Legs Of Individuals Research Articles

Kinetic changes of gait initiation in individuals with chronic ankle instability: A systematic review.

Gait initiation (GI) in individuals with chronic ankle instability (CAI) has shown differences in the center of pressure (COP) and muscular measures compared to healthy controls. Some studies reported that these alterations appeared when GI was with the affected leg, while others indicated that they occurred when GI was with the non-affected leg. This systematic review aimed to understand kinetic and muscular differences between individuals with CAI, healthy controls, and the affected and non-affected legs of individuals with CAI. PubMed, Science Direct, Web of Science, Google Scholar, and Scopus databases (1990-2023) were searched using the Population, Exposure, Comparator, and Outcome measure. The PRISMA guidelines were followed. The outcome measures were the peak and rate of COP displacement in the medial-lateral and anterior-posterior directions, and resultant plane during phases 1, 2, and 3 of COP trace during GI and the duration of each phase. The other measures included the onset time of the tibialis anterior and soleus muscle activity between individuals with CAI, healthy controls, and the affected and non-affected legs of the individuals with CAI. The studies' quality assessment was conducted based on the Strengthening the Reporting of Observational Studies in Epidemiology checklist. Five studies were included in the final evaluation. The results of included studies showed, individuals with CAI spent less time during phases 1 and 2, as well as a shorter peak of COP displacement in the lateral direction during phase 1 compared to healthy controls, regardless of whether the GI was with the affected or non-affected leg. Individuals with CAI have probably adopted a strategy involving adjusting the peak of COP displacement to manage internal sway while in a single-leg stance. Overall, there was no comprehensive conclusion about differences between the two legs in individuals with CAI.

Cortical drive may facilitate enhanced use of the paretic leg induced by random constraint force to the non-paretic leg during walking in chronic stroke.

The goal of this study was to determine the effects of applying random vs. constant constraint force to the non-paretic leg during walking on enhanced use of the paretic leg in individuals post-stroke, and examine the underlying brain mechanisms. Twelve individuals with chronic stroke were tested under two conditions while walking on a treadmill: random vs. constant magnitude of constraint force applied to the non-paretic leg during swing phase of gait using a custom designed robotic system. Leg kinematics, muscle activity of the paretic leg, and electroencephalography (EEG) were recorded during treadmill walking. Paretic step length and muscle activity of the paretic ankle plantarflexors significantly increased after walking with random and constant constraint forces. Cortico-cortical connectivity between motor cortices and cortico-muscular connectivity from the lesioned motor cortex to the paretic ankle plantarflexors significantly increased for the random force condition but not for the constant force condition. In addition, individuals post-stroke with greater baseline gait variability showed greater improvements in the paretic step length after walking with random force condition but not with the constant force condition. In conclusion, application of random constraint force to the non-paretic leg may enhance the use of the paretic leg during walking by facilitating cortical drive from the lesioned motor cortex to the paretic ankle plantarflexors. Results from this study may be used for the development of constraint induced locomotor intervention approaches aimed at improving locomotor function in individuals after stroke.

Delayed Cortical Responses During Reactive Balance After Stroke Associated With Slower Kinetics and Clinical Balance Dysfunction.

Slowed balance and mobility after stroke have been well-characterized. Yet the effects of unilateral cortical lesions on whole-body neuromechanical control is poorly understood, despite increased reliance on cortical resources for balance and mobility with aging. Objective. We tested whether individuals post stroke show impaired cortical responses evoked during reactive balance, and the effect of asymmetrical interlimb contributions to balance recovery and the evoked cortical response. Using electroencephalography, we assessed cortical N1 responses evoked over fronto-midline regions (Cz) during backward support-surface perturbations loading both legs and posterior-lateral directions that preferentially load the paretic or nonparetic leg in individuals' post-stroke and age-matched controls. We tested relationships between cortical responses and clinical balance/mobility function, as well as to center of pressure (CoP) rate of rise (RoR) during balance recovery. Cortical N1 responses were smaller and delayed after stroke (P < .047), regardless of perturbation condition. In contrast to controls, slower cortical response latencies associated with lower clinical function in stroke (Mini Balance Evaluation Systems Test: r = -.61, P = .007; Timed-Up-and-Go: r = .53, P = .024; walking speed: r = -.46, P = .055). Paretic-loaded balance recovery revealed slower CoP RoR (P = .012) that was associated with delayed cortical response latencies (r = -.70, P = .003); these relationships were not present during bilateral and nonparetic-loaded conditions, nor in the older adults control group. Individuals after stroke may be limited in their balance ability by the slowed speed of their cortical responses to destabilization. In particular, paretic leg loading may reveal cortical response impairments that reflect reduced paretic motor capacity.

Neurocognitive demands reducejump distance and coordination variability of the injured leg in athletes after anterior cruciate ligament reconstruction.

The study aimed to evaluate the impact of neurocognitive reliance on jump distance and lower extremity kinematics in individuals who had undergone anterior cruciate ligament reconstruction (ACLR). This was achieved by comparing hop performance under standard and neurocognitive conditions. Thirty-two patients after ACLR and 32 healthy controls (CTRL) participated. Both groups performed a single-leg hop for distance (SLHD) and two neurocognitive hop tests, each designed to evaluate distinct aspects of neurocognition. The neurocognitive tests included the reaction SLHD (R-SLHD), measuring reaction to a central stimulusand working memory SLHD (WM-SLHD) assessing response to a memorized stimulus amidst distractor stimuli. Distances were assessed for the three-hop tests. In addition, joint kinematics were collected to calculate lower extremity coordination of the lower extremity. SLHD performance was defined as the mean hop distance per condition per leg for each participant and was analyzed using a mixed ANOVA with condition and leg as the within-subjects factors and the group (ACLR or CTRL) as the between-subjects factor. Differences in joint coordination variability were analyzed using two-sample t-test statistical parametric mapping (SPM) with linear regression. The WM-SLHD resulted in a significantly decreased jump distance compared with the standard hop test both for ACLR and CTRL. Furthermore, the leg difference within the ACLR group increased under higher cognitive load as tested with the WM-SLHD, indicating leg-specific adaptations in lower extremity coordination. Neurocognitive single-leg hop tests resulted in reduced jump distance in CTRL and ACLR. The neurocognitive hop test revealed changes in coordination variability for the CTRL and the uninjured leg of ACLR individuals, whereas the injured leg's coordination variability remained unaltered, suggesting persistent cognitive control of movements post-ACLR. Level III.

Motor interference on lateral pelvis shifting towards the paretic leg during walking and its cortical mechanisms in persons with stroke.

Motor interference, where new skill acquisition disrupts the performance of a previously learned skill, is a critical yet underexplored factor in gait rehabilitation post-stroke. This study investigates the interference effects of two different practice schedules, applying interleaved (ABA condition) and intermittent (A-A condition) pulling force to the pelvis during treadmill walking, on lateral pelvis shifting towards the paretic leg in individuals with stroke. Task A involved applying resistive pelvis force (pulling towards the non-paretic side), and Task B applied assistive force (pulling towards the paretic side) at the stance phase of the paretic leg during walking. Sixteen individuals with chronic stroke were tested for gait pattern changes, including lateral pelvis shifting and spatiotemporal gait parameters, and neurophysiological changes, including muscle activity in the paretic leg and beta band absolute power in the lesioned cortical areas. A-A condition demonstrated increased lateral pelvis shifting towards the paretic side, extended paretic stance time and longer non-paretic step length after force release while ABA condition did not show any changes. These changes in gait pattern after A-A condition were accompanied by increased muscle activities of the ankle plantarflexors, and hip adductors/abductors. A-A condition demonstrated greater changes in beta band power in the sensorimotor regions compared to ABA condition. These findings suggest that while walking practice with external force to the pelvis can improve lateral pelvis shifting towards the paretic leg post-stroke, practicing a new pelvis shifting task in close succession may hinder the performance of a previously obtained lateral pelvis shifting pattern during walking.

Differential Association of Glycation Products with Bone Mineral Density and Fat Mass in Healthy and Diabetes Type 2 Subjects from Mexican Southeastern: A Cross Sectional Study.

Background: Glycation products have been linked to decreased bone mineral density (BMD) in a number of clinical settings. This study examined the correlation between early glycation products (HbA1c and glycated albumin (ALB-g)) and advanced glycation end products (pentosidine (PTD)) with BMD in two groups of participants: those with type 2 diabetes mellitus (DM2) and those without diabetes or any other comorbidities (noDM). All of the participants had resided in southeastern Mexico for a minimum of 10 years. Material and Methods: This study included 204 participants: 112 (55%) with DM2 and 92 (45%) healthy subjects. We utilized dual X-ray absorptiometry (DXA) to measure both the total and segment-specific BMD and adipose mass. In addition, the fasting blood glucose, HbA1c, PTD, and ALB-g parameters were measured. Correlation and logistic regression analyses were conducted. Results: There was an inverse correlation between PTD and BMD in all anatomical regions among postmenopausal women (PMW) in the DM2 group, whereas in non-PMW, only the waist-to-height ratio was statistically significant. A negative correlation was observed between HbA1c levels and BMD in the arms and legs of DM2 individuals. However, in the noDM group, a negative correlation was found between HbA1c levels and BMD in the pelvis, while a positive association was observed between HbA1c and indicators of adipose tissue. ALB-g, demonstrated a negative correlation with fat mass. After performing binary logistic regressions, the following odds ratios (OR) for osteopenia/osteoporosis risk were determined: PTD OR 1.1 (p = 0.047) for DM2 PMW, HbA1c OR 1.4 (p = 0.048), and fat mass content OR 1.011 (p = 0.023) for the entire sample. Conclusions: Glycation products are associated with BMD differentially depending on the analyzed anatomical segment, but PTD, HbA1c, and fat mass are significant predictors of low bone mass. In prospective studies, this association could be determined using other techniques involving three-dimensional analysis of bone architecture to evaluate bone architecture.

Phenotypical characterization, and antibiotics susceptibility patterns of skin bacteria found in podoconiosis patients in the North West Region of Cameroon

BackgroundPodoconiosis, a non-infectious disease originating from long-term exposure of bare feet to irritant red clay soil is a lifelong, disabling disease with no specific diagnostic tool, classified into 5 stages based on the severity of leg swelling (lymphoedema). Secondary bacterial infections have been suggested to cause acute dermatolymphangioadenitis (ADLA) attacks and drive disease progression. Although the North West Region of Cameroon has a proven history of podoconiosis endemicity, the bacterial composition of lymphoedema due to this condition has not been studied. Thus, this study investigated the leg bacterial diversity of patients who suffered from the lymphoedema and their susceptibility pattern to selected antibiotics.MethodsA cross-sectional study was carried out in which podoconiosis affected and non-lymphoedema individuals living in the same community were purposively selected. Samples were collected by swabbing the skin between the toes and around the anklebone, then cultured and sub-cultured on nutrient agar to obtain pure isolates. The cultured isolates were then morphologically and biochemically classified using microscopy and analytic profile index test kits, respectively. The disk diffusion technique was used to determine antibiotic susceptibility.ResultsThirty-three participants were recruited, and 249 bacterial isolates were characterized into 29 genera, 60 species; with 30 (50%) being gram positive rods, 19 (31.7%) gram positive cocci, and 11 (18.3%) gram negative rods. Thirteen gram positive rods, fifteen gram positive cocci, and eight gram negative rods of bacterial species were found only in podoconiosis individuals among which Cellulomonas spp / Microbacterium spp. (2.8%), Staphylococcus lentus (3.3%), and Burkholderia cepacia (4.0%) dominated. 90% (90%) of the bacterial isolates were sensitive to doxycycline, whereas ampicillin had a high level of intermediate resistance, and penicillin G had the greatest resistant profile.ConclusionOur findings show that 94 (37.8%) out of 249 described bacterial isolates were exclusively found in the legs of podoconiosis individuals, and their susceptibility pattern to antibiotics was similar to that of others.

Muscle oxygenation of the paretic and nonparetic legs during and after exercise in chronic stroke: Implications for mobility.

Oxygen delivery and demand are reduced in the paretic leg of individuals after stroke. However, it is unknown how muscle oxygenation, the balance between delivery and utilization of oxygen at the muscle, is altered post-stroke during aerobic exercise and how it relates to mobility. To monitor muscle oxygenation changes between the paretic and nonparetic legs of individuals after stroke during treadmill exercise and the 6-minute walk test and analyze the association with mobility. Cross-sectional study. Cardiac rehabilitation program. Eleven male participants were enrolled in the study. Ten men (30.8 ± 4.1months post-stroke; age 63.9 ± 13.9 years) with hemiparetic gait pattern finished the study. Not applicable. Muscle oxygenation was measured with near-infrared spectroscopy placed on the vastus lateralis of each leg during treadmill exercise at the first ventilatory threshold and during a 6-minute walk test. The desaturation slope during treadmill exercise was significantly steeper (p=.047) in the paretic (-0.7 ± 0.6%/s) compared to the nonparetic leg (-0.3 ± 0.2%/s). There was no other significant difference between legs. The 6-minute walk test distance was not correlated with 6-minute walk test muscle oxygenation in either leg (paretic: r=0.20, p=0.590; nonparetic: r=0.42, p=.232). At the onset of treadmill exercise, the paretic leg was unable to effectively match the oxygen demand and extraction of the nonparetic leg, suggesting the need for an immediate cardiovascular warmup prior to initiating moderate intensity exercise in this population. Because the exercise desaturation rate is thought to indicate increased anaerobic metabolism and lactate production, efforts to delay rapid desaturation could improve the sustainability of activities of daily living and exercise.

Evidence of Seasonal Variation in Body Color in Adults of the Parasitoid Cirrospilus pictus (Hymenoptera: Eulophidae) in Sicily, Italy.

As part of the studies on the morphological color variation of insects, a case study on the seasonal body color variation of Cirrospilus pictus (Nees) (Hymenoptera: Eulophidae: Eulophinae) parasitoid of leafminers is reported. Observations were made from January 2000 to December 2003 in north-western Sicily (Italy), in relation to sex, body regions of adults and seasonal periods. Wasps parasitizing Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) were collected from organic citrus orchards (Citrus limon L., var. "Femminello zagara bianca" and "Femminello comune"). Adults were grouped in classes: yellow males, black males, yellow females, yellow-black females and black females. The results highlighted a phenotypic pigmentation variation in the head, thorax, gaster and legs of individuals influenced by the season of sampling. Adults were yellow-green in summer months, whereas individuals with dark pigmentation were found in autumn and winter months. A correlation between color patterns and seasonal temperatures was found for both females and males. This work provides a contribution to the description of the intraspecific variability of this species, improving its identification.

Антропологические материалы из раскопок некрополя Эски-Кермена (по материалам раскопок 2017 года)

In 2017, the joint expedition of the Institute of Archaeology of the Crimea of the Russian Academy of Sciences and the History and Archaeology of the Crimea Research Centre of the V. I. Vernadsky Crimean Federal University continued rescue excavations of the site of ancient settlement on Eski-Kermen plateau and the cemetery on the slope of the mountain. The excavation at the cemetery uncovered ten burial constructions from various chronological periods: a burial vault and two undercut graves dating back to the early stage of the ancient town, though seven flat graves date from a later period. The flat graves were found close to the Three Holy Riders’s Church on the slope of Eski-Kermen. This article examines the palaeoanthropological materials obtained from the said burial constructions. The preservation of osseous remains from the undercut graves and burial vault was poor; the materials required preliminary restoration. Studying the materials from the burial vault was impeded since the skeletons were incomplete and osseous material was damaged. The materials from the flat graves were of good and satisfactory level of preservation. Most of the skeletons preserved in complete anatomic order. In investigation determined quantitative and sex-and-age structure of the deceased; the analysis of palaeopathological condition was undertaken; some non-metric features were recorded. Epigenetic peculiarities more often occurred on the cranial bones. The most common diseases among pathological cases were related to the teeth-maxillary apparatus. Diseases of locomotor apparatus occurred on vertebral column and big joints of long bones of arms and legs of mature male individuals. One of the buried female individuals had some changes on the sacrum bones known as spina bifida. There were pathological changes related with iron-deficient conditions, inflammations, and changes of bone tissue in result of overstrain of osseous apparatus due to excessive physical load. Only one case of traumatic lesion was documented. The cleaning of the skeleton from grave 395 uncovered the incompleteness of post-cranial skeleton: it laid in anatomic order, but there were no fibulae.

The Association of Variants within Types V and XI Collagen Genes with Knee Joint Laxity Measurements.

Joint laxity is a multifactorial phenotype with a heritable component. Mutations or common polymorphisms within the α1(V) (COL5A1), α1(XI) (COL11A1) and α2(XI) (COL11A2) collagen genes have been reported or proposed to associate with joint hypermobility, range of motion and/or genu recurvatum. The aim of this study was to investigate whether polymorphisms within these collagen-encoding genes are associated with measurements of knee joint laxity and computed ligament length changes within the non-dominant leg. One hundred and six healthy participants were assessed for genu recurvatum (knee hyperextension), anterior-posterior tibial translation, external-internal tibial rotation and ligament length changes during knee rotation of their non-dominant leg. Participants were genotyped for COL5A1 rs12722 (T/C), COL11A1 rs3753841 (C/T), COL11A1 rs1676486 (T/C) and COL11A2 rs1799907 (A/T). The genotype-genotype combination of any two or more of the four COL5A1 rs12722 CC, COL11A1 rs3753841 CC, COL11A1 rs1676486 TT and COL11A2 rs1799907 AA genotypes was associated with decreased active and passive knee hyperextension. These genotype-genotype combinations, including sex (male), increased age and decreased body mass collectively, also contributed to decreased passive knee hyperextension. These findings suggest that COL5A1, COL11A1 and COL11A2 gene-gene interactions are associated with knee hyperextension measurements of the non-dominant leg of healthy individuals.

Corticospinal Control of a Challenging Ankle Task in Incomplete Spinal Cord Injury.

After incomplete spinal cord injury (iSCI), the control of lower extremity movements may be affected by impairments in descending corticospinal tract function. Previous iSCI studies demonstrated relatively well-preserved movement control during simple alternating dorsiflections and plantar flexions albeit with severely reduced motor strength and range of motion. This task, however, required comparably limited fine motor control, impeding the sensitivity to assess the modulatory capacity of corticospinal control. Therefore, we introduced a more challenging ankle motor task necessitating complex and dynamic feedback-based movement adjustments to modulate corticospinal drive. Nineteen individuals with iSCI and 22 control subjects performed two different ankle movement tasks: (1) a regular, auditory-guided ankle movement task at a constant frequency as baseline assessment and (2) an irregular, visually guided ankle movement task following a pre-defined trajectory as a more challenging motor task. Both tasks were performed separately and in a randomized order. Electromyography (EMG) and kinematic data were recorded. The EMG frequency characteristics were investigated using wavelet transformations. Control participants exhibited a shift of relative EMG intensity from higher (>100 Hz) to lower frequencies (20-60 Hz) comparing the regular with the irregular movement task. There is evidence that EMG activity within these lower frequencies comprise information on corticospinal drive. The EMG frequency shift was less pronounced for the less impaired leg and absent for the more impaired leg of individuals with iSCI. The precision error during the irregular task was significantly higher for individuals with iSCI (more impaired leg: 12.34 ± 11.14%; less impaired leg: 6.93 ± 2.74%) compared with control participants (4.10 ± 0.84%). These results, along with the walking performance, correlated well with the delta frequency shift between the regular and irregular movement task in the 38 Hz band (corticospinal drive frequency) in the iSCI group, suggesting that task performance is related to the capacity to modulate corticospinal control. The irregular movement task holds promise as a tool for revealing further insights into corticospinal control of single-joint movements. It may serve as a surrogate marker for the assessment of modulatory capacity and the integrity of corticospinal control in individuals with iSCI early after injury and throughout rehabilitation.

Timing of propulsion-related biomechanical variables is impaired in individuals with post-stroke hemiparesis

BackgroundIn individuals with post-stroke hemiparesis, reduced paretic leg propulsion, measured through anterior ground reaction forces (AGRF), is a common and functionally-relevant gait impairment. Deficits in other biomechanical variables such as plantarflexor moment, ankle power, and ankle excursion contribute to reduced propulsion. While reduction in the magnitude of propulsion post-stroke is well studied, here, our objective was to compare the timing of propulsion-related biomechanical variables. Research questionAre there differences in the timing of propulsion and propulsion-related biomechanical variables between able-bodied individuals, the paretic leg, and non-paretic leg of post-stroke individuals? MethodsNine able-bodied and 13 post-stroke individuals completed a gait analysis session comprising treadmill walking trials at each participant’s self-selected speed. Two planned independent sample t-tests were conducted to detect differences in the timing of dependent variables between the paretic versus non-paretic leg post-stroke and paretic leg versus the dominant leg of able-bodied individuals. ResultsPost-stroke individuals demonstrated significantly earlier timing of peak AGRF of their paretic leg versus their non-paretic leg and able-bodied individuals. Post-stroke participants displayed earlier timing of peak power of their paretic leg versus their non-paretic leg and able-bodied individuals, and earlier timing of peak ankle moment of the paretic leg versus able-bodied. No significant differences were detected in the timing of peak ankle angle. SignificanceThe earlier onset of peak AGRF, peak ankle power, and peak ankle moment may be an important, under-studied biomechanical factor underlying stroke gait impairments, and a potential therapeutic target for stroke gait retraining. Future investigations can explore the use of interventions such as gait biofeedback to normalize the timing of these peaks, thereby improving propulsion and walking function post-stroke.

A tarsal spinning organ in glomeridesmid millipedes (Diplopoda: Pentazonia: Glomeridesmida)

Abstract The production of sticky threads from spinnerets is known from various myriapod groups including some representatives of the millipedes (Diplopoda). In Diplopoda the thread-producing glands are mostly seta-like and positioned terminally on the telson, and the secretion product is typically used to build molting chambers or egg sacs. So far, no such secretions or organs have been documented for the subgroup Pentazonia. Here we describe thread-producing glands from the species-poor Glomeridesmida. These putative spinning organs are single circular fields of small pores (spinning fields) positioned on the outer side of the tarsi of all walking legs of mature and juvenile individuals of both sexes. These pores are the openings of cuticular tubuli (conducting canals), which extend from the tarsus to an aggregation of cells, a putative gland, within the femur. In several specimens thin threads were observed to be extruded from the pores. The tarsal spinning fields are present in all 21 investigated Glomeridesmida morphospecies, including Termitodesmidae and Glomeridesmidae from South East Asia, the Indian subcontinent, Oceania, and South and Central America. These organs might constitute an apomorphic character of the Glomeridesmida, as similar organs are absent in other Myriapoda. The function of the extruded threads in Glomeridesmida remains speculative, because observations of living specimens of the group are almost non-existing. We suggest that the secretion might be used for defense, to build molting chambers or to secure tunnels burrowed in the substrate.

MUSCLE OXYGENATION BETWEEN THE PARETIC AND NONPARETIC LEG MEASURED DURING ARTERIAL OCCLUSION AND EXERCISE IN CHRONIC STROKE

<h3>BACKGROUND</h3> Oxygen delivery and demand are reduced in the paretic leg of individuals post-stroke, reflecting decreases of vascular function and reductions of muscle quantity and quality. However, it is unknown how muscle oxygenation, the balance between delivery and utilization of oxygen, at the muscle is altered post-stroke and how it relates to functional ambulation and aerobic exercise. The purpose of this study was to determine the difference in muscle oxygenation between the paretic and nonparetic leg of post-stroke individuals and determine if there is an association with the six-minute walk test (6MWT) distance. <h3>METHODS AND RESULTS</h3> This was a single group cross-sectional study and a sub-study of a larger two-arm parallel-group superiority trial. Skeletal muscle O2 saturation (SMO2) of the paretic and nonparetic vastus lateralis muscles were monitored continuously with two near-infrared spectroscopy (NIRS) devices, a non-invasive measure of muscle oxygenation. NIRS outcomes were measured at rest, during arterial occlusion, acute submaximal exercise and 6MWT. Muscle oxygenation was evaluated by the rate of SMO2 deoxygenation and reoxygenation during and after occlusion and exercise, and by SMO2 averages for rest and the 6MWT (see figure). Eleven subjects (91% male; 32.2±6.1 months post-stroke; age 62.9±13.6 years, with a Chedoke–McMaster Stroke Assessment score of 4.1±1.4 of the paretic leg; 7 representing normal movement) participated. There was no significant difference in SMO2 between legs at rest (p=0.13) or during the 6MWT (p=0.26). The arterial occlusion desaturation slope in the nonparetic leg (-0.70±0.36%/second) was significantly steeper than the paretic leg (-0.53±0.24%/second; p=0.03), suggesting impaired oxygen consumption in the paretic leg. The post-occlusion resaturation slope was significantly steeper in the nonparetic leg (5.7±1.6%/second) compared to the paretic leg (4.6±1.8%/second; p=0.04), indicating poorer microvascular function in the paretic leg. The exercise deoxygenation slope in the paretic leg (-0.6±0.6%/second) was significantly steeper than the non-paretic leg (-0.3±0.2%/second; p=0.047), indicating a greater mismatch between oxygen delivery and consumption at the onset of exercise, however, there was no significant difference between legs in the post-exercise resaturation slope (p=0.39). Average 6MWT SMO2 of each leg was not significantly correlated with 6MWT distance (Paretic: r=-0.06, p=0.85; Nonparetic: r=0.25, p=0.46). <h3>CONCLUSION</h3> Oxygen consumption and microvascular responsiveness are reduced in the paretic compared to the nonparetic leg. At the onset of exercise there is a mismatch between oxygen delivery and consumption in the paretic leg, which may require strategies to improve muscle oxygenation in this population.

Intravoxel Incoherent Motion Magnetic Resonance Imaging in Skeletal Muscle: Review and Future Directions.

Throughout the body, muscle structure and function can be interrogated using a variety of noninvasive magnetic resonance imaging (MRI) methods. Recently, intravoxel incoherent motion (IVIM) MRI has gained momentum as a method to evaluate components of blood flow and tissue diffusion simultaneously. Much of the prior research has focused on highly vascularized organs, including the brain, kidney, and liver. Unique aspects of skeletal muscle, including the relatively low perfusion at rest and large dynamic range of perfusion between resting and maximal hyperemic states, may influence the acquisition, postprocessing, and interpretation of IVIM data. Here, we introduce several of those unique features of skeletal muscle; review existing studies of IVIM in skeletal muscle at rest, in response to exercise, and in disease states; and consider possible confounds that should be addressed for muscle-specific evaluations. Most studies used segmented nonlinear least squares fitting with a b-value threshold of 200 sec/mm2 to obtain IVIM parameters of perfusion fraction (f), pseudo-diffusion coefficient (D*), and diffusion coefficient (D). In healthy individuals, across all muscles, the average ± standard deviation of D was 1.46 ± 0.30 × 10-3 mm2 /sec, D* was 29.7 ± 38.1 × 10-3 mm2 /sec, and f was 11.1 ± 6.7%. Comparisons of reported IVIM parameters in muscles of the back, thigh, and leg of healthy individuals showed no significant difference between anatomic locations. Throughout the body, exercise elicited a positive change of all IVIM parameters. Future directions including advanced postprocessing models and potential sequence modifications are discussed. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 2.

Reliability and Validity of the Y-balance Test in Young Adults with Chronic Low Back Pain.

BackgroundIndividuals with chronic low back pain (CLBP) may demonstrate reduced ability to perform dynamic tasks due to fear of additional pain and injury in response to the movement. The Y-balance test (YBT) is a functional and inexpensive test used with various populations. However, the reliability and validity of the YBT used for assessing dynamic balance in young adults with CLBP have not yet been examined.PurposeTo determine the inter-rater reliability of the YBT and to compare dynamic balance between young adults with CLBP and an asymptomatic group.Study DesignReliability and validity study.MethodsFifteen individuals with CLBP (≥ 12 weeks) and 15 age- and gender-matched asymptomatic adults completed the study. Each group consisted of 6 males and 9 females who were 21-38 years of age (27.47 ± 5.0 years). The YBT was used to measure participant’s dynamic balance in the anterior (ANT), posteromedial (PM) and posterolateral (PL) reach directions. The scores for each participant were independently determined and recorded to the nearest centimeter by two raters. Both the YBT reach distances and composite scores were collected from the dominant leg of asymptomatic individuals and the involved side of participants with CLBP and were used for statistical analysis.ResultsThe YBT demonstrated excellent inter-rater reliability, with intraclass correlation coefficients ranging from 0.99 to 1.0 for the YBT scores of both asymptomatic and CLBP groups. The CLBP group had lower scores than those of the asymptomatic group in the reach distances of the ANT (p = 0.023), PM (p < 0.001), and PL (p = 0.001) directions, and the composite scores (p < 0.001).ConclusionsThe results demonstrated excellent inter-rater reliability and validity of the YBT for assessing dynamic balance in the CLBP population. The YBT may be a useful tool for clinicians to assess dynamic balance deficits in patients with CLBP.Level of Evidence2b.

Gradual adaptation to pelvis perturbation during walking reinforces motor learning of weight shift toward the paretic side in individuals post-stroke.

The purpose of this study was to determine whether the gradual versus abrupt adaptation to lateral pelvis assistance force improves weight shift toward the paretic side and enhance forced use of the paretic leg during walking. Sixteen individuals who had sustained a hemispheric stroke participated in two experimental sessions, which consisted of (1) treadmill walking with the application of lateral pelvis assistance force (gradual vs. abrupt condition) and (2) overground walking. In the "gradual" condition, during treadmill walking, the assistance force was gradually increased from 0 to 100% of the predetermined force step by step. In the abrupt condition, the force was applied at 100% of the predetermined force throughout treadmill walking. Participants exhibited significant improvements in hip abductor and adductor, ankle dorsiflexor, and knee extensor muscle activities, weight shift toward the paretic side, and overground walking speed in the gradual condition (P < 0.05), but showed no significant changes in the abrupt condition (P > 0.20). Changes in weight shift toward the paretic side were statistically different between conditions (P < 0.001), although changes in muscle activities were not (P > 0.11). In the gradual condition, the error amplitude was proportional to the improvement in weight shift during the late post-adaptation (R2 = 0.32, P = 0.03), but not in the abrupt condition (R2 = 0.001, P = 0.93). In conclusion, the "gradual adaptation" inducing "small errors" during constraint-induced walking may improve weight shift and enhance forced use of the paretic leg in individuals post-stroke. Applying gradual pelvis assistance force during walking may be used as an intervention strategy to improve walking in individuals post-stroke.

Effects of augmented somatosensory input using vibratory insoles to improve walking in individuals with chronic post-stroke hemiparesis

BackgroundStroke survivors suffer from hemiparesis and somatosensory impairments, which adversely impact walking performance, placing them at higher risks for trips and falls. Post-stroke, somatosensory deficits are commonly observed as impaired interpretation of afferent input and increased threshold. Diminishing or augmenting somatosensory inputs via various techniques have been demonstrated to be able to modify static and dynamic balance, postural and locomotor control in non-neurologically impaired as well as neurologically impaired individuals.Research question: We sought to investigate whether enhancing somatosensory input using vibratory insoles, can improve post-stroke gait. We hypothesized that with augmentation of somatosensory input at the soles via vibratory insoles would improve post-stroke gait via increased propulsive forces, decreased braking forces and increased ankle angle movements in the paretic legs of individuals with chronic post-stroke hemiparesis. MethodsFifteen individuals with chronic post-stroke hemiparesis and 15 age-similar non-neurologically impaired controls participated in this cross-sectional study. Enhanced somatosensory stimulation was delivered using a pair of tactor-embedded insoles, providing suprathreshold vibratory stimulation to the bottom of the feet. Participants walked over an instrumented treadmill with self-selected speeds, under 5 conditions: no insole in shoe (NT), insoles in shoe with no vibration (BOFF), vibration under both feet (BON), vibration under one foot only (ION, CON). Kinetics and kinematics during walking were recorded and analyzed offline. ResultsSuprathreshold vibratory stimulations did not alter gait kinetics under any stimulation conditions. We observed increased paretic ankle dorsiflexions in the paretic legs, when vibratory stimuli were applied unilaterally. SignificanceVibratory stimulations applied at suprathreshold intensity to the bottom of the feet to augment somatosensory feedback can potentially be used as a low-cost solution to address the inadequate toe clearance during walking in people post-stroke, which is an important goal in post-stroke rehabilitation.

DNA barcoding in some Belarusian insects

Due to a number of factors in the anthropogenic load on ecosystems, environmental changes, and competition between native and invasive species, the loss of species diversity has currently risen to an alarming scale. One of the prospective approaches to remedy the current state and halt the loss is the international project “Barcode of Life”. The report describes the results of molecular genetic research on the insect representatives of such orders as Coleoptera (beetles), Lepidoptera (butterflies), and Trichoptera (caddisflies) using the cytochrome c oxidase subunit 1 of the mitochondrial region (COI). We proposed a technique for the sampling of biological material to isolate DNA from the hind legs of individuals. The technique prevents removal of the individuals of the most valuable species collected on the territory of the Republic of Belarus from their habitats. The DNA sample collection of order representatives was investigated. For the subfamily Cetoniinae (flower chafer), significant differences in haplotypes among the representatives of the Belarusian and European parts of their areal were found. For Trichoptera, it was shown that the COI gene has high variability to differentiate species. It was also revealed that some species of caddisflies, which Belarusian researchers believe to be synonymous ones, have sequences with big differences according to the BoldSystem database. This fact should be explored in the future. So, our analysis allows considering the COI gene as a satisfactory marker for the species identification in the Belarusian insects’ taxa studied.