ResearchPad - legs https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Remote monitoring of clubfoot treatment with digital photographs in low resource settings: Is it accurate?]]> https://www.researchpad.co/article/elastic_article_14742 Clinical examination and functional assessment are often the first steps to assess outcome of clubfoot treatment. Clinical photographs may be an adjunct used to assess treatment outcomes in lower resourced settings where physical review by a specialist is limited. We aimed to evaluate the diagnostic performance of photographic images of patients with clubfoot in assessing outcome following treatment.MethodsIn this single-centre diagnostic accuracy study, we included all children with clubfoot from a cohort treated between 2011 and 2013, in 2017. Two physiotherapists trained in clubfoot management calculated the Assessing Clubfoot Treatment (ACT) score for each child to decide if treatment was successful or if further treatment was required. Photographic images were then taken of 79 feet. Two blinded orthopaedic surgeons assessed three sets of images of each foot (n = 237 in total) at two time points (two months apart). Treatment for each foot was rated as ‘success’, ‘borderline’ or ‘failure’. Intra- and inter-observer variation for the photographic image was assessed. Sensitivity, specificity, positive and negative predictive values were calculated for the photographic image compared to the ACT score.ResultsThere was perfect correlation between clinical assessment and photographic evaluation of both raters at both time-points in 38 (48%) feet. The raters demonstrated acceptable reliability with re-scoring photographs (rater 1, k = 0.55; rater 2, k = 0.88). Thirty percent (n = 71) of photographs were assessed as poor quality image or sub-optimal patient position. Sensitivity of outcome with photograph compared to ACT score was 83.3%–88.3% and specificity ranged from 57.9%–73.3%.ConclusionDigital photography may help to confirm, but not exclude, success of clubfoot treatment. Future work to establish photographic parameters as an adjunct to assessing treatment outcomes, and guidance on a standardised protocol for photographs, may be beneficial in the follow up of children who have treated clubfoot in isolated communities or lower resourced settings. ]]> <![CDATA[Order of same-day concurrent training influences some indices of power development, but not strength, lean mass, or aerobic fitness in healthy, moderately-active men after 9 weeks of training]]> https://www.researchpad.co/article/elastic_article_14640 The importance of concurrent exercise order for improving endurance and resistance adaptations remains unclear, particularly when sessions are performed a few hours apart. We investigated the effects of concurrent training (in alternate orders, separated by ~3 hours) on endurance and resistance training adaptations, compared to resistance-only training.Materials and methodsTwenty-nine healthy, moderately-active men (mean ± SD; age 24.5 ± 4.7 y; body mass 74.9 ± 10.8 kg; height 179.7 ± 6.5 cm) performed either resistance-only training (RT, n = 9), or same-day concurrent training whereby high-intensity interval training was performed either 3 hours before (HIIT+RT, n = 10) or after resistance training (RT+HIIT, n = 10), for 3 d.wk-1 over 9 weeks. Training-induced changes in leg press 1-repetition maximal (1-RM) strength, countermovement jump (CMJ) performance, body composition, peak oxygen uptake (V˙O2peak), aerobic power (W˙peak), and lactate threshold (W˙LT) were assessed before, and after both 5 and 9 weeks of training.ResultsAfter 9 weeks, all training groups increased leg press 1-RM (~24–28%) and total lean mass (~3-4%), with no clear differences between groups. Both concurrent groups elicited similar small-to-moderate improvements in all markers of aerobic fitness (V˙O2peak ~8–9%; W˙LT ~16-20%; W˙peak ~14-15%). RT improved CMJ displacement (mean ± SD, 5.3 ± 6.3%), velocity (2.2 ± 2.7%), force (absolute: 10.1 ± 10.1%), and power (absolute: 9.8 ± 7.6%; relative: 6.0 ± 6.6%). HIIT+RT elicited comparable improvements in CMJ velocity only (2.2 ± 2.7%). Compared to RT, RT+HIIT attenuated CMJ displacement (mean difference ± 90%CI, -5.1 ± 4.3%), force (absolute: -8.2 ± 7.1%) and power (absolute: -6.0 ± 4.7%). Only RT+HIIT reduced absolute fat mass (mean ± SD, -11.0 ± 11.7%).ConclusionsIn moderately-active males, concurrent training, regardless of the exercise order, presents a viable strategy to improve lower-body maximal strength and total lean mass comparably to resistance-only training, whilst also improving indices of aerobic fitness. However, improvements in CMJ displacement, force, and power were attenuated when RT was performed before HIIT, and as such, exercise order may be an important consideration when designing training programs in which the goal is to improve lower-body power. ]]> <![CDATA[Discriminant validity of 3D joint kinematics and centre of mass displacement measured by inertial sensor technology during the unipodal stance task]]> https://www.researchpad.co/article/elastic_article_14569 The unipodal stance task is a clinical task that quantifies postural stability and alignment of the lower limb joints, while weight bearing on one leg. As persons with knee osteoarthritis (KOA) have poor postural and knee joint stability, objective assessment of this task might be useful.ObjectiveTo investigate the discriminant validity of three-dimensional joint kinematics and centre of mass displacement (COM) between healthy controls and persons with knee KOA, during unipodal stance using inertial sensors. Additionally, the reliability, agreement and construct validity are assessed to determine the reproducibility and accuracy of the discriminating parameters.MethodsTwenty healthy controls and 19 persons with unilateral severe KOA were included. Five repetitions of the unipodal stance task were simultaneously recorded by an inertial sensor system and a camera-based system (gold standard). Statistical significant differences in kinematic waveforms between healthy controls and persons with severe knee KOA were determined using one-dimensional statistical parametric mapping (SPM1D).ResultsPersons with severe knee KOA had more lateral trunk lean towards the contralateral leg, more hip flexion throughout the performance of the unipodal stance task, more pelvic obliquity and COM displacement towards the contralateral side. However, for the latter two parameters the minimum detectable change was greater than the difference between healthy controls and persons with severe knee KOA. The construct validity was good (coefficient of multiple correlation 0.75, 0.83 respectively) and the root mean squared error (RMSE) was low (RMSE <1.5°) for the discriminant parameters.ConclusionInertial sensor based movement analysis can discriminate between healthy controls and persons with severe knee KOA for lateral trunk lean and hip flexion, but unfortunately not for the knee angles. Further research is required to improve the reproducibility and accuracy of the inertial sensor measurements before they can be used to assess differences in tasks with a small range of motion. ]]> <![CDATA[Special footwear designed for pregnant women and its effect on kinematic gait parameters during pregnancy and postpartum period]]> https://www.researchpad.co/article/elastic_article_13821 During pregnancy, an array of changes occurs in women body to enable the growth and development of the future baby and the consequent delivery. These changes are reflected in the range of motion of trunk, pelvis, lower limbs and other body segments, affect the locomotion and some of these changes may persist to the postpartum period. The aim of this study was to describe the changes affecting the gait during pregnancy and to determine the effect of tested footwear on kinematic gait characteristics during pregnancy as previous studies indicate that special orthopaedic insoles and footwear might be useful in prevention of the common musculoskeletal pain and discomfort related to pregnancy. Participants from the control group (n = 18), without any intervention, and the experimental group (n = 23), which was wearing the tested shoes, were measured at their 14, 28 and 37 gestational weeks and 28 weeks postpartum to capture the complete pregnancy-related changes in gait. The gait 3D kinematic data were obtained using Simi Motion System. The differences between the control and experimental group at the first data collection session in most of the analysed variables, as well as relatively high standard deviations of analysed variables indicate large individual differences in the gait pattern. The effect of tested footwear on kinematic gait pattern changes may be explained by its preventive effect against the foot arches falling. In the control group, changes associated previously with the foot arches falling and hindfoot hyperpronation were observed during advanced phases of pregnancy and postpartum, e.g. increase in knee flexion or increase in spinal curvature. For the comprehensive evaluation of the tested footwear on pregnancy gait pattern, future studies combining the kinematic and dynamic plantographic methods are needed.

]]>
<![CDATA[Assessment of the genomic prediction accuracy for feed efficiency traits in meat-type chickens]]> https://www.researchpad.co/article/5989db51ab0ee8fa60bdc4ab

Feed represents the major cost of chicken production. Selection for improving feed utilization is a feasible way to reduce feed cost and greenhouse gas emissions. The objectives of this study were to investigate the efficiency of genomic prediction for feed conversion ratio (FCR), residual feed intake (RFI), average daily gain (ADG) and average daily feed intake (ADFI) and to assess the impact of selection for feed efficiency traits FCR and RFI on eviscerating percentage (EP), breast muscle percentage (BMP) and leg muscle percentage (LMP) in meat-type chickens. Genomic prediction was assessed using a 4-fold cross-validation for two validation scenarios. The first scenario was a random family sampling validation (CVF), and the second scenario was a random individual sampling validation (CVR). Variance components were estimated based on the genomic relationship built with single nucleotide polymorphism markers. Genomic estimated breeding values (GEBV) were predicted using a genomic best linear unbiased prediction model. The accuracies of GEBV were evaluated in two ways: the correlation between GEBV and corrected phenotypic value divided by the square root of heritability, i.e., the correlation-based accuracy, and model-based theoretical accuracy. Breeding values were also predicted using a conventional pedigree-based best linear unbiased prediction model in order to compare accuracies of genomic and conventional predictions. The heritability estimates of FCR and RFI were 0.29 and 0.50, respectively. The heritability estimates of ADG, ADFI, EP, BMP and LMP ranged from 0.34 to 0.53. In the CVF scenario, the correlation-based accuracy and the theoretical accuracy of genomic prediction for FCR were slightly higher than those for RFI. The correlation-based accuracies for FCR, RFI, ADG and ADFI were 0.360, 0.284, 0.574 and 0.520, respectively, and the model-based theoretical accuracies were 0.420, 0.414, 0.401 and 0.382, respectively. In the CVR scenario, the correlation-based accuracy and the theoretical accuracy of genomic prediction for FCR was lower than RFI, which was different from the CVF scenario. The correlation-based accuracies for FCR, RFI, ADG and ADFI were 0.449, 0.593, 0.581 and 0.627, respectively, and the model-based theoretical accuracies were 0.577, 0.629, 0.631 and 0.638, respectively. The accuracies of genomic predictions were 0.371 and 0.322 higher than the conventional pedigree-based predictions for the CVF and CVR scenarios, respectively. The genetic correlations of FCR with EP, BMP and LMP were -0.427, -0.156 and -0.338, respectively. The correlations between RFI and the three carcass traits were -0.320, -0.404 and -0.353, respectively. These results indicate that RFI and FCR have a moderate accuracy of genomic prediction. Improving RFI and FCR could be favourable for EP, BMP and LMP. Compared with FCR, which can be improved by selection for ADG in typical meat-type chicken breeding programs, selection for RFI could lead to extra improvement in feed efficiency.

]]>
<![CDATA[Prevalence of PD-L1 expression in matched recurrent and/or metastatic sarcoma samples and in a range of selected sarcomas subtypes]]> https://www.researchpad.co/article/Nd4648af7-aaea-40d4-a97f-7213e9d16a5c

We assessed the frequency of programmed death-ligand 1 (PD-L1) expression by immunohistochemistry (IHC) in a cohort of 522 sarcomas from 457 patients, incuding a subset of 46 patients with 63 matched samples from local recurrence or metastases with primary tumours and/or metachronous metastases. We also investigated the correlation of PD-L1 with the presence and degree of tumour-infiltrating lymphocytes (TILs) in a subset of cases. IHC was performed using the PD-L1 SP263 companion kit (VENTANA) on tissue microarrays from an archival cohort. Evaluation of PD-L1 and TILs was performed on full sections for a subset of 23 cases. Fisher’s exact and Mann Whitney test were used to establish significance (P <0.05). PD-L1 positive expression (≥1%) was identified in 31% of undifferentiated pleomorphic sarcomas, 29% of angiosarcomas, 26% of rhabdomyosarcomas, 18% of myxofibrosarcomas, 11% of leiomyosarcomas and 10% of dedifferentiated liposarcomas. Negative expression was present in all atypical lipomatous tumous/well-differentiated lipoasarcomas, myxoid liposarcomas, synovial sarcomas, pleomorphic liposarcomas, and Ewing sarcomas. PD-L1 IHC was concordant in 81% (38 of 47) of matched/paired samples. PD-L1 IHC was discordant in 19% (9 of 47 matched/paired samples), displaying differences in the proportion of cells expressing PD-L1 amongst paired samples with the percentage of PD-L1-positive cells increasing in the metastatic/recurrent site compared to the primary in 6 of 9 cases (67%). Significant correlation between PD-L1 expression and the degree of TILs was exclusively identified in the general cohort of leiomyosarcomas, but not in other sarcoma subtypes or in metastatic/recurrent samples. We conclude that the prevalence of PD-L1 expression in selected sarcomas is variable and likely to be clone dependent. Importantly, we demonstrated that PD-L1 can objectively increase in a small proportion of metastases/recurrent sarcomas, offering the potential of treatment benefit to immune checkpoint inhibitors in this metastatic setting.

]]>
<![CDATA[pyKNEEr: An image analysis workflow for open and reproducible research on femoral knee cartilage]]> https://www.researchpad.co/article/N0686bd46-1746-4f66-8610-270f1b75b482

Transparent research in musculoskeletal imaging is fundamental to reliably investigate diseases such as knee osteoarthritis (OA), a chronic disease impairing femoral knee cartilage. To study cartilage degeneration, researchers have developed algorithms to segment femoral knee cartilage from magnetic resonance (MR) images and to measure cartilage morphology and relaxometry. The majority of these algorithms are not publicly available or require advanced programming skills to be compiled and run. However, to accelerate discoveries and findings, it is crucial to have open and reproducible workflows. We present pyKNEEr, a framework for open and reproducible research on femoral knee cartilage from MR images. pyKNEEr is written in python, uses Jupyter notebook as a user interface, and is available on GitHub with a GNU GPLv3 license. It is composed of three modules: 1) image preprocessing to standardize spatial and intensity characteristics; 2) femoral knee cartilage segmentation for intersubject, multimodal, and longitudinal acquisitions; and 3) analysis of cartilage morphology and relaxometry. Each module contains one or more Jupyter notebooks with narrative, code, visualizations, and dependencies to reproduce computational environments. pyKNEEr facilitates transparent image-based research of femoral knee cartilage because of its ease of installation and use, and its versatility for publication and sharing among researchers. Finally, due to its modular structure, pyKNEEr favors code extension and algorithm comparison. We tested our reproducible workflows with experiments that also constitute an example of transparent research with pyKNEEr, and we compared pyKNEEr performances to existing algorithms in literature review visualizations. We provide links to executed notebooks and executable environments for immediate reproducibility of our findings.

]]>
<![CDATA[The faster, the better? Relationships between run-up speed, the degree of difficulty (D-score), height and length of flight on vault in artistic gymnastics]]> https://www.researchpad.co/article/5c99030dd5eed0c484b98b90

On vault in artistic gymnastics, a high run-up speed is thought to be important when performing difficult vaults. To test this assumption in a large cohort of elite athletes, we calculated the correlations between the run-up speed, scores, height and length of flight for handspring-, Tsukahara- and Yurchenko-style vaults and compared the performances of male and female elite and junior athletes (n = 407) during the 2016 European Championships. In females, run-up speed correlated significantly with the difficulty (D-) score and height of flight for all vaulting styles (r ≤ 0.80). In males, run-up speed correlated significantly with the D-score, height and length of flight of Tsukahara (r ≤ 0.69) and Yurchenko vaults only (r ≤ 0.65). Males reached 8–9% higher run-up speeds performing handspring and Tsukahara vaults than did females, but similar run-up speeds performing Yurchenko vaults. Elite females achieved higher run-up speeds than junior females performing Yurchenko vaults. Elite males displayed higher run-up speeds than junior males performing handspring and Tsukahara vaults. We conclude that, in females, more difficult vaults require higher run-up speeds than vaults with lower D-scores and thus, within the measured range of speeds, the faster the run-up, the better, regardless of vaulting style. Males, on the other hand, may not need to exhaust their sprinting capacity, even for the most difficult vaults. Finally, the knowledge of the required run-up speed for each vault helps coaches to estimate each athlete’s potential and/or to focus the training on developing the required physical qualities.

]]>
<![CDATA[Postural control of a musculoskeletal model against multidirectional support surface translations]]> https://www.researchpad.co/article/5c897754d5eed0c4847d2a0a

The human body is a complex system driven by hundreds of muscles, and its control mechanisms are not sufficiently understood. To understand the mechanisms of human postural control, neural controller models have been proposed by different research groups, including our feed-forward and feedback control model. However, these models have been evaluated under forward and backward perturbations, at most. Because a human body experiences perturbations from many different directions in daily life, neural controller models should be evaluated in response to multidirectional perturbations, including in the forward/backward, lateral, and diagonal directions. The objective of this study was to investigate the validity of an NC model with FF and FB control under multidirectional perturbations. We developed a musculoskeletal model with 70 muscles and 15 degrees of freedom of joints, positioned it in a standing posture by using the neural controller model, and translated its support surface in multiple directions as perturbations. We successfully determined the parameters of the neural controller model required to maintain the stance of the musculoskeletal model for each perturbation direction. The trends in muscle response magnitudes and the magnitude of passive ankle stiffness were consistent with the results of experimental studies. We conclude that the neural controller model can adapt to multidirectional perturbations by generating suitable muscle activations. We anticipate that the neural controller model could be applied to the study of the control mechanisms of patients with torso tilt and diagnosis of the change in control mechanisms from patients’ behaviors.

]]>
<![CDATA[The effect of contact sport expertise on postural control]]> https://www.researchpad.co/article/5c6f14f5d5eed0c48467abb2

It has been demonstrated that expertise in sport influences standing balance ability. However, little is known concerning how physical contact in sport affects balance ability. The aim of this study was to examine whether differences between contact and limited-contact sport experiences results in differences in postural control. Twenty male collegiate athletes (10 soccer/contact, 10 baseball/limited contact) and ten male untrained students stood quietly on a force plate under various bipedal and unipedal conditions, with and without vision. Significant differences for sway area and COP speed were found between the soccer players and the other two groups for unipedal stances without vision. Soccer players were found to have superior postural control compared with participants involved in limited contact sport or no sport at all. Contact sports may lead to increased postural control through enhanced use of proprioceptive and vestibular information.

]]>
<![CDATA[Affordable gait analysis using augmented reality markers]]> https://www.researchpad.co/article/5c6f1519d5eed0c48467adab

A typical optical based gait analysis laboratory uses expensive stereophotogrammetric motion capture systems. The study aims to propose and validate an affordable gait analysis method using augmented reality (AR) markers with a single action camera. Image processing software calculates the position and orientation of the AR markers. Anatomical landmark calibration is applied on the subject to calibrate each of the anatomical points with respect to their corresponding AR markers. This way, anatomical points are tracked through AR markers using homogeneous coordinate transformations, and the further processing of gait analysis is identical with conventional solutions. The proposed system was validated on nine participants of varying age using a conventional motion capture system on simultaneously measured treadmill gait trials on 2, 3 and 4.5 km/h walking speeds. Coordinates of the virtual anatomical points were compared using the Bland-Altman analysis. Spatial-temporal gait parameters (step length, stride length, walking base, cadence, pelvis range of motion) and angular gait parameters (range of motion of knee, hip and pelvis angles) were compared between measurement systems by RMS error and Bland-Altman analysis. The proposed method shows some differences in the raw coordinates of virtually tracked anatomical landmarks and gait parameters compared to the reference system. RMS errors of spatial parameters were below 23 mm, while the angular range of motion RMS errors varies from 2.55° to 6.73°. Some of these differences (e.g. knee angle range of motion) is comparable to previously reported differences between commercial motion capture systems and gait variability. The proposed method can be a very cheap gait analysis solution, but precision is not guaranteed for every aspect of gait analysis using the currently exemplified implementation of the AR marker tracking approach.

]]>
<![CDATA[Reliability of a new analysis to compute time to stabilization following a single leg drop jump landing in children]]> https://www.researchpad.co/article/5c6c75d0d5eed0c4843d024a

Although a number of different methods have been proposed to assess the time to stabilization (TTS), none is reliable in every axis and no tests of this type have been carried out on children. The purpose of this study was thus to develop a new computational method to obtain TTS using a time-scale (frequency) approach [i.e. continuous wavelet transformation (WAV)] in children. Thirty normally-developed children (mean age 10.16 years, SD = 1.52) participated in the study. Every participant performed 30 single-leg drop jump landings with the dominant lower limb (barefoot) on a force plate from three different heights (15cm, 20cm and 25cm). Five signals were used to compute the TTS: i) Raw, ii) Root mean squared, iii) Sequential average processing, iv) the fitting curve of the signal using an unbounded third order polynomial fit, and v) WAV. The reliability of the TTS was determined by computing both the Intraclass Correlation Coefficient (ICC) and the Standard Error of the Measurement (SEM).In the antero-posterior and vertical axes, the values obtained with the WAV signal from all heights were similar to those obtained by raw, root mean squared and sequential average processing. The values obtained for the medio-lateral axis were relatively small. This WAV provided substantial-to-good ICC values and low SEM for almost all the axes and heights. The results of the current study thus suggest the WAV method could be used to compute overall TTS when studying children’s dynamic postural stability.

]]>
<![CDATA[Multifractality of posture modulates multisensory perception of stand-on-ability]]> https://www.researchpad.co/article/5c6c7582d5eed0c4843cfe31

By definition, perception is a multisensory process that unfolds in time as a complex sequence of exploratory activities of the organism. In such a system perception and action are integrated, and multiple energy arrays are available simultaneously. Perception of affordances interweaves sensory and motor activities into meaningful behavior given task constraints. The present contribution offers insight into the manner in which perception and action usher the organism through competent functional apprehension of its surroundings. We propose that the tensegrity structure of the body, manifested via multifractality of exploratory bodily movements informs perception of affordances. The affordance of stand-on-ability of ground surfaces served as the experimental paradigm. Observers viewed a surface set to a discrete angle and attempted to match it haptically with a continuously adjustable surface occluded by a curtain, or felt an occluded surface set to a discrete angle then matched it visually with a continuously adjustable visible surface. The complex intertwining of perception and action was demonstrated by the interactions of multifractality of postural sway with multiple energy arrays, responses, and changing geometric task demands.

]]>
<![CDATA[Dynamic stability and stepping strategies of young healthy adults walking on an oscillating treadmill]]> https://www.researchpad.co/article/5c6dc9dad5eed0c48452a314

Understanding how people modify their stepping to maintain gait stability may provide information on fall risk and help to understand strategies used to reduce loss of balance. The purpose of this study was to identify the stepping strategies healthy young individuals select to maintain balance while walking on a destabilizing surface in various directions. A treadmill mounted on top of a 6 degree-of-freedom motion base was used to generate support surface oscillations in different degrees of freedom and amplitudes. Fifteen healthy young adults (21.3 ± 1.4 years) walked at self-selected speeds while continuous sinusoidal oscillations were imposed to the support surface in a one degree of freedom: rotation or translation in the mediolateral (ML) direction and rotation or translation in the anteroposterior (AP) direction, with each condition repeated at three different amplitudes. We compared step width, length, and frequency and the mean and variability of margin of stability (MoS) during each experimental walking condition with a control condition, in which the support surface was stationary. Subjects chose a common strategy of increasing step width (p < 0.001) and decreasing step length (p = 0.008) while increasing mediolateral MoS (p < 0.001), particularly during oscillations that challenged frontal plane control, with rotations of the walking surface producing the greatest changes to stepping.

]]>
<![CDATA[Very severe tungiasis in Amerindians in the Amazon lowland of Colombia: A case series]]> https://www.researchpad.co/article/5c65dce5d5eed0c484dec4b0

Background

Tungiasis is a parasitic skin disease caused by penetrating female sand fleas. By nature, tungiasis is a self-limiting infection. However, in endemic settings re-infection is the rule and parasite load gradually accumulates over time. Intensity of infection and degree of morbidity are closely related.

Methodology/principal findings

This case series describes the medical history, the clinical pathology, the socio-economic and the environmental characteristics of very severe tungiasis in five patients living in traditional Amerindian communities in the Amazon lowland of Colombia. Patients had between 400 and 1,300 penetrated sand fleas. The feet were predominantly affected, but clusters of embedded sand fleas also occurred at the ankles, the knees, the elbows, the hands, the fingers and around the anus. The patients were partially or totally immobile. Patients 1 and 3 were cachectic, patient 2 presented severe malnutrition. Patient 3 needed a blood transfusion due to severe anemia. All patients showed a characteristic pattern of pre-existing medical conditions and culture-dependent behavior facilitating continuous re-infection. In all cases intradomiciliary transmission was very likely.

Conclusion/significance

Although completely ignored in the literature, very severe tungiasis occurs in settings where patients do not have access to health care and are stricken in a web of pre-existing illness, poverty and neglect. If not treated, very severe tungiasis may end in a fatal disease course.

]]>
<![CDATA[Balancing selection at a premature stop mutation in the myostatin gene underlies a recessive leg weakness syndrome in pigs]]> https://www.researchpad.co/article/5c5b52bfd5eed0c4842bcf6f

Balancing selection provides a plausible explanation for the maintenance of deleterious alleles at moderate frequency in livestock, including lethal recessives exhibiting heterozygous advantage in carriers. In the current study, a leg weakness syndrome causing mortality of piglets in a commercial line showed monogenic recessive inheritance, and a region on chromosome 15 associated with the syndrome was identified by homozygosity mapping. Whole genome resequencing of cases and controls identified a mutation causing a premature stop codon within exon 3 of the porcine Myostatin (MSTN) gene, similar to those causing a double-muscling phenotype observed in several mammalian species. The MSTN mutation was in Hardy-Weinberg equilibrium in the population at birth, but significantly distorted amongst animals still in the herd at 110 kg, due to an absence of homozygous mutant genotypes. In heterozygous form, the MSTN mutation was associated with a major increase in muscle depth and decrease in fat depth, suggesting that the deleterious allele was maintained at moderate frequency due to heterozygous advantage (allele frequency, q = 0.22). Knockout of the porcine MSTN by gene editing has previously been linked to problems of low piglet survival and lameness. This MSTN mutation is an example of putative balancing selection in livestock, providing a plausible explanation for the lack of disrupting MSTN mutations in pigs despite many generations of selection for lean growth.

]]>
<![CDATA[Community based cross sectional study of podoconiosis and associated factors in Dano district, Central Ethiopia]]> https://www.researchpad.co/article/5c58d630d5eed0c484031865

Background

Podoconiosis, affects lower limb, is an entirely preventable non-communicable tropical disease common in low income countries. Globally it is estimated that there are 4 million peoples with podoconiosis and nationally it is estimated that there are 1.56 million cases of podoconiosis. Even though nationwide mapping has been conducted including the current district under investigation, there are no studies conducted to identify factors associated with podoconiosis in the district. Hence, this study was aimed to determine the prevalence of podoconiosis and associated factors in the west Shewa of Dano district community.

Method

A community based cross sectional study was conducted from March 1 to 26, 2018. Seven kebeles out of the total of twenty-three kebeles found in the district were selected randomly. The total sample size was allocated by probability proportional to size to each kebele based on the number of households they had. Then, systematic random sampling was employed to select 652 study participants from the seven kebeles. Data was collected using interviewer administered structured questionnaire and observation. In addition, a blood sample was collected from the study subjects who had leg swelling for ruling out lymphedema due to lymphatic filarasis by using Immunochromatographic test card. Podoconiosis case was defined as bilateral but asymmetric swelling which develop first in the foot often confined to the lower leg and negative result for immune-chromatographic test (ICT card). The prevalence of podoconiosis was determined and multiple logistic regression model was fitted using SPSS version 23 to identify factors associated with podoconiosis.

Result

The prevalence of podoconiosis in Dano district was found to be 6.3% (95%CI: 5.8, 6.8). Age at first shoe wearing (AOR = 1.08,95% CI = 1.06–1.11), washing practice of feet by water only (AOR = 3.68, 95% CI = 1.47–9.24) and not wearing shoe daily (AOR = 9.32, 95% CI = 4.27–20.4) were found to be significantly associated with increased odds of podoconiosis.

Conclusion

This study revealed that there was significant burden of podoconiosis in the study area. Age at first shoe wearing, washing practice and frequency of shoe wearing were associated with the development of podoconiosis disease. Modalities to enhance the shoe wearing behaviour of the communities should be planned by high level decision makers working in the area of Health. Moreover, collaboration between local government and non-government stakeholders, and integration with existing programs addressing foot hygiene which involves washing feet with soap and water needs to be addressed.

]]>
<![CDATA[Peak torque angle of anterior cruciate ligament-reconstructed knee flexor muscles in patients with semitendinosus and gracilis autograft is shifted towards extension regardless of the postoperative duration of supervised physiotherapy]]> https://www.researchpad.co/article/5c633944d5eed0c484ae6385

Background

The observational cohort study investigated whether the flexor muscles peak torque (PT) angle shifting towards extension observed in the involved knee in patients after anterior cruciate ligament reconstruction (ACLR) using semitendinosus and gracilis tendon (STGR) autograft is associated with the postoperative physiotherapy supervision duration.

Methods

From 230 ACL-reconstructed males, we identified patients after ACLR utilizing STGR autograft and divided them into those who completed supervised physiotherapy <6 months (Group I; n = 77) and those who completed supervised physiotherapy ≥6 months (Group II; n = 66). The mean follow-up time was 6.84 ± 1.47 months. The ACL-reconstructed patients were compared to 98 controls (Group III). Bilateral knee flexor muscle PT measurements were performed. The relative PT at 180°/s (RPT), PT angle at 180°/s, and range of motion at 180°/s were analysed. The RPT limb symmetry index (LSI) was calculated. Tests for dependent samples, one-way analysis of variance, post hoc test, and linear Pearson’s correlation coefficient (r) calculations were performed.

Results

The shift towards extension was noted when comparing the ACL-reconstructed limb to the uninvolved limb (Group I, p ≤ 0.001; Group II, p ≤ 0.001) and to Group III (p ≤ 0.001), but it was not correlated with physiotherapy supervision duration (r = -0.037, p = 0.662). In ACL-reconstructed patients, there was a moderate association of supervision duration and knee flexor LSI (r = 0.587, p < 0.001).

Conclusions

The ACL-reconstructed knee flexors PT angle shift towards extension was observed regardless of the duration of postoperative physiotherapy supervision. However, the analysis revealed that the duration of supervised physiotherapy positively influenced the RPT and LSI in patients after the ACLR.

]]>
<![CDATA[Automatic real-time gait event detection in children using deep neural networks]]> https://www.researchpad.co/article/5c5ca2a9d5eed0c48441e836

Annotation of foot-contact and foot-off events is the initial step in post-processing for most quantitative gait analysis workflows. If clean force plate strikes are present, the events can be automatically detected. Otherwise, annotation of gait events is performed manually, since reliable automatic tools are not available. Automatic annotation methods have been proposed for normal gait, but are usually based on heuristics of the coordinates and velocities of motion capture markers placed on the feet. These heuristics do not generalize to pathological gait due to greater variability in kinematics and anatomy of patients, as well as the presence of assistive devices. In this paper, we use a data-driven approach to predict foot-contact and foot-off events from kinematic and marker time series in children with normal and pathological gait. Through analysis of 9092 gait cycle measurements we build a predictive model using Long Short-Term Memory (LSTM) artificial neural networks. The best-performing model identifies foot-contact and foot-off events with an average error of 10 and 13 milliseconds respectively, outperforming popular heuristic-based approaches. We conclude that the accuracy of our approach is sufficient for most clinical and research applications in the pediatric population. Moreover, the LSTM architecture enables real-time predictions, enabling applications for real-time control of active assistive devices, orthoses, or prostheses. We provide the model, usage examples, and the training code in an open-source package.

]]>
<![CDATA[Which osteoarthritic gait features recover following total knee replacement surgery?]]> https://www.researchpad.co/article/5c79afe0d5eed0c4841e38ee

Background

Gait analysis can be used to measure variations in joint function in patients with knee osteoarthritis (OA), and is useful when observing longitudinal biomechanical changes following Total Knee Replacement (TKR) surgery. The Cardiff Classifier is an objective classification tool applied previously to examine the extent of biomechanical recovery following TKR. In this study, it is further developed to reveal the salient features that contribute to recovery towards healthy function.

Methods

Gait analysis was performed on 30 patients before and after TKR surgery, and 30 healthy controls. Median TKR follow-up time was 13 months. The combined application of principal component analysis (PCA) and the Cardiff Classifier defined 18 biomechanical features that discriminated OA from healthy gait. Statistical analysis tested whether these features were affected by TKR surgery and, if so, whether they recovered to values found for the controls.

Results

The Cardiff Classifier successfully discriminated between OA and healthy gait in all 60 cases. Of the 18 discriminatory features, only six (33%) were significantly affected by surgery, including features in all three planes of the ground reaction force (p<0.001), ankle dorsiflexion moment (p<0.001), hip adduction moment (p = 0.003), and transverse hip angle (p = 0.007). All but two (89%) of these features remained significantly different to those of the control group after surgery.

Conclusions

This approach was able to discriminate gait biomechanics associated with knee OA. The ground reaction force provided the strongest discriminatory features. Despite increased gait velocity and improvements in self-reported pain and function, which would normally be clinical indicators of recovery, the majority of features were not affected by TKR surgery. This TKR cohort retained pre-operative gait patterns; reduced sagittal hip and knee moments, decreased knee flexion, increased hip flexion, and reduced hip adduction. The changes that were associated with surgery were predominantly found at the ankle and hip, rather than at the knee.

]]>