Abstract Obesity is a known risk factor for development of osteoarthritis (OA). Numerical tools like finite‐element (FE) models combined with degenerative algorithms have been developed to understand ...the interplay between OA and obesity. In this study, we aimed to predict knee cartilage degeneration in a cohort of obese adults to investigate the importance of patient‐specific information on degeneration predictions. We used a validated FE modeling approach and three different age‐dependent functions (step‐wise, exponential, and linear) to simulate cartilage degradation under overloading in the knee joint. Gait motion analysis and magnetic resonance imaging data from 115 obese individuals with knee OA were used for musculoskeletal and FE modeling. Cartilage degeneration predictions were contrasted with Kellgren–Lawrence (KL) and Boston–Leeds Osteoarthritis Knee Score (BLOKS) grades. The findings show that overall, the similarities between numerical predictions and clinical measures were better for the medial (average area under the curve (AUC) = 0.62) compared to the lateral compartment (average AUC = 0.52) of the knee. Classification results for KL grades, full patient‐specific models and patient‐specific geometry with generic gait data showed higher AUC values (AUC = 0.71 and AUC = 0.68, respectively) compared to generic geometry and patient‐specific gait (AUC = 0.48). For BLOKS grades, AUC values for both full patient‐specific models and for patient‐specific geometry with generic gait locomotion were higher (AUC = 0.66 and AUC = 0.64, respectively) compared to when the generic geometry and patient‐specific gait were used (AUC = 0.53). In summary, our study highlights the importance of considering individual information in knee OA prediction. Nevertheless, our findings suggest that personalized gait play a smaller role in the OA prediction and classification capacity than personalized joint geometry.
Skeletal muscle function can be affected by multiple disorders in dogs of which cranial cruciate ligament rupture or disease (CCLD) is one of the most common. Despite the significance of this ...condition only sparse research exists regarding assessment of muscle function in dogs. This scoping review aimed to identify the non-invasive methods for canine muscle function assessments that have been reported in the literature in the past 10 years. A systematic literature search was conducted 1
March 2022 across six databases. After screening, 139 studies were considered eligible for inclusion. Among the included studies, 18 different muscle function assessment categories were identified, and the most frequently reported disease state was CCLD. We included an attempt to elucidate the clinical applicability of the 18 reported methods, as experts were asked to subjectively assess the methods for their clinical relevance as well as their practical applicability in dogs with CCLD.
The present study investigated the feasibility and reliability of continuous relative phase (CRP) and deviation phase (DP) to assess intersegmental hind limb coordination pattern and coordination ...variability in rats during walking. Twenty-six adult rats walked at 8 m/min, 12 m/min and 16 m/min while two-dimensional kinematics were recorded. Segment angles and segment angular velocities of the paw, shank and thigh on the left hind-limb were extracted from 15 strides and CRP was calculated for the paw-shank and shank-thigh coupling. The effect of walking speed on the time point average curve of the CRP (ACRP) and DP and on the mean ACRP and mean DP was established by statistical parametric mapping (SPM) and a one-way ANOVA for repeated measures. Absolute and relative reliability were assessed by measurement error and intra-class correlation coefficient. The SPM analysis revealed time dependent differences in the effect of speed. Thus, the CRP of the paw-shank coupling decreased with increasing speed during most of the gait cycle while the CRP of the shank-thigh coupling was decreased during the swing phase. The session-to-session reliability was fair to good for the coordination measure and poor for the variability measure.
The human locomotor system is flexible and enables humans to move without falling even under less than optimal conditions. Walking with high-heeled shoes constitutes an unstable condition and here we ...ask how the nervous system controls the ankle joint in this situation? We investigated the movement behavior of high-heeled and barefooted walking in eleven female subjects. The movement variability was quantified by calculation of approximate entropy (ApEn) in the ankle joint angle and the standard deviation (SD) of the stride time intervals. Electromyography (EMG) of the soleus (SO) and tibialis anterior (TA) muscles and the soleus Hoffmann (H-) reflex were measured at 4.0 km/h on a motor driven treadmill to reveal the underlying motor strategies in each walking condition. The ApEn of the ankle joint angle was significantly higher (p<0.01) during high-heeled (0.38±0.08) than during barefooted walking (0.28±0.07). During high-heeled walking, coactivation between the SO and TA muscles increased towards heel strike and the H-reflex was significantly increased in terminal swing by 40% (p<0.01). These observations show that high-heeled walking is characterized by a more complex and less predictable pattern than barefooted walking. Increased coactivation about the ankle joint together with increased excitability of the SO H-reflex in terminal swing phase indicates that the motor strategy was changed during high-heeled walking. Although, the participants were young, healthy and accustomed to high-heeled walking the results demonstrate that that walking on high-heels needs to be controlled differently from barefooted walking. We suggest that the higher variability reflects an adjusted neural strategy of the nervous system to control the ankle joint during high-heeled walking.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
1 Clinical Motor Function Laboratory, Parker Institute, Frederiksberg Hospital, Frederiksberg; 2 Institute of Medical Anatomy Section C, Panum Institute, University of Copenhagen, Copenhagen N; and 3 ...Center for Sensory-Motor Interaction, Laboratory for Experimental Pain Research, Aalborg University, Aalborg East, Denmark
Submitted 2 October 2006
; accepted in final form 7 April 2007
Pain is a cardinal symptom in musculoskeletal diseases involving the knee joint, and aberrant movement patterns and motor control strategies are often present in these patients. However, the underlying neuromuscular mechanisms linking pain to movement and motor control are unclear. To investigate the functional significance of muscle pain on knee joint control during walking, three-dimensional gait analyses were performed before, during, and after experimentally induced muscle pain by means of intramuscular injections of hypertonic saline (5.8%) into vastus medialis (VM) muscle of 20 healthy subjects. Isotonic saline (0.9%) was used as control. Surface electromyography (EMG) recordings of VM, vastus lateralis (VL), biceps femoris, and semitendinosus muscles were synchronized with the gait analyses. During experimental muscle pain, the loading response phase peak knee extensor moments were attenuated, and EMG activity in the VM and VL muscles was reduced. Compressive forces, adduction moments, knee joint kinematics, and hamstring EMG activity were unaffected by pain. Interestingly, the observed changes persisted when the pain had vanished. The results demonstrate that muscle pain modulated the function of the quadriceps muscle, resulting in impaired knee joint control and joint instability during walking. The changes are similar to those observed in patients with knee pain. The loss of joint control during and after pain may leave the knee joint prone to injury and potentially participate in the chronicity of musculoskeletal problems, and it may have clinically important implications for rehabilitation and training of patients with knee pain of musculoskeletal origin.
experimental muscle pain; motor function; motor control; gait
Address for reprint requests and other correspondence: M. Henriksen, The Clinical Motor Function Laboratory, The Parker Institute, Frederiksberg Hospital, Ndr. Fasanvej 57, DK 2000 Frederiksberg, Denmark (e-mail: marius.henriksen{at}frh.regionh.dk )
Joint loading may affect the development of osteoarthritis, but patient-specific load estimation requires cumbersome motion laboratory equipment. This reliance could be eliminated using artificial ...neural networks (ANNs) to predict loading from simple input predictors. We used subject-specific musculoskeletal simulations to estimate knee joint contact forces for 290 subjects during over 5000 stance phases of walking and then extracted compartmental and total joint loading maxima from the first and second peaks of the stance phase. We then trained ANN models to predict the loading maxima from predictors that can be measured without motion laboratory equipment (subject mass, height, age, gender, knee abduction-adduction angle, and walking speed). When compared to the target data, our trained models had NRMSEs (RMSEs normalized to the mean of the response variable) between 0.14 and 0.42 and Pearson correlation coefficients between 0.42 and 0.84. The loading maxima were predicted most accurately using the models trained with all predictors. We demonstrated that prediction of knee joint loading maxima may be possible without laboratory-measured motion capture data. This is a promising step in facilitating knee joint loading predictions in simple environments, such as a physician’s appointment. In future, the rapid measurement and analysis setup could be utilized to guide patients in rehabilitation to slow development of joint disorders, such as osteoarthritis.
In rehabilitation, four single‐leg hop tests are frequently used for evaluation of ACL‐injured children. However, reference values on single‐leg hop performance and the corresponding limb symmetry ...indexes (LSIs) of healthy children younger than 15 years of age are lacking. Thus, the purpose was to describe hop performance and LSIs in healthy Danish children, and to quantify the proportion of participants passing LSI values of ≥85% as well as ≥90%. Healthy children aged 9–15 years were invited to participate in the study. Hop performance (single hop, 6‐m timed hop, triple hop, and cross‐over hop) was assessed for each leg for each hop test and expressed as absolute, normalized (to body height), and LSI values. Descriptive statistics were applied to calculate mean ±SD for all outcomes within age and gender groups. Further, the 95% reference interval was calculated for each age and gender group. A total of 531 healthy children (52% girls) were included in the study, representing seven age groups (9‐15 years). The LSI group means across all participants for the four hop tests ranged between 84 and 95%. Between 70 and 83% of the children had an LSI of ≥85%, while 50 to 65% of the children had an LSI of ≥90%. The present reference material can be used in clinical practice when evaluating hop performance in pediatric ACL patients.
To study differences in gait patterns in 10-year-old children with Generalized Joint Hypermobility (GJH) and with no GJH (NGJH).
A total of 37 children participated (19 GJH, 18 NGJH, mean age 10.2 ...(SD 0.5) years). Inclusion criteria for GJH were a Beighton score of ≥5, with at least one hypermobile knee joint; for NGJH a Beighton score of ≤4, and no hypermobile knees and for both groups no knee pain during the previous week. All children were recorded by five video cameras, while they walked across three force platforms. Net joint moments were calculated in 3D by inverse dynamics and peak values provided input to statistical analyses.
In the frontal plane, children with GJH had a significantly lower peak knee abductor moment and peak hip abductor moment. In the sagittal plane, the peak knee flexor moment and the peak hip extensor moment were significantly lower in the GJH group although the absolute difference was small.
The walking pattern was the same for children with GJH and for healthy children, as there were no differences in kinematics, but it was, however, performed with different kinetics. Children with GJH walked with lower ankle, knee and hip joint moments compared to children with NGJH. However, the clinical importance of these differences during normal gait is unknown. To obtain this knowledge, children with GJH must be followed longitudinally.
The study was approved by the Committee on Biomedical Research Ethics for Copenhagen and Frederiksberg, Denmark (jnr. KF01-2006-178).
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This study examined the effects of 4 weeks of intensive drop jump training in well‐trained athletes on jumping performance and underlying changes in biomechanics and neuromuscular adaptations. Nine ...well‐trained athletes at high national competition level within sprinting and jumping disciplines participated in the study. The training was supervised and augmented feedback on performance was used to ensure maximal training intensity. The drop jumps were performed with minimal contact time and maximal jumping height. Assessment of performance during training showed effects of motor learning. Before and after the training intervention maximal isometric muscle strength, the biomechanics, muscle activity pattern of the lower extremities and the soleus H‐reflex and V‐wave during drop jumping were measured. Maximal jump height and performance index (PI) defined as jumping height divided by contact time improved significantly by 11.9% (P = 0.024) and 16.2% (P = 0.009), respectively. Combined ankle and knee joint peak power was significantly increased by 7% after training (P = 0.047). The preactivity in the soleus muscle decreased 16% (P = 0.015). The soleus H‐reflex was unchanged after training, while the soleus V‐wave increased significantly at 45 msec after touchdown. This may indicate an increased drive to the α‐motor neuron pool following training. Muscle strength parameters were unaffected by the training. The results demonstrate that 4 weeks of intensive drop jump training can improve jumping performance also in well‐trained athletes without concomitant changes in muscle strength. It is suggested that the behavioral improvement is primarily due to neural factors regulating the activation pattern controlling the drop jump movement.
e00099
This manuscript reports results from a study on the effects of 4 weeks of intensive drop jump training in well‐trained athletes. The overall conclusion was that drop jump performance increased significantly after training and that this behavioral improvement is primarily due to neural factors.
Aim
To test whether wearable textile electromyography (EMG) recording systems may detect differences in muscle activity levels during daily activities between children with cerebral palsy (CP) and ...age‐matched typically developing children.
Method
Wearable textile EMG recording systems were used to obtain leg muscle activity in 10 children with spastic CP (four females, six males; mean age 9y 6mo, standard deviation SD 2y 4mo, range: 6–13y; Gross Motor Function Classification System GMFCS level I and II) and 11 typically developing children (four females, seven males; mean age 9y 9mo, SD 1y 11mo, 7–12y) at rest and while performing seven daily activities.
Results
Children with CP showed significantly lower absolute EMG levels during maximal voluntary contractions (MVCs) of muscles on the most affected side as compared to the least affected side and to typically developing children. None of the typically developing children or children with CP showed detectable EMG activity in resting situations. EMG activity relative to MVC was greater in children with CP during walking, jumping, and kicking on the most affected side as compared to the least affected side and to typically developing children.
Interpretation
Wearable textile EMG recording systems may be used to determine differences in muscle activity during daily activities in children with CP. Children with CP showed reduced muscle activity during daily activities compared to their peers, but used a significantly larger part of their maximal voluntary muscle strength to perform these activities.
What this paper adds
Wearable textile electromyography (EMG) systems are feasible for measurement of daily muscle activity in children with cerebral palsy (CP).
Children with CP showed reduced EMG levels during maximal voluntary contractions.
Neither typically developing children or children with CP showed EMG activity in resting situations.
Children with CP used a larger part of their voluntary muscle strength during daily activities.
Resumen
Grabaciones de electromiografía portátil durante las actividades de la vida diaria en niños con parálisis cerebral
Objetivo
Probar si los sistemas de registro de electromiografía textil portátil (EMG) pueden detectar diferencias en los niveles de actividad muscular durante las actividades diarias entre los niños con parálisis cerebral (PC) y los niños de desarrollo típico de la misma edad.
Método
Se utilizaron sistemas de registro de EMG textiles portátiles para obtener actividad muscular de las piernas en 10 niños con PC espástica (cuatro mujeres, seis varones; edad media 9 años y 6 meses, desviación estándar ED 2 años y 4 meses, rango: 6‐13 años; Escala de clasificación de función motora gruesa GMFCS nivel I y II) y 11 niños típicamente en desarrollo (cuatro mujeres, siete varones; edad media 9 años y 9 meses, DE 1 años y 11 meses, 7–12 años) en reposo y mientras realizan siete actividades diarias.
Resultados
Los niños con PC mostraron niveles de EMG absolutos significativamente más bajos durante las contracciones voluntarias máximas (CVM) de los músculos en el lado más afectado en comparación con el lado menos afectado y en los niños con desarrollo típico. Ninguno de los niños con desarrollo típico o niños con PC mostró actividad EMG detectable en situaciones de reposo. La actividad EMG en relación con CVM fue mayor en niños con PC al caminar, saltar y patear en el lado más afectado en comparación con el lado menos afectado y en los niños con desarrollo típico.
Interpretación
Los sistemas de registro de EMG textiles portátiles pueden usarse para determinar las diferencias en la actividad muscular durante las actividades diarias en niños con PC. Los niños con PC mostraron una actividad muscular reducida durante las actividades diarias en comparación con sus compañeros, pero utilizaron una parte significativamente mayor de su fuerza muscular voluntaria máxima para realizar estas actividades.
Resumo
Registros vestíveis de eletromiografia durante atividades de vida diária em crianças com paralisia cerebral
Objetivo
Testar se registros têxteis vestíveis de eletromiografia (EMG) podem detector diferenças nos níveis de atividade muscular durante atividades de vida diária entre crianças com paralisia cerebral (PC) e crianças com desenvolvimento típico da mesma idade.
Método
Sistemas têxteis vestíveis de EMG foram usados para obter a atividade muscular em 10 crianças com PC espástica (quatro do sexo feminino, seis do sexo masculino; média de idade 9a6m, desvio padrão DP 2a 4m, variação: 6–13a; Sistema de Classificação da Função Motora Grossa GMFCS nível I e II) e 11 crianças com desenvolvimento típico (quatro do sexo feminino, sete do sexo masculino; média de idade 9a 9m, DP 1a 11m, 7–12a) em repouso e durante a realização de sete atividades de vida diária.
Resultados
Crianças com PC mostraram níveis de EMG significativamente menores durante contrações voluntárias máximas (CVMs) de músculos no lado mais afetado, em comparação com o lado menos afetado e com crianças típicas. Nenhuma das crianças típicas ou com PC mostrou atividade de EMG detectável nas situações de repouso. A atividade de EMG relativa a CVM foi maior em crianças com PC durante a marcha, salto e chutes no lado mais afetado em comparação com o lado menos afetado e com crianças típicas.
Interpretação
Sistemas têxteis vestíveis para registro de EMG podem ser usados para determinar diferenças na atividade muscular durante atividades de vida diária em crianças com PC. Crianças com PC mostraram reduzida atividade muscular durante atividades diárias comparadas com seus pares, mas usaram uma porção significativamente maior de sua força voluntária máxima para realizar estas atividades.
What this paper adds
Wearable textile electromyography (EMG) systems are feasible for measurement of daily muscle activity in children with cerebral palsy (CP).
Children with CP showed reduced EMG levels during maximal voluntary contractions.
Neither typically developing children or children with CP showed EMG activity in resting situations.
Children with CP used a larger part of their voluntary muscle strength during daily activities.
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