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1.
Sensors (Basel) ; 21(4)2021 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-33669674

RESUMEN

The quantification of plantar pressure distribution is widely done in the diagnosis of lower limbs deformities, gait analysis, footwear design, and sport applications. To date, a number of pressure insole layouts have been proposed, with different configurations according to their applications. The goal of this study is to assess the validity of a 16-sensors (1.5 × 1.5 cm) pressure insole to detect plantar pressure distribution during different tasks in the clinic and sport domains. The data of 39 healthy adults, acquired with a Pedar-X® system (Novel GmbH, Munich, Germany) during walking, weight lifting, and drop landing, were used to simulate the insole. The sensors were distributed by considering the location of the peak pressure on all trials: 4 on the hindfoot, 3 on the midfoot, and 9 on the forefoot. The following variables were computed with both systems and compared by estimating the Root Mean Square Error (RMSE): Peak/Mean Pressure, Ground Reaction Force (GRF), Center of Pressure (COP), the distance between COP and the origin, the Contact Area. The lowest (0.61%) and highest (82.4%) RMSE values were detected during gait on the medial-lateral COP and the GRF, respectively. This approach could be used for testing different layouts on various applications prior to production.


Asunto(s)
Zapatos , Caminata , Adulto , Fenómenos Biomecánicos , Marcha , Alemania , Humanos , Proyectos Piloto , Presión , Dispositivos Electrónicos Vestibles
2.
Sensors (Basel) ; 21(4)2021 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-33670498

RESUMEN

Currently available jaw motion tracking methods require large accessories mounted on a patient and are utilized in controlled environments, for short-time examinations only. In some cases, especially in the evaluation of bruxism, a non-restrictive, 24-h jaw tracking method is needed. Bruxism oriented, electromyography (EMG)-based devices and sensor-enhanced occlusal splints are able to continuously detect masticatory activity but are uninformative in regards to movement trajectories and kinematics. This study explores a possibility to use a permanent magnet and a 3-axial magnetometer to track the mandible's spatial position in relation to the maxilla. An algorithm for determining the sensor's coordinates from magnetic field values was developed, and it was verified via analytical and finite element modeling and by using a 3D positioning system. Coordinates of the cubic test trajectory (a = 10 mm) were determined with root-mean-square error (RMSE) of 0.328±0.005 mm. Possibility for teeth impact detection by accelerometry was verified. Test on a 6 degrees-of-freedom (DOF), hexapod-based jaw motion simulator moving at natural speed confirmed the system's ability to simultaneously detect jaw position and the impacts of teeth. Small size of MEMS sensors is suitable for a wearable intra-oral system that could allow visualization of continuous jaw movement in 3D models and could enable new research on parafunctional jaw activities.


Asunto(s)
Acelerometría , Maxilares , Movimiento , Fenómenos Biomecánicos , Humanos , Fenómenos Magnéticos , Movimiento (Física)
3.
Sensors (Basel) ; 21(4)2021 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-33670561

RESUMEN

Although the external knee adduction moment (KAM) during gait was shown to be a quantitative parameter of medial knee osteoarthritis (OA), it requires expensive equipment and a dedicated large space to measure. Therefore, it becomes a major reason to limit KAM measurement in a clinical environment. The purpose of this study was to estimate KAM using a single inertial measurement unit (IMU) during gait in patients with knee OA. A total of 22 medial knee OA patients (44 knee joints) performed conventional gait analysis using three-dimensional (3D) motion capture system. At the same time, we attached commercial IMUs to six body segments (sternum, pelvis, both thighs, and both shanks), and IMU signals during gait were recorded synchronized with the motion capture system. The peak-to-peak difference of acceleration in the lateral/medial axis immediately after heel contact was defined as the thrust acceleration (TA). We hypothesized that TA would represent the lateral thrust of the knee during the stance phase and correlate with the first peak of KAM. The relationship between the peak KAM and TA of pelvis (R = 0.52, p < 0.001), shanks (R = 0.57, p < 0.001) and thighs (R = 0.49, p = 0.001) showed a significant correlation. The root mean square error (RMSE) of linear regression models of pelvis, shanks, and thighs to estimate KAM were 0.082, 0.079, and 0.084 Nm/(kg·m), respectively. Our newly established parameter TA showed a moderate correlation with conventional KAM. The current study confirmed our hypothesis that a single IMU would predict conventional KAM during gait. Since KAM is known as an indicator for prognosis and severity of knee OA, this new parameter has the potential to become an accessible predictor for medial knee OA instead of KAM.


Asunto(s)
Articulación de la Rodilla , Osteoartritis de la Rodilla , Fenómenos Biomecánicos , Femenino , Marcha , Humanos , Rodilla , Masculino , Osteoartritis de la Rodilla/diagnóstico , Caminata , Dispositivos Electrónicos Vestibles
4.
Fa Yi Xue Za Zhi ; 37(1): 1-6, 2021 Feb.
Artículo en Inglés, Chino | MEDLINE | ID: mdl-33780176

RESUMEN

Abstract: Objective To study the relationship between material mechanics and bone material parameters of rat skulls and their correlation with age by examination of the parameters. Methods Forty-eight healthy male SD rats were divided into 2, 4, 6, 8, 17, 26, 52 and 104 week groups according to their age. Each group had six rats. The right cranium was compressed by KD Ⅱ-0.2 microcomputer controlled electronic universal testing machine, and material mechanics parameters (ultimate load, compression strength and compression modulus) were measured, then the skull slices were cut off and scanned by Micro-CT system to detect bone material parameters (skull thickness, bone mineral density, bone volume, and trabecular thickness). Results The differences in ultimate load, compression strength and compression modulus among all groups had statistical significance (P<0.05), and were positively correlated with age within 26 weeks (P<0.05). The differences in skull thickness, bone mineral density, bone volume and trabecular thickness among all groups had statistical significance (P<0.05), and were positively correlated with age within 52 weeks (P<0.05). All material mechanics parameters were positively correlated with bone material parameters (P<0.05). Conclusion There is a positive correlation between bone material parameters (skull thickness, bone mineral density, bone volume, trabecular thickness), material mechanics parameter (skull ultimate load, compression strength, compression modulus) and age in a certain range, which can be used to infer age.


Asunto(s)
Densidad Ósea , Cráneo , Animales , Fenómenos Biomecánicos , Masculino , Ratas , Ratas Sprague-Dawley , Cráneo/diagnóstico por imagen
5.
Braz J Med Biol Res ; 54(5): e10693, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33729393

RESUMEN

The present study compared the effects of a footwear designed to enhance energy return (thermoplastic polyurethane, TPU) vs minimalist shoes on running economy (RE) and endurance performance. In this counterbalanced and crossover design study, 11 recreational male runners performed two submaximal constant-speed running tests and two 3-km time-trials with the two shoe models. Oxygen uptake was measured during submaximal constant-speed running tests in order to determine the RE at 12 km/h and oxygen cost of running (CTO2) at individual average speed sustained during the 3-km running time-trials wearing either of the two shoes. Our results revealed that RE was improved (2.4%) with TPU shoes compared with minimalist shoes (P=0.01). However, there was no significant difference for CTO2 (P=0.61) and running performance (P=0.52) comparing the TPU (710±60 s) and the minimalist (718±63 s) shoe models. These novel findings demonstrate that shoes with enhanced mechanical energy return (i.e. TPU) produced a lower energy cost of running at low (i.e., 12 km/h) but not at high speeds (i.e., average speed sustained during the 3-km running time-trial, ∼15 km/h), ultimately resulting in similar running performance compared to the minimalist shoe.


Asunto(s)
Carrera , Fenómenos Biomecánicos , Estudios Cruzados , Masculino , Consumo de Oxígeno , Zapatos
6.
Medicine (Baltimore) ; 100(8): e24834, 2021 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-33663103

RESUMEN

ABSTRACT: The influencing factors in closed reduction internal fixation with cannulated screw of femoral neck fractures have not been well investigated. This study evaluated these factors in patients with femoral neck fractures.Fifty-seven patients (36 males and 21 females) diagnosed with femoral neck fracture with the average age of 52.44 ±â€Š15.04 years who underwent closed reduction internal fixation with cannulated screw were included in this study. Data were collected through case report reviews, phone call follow-ups, and outpatient follow-ups to evaluate pre- and postoperative radiograph images. Statistical analysis was performed using Garden classification, binary and multinomial logistic regression analysis by including factors such as patient's age, gender, fracture type, time to fixation, reduction quality, functional recovery period, removal of cannulated screw, and preoperative traction. Logistic regression analysis revealed that age and reduction quality was statistically significant (P < .05) to clinical outcome and other factors were not statistically significant.The main factors affecting clinical outcomes were functional recovery and reduction quality. The biomechanical effects of fixation provide a good foundation for fracture healing. Patient's conditions should be carefully evaluated before selecting reduction procedures to reach an optimal surgical outcome.


Asunto(s)
Reducción Cerrada/métodos , Fracturas del Cuello Femoral/cirugía , Fijación Interna de Fracturas/métodos , Adulto , Factores de Edad , Anciano , Fenómenos Biomecánicos , Tornillos Óseos , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento
7.
J Neuroeng Rehabil ; 18(1): 47, 2021 03 10.
Artículo en Inglés | MEDLINE | ID: mdl-33691710

RESUMEN

BACKGROUND: While walking, people swing their arms in a specific pattern. This specific arm swing pattern during walking has shown to have a beneficial effect on gait as it reduces walking energy cost and optimizes balance. In several patient populations the arm movements can be directly affected (e.g. in patients with acquired brain injury (ABI)), which in turn has a negative effect on their gait pattern, balance and energy cost of walking. MAIN TEXT: In December 2019, Kahn et al. published a paper in JNER concerning the quantification of upper limb associated reactions (ARs) during walking in people with ABI. ARs are defined as "an effort-dependent phenomenon causing an involuntary increase in upper limb muscle tone, with awkward and uncomfortable postures". These upper limb ARs appear often in patients with ABI and can have an important effect on their gait. The authors calculated kinematic measures using three-dimensional gait analysis relating to range of motion, variability and mean position over the gait cycle for the different upper limb joints (shoulder, elbow, wrist) during self-selected steady-state walking. Based on differences they found between an ABI cohort and healthy control cohort, the authors concluded that they were able to quantify ARs during walking in this population. This calculation, however, is not specific for upper limb ARs. In fact, the authors calculated general measures of arm posture (e.g. mean position over the gait cycle) or arm movement (e.g. range of motion and variability) during gait. Previous research has already indicated that other factors than ARs can influence the posture or movement of the arm during gait in patients with brain injury, such as voluntary compensations for gait instability and contractures or spasticity of upper arm muscles. Yet, it is not possible to disentangle the different causes of the altered arm posture during steady-state walking based on the proposed measures. CONCLUSION: The kinematic arm measures proposed by Kahn et al. (J Neuroeng Rehabil 16(1):160, 2019) are not a direct measure of ARs, but provide a quantification of overall deviation of arm posture or movement during gait. Depending on the specific study design these measures may provide insights in ARs.


Asunto(s)
Lesiones Encefálicas , Caminata , Brazo , Fenómenos Biomecánicos , Marcha , Humanos , Movimiento , Extremidad Superior
8.
Niger J Clin Pract ; 24(3): 369-379, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33723111

RESUMEN

Background: Proximal femoral geometry(PFG) plays a role in the biomechanics of the hip. During total hip replacement detailed efforts are made to restore this biomechanics in other to ensure patients satisfaction and implant survival. There are variations in these parameters. Ethnicity is one of the most influential factors accounting for these variations. Aim: To determine the values of the parameters of the proximal femoral geometry among the ethnic Igbos of the South Eastern Nigeria, determine any correlation between these parameters, and compare these values with known populations as well as discuss the clinical application in total hip replacement and other hip surgeries. Materials and Method: Seven hundred and sixteen (716) femoral bones taken from the osteology unit of department of anatomy of University of Nigeria Enugu Campus (UNEC) were screened and proximal femoral parameters measured using Vernier calipers. Results: There were 356 right and 360 left femoral bones with the following values: Femoral Neck Anteversion Angle (FNAVA): M=19.04°, SD=2.075°, Proximal Femoral Length(PFL): M=73.24mm,SD=7.622, Femoral Head Vertical Diameter(FHVD):M= 44.64mm, SD=3.134, Femoral Head Transverse Diameter(FHTD),M=44.55mm, SD=3.379mm, Femoral Head Diameter(FHD),M=44.60mm, SD=3.119mm, Femoral Neck Anterior Length(FNAL), M=31.86mm, SD=5.383mm, Femoral Posterior Neck Length(FPNL):M=22.23mm, SD=3.520mm, Femoral Neck Diameter (FND), M=32.71mm,SD= 3.315mm, Proximal Femoral Width Head to Side (PFWHS), M=89mm.80,SD= 10.331mm, Proximal Femoral Width Side to Side (PFWSS), M=31.47mm, SD=2.812mm, Femoral Neck Shaft Angle(FNSA), M=132.15°, 7.305°. Conclusion: The parameters of the proximal femoral geometry of the ethnic Igbos of the South East of Nigeria, differed from other populations and exhibited laterality.


Asunto(s)
Artroplastia de Reemplazo de Cadera , Fenómenos Biomecánicos , Fémur/diagnóstico por imagen , Fémur/cirugía , Cuello Femoral/cirugía , Humanos , Nigeria
9.
Zhongguo Gu Shang ; 34(2): 126-30, 2021 Feb 25.
Artículo en Chino | MEDLINE | ID: mdl-33665998

RESUMEN

OBJECTIVE: To study mechanism of improvement of stress concentration on patellofemoral joint by stiletto needle releasing lateral patellar retinaculum guided by the theory of Jinshugu() and based on the finite element model of knee joint. and to elucidate the biomechanical mechanism of stiletto needle releasing changing patellar trajectory and reducing patellofemoral joint pressure. METHODS: CT data of knee joint from a normal male (aged 29, heighted 171 cm, weighted 58 kg) was selected. Starting with construction of three-dimensional model of knee joint by using finite element software, the finite element model of knee joint with complete tendonand bone structures were established through several steps, such as geometric reconstruction, reverse engineering, meshing, material assignment and loading analysis. The loading condition was set as 500 N load on knee joint, and the average tensile stress of quadriceps femoris tendon was about 200 N. To simulate the release of lateral patellar retinaculum by stiletto needle at 30 and 90 position of knee flexion in finite element model separately, and to compare the improvement of stress concentration of patellofemoral joint by stiletto needle intervention under different knee flexion conditions. RESULTS: The peak stress of patellofemoral joint and tibiofemoral joint decreased after stiletto needle releasing of patellofemoral lateral retinaculum compared with before intervention, which was(1) knee flexion at 30 degrees:patellar cartilage decreased by 0.498 MPa (decreased 9.06%), femoral trochlea decreased by 0.886 MPa(decreased 16.27%);(2) knee flexion at 90 degrees:patellar cartilage decreased by 0.558 MPa (decreased 8.6%), femoral trochlea decreasedby 0.607 MPa (decreased 9.94%). CONCLUSION: Releasing lateral patellofemoral retinaculum with stiletto needle could effectively alleviate the stress concentration of patellofemoral joint and reduce local stress peak value, which it is helpful to improve patellar trajectory and make stress distribution more uniform.


Asunto(s)
Articulación Patelofemoral , Adulto , Fenómenos Biomecánicos , Análisis de Elementos Finitos , Humanos , Articulación de la Rodilla , Masculino , Rótula , Músculo Cuádriceps , Rango del Movimiento Articular
10.
Zhongguo Gu Shang ; 34(2): 191-4, 2021 Feb 25.
Artículo en Chino | MEDLINE | ID: mdl-33666010

RESUMEN

Femorotibial mechanical axis (FTMA) is one of important factors influencing clinical effect after total knee arthroplasty (TKA). It is generally believed that the range of lower limb alignment after TKA is controlled within neutral FTMA ± 3 °, which has more advantages in improving joint function, prolonging prosthesis survival rate and reducing revision rate, and obtain better clinical results. Therefore, neutral FTMA is also considered to be the gold standard for TKA. However, with the application of computer-assisted surgery and other technologies, the alignment of FTMA is more accurate than before, but the clinical effect after surgery has not significantly improved. Some scholars have begun to question the necessity of neutral alignment of FTMA, and proposed alignment methods such as kinematics and retained residual deformity, which could achieve better clinical effects. In recent years, it has been reported that FTMA might not be the most important factor influencing postoperative clinical effects, and it is suggested that the arrangement and measurement of lower limbs and the effects on adjacent joint functions could affect clinical effect after TKA. The paper reviews neutral FTMA alignment is still an important factor for success of TKA. After a thorough evaluation according to the patient's condition, it should be appropriately applied in the case of neutral FTMA alignment; the operator should explore other factors which affect clinical outcome after TKA, and improve it to achieve the best therapeutic effect.


Asunto(s)
Artroplastia de Reemplazo de Rodilla , Prótesis de la Rodilla , Osteoartritis de la Rodilla , Cirugía Asistida por Computador , Fenómenos Biomecánicos , Humanos , Articulación de la Rodilla/cirugía , Extremidad Inferior , Osteoartritis de la Rodilla/cirugía , Falla de Prótesis
11.
Zhongguo Gu Shang ; 34(1): 26-33, 2021 Jan 25.
Artículo en Chino | MEDLINE | ID: mdl-33666016

RESUMEN

OBJECTIVE: To establish a three-dimensional finite element model of osteoporosis and to study the stiffness recovery of injured vertebrae and stress analysis of adjacent vertebrae after percutaneous vertebroplasty under different perfusion and distribution conditions by simulating fluid flow into the vertebral body. METHODS: A male healthy volunteer was selected. CT scans were performed from T11 to L2. Mimics 15.0 and ABAQUS 6.11 software were used to extract CT images. The vertebral model of osteoporotic fracture was established. The flow physical field and conduction and diffusion physical field were coupled to simulate the process and parts of the injection of bone cement into the vertebral fracture model. The amount of bone cement injected into the vertebral fracture model was 2 ml, 4 ml, 6 ml respectively. The diffusion range of bone cement was simulated on the image, and the post injection model of bone cement was obtained. Vertical downward, forward and backward pressure of 300 N were applied on the surface of the model to simulate vertebral movement. The stress changes of upper and lower vertebrae and diseased vertebrae under different conditions were calculated. RESULTS: (1) The VonMises stress of T12 inferior endplate was the largest in the three states before and after fracture.(2) The VonMises stress of the intervertebral disc and each endplate after fracture was significantly higher than before fracture. When percutaneous vertebroplasty was applied, as the amount of bone cement injection increases, the VonMises stress of the adjacent vertebral endplates increases. In the diseased vertebrae, as the amount of bone cement increases, the VonMises stress of the vertebral body endplate showed a downward trend. CONCLUSION: Reliable biomechanical model of lumbar vertebral fracture can be established by using CT scanning data through software simulation. Vertebral fracture and vertebroplasty will cause biomechanical changes of adjacent vertebral bodies. With the increase of bone cement injection, the influence of biomechanical changes will increase significantly. Neighbouring vertebral fractures are more likely. For this experiment, percutaneous vertebroplasty has a suitable amount of cement injection of 4 ml.


Asunto(s)
Fracturas por Compresión , Fracturas Osteoporóticas , Fracturas de la Columna Vertebral , Vertebroplastia , Fenómenos Biomecánicos , Cementos para Huesos , Análisis de Elementos Finitos , Fracturas por Compresión/cirugía , Humanos , Vértebras Lumbares/cirugía , Masculino , Fracturas Osteoporóticas/cirugía , Fracturas de la Columna Vertebral/cirugía
12.
Zhongguo Gu Shang ; 34(1): 40-4, 2021 Jan 25.
Artículo en Chino | MEDLINE | ID: mdl-33666018

RESUMEN

OBJECTIVE: To investigate the biomechanical affect of percutaneous transforaminal endoscopic discectomy(PTED) on adjacent segments with different degrees of degeneration and related risk of adjacent segment diseases (ASD) caused by this operation. METHODS: A healthy male adult volunteer was selected, and the lumbosacral vertebra image data was obtained by CT scan, and the external contour of the bone structure was reconstructed. On this basis, the external contour of the bone structure was fitted by using the smooth curve in 3D-CAD software, and the complete three-dimensional finite element modelof the non degenerate L3-S1 segment and the degenerative models of the L3-L4 and L5-S1 segment were drawn forward. In L4, L5 segment simulating PTED surgery through the removal of right part of articular process and nucleus pulposus and anulus fibrosus. After PTED was simulated in the L4-L5 segment and the risk of ASD has been evaluated by six changes of biomechanical indicators in flexion, extension, left and right lateral bending, left and right axial rotation conditions. RESULTS: In the finite element model without adjacent segmental disc degeneration, the annulus fibrosus von Mises stress and intradiscal pressure of the PTED model showed only a slight increase under most stress conditions, and a slight decrease in a few conditions, and there was no significant change trend before and after surgery. In the original degenerated adjacent segment disc model, the biomechanical indicators related to disc degeneration in the pre- and post-PTED model showed significant deterioration, leading to an increased risk of potential adjacent spondylopathy. CONCLUSION: PTED surgery will not lead to the significant deterioration of postoperative biomechanical environment of non-degeneration adjacent intervertebral discs, and the original degeneration of adjacent intervertebral discs is a important risk factor for ASD.


Asunto(s)
Discectomía Percutánea , Degeneración del Disco Intervertebral , Disco Intervertebral , Adulto , Fenómenos Biomecánicos , Análisis de Elementos Finitos , Humanos , Disco Intervertebral/cirugía , Degeneración del Disco Intervertebral/cirugía , Vértebras Lumbares/cirugía , Masculino , Rango del Movimiento Articular
13.
Med Probl Perform Art ; 36(1): 18-26, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33647093

RESUMEN

OBJECTIVE: Altered ground reaction force (GRF) and joint torsional stiffness are associated with various lower extremity injuries, but these have yet to be examined in dancers with flexor hallucis longus (FHL) tendinopathy. Additionally, a simple, field-friendly kinematic correlate to ground contact kinetics would be useful for clinical application. The purpose of this study was to compare lower extremity biomechanics during takeoff of a dance leap (saut de chat) in dancers with and without FHL tendinopathy, and to examine lower limb posture at initial contact as a clinical correlate of injury-related kinetic factors. METHODS: Motion capture and inverse dynamics were used to analyze saut de chat takeoff performed by 11 uninjured dancers and 8 dancers with FHL tendinopathy. GRF parameters, joint torsional stiffness of the metatarsophalangeal, ankle, and knee joints, and lower extremity posture at initial contact were compared between groups using Welch's t-tests. RESULTS: Dancers with FHL tendinopathy maintained similar jump height as the uninjured dancers, but exhibited lower peak vertical GRF, longer time to peak force, and less joint torsional stiffness at the metatarsophalangeal, ankle, and knee joints during loading response of the takeoff step. Lower extremity contact angle was smaller and the horizontal distance between center-of-mass and center-of-pressure was greater in dancers with FHL tendinopathy. These two measures of lower limb posture at initial contact were significantly correlated with kinetic factors occurring later in ground contact (R2=0.29-0.51). CONCLUSION: Dancers with FHL tendinopathy demonstrated altered lower extremity kinetics during takeoff of a leap compared to uninjured dancers, which may contribute to, or be a compensation response to, injury.


Asunto(s)
Baile , Tendinopatía , Articulación del Tobillo , Fenómenos Biomecánicos , Pie , Humanos , Extremidad Inferior
14.
Med Probl Perform Art ; 36(1): 45-53, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33647097

RESUMEN

BACKGROUND: Dancing requires a high range of motion in the foot as well as a good shock-absorbing system formed by the foot and ankle joints. Although there is a broad consensus in dance that excessive calcaneal eversion can cause injury and should be avoided, calcaneal eversion is discussed controversially in the dance literature. An increased research focus on the biomechanics of dance, particularly research pertaining to the foot and ankle joints, might help to resolve this controversy. OBJECTIVES: The study's main purpose was to generate hitherto lacking kinematic data of calcaneal eversion in a dancer's demi-plié. METHODS: Thirty-two contemporary dancers performed three trials in two different conditions: demi-plié in parallel and in turned-out positions. The motion capture system FASTRAK was used to measure calcaneal eversion and foot and lower leg alignment during demi-plié. RESULTS: Maximal calcaneal eversion in turned-out demi-pliés was 3.36°±4° and total range of motion (i.e., maximal minus minimal angle) of calcaneal eversion was 3.73°±1.42°, where the large standard deviations indicate substantial variability across participants. Calcaneal eversion was significantly different between turned-out (3.36°±4°) and parallel (1.17°±4.06°) demi-pliés, as was the alignment of the lower leg and foot, where the lower leg tracked more medially relative to the foot during turned-out pliés. Crucially, both the magnitude of calcaneal eversion and its temporal coupling with ankle dorsiflexion were highly variable across participants. CONCLUSIONS: Average calcaneal eversion is a poor indicator of the role calcaneal eversion plays in the demi-plié of contemporary dancers. Rather, the temporal coupling between calcaneal eversion and ankle dorsiflexion needs to be considered.


Asunto(s)
Tobillo , Baile , Articulación del Tobillo , Fenómenos Biomecánicos , Humanos , Pierna , Rango del Movimiento Articular
15.
Am J Vet Res ; 82(4): 292-301, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33764831

RESUMEN

OBJECTIVE: To assess the effect of horseshoes with and without traction adaptations on the gait kinetics of nonlame horses during a trot on a concrete runway. ANIMALS: 5 nonlame adult light-breed horses. PROCEDURES: Kinetic data were obtained for each horse when it was trotted across a force platform within a concrete runway unshod (control) and shod with standard horseshoes; standard horseshoes with high profile-low surface area calks, with low profile-high surface area calks, and coated with a thin layer of tungsten carbide (TLTC); and plastic-steel composite (PSC) horseshoes. Kinetic data were obtained for the control treatment first, then for each of the 5 shoe types, which were applied to each horse in a random order. Kinetic variables were compared among the 6 treatments. RESULTS: Body weight distribution did not differ among the 6 treatments. Compared with the control, the greatest increase in forelimb peak vertical force was observed when horses were shod with PSC shoes. In the hind limbs, the greatest increase in peak braking force was observed when horses were shod with PSC shoes, followed by the TLTC and low profile-high surface area calked shoes. The PSC shoes yielded the greatest coefficient of friction in both the forelimbs and hind limbs. Stance time was longest when horses were shod with standard shoes. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that PSC and TLTC shoes provided the best hoof protection and traction and might be good options for horses that spend a large amount of time traversing paved surfaces.


Asunto(s)
Pezuñas y Garras , Tracción , Animales , Fenómenos Biomecánicos , Miembro Anterior , Marcha , Caballos , Cinética , Zapatos , Tracción/veterinaria
16.
Am J Vet Res ; 82(4): 302-309, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33764835

RESUMEN

OBJECTIVE: To evaluate the effect of a continuous locking novel epitendinous suture (nES) pattern with and without a core locking-loop (LL) suture on the biomechanical properties of ex vivo canine superficial digital flexor tendon (SDFT) tenorrhaphy constructs. SAMPLE: 54 cadaveric forelimb SDFTs from 27 musculoskeletally normal adult dogs. PROCEDURES: Tendons were assigned to 3 groups (18 SDFTs/group): sharply transected and repaired with a core LL suture alone (group 1), an nES pattern alone (group 2), or a combination of a core LL suture and nES pattern (group 3). All constructs underwent a single load-to-failure test. Yield, peak, and failure loads; gap formation incidence; and mode of failure were compared among the 3 groups. RESULTS: Mean yield, peak, and failure loads differed significantly among the 3 groups and were greatest for group 3 and lowest for group 1. Mean yield, peak, and failure loads for group 3 constructs were greater than those for group 1 constructs by 50%, 47%, and 44%, respectively. None of the group 3 constructs developed 3-mm gaps. The most common mode of failure was suture pulling through the tendon for groups 1 (12/18) and 2 (12/18) and suture breakage for group 3 (13/18). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested augmentation of a core LL suture with an nES pattern significantly increased the strength of and prevented 3-mm gap formation at the tenorrhaphy site in ex vivo canine SDFTs. In vivo studies are necessary to assess the effectiveness and practicality of the nES pattern for SDFT repair in dogs.


Asunto(s)
Enfermedades de los Perros , Laceraciones , Traumatismos de los Tendones , Animales , Fenómenos Biomecánicos , Cadáver , Perros , Laceraciones/cirugía , Laceraciones/veterinaria , Técnicas de Sutura/veterinaria , Suturas/veterinaria , Traumatismos de los Tendones/cirugía , Traumatismos de los Tendones/veterinaria , Tendones/cirugía , Resistencia a la Tracción
17.
Acta Chir Orthop Traumatol Cech ; 88(1): 39-44, 2021.
Artículo en Checo | MEDLINE | ID: mdl-33764866

RESUMEN

PURPOSE OF THE STUDY Knee injuries accompanied by anterior cruciate ligament (ACL) tears can also result in rotational instability of the joint. Subsequent insufficient rotational stability after the ACL reconstruction can be a direct consequence also of injuries to lateral knee structures, specifically the anterolateral ligament (ALL). This residual postoperative rotational instability may be prevented by multiple surgical techniques. The purpose of this study was (1) to evaluate the knee stability in internal rotation after the "anatomical" single-bundle (SB) anterior cruciate ligament reconstruction together with ALL reconstruction compared to the double-bundle (DB) ACL reconstruction two years after surgery; (2) to compare the knee joint stability after the ACL and ALL reconstruction with the healthy contralateral knee joint. MATERIAL AND METHODS All the measurements were conducted by the computer navigation system. The study included 20 patients after the single-bundle ACL and ALL reconstruction and 20 patients after the double-bundle ACL reconstruction. The follow-up examination was carried out at 25 months after surgery on average (24 months at least). All measurements were performed in both the healthy and operated knee. Once the data necessary for navigation were determined, the patient remained in standing position with both feet firmly placed on the mat with intermalleolar distance of 20 cm. Then, at 30-degree flexion of the knee joints, the patient first performed the joint internal rotation by trunk torsion, followed by external rotation. Each measurement was repeated 3 times. A non-parametric t-test was used for statistical processing. RESULTS The mean internal rotation in the injured knee joint was 19.1 degrees preoperatively and 8.1 degrees postoperatively, while in the healthy knee it was 8.4 degrees. External rotation was not assessed. The reported internal rotation in the knees after DB ACL reconstruction was 9.2 degrees (p ≥ 0.05). DISCUSSION The double-bundle ACL reconstruction is a complex technique that can lead to many intraoperative and postoperative complications. Grafts harvested from both hamstrings can have an effect on the rotational stability of the joint. In order to restore the knee rotational stability with fewer potential complications, the method of choice can be the ACL reconstruction using the quadriceps femoris muscle graft and the ALL reconstruction using the gracilis muscle graft, leaving the semitendinosus tendon intact. CONCLUSIONS The obtained values reveal that the single-bundle ACL reconstruction in combination with ALL reconstruction results in the same internal rotational stability in the knee joint as the double-bundle ACL reconstruction. Similar joint rotational stability is observed in all the knee joints reconstructed with the use of these techniques and in the contralateral healthy knee joint. Key words: anterolateral ligament, anterior cruciate ligament, internal rotational stability, objective measurement.


Asunto(s)
Lesiones del Ligamento Cruzado Anterior , Reconstrucción del Ligamento Cruzado Anterior , Inestabilidad de la Articulación , Lesiones del Ligamento Cruzado Anterior/cirugía , Fenómenos Biomecánicos , Cadáver , Humanos , Inestabilidad de la Articulación/etiología , Inestabilidad de la Articulación/cirugía , Articulación de la Rodilla/cirugía , Rango del Movimiento Articular
18.
Sensors (Basel) ; 21(4)2021 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-33671497

RESUMEN

Fatigue increases the risk of injury during sports training and rehabilitation. Early detection of fatigue during exercises would help adapt the training in order to prevent over-training and injury. This study lays the foundation for a data-driven model to automatically predict the onset of fatigue and quantify consequent fatigue changes using a force plate (FP) or inertial measurement units (IMUs). The force plate and body-worn IMUs were used to capture movements associated with exercises (squats, high knee jacks, and corkscrew toe-touch) to estimate participant-specific fatigue levels in a continuous fashion using random forest (RF) regression and convolutional neural network (CNN) based regression models. Analysis of unseen data showed high correlation (up to 89%, 93%, and 94% for the squat, jack, and corkscrew exercises, respectively) between the predicted fatigue levels and self-reported fatigue levels. Predictions using force plate data achieved similar performance as those with IMU data; the best results in both cases were achieved with a convolutional neural network. The displacement of the center of pressure (COP) was found to be correlated with fatigue compared to other commonly used features of the force plate. Bland-Altman analysis also confirmed that the predicted fatigue levels were close to the true values. These results contribute to the field of human motion recognition by proposing a deep neural network model that can detect fairly small changes of motion data in a continuous process and quantify the movement. Based on the successful findings with three different exercises, the general nature of the methodology is potentially applicable to a variety of other forms of exercises, thereby contributing to the future adaptation of exercise programs and prevention of over-training and injury as a result of excessive fatigue.


Asunto(s)
Ejercicio Físico , Dispositivos Electrónicos Vestibles , Fenómenos Biomecánicos , Fatiga/diagnóstico , Femenino , Humanos , Masculino , Movimiento (Física)
19.
Sensors (Basel) ; 21(4)2021 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-33672353

RESUMEN

Vertical ground reaction force (vGRF) can be measured by force plates or instrumented treadmills, but their application is limited to indoor environments. Insoles remove this restriction but suffer from low durability (several hundred hours). Therefore, interest in the indirect estimation of vGRF using inertial measurement units and machine learning techniques has increased. This paper presents a methodology for indirectly estimating vGRF and other features used in gait analysis from measurements of a wearable GPS-aided inertial navigation system (INS/GPS) device. A set of 27 features was extracted from the INS/GPS data. Feature analysis showed that six of these features suffice to provide precise estimates of 11 different gait parameters. Bagged ensembles of regression trees were then trained and used for predicting gait parameters for a dataset from the test subject from whom the training data were collected and for a dataset from a subject for whom no training data were available. The prediction accuracies for the latter were significantly worse than for the first subject but still sufficiently good. K-nearest neighbor (KNN) and long short-term memory (LSTM) neural networks were then used for predicting vGRF and ground contact times. The KNN yielded a lower normalized root mean square error than the neural network for vGRF predictions but cannot detect new patterns in force curves.


Asunto(s)
Marcha , Aprendizaje Automático , Caminata , Fenómenos Biomecánicos , Zapatos
20.
Sensors (Basel) ; 21(4)2021 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-33672802

RESUMEN

This study investigated the whole-body coordination patterning in successful and faulty spikes using self-organising map-based cluster analysis. Ten young, elite volleyball players (aged 15.5 ± 0.7 years) performed 60 volleyball spikes in a real-game environment. Adopting the cluster analysis, based on a self-organising map, whole-body coordination patterning was explored between successful and faulty spikes of individual players. The self-organising maps (SOMs) portrayed whole body, lower and upper limb coordination dissimilarities during the jump phase and the ball impact phases between the successful and faulty spikes. The cluster analysis illustrated that the whole body, upper limb and lower limb coordination patterning of each individual's successful spikes were similar to their faulty spikes. Range of motion patterning also demonstrated no differences in kinematics between spike outcomes. Further, the upper limb angular velocity patterning of the players' successful/faulty spikes were similar. The SPM analysis portrayed significant differences between the normalized upper limb angular velocities from 35% to 45% and from 76% to 100% of the spike movement. Although the lower limb angular velocities are vital for achieving higher jumps in volleyball spikes, the results of this study portrayed that the upper limb angular velocities distinguish the differences between successful and faulty spikes among the attackers. This confirms the fact that volleyball coaches should shift their focus toward the upper limb velocity and coordination training for higher success rates in spiking for volleyball attackers.


Asunto(s)
Rendimiento Atlético , Voleibol , Adolescente , Fenómenos Biomecánicos , Análisis por Conglomerados , Humanos , Extremidad Inferior , Movimiento , Rango del Movimiento Articular
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