Hip circumduction is not a compensation for reduced knee flexion angle during gait

It has long been held that hip abduction compensates for reduced swing-phase knee flexion angle, especially in those after stroke. However, there are other compensatory motions such as pelvic obliquity (hip hiking) that could also be used to facilitate foot clearance with greater energy efficiency. Our previous work suggested that hip abduction may not be a compensation for reduced knee flexion after stroke. Previous study applied robotic knee flexion assistance in people with post-stroke Stiff-Knee Gait (SKG) during pre-swing, finding increased abduction despite improved knee flexion and toe clearance. Thus, our hypothesis was that hip abduction is not a compensation for reduced knee flexion. We simulated the kinematics of post-stroke SKG on unimpaired individuals with three factors: a knee orthosis to reduce knee flexion, an ankle-foot orthosis commonly worn by those post-stroke, and matching gait speeds. We compared spatiotemporal measures and kinematics between experimental factors within healthy controls and with a previously recorded cohort of people with post-stroke SKG. We focused on frontal plane motions of hip and pelvis as possible compensatory mechanisms. We observed that regardless of gait speed, knee flexion restriction increased pelvic obliquity (2.8°, p < 0.01) compared to unrestricted walking (1.5°, p < 0.01), but similar to post-stroke SKG (3.4°). However, those with post-stroke SKG had greater hip abduction (8.2°) compared to unimpaired individuals with restricted knee flexion (4.2°, p < 0.05). These results show that pelvic obliquity, not hip abduction, compensates for reduced knee flexion angle. Thus, other factors, possibly neural, facilitate exaggerated hip abduction observed in post-stroke SKG.     

Improved walking function in laboratory does not guarantee increased community walking in stroke survivors: Potential role of gait biomechanics

Reduced daily stepping in stroke survivors may contribute to decreased functional capacity and increased mortality. We investigated the relationships between clinical and biomechanical walking measures that may contribute to changes in daily stepping activity following physical interventions provided to participants with subacute stroke. Following ≤40 rehabilitation sessions, 39 participants were categorized into three groups: responders/retainers increased daily stepping >500 steps/day post-training (POST) without decreases in stepping at 2–6 month follow-up (F/U); responders/non-retainers increased stepping at POST but declined >500 steps/day at F/U; and, non-responders did not change daily stepping from baseline testing (BSL). Gait kinematics and kinetics were evaluated during graded treadmill assessments at BSL and POST. Clinical measures of gait speed, timed walking distance, balance and balance confidence were measured at BSL, POST and F/U. Between-group comparisons and regression analyses were conducted to predict stepping activity from BSL and POST measurements. Baseline and changes in clinical measures of walking demonstrated selective associations with stepping, although kinematic measures appeared to better discriminate responders. Specific measures suggest greater paretic vs non-paretic kinematic changes in responders with training, although greater non-paretic changes predicted greater gains (i.e., smaller declines) in stepping in retainers at F/U. No kinetic variables were primary predictors of changes in stepping activity at POST or F/U. The combined findings indicate specific biomechanical assessments may help differentiate changes in daily stepping activity post-stroke.     

Stance and swing phase knee flexion recover at different rates following total knee arthroplasty: An inertial measurement unit study

Total knee arthroplasty (TKA) is the most common joint replacement in the United States. Range of motion (ROM) monitoring includes idealized clinic measures (e.g. goniometry during passive ROM) that may not accurately represent knee function. Accordingly, a novel, portable, inertial measurement unit (IMU) based ROM measurement method was developed, validated, and implemented. Knee flexion was computed via relative motion between two IMUs and validated via optical motion capture (p > 0.05). Prospective analyses of 10 healthy individuals (5M, 50 ± 19 years) and 20 patients undergoing TKA (3 lost to follow up, 10M, 65 ± 6 years) were completed. Controls wore IMUs for 1-week. Patients wore IMUs for 1-week pre-TKA, 6-weeks immediately post-TKA, and 1-week at 1-year post-TKA. Flexion was computed continuously each day (8–12 h). Metrics included daily maximum flexion and flexion during stance/swing phases of gait. Maximum flexion was equal between cohorts at all time points. Contrastingly, patient stance and swing flexion were reduced pre-TKA, yet improved post-TKA. Specifically, patient stance and swing flexion were reduced below control/pre-TKA values during post-TKA week 1. Stance flexion exceeded pre-TKA and equaled control levels after week 2. However, swing flexion only exceeded pre-TKA and equaled control levels at 1-year post-TKA. This novel method improves upon the accuracy/portability of current methods (e.g. goniometry). Interestingly, surgery did not impact maximum ROM, yet improved the ability to flex during gait allowing more efficient and safe ambulation. This is the first study continuously monitoring long-term flexion before/after TKA. The results offer richer information than clinical measures about expected TKA rehabilitation.     

Use of whole body vibration in individuals with chronic stroke: Transmissibility and signal purity

This study examined (1) the influence of whole body vibration (WBV) frequency (20 Hz, 30 Hz, 40 Hz), amplitude (low: 0.8 mm and high: 1.5 mm) and body postures (high-squat, deep-squat, tip-toe standing) on WBV transmissibility and signal purity, and (2) the relationship between stroke motor impairment and WBV transmissibility/signal purity. Thirty-four participants with chronic stroke were tested under 18 different conditions with unique combinations of WBV frequency, amplitude, and body posture. Lower limb motor function and muscle spasticity were assessed using the Fugl-Meyer Assessment and Modified Ashworth Scale respectively. Nine tri-axial accelerometers were used to measure acceleration at the WBV platform, and the head, third lumbar vertebra, and bilateral hips, knees, and ankles. The results indicated that WBV amplitude, frequency, body postures and their interactions significantly influenced the vibration transmissibility and signal purity among people with chronic stroke. In all anatomical landmarks except the ankle, the transmissibility decreased with increased frequency, increased amplitude or increased knee flexion angle. The transmissibility was similar between the paretic and non-paretic side, except at the ankle during tip-toe standing. Less severe lower limb motor impairment was associated with greater transmissibility at the paretic ankle, knee and hip in certain WBV conditions. Leg muscle spasticity was not significantly related to WBV transmissibility. In clinical practice, WBV amplitude, frequency, body postures need to be considered regarding the therapeutic purpose. Good contact between the feet and vibration platform and symmetrical body-weight distribution pattern should be ensured.     

Bilateral knee osteoarthritis does not affect inter-joint coordination in older adults with gait deviations during obstacle-crossing

Fifteen elderly subjects with bilateral medial knee osteoarthritis (OA) and 15 healthy elderly subjects walked and crossed obstacles with heights of 10%, 20%, and 30% of their leg lengths while sagittal angles and angular velocities of each joint were measured and their phase angles () calculated. Continuous relative phase (CRP) were also obtained, i.e., _hip−knee and _knee−ankle. The standard deviations of the CRP curve points were averaged to obtain deviation phase (DP) values for the stance and swing phases. Significant differences between the OA and control groups were found in several of the peak and crossing angles, and angular velocities at the knee and ankle. Both groups had similar CRP patterns, and the DP values of the hip–knee and knee–ankle CRP curves were not significantly different between the two groups. Despite significant changes in the joint kinematics, knee OA did not significantly change the way the motions of the lower limb joints are coordinated during obstacle-crossing. It appears that the OA groups adopted a particular biomechanical strategy among all possible strategies that can accommodate the OA-induced changes of the knee mechanics using unaltered inter-joint coordination control. This enabled the OA subjects to accommodate reliably the mechanical demands related to bilateral knee OA in the sagittal plane during obstacle-crossing. Maintaining normal and reliable inter-joint coordination may be considered a goal of therapeutic intervention, and the patterns and variability of inter-joint coordination can be used for the evaluation of treatment effects.     

Combining muscle synergies and biomechanical analysis to assess gait in stroke patients

The understanding of biomechanical deficits and impaired neural control of gait after stroke is crucial to prescribe effective customized treatments aimed at improving walking function. Instrumented gait analysis has been increasingly integrated into the clinical practice to enhance precision and inter-rater reliability for the assessment of pathological gait. On the other hand, the analysis of muscle synergies has gained relevance as a novel tool to describe the neural control of walking. Since muscle synergies and gait analysis capture different but equally important aspects of walking, we hypothesized that their combination can improve the current clinical tools for the assessment of walking performance.To test this hypothesis, we performed a complete bilateral, lower limb biomechanical and muscle synergies analysis on nine poststroke hemiparetic patients during overground walking. Using stepwise multiple regression, we identified a number of kinematic, kinetic, spatiotemporal and synergy-related features from the paretic and non-paretic side that, combined together, allow to predict impaired walking function better than the Fugl-Meyer Assessment score. These variables were time of peak knee flexion, VAF_total values, duration of stance phase, peak of paretic propulsion and range of hip flexion. Since these five variables describe important biomechanical and neural control features underlying walking deficits poststroke, they may be feasible to drive customized rehabilitation therapies aimed to improve walking function.This paper demonstrates the feasibility of combining biomechanical and neural-related measures to assess locomotion performance in neurologically injured individuals.     

血清细胞因子与脑卒中后失眠的相关性研究

目的 探讨血清细胞因子与脑卒中后失眠的相关性。方法 选取我院2014年11月—2015年12月收治的70例脑卒中后失眠且中医辨证为心脾两虚型患者（观察组）,同时选取同期脑卒中后非失眠患者70例（对照组）。比较两组患者血清肿瘤坏死因子-α（TNF-α）、白细胞介素-6（IL-6）、白细胞介素-1β（IL-1β）水平,并比较不同程度失眠患者血清TNF-α、IL-6、IL-1β水平。结果 观察组PSQI总评分（13.10±3.45）显著高于对照组的（4.23±2.35）（t=17.90,P<0.05）。观察组患者IL-6、IL-1β水平均显著高于对照组,TNF-α显著低于对照组,差异具有统计学意义（t=38.56,13.61,14.35,均P<0.05）。不同程度睡眠障碍患者TNF-α、IL-6、IL-1β水平比较,差异具有统计学意义（F=8.47,10.36,11.27,均P<0.05）,且随着睡眠障碍程度的增加,IL-6、IL-1β水平呈上升趋势,TNF-α水平呈下降的趋势。进一步相关性分析结果显示睡眠障碍程度与血清TNF-α水平呈负相关,r=-1.856（P<0.05）;IL-6、IL-1β水平呈正相关,r=0.720,0.745（均P<0.05）。结论 细胞因子TNF-α、IL-6、IL-1β与卒中后失眠有显著相关性,在临床工作中对有上述血清细胞因子异常的脑卒中患者给予必要的干预有重要的临床意义。     

Males and females have different muscle activity patterns during gait after ACL injury and reconstruction

Kinematic and kinetic changes following anterior cruciate ligament (ACL) rupture and reconstruction (ACLR) have been fundamental to the understanding of mechanical disrupted load as it contributes to the development of posttraumatic osteoarthritis. These analyses overlook the potential contribution of muscle activity as it relates to the joint loading environment. Males and females classified as non-copers present with unique knee kinematics and kinetics after ACL injury. The purpose of this study was to perform sex-specific analyses in these individuals to explore muscle activity timing during gait after ACL rupture. Thirty-nine participants (12 females, 27 males) were enrolled. Muscle activity during gait was evaluated before and after pre-operative physical therapy, and six months after ACLR. Surface electromyography data were evaluated to determine timing (e.g., the time the muscle activity begins (‘On’) and ends (‘Off’)) for seven muscles: vastus lateralis and medialis (VL, VM), lateral and medial hamstrings (LH, MH), lateral and medial gastrocnemius (LG, MG), and soleus (SOL). General linear models with generalized estimating equations detected the effects of limb and time for muscle activity timing. Males presented with more limb asymmetries before and after pre-operative PT in the VL On (p < 0.001) and Off (p = 0.007), VM On and Off (p < 0.001), and MH off (p < 0.001), but all limb differences resolved by six months post ACLR. Changes in muscle activity in males were pervasive over time in both limbs. Females presented with no interlimb differences pre-operatively, and only involved limb VL off (p = 0.027) and VM off (p = 0.003) and the LH off in both limbs (p < 0.038) changed over time. Our data indicate that inter-limb differences in muscle activity across time points and changes in muscle activity timing over the course of physical therapy were sex specific. Males presented with more inter-limb differences in muscle activity across time points, and females presented with fewer asymmetries before and after pre-operative physical therapy. These data support that sex-specific adaptations should be taken into consideration when assessing biomechanical changes after ACLR.     

Real-time biofeedback can increase and decrease vertical ground reaction force,knee flexion excursion,and knee extension moment during walking in individuals with anterior cruciate ligament reconstruction

Individuals with anterior cruciate ligament reconstruction (ACLR) often exhibit a “stiffened knee strategy” or an excessively extended knee during gait, characterized by lesser knee flexion excursion and peak internal knee extension moment (KEM). The purpose of this study was to determine the effect of real-time biofeedback (RTBF) cuing an acute change in peak vertical ground reaction force (vGRF) during the first 50% of the stance phase of walking gait on: (1) root mean square error (RMSE) between actual vGRF and RTBF target vGRF; (2) perceived difficulty; and (3) knee biomechanics. Acquisition and short-term recall of these outcomes were evaluated. Thirty individuals with unilateral ACLR completed 4 separate walking sessions on a force-measuring treadmill that consisted of a control (no RTBF) and 3 experimental loading conditions using RTBF including: (1) 5% vGRF increase (high-loading), (2) 5% vGRF decrease (low-loading) and (3) symmetric vGRF between limbs. Bilateral biomechanical outcomes were analyzed during the first 50% of the stance phase, and included KEM, knee flexion excursion, peak vGRF, and instantaneous vGRF loading rate (vGRF-LR) for each loading condition. Peak vGRF significantly increased and decreased during high-loading and low-loading, respectively compared to control loading. Instantaneous vGRF-LR, peak KEM and knee flexion excursion significantly increased during the high-loading condition compared to low-loading. Perceived difficultly and RMSE were lower during the symmetrical loading condition compared to the low-loading condition. Cuing an increase in peak vGRF may be beneficial for increasing KEM, knee flexion excursion, peak vGRF, and vGRF-LR in individuals with ACLR. Clinical Trials Number: NCT03035994.     

Climate‐driven diversity change in annual grasslands: Drought plus deluge does not equal normal

Climate forecasts agree that increased variability and extremes will tend to reduce the availability of water in many terrestrial ecosystems. Increasingly severe droughts may be exacerbated both by warmer temperatures and by the relative unavailability of water that arrives in more sporadic and intense rainfall events. Using long‐term data and an experimental water manipulation, we examined the resilience of a heterogeneous annual grassland community to a prolonged series of dry winters that led to a decline in plant species richness (2000–2014), followed by a near‐record wet winter (2016–2017), a climatic sequence that broadly resembles the predicted future in its high variability. In our 80, 5‐m² observational plots, species richness did not recover in response to the wet winter, and the positive relationship of richness to annual winter rainfall thus showed a significant weakening trend over the 18‐year time period. In experiments on 100, 1‐m² plots, wintertime water supplementation increased and drought shelters decreased the seedling survival and final individual biomass of native annual forbs, the main functional group contributing to the observed long‐term decline in richness. Water supplementation also increased the total cover of native annual forbs, but only increased richness within nested subplots to which seeds were also added. We conclude that prolonged dry winters, by increasing seedling mortality and reducing growth of native forbs, may have diminished the seedbank and thus the recovery potential of diversity in this community. However, the wet winter and the watering treatment did cause recovery of the community mean values of a key functional trait (specific leaf area, an indicator of drought intolerance), suggesting that some aggregate community properties may be stabilized by functional redundancy among species.     

Cross-frequency and iso-frequency estimation of functional corticomuscular coupling after stroke

Functional corticomuscular coupling (FCMC) between the brain and muscles has been used for motor function assessment after stroke. Two types, iso-frequency coupling (IFC) and cross-frequency coupling (CFC), are existed in sensory-motor system for healthy people. However, in stroke, only a few studies focused on IFC between electroencephalogram (EEG) and electromyogram (EMG) signals, and no CFC studies have been found. Considering the intrinsic complexity and rhythmicity of the biological system, we first used the wavelet package transformation (WPT) to decompose the EEG and EMG signals into several subsignals with different frequency bands, and then applied transfer entropy (TE) to analyze the IFC and CFC relationship between each pair-wise subsignal. In this study, eight stroke patients and eight healthy people were enrolled. Results showed that both IFC and CFC still existed in stroke patients (EEG → EMG: 1:1, 3:2, 2:1; EMG → EEG: 1:1, 2:1, 2:3, 3:1). Compared with the stroke-unaffected side and healthy controls, the stroke-affected side yielded lower alpha, beta and gamma synchronization (IFC: beta; CFC: alpha, beta and gamma). Further analysis indicated that stroke patients yielded no significant difference of the FCMC between EEG → EMG and EMG → EEG directions. Our study indicated that alpha and beta bands were essential to concentrating and maintaining the motor capacities, and provided a new insight in understanding the propagation and function in the sensory-motor system.     

When fecundity does not equal fitness: evidence of an offspring quantity versus quality trade-off in pre-industrial humans

Maternal fitness should be maximized by the optimal division of reproductive investment between offspring number and offspring quality. While evidence for this is abundant in many taxa, there have been fewer tests in mammals, and in particular, humans. We used a dataset of humans spanning three generations from pre-industrial Finland to test how increases in maternal fecundity affect offspring quality and maternal fitness in contrasting socio-economic conditions. For 'resource-poor' landless families, but not 'resource-rich' landowning families, maternal fitness returns diminished with increased maternal fecundity. This was because the average offspring contribution to maternal fitness declined with increased maternal fecundity for landless but not landowning families. This decline was due to reduced offspring recruitment with increased maternal fecundity. However, in landowning families, recruited offspring fecundity increased with increased maternal fecundity. This suggests that despite decreased offspring recruitment, maternal fitness is not reduced in favourable socio-economic conditions due to an increase in subsequent offspring fecundity. These results provide evidence consistent with an offspring quantity-quality trade-off in the lifetime reproduction of humans from poor socio-economic conditions. The results also highlight the importance of measuring offspring quality across their whole lifespan to estimate reliably the fitness consequences of increased maternal fecundity.     

Massive acute ischemic stroke after Bothrops spp. envenomation in southwestern Colombia: Case report and literature review

Bothrops spp. envenomation and its relationship with ischemic stroke has complex pathogenesis. Local effects such as edema, pain, redness, necrosis, and systemic manifestations like coagulation disorders, thrombosis, renal failure, and hemorrhage have been reported. Hemorrhagic stroke is a common neurological complication but ischemic stroke is poorly understood.We present here the case of a 50-year-old male with no comorbidities referred from a rural area in southwest Colombia with a Bothrops spp. snakebite on the left hand. On admission, the patient presented with a deterioration of consciousness and required mechanical ventilation assistance. The MRI showed multiple ischemic areas in the bilateral frontal- temporal and occipital regions. Two months later, the patient had a favorable resolution, although central paresis in the III and VI cranial nerves and positive Babinski’s sign persisted. As already mentioned, the pathophysiology of ischemic stroke due to snakebite is complex but the procoagulant activity of the venom components, the hypovolemic shock, the endothelial damage, and the thromboinflammation can explain it, and although it rarely occurs, it should be considered as a complication of ophidian accidents caused by Bothrops spp.     

Laminin isoforms and lung development: all isoforms are not equal

Laminins are a major component of basement membranes. Each laminin molecule is a heterotrimeric glycoprotein composed of one alpha, one beta, and one gamma chain. Fifteen laminin isoforms exist, assembled from various combinations of 5alpha, 3beta, and 3gamma chains. The embryonic lung has abundant laminin isoforms. Increasing evidence suggests that different laminin isoforms have unique functions in lung development. Studies of embryonic lung explants and organotypic co-cultures show that laminin alpha1 and laminin 111 are important for epithelial branching morphogenesis and that laminin alpha2 and laminin 211 have a role in smooth muscle cell differentiation. In vivo studies of laminin alpha5-deficient mice indicate that this laminin chain, found in laminins 511 and 521, is essential for normal lobar septation in early lung development and normal alveolization and distal epithelial cell differentiation and maturation in late lung development. However, not all of the laminin chains present in the developing lung appear to be necessary for normal lung development since laminin alpha4 null mice do not have obvious lung abnormalities and laminin gamma2 null mice have only minimal changes in lung development. The mechanisms responsible for the lung phenotypes in mice with laminin mutations are unknown, but it is clear that multiple laminin isoforms are crucial for lung development and that different laminin isoforms exhibit specific, non-overlapping functions.     

Assessment of isometric muscle strength and rate of torque development with hand-held dynamometry: Test-retest reliability and relationship with gait velocity after stroke

Isometric rate of torque development examines how quickly force can be exerted and may resemble everyday task demands more closely than isometric strength. Rate of torque development may provide further insight into the relationship between muscle function and gait following stroke. Aims of this study were to examine the test-retest reliability of hand-held dynamometry to measure isometric rate of torque development following stroke, to examine associations between strength and rate of torque development, and to compare the relationships of strength and rate of torque development to gait velocity. Sixty-three post-stroke adults participated (60 years, 34 male). Gait velocity was assessed using the fast-paced 10 m walk test. Isometric strength and rate of torque development of seven lower-limb muscle groups were assessed with hand-held dynamometry. Intraclass correlation coefficients were calculated for reliability and Spearman’s rho correlations were calculated for associations. Regression analyses using partial F-tests were used to compare strength and rate of torque development in their relationship with gait velocity. Good to excellent reliability was shown for strength and rate of torque development (0.82–0.97). Strong associations were found between strength and rate of torque development (0.71–0.94). Despite high correlations between strength and rate of torque development, rate of torque development failed to provide significant value to regression models that already contained strength. Assessment of isometric rate of torque development with hand-held dynamometry is reliable following stroke, however isometric strength demonstrated greater relationships with gait velocity. Further research should examine the relationship between dynamic measures of muscle strength/torque and gait after stroke.     

Knee moment outcomes using inverse dynamics and the cross product function in moderate knee osteoarthritis gait: A comparison study

Inverse dynamics are the cornerstone of biomechanical assessments to calculate knee moments during walking. In knee osteoarthritis, these outcomes have been used to understand knee pathomechanics, but the complexity of an inverse dynamic model may limit the uptake of joint moments in some clinical and research structures. The objective was to determine whether discrete features of the sagittal and frontal plane knee moments calculated using inverse dynamics compare to knee moments calculated using a cross product function. Knee moments from 74 people with moderate knee osteoarthritis were assessed after ambulating at a self-selected speed on an instrumented dual belt treadmill. Standardized procedures were used for surface marker placement, gait speed determination and data processing. Net external frontal and sagittal plane knee moments were calculated using inverse dynamics and the three-dimensional position of the knee joint center with respect to the center of pressure was crossed with the three-dimensional ground reaction forces in the cross product function. Correlations were high between outcomes of the moment calculations (r > 0.9) and for peak knee adduction moment, knee adduction moment impulse and difference between peak flexion and extension moments, the cross product function resulted in absolute values less than 10% of those calculated using inverse dynamics in this treadmill walking environment. This computational solution may allow the integration of knee moment calculations to understand knee osteoarthritis gait without data collection or computational complexity.     

Effect of leg kick on active drag in front-crawl swimming: Comparison of whole stroke and arms-only stroke during front-crawl and the streamlined position

The purpose of this study was to examine the effect of leg kick on the resistance force in front-crawl swimming. The active drag in front-crawl swimming with and without leg motion was evaluated using measured values of residual thrust (MRT method) and compared with the passive drag of the streamlined position (SP) for the same swimmers. Seven male competitive swimmers participated in this study, and the testing was conducted in a swimming flume. Each swimmer performed front-crawl under two conditions: using arms and legs (whole stroke: WS) and using arms only (arms-only stroke: AS). Active drag and passive drag were measured at swimming velocities of 1.1 and 1.3 m s⁻¹ using load cells connected to the swimmer via wires. We calculated a drag coefficient to compare the resistances of the WS, AS and SP at each velocity. For both the WS and AS at both swimming velocities, active drag coefficient was found to be about 1.6–1.9 times larger than that in passive conditions. In contrast, although leg movement did not cause a difference in drag coefficient for front-crawl swimming, there was a large effect size (d = 1.43) at 1.3 m s⁻¹. Therefore, although upper and lower limb movements increase resistance compared to the passive condition, the effect of leg kick on drag may depend on swimming velocity.     

Bilateral deficit in plantar flexion: relation to knee joint position, muscle activation, and reflex excitability

Six male subjects made maximal isometric plantar flexions unilaterally (UL) and bilaterally (BL), with the knee joint angle positioned at 90° and 0° (full extension) and the ankle joint kept at 90°. Plantar flexion torque and electromyogram (EMG) of the lateral gastrocnemius (LG) and the soleus (Sol) muscles were recorded. There was a deficit in torque in BL compared to UL (P<0.05), and the deficit was greater when the knee was extended than when bent to 90° (13.9% vs 6.6%). The integrated EMG (iEMG) of UL and BL did not differ when the knee was at 90°. On the other hand, when the knee was extended iEMG of LG was smaller for BL than for UL, suggesting that the larger bilateral deficit when the knee was extended was due to a reduced activity of the LG motor units. In addition, the H-reflex recorded from Sol when the contralateral leg was performing a maximal unilateral plantarflexion was reduced. This would indicate that the force deficit was associated with a reduction of motoneuron excitability. Accepted: 18 August 1997     

益生菌制剂对脑卒中患者肠道菌群及肠道功能影响的Meta分析

目的探讨益生菌制剂对脑卒中患者肠道菌群及肠道功能的影响。方法通过检索PubMed、EMbase、Cochrane Library、CNKI、维普和万方数据库,收集各数据库从建库至2020年3月发表的所有关于脑卒中患者应用益生菌制剂的随机对照试验,由2名研究者独立筛选文献,按照系统评价的要求对文献质量进行评估,使用RevMan 5.3和Stata 14.0统计软件进行Meta分析。结果共纳入19篇文献(1 528例患者),Meta分析结果显示,2组患者肠道中肠球菌的数量差异没有统计学意义[SMD=-0.74,95%CI(-1.64,0.17),P=0.110],而益生菌组患者肠道中大肠埃希菌的数量低于对照组[SMD=-1.27,95%CI(-1.81,-0.73),P0.001];益生菌组患者肠道中乳杆菌和双歧杆菌数量高于对照组[SMD=1.50,95%CI(0.96,2.03),P0.001;SMD=1.66,95%CI(1.16,2.15),P0.001]。益生菌组患者血清中二胺氧化酶(DAO)和D-乳酸水平低于对照组[SMD=-1.76,95%CI(-2.39,-1.13),P0.001;SMD=-2.21,95%CI(-2.92,-1.51),P0.001];益生菌组患者粪便中分泌型免疫球蛋白A(sIgA)的量高于对照组[SMD=1.76,95%CI(0.84,2.68),P0.001]。结论在肠内营养的基础上添加益生菌制剂对脑卒中患者进行营养治疗,能够有效调节患者肠道菌群,改善患者的肠道功能。