher rates for the failure stress than for the elastic modulus. Overall, the material properties of intact liver and kidney were characterized, and the strain rate dependency was numerically modelled. The study findings suggest that some kidney and liver material properties vary from human to porcine tissue. Therefore, it is not always appropriate to use material properties of porcine tissue in computational or physical models of the human liver and kidney.
{"title":"Characterizing the Material Properties of the Kidney and Liver in Unconfined Compression and Probing Protocols with Special Reference to Varying Strain Rate","authors":"Blake Johnson, Scott Campbell, Naira Campbell-Kyureghyan","doi":"10.3390/biomechanics1020022","DOIUrl":"https://doi.org/10.3390/biomechanics1020022","url":null,"abstract":"The liver and kidneys are the most commonly injured organs due to traumatic impact forces applied to the abdomen and pose a challenge to physicians due to a hard-to-diagnose risk of internal bleeding. A better understanding of the mechanism of injury will improve diagnosis, treatment, forensics, and other fields. Finite element modelling is a tool that can aid in this understanding, but accurate material properties are required including the strain rate dependency and the feasibility of using animal tissue properties instead of human. The elastic modulus in a probing protocol and the elastic modulus, failure stress, and failure strain in a compression protocol were found for both liver and kidney tissue from human and porcine specimens at varying strain rates. Increases in the elastic modulus were seen for both the human kidney and liver, but only for the porcine kidney, when comparing the unconfined compression and probing protocols. A strain rate dependency was found for both the liver and kidney properties and was observed to have a larger saturation effect at higher rates for the failure stress than for the elastic modulus. Overall, the material properties of intact liver and kidney were characterized, and the strain rate dependency was numerically modelled. The study findings suggest that some kidney and liver material properties vary from human to porcine tissue. Therefore, it is not always appropriate to use material properties of porcine tissue in computational or physical models of the human liver and kidney.","PeriodicalId":72381,"journal":{"name":"Biomechanics (Basel, Switzerland)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48296094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-03DOI: 10.3390/biomechanics1020021
A. T. Abd, Rajat Emanuel Singh, K. Iqbal, G. White
The human motor system is a complex neuro-musculo sensory system that needs further investigations of neuro-muscular commands and sensory-motor coupling to decode movement execution. Some researchers suggest that the central nervous system (CNS) activates a small set of modules termed muscle synergies to simplify motor control. Further, these modules form functional building blocks of movement as they can explain the neurophysiological characteristics of movements. We can identify and extract these muscle synergies from electromyographic signals (EMG) recorded in the laboratory by using linear decomposition algorithms, such as principal component analysis (PCA) and non-Negative Matrix Factorization Algorithm (NNMF). For the past three decades, the hypothesis of muscle synergies has received considerable attention as we attempt to understand and apply the concept of muscle synergies in clinical settings and rehabilitation. In this article, we first explore the concept of muscle synergies. We then present different strategies of adaptation in these synergies that the CNS employs to accomplish a movement goal.
{"title":"A Perspective on Muscle Synergies and Different Theories Related to Their Adaptation","authors":"A. T. Abd, Rajat Emanuel Singh, K. Iqbal, G. White","doi":"10.3390/biomechanics1020021","DOIUrl":"https://doi.org/10.3390/biomechanics1020021","url":null,"abstract":"The human motor system is a complex neuro-musculo sensory system that needs further investigations of neuro-muscular commands and sensory-motor coupling to decode movement execution. Some researchers suggest that the central nervous system (CNS) activates a small set of modules termed muscle synergies to simplify motor control. Further, these modules form functional building blocks of movement as they can explain the neurophysiological characteristics of movements. We can identify and extract these muscle synergies from electromyographic signals (EMG) recorded in the laboratory by using linear decomposition algorithms, such as principal component analysis (PCA) and non-Negative Matrix Factorization Algorithm (NNMF). For the past three decades, the hypothesis of muscle synergies has received considerable attention as we attempt to understand and apply the concept of muscle synergies in clinical settings and rehabilitation. In this article, we first explore the concept of muscle synergies. We then present different strategies of adaptation in these synergies that the CNS employs to accomplish a movement goal.","PeriodicalId":72381,"journal":{"name":"Biomechanics (Basel, Switzerland)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49520893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-02DOI: 10.3390/biomechanics1020020
Anas Ben Achour, C. Petto, H. Meissner, A. Mostofa, U. Teicher, D. Haim, S. Ihlenfeldt, G. Lauer
Background: The aim is to evaluate methods to quantify the interstitial splitting force and thermal load input of self-tapping and self-drilling osteosynthesis screws. Methods: A specialized modular test bench was developed to measure the induced splitting force of self-drilling and self-tapping osteosynthesis screws using porcine mandibular bone. In addition, a fundamentally new approach to measure the temperature near the contact zone of osteosynthesis screws (fiber-optic sensor in the axis of the screw) was established. Results: The self-drilling screw type induces a splitting force of about 200 N in the surrounding tissue, so that microdamage of the bone and increased resorption can be assumed. Even pre-drilling induces a short-time force into the tissue, which is comparable to the splitting force of the self-tapping screw. The temperature increase in the screw is clearly higher compared to the temperature increase in the surrounding tissue, but no significant difference in temperature between the two screw types could be measured. Based on the measured temperatures of both screw types, the temperature increase in the contact zone is considered critical. Complications during the screwing process caused by the manual tool guidance resulted in numerous breakages of the fiber-optic sensors. Conclusions: The developed methods provide additional insight regarding the thermomechanical load input of self-drilling and self-tapping screws. However, based upon the optical fiber breakages, additional refinement of this technique may still be required.
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