Single Limbs Research Articles

Trunk kinematics and limb movement of horses walking backwards and forwards in hand and lifting a single limb

Equine physiotherapy commonly includes basic exercises such as walking backward (BW) and voluntary lifting of single limbs (SLL), but trunk movements during these have not been studied. In order to compare the trunk kinematics during BW and SLL with forward walking (FW), nine horses were measured in FW, BW and during SLL triggered by tactile cue. Kinematics were obtained from skin markers captured by ten high-speed video cameras. Trunk angles were calculated in sagittal and horizontal planes from withers, dorsal to spinous processes of the 16th thoracic vertebra (T16), 2nd and 4th sacral vertebrae (S2, S4), WT16S2 and T16S2S4 respectively. From the hooves, maximum hoof height during swing phase and horizontal distance between hoof and median body plane during swing and stance phases were determined.Dorsoventral range of motion (ROM) and maximum flexion of WT16S2 was significantly larger in BW than in FW, while laterolateral ROM was significantly smaller during hindlimb swing phase in BW and SLL than in FW. In contrast, dorsoventral ROM of T16S2S4 was significantly smaller during stance and swing phases of hindlimbs in BW compared to FW, and throughout the movement. During forelimb swing phase, T16S2S4 ROM was significantly larger in BW than SLL. Hindhoof height in SLL was significantly higher than in FW. Distance between median body plane and hooves was significantly larger in BW than in FW, and significantly larger in BW than in SLL for hindlimb swing phase. In BW, increased lumbosacral stabilisation and the larger area of support created by fore- and hindlimbs may represent a strategy to enhance body stabilisation, as BW entails some insecurity.

Local Tetanus Begins with a Neuromuscular Junction Paralysis around the Site of Tetanus Neurotoxin Release due to Cleavage of the Vesicle-Associated Membrane Protein

Local tetanus develops when limited amounts of tetanus neurotoxin (TeNT) are released by Clostridium tetani generated from spores inside a necrotic wound. Within days, a spastic paralysis restricted to the muscles of the affected anatomical area develops. This paralysis follows the retrograde transport of TeNT inside the axons of spinal cord motoneurons and its uptake by inhibitory interneurons with cleavage of VAMP, a synaptic vesicle protein required for neurotransmitter release. Consequently, incontrollable excitation of motoneurons causes contractures of innervated muscles and to local spastic paralysis.Here, the initial events occurring close to the site of TeNT release were investigated in a mouse model of local tetanus. A peripheral flaccid paralysis was found to occur, before or overlapping, the spastic one. At variance from the confined TeNT proteolytic activity at the periphery, central VAMP cleavage can be detected within inhibitory interneurons controlling motor neuron efferents innervating muscle groups distant from the site of TeNT release. These results indicate that TeNT does have a peripheral activity in tetanus and explains why the spastic paralysis observed in local tetanus, although confined to single limbs, generally affects multiple muscles. The initial TeNT neuroparalytic activity can be detected by measuring the compound muscle action potential providing a very early diagnosis and therapy thus preventing the ensuing life-threatening generalized tetanus.

TDLNet: Transfer Data Learning Network for Cross-Subject Classification Based on Multiclass Upper Limb Motor Imagery EEG.

The limited number of brain-computer interface based on motor imagery (MI-BCI) instruction sets for different movements of single limbs makes it difficult to meet practical application requirements. Therefore, designing a single-limb, multi-category motor imagery (MI) paradigm and effectively decoding it is one of the important research directions in the future development of MI-BCI. Furthermore, one of the major challenges in MI-BCI is the difficulty of classifying brain activity across different individuals. In this article, the transfer data learning network (TDLNet) is proposed to achieve the cross-subject intention recognition for multiclass upper limb motor imagery. In TDLNet, the Transfer Data Module (TDM) is used to process cross-subject electroencephalogram (EEG) signals in groups and then fuse cross-subject channel features through two one-dimensional convolutions. The Residual Attention Mechanism Module (RAMM) assigns weights to each EEG signal channel and dynamically focuses on the EEG signal channels most relevant to a specific task. Additionally, a feature visualization algorithm based on occlusion signal frequency is proposed to qualitatively analyze the proposed TDLNet. The experimental results show that TDLNet achieves the best classification results on two datasets compared to CNN-based reference methods and transfer learning method. In the 6-class scenario, TDLNet obtained an accuracy of 65%±0.05 on the UML6 dataset and 63%±0.06 on the GRAZ dataset. The visualization results demonstrate that the proposed framework can produce distinct classifier patterns for multiple categories of upper limb motor imagery through signals of different frequencies. The ULM6 dataset is available at https://dx.doi.org/10.21227/8qw6-f578.

Neurophysiology of movement inhibition during full body reaching

Our current understanding of response inhibition comes from go/no-go studies that draw conclusions based on the overt movement of single limbs (i.e., a single finger pushing a button). In general, go/no-go paradigms have found that an individual’s ability to correctly inhibit the motor system is indicative of a healthy central nervous system. However, measuring inhibition by an overt behavioral response may lack the sensitivity to conclude whether the motor system is completely inhibited. Therefore, our goal was to use behavioral and neurophysiological measures to investigate inhibition of the motor system during a full-body reaching task. When directly comparing neurophysiological and behavioral measures, we found that neurophysiological measures were associated with a greater number of errors during no-go trials and faster onset times during go trials. Further analyses revealed a negative correlation between errors and onset times, such that the muscles that activated the earliest during go trials also had the greatest number of errors during no-go trials. Together, our observations show that the absence of an overt behavioral response does not always translate to total inhibition of the motor system.

Studying Stickiness: Methods, Trade-Offs, and Perspectives in Measuring Reversible Biological Adhesion and Friction.

Controlled, reversible attachment is widely spread throughout the animal kingdom: from ticks to tree frogs, whose weights span from 2 mg to 200 g, and from geckos to mosquitoes, who stick under vastly different situations, such as quickly climbing trees and stealthily landing on human hosts. A fascinating and complex interplay of adhesive and frictional forces forms the foundation of attachment of these highly diverse systems to various substrates. In this review, we present an overview of the techniques used to quantify the adhesion and friction of terrestrial animals, with the aim of informing future studies on the fundamentals of bioadhesion, and motivating the development and adoption of new or alternative measurement techniques. We classify existing methods with respect to the forces they measure, including magnitude and source, i.e., generated by the whole body, single limbs, or by sub-structures. Additionally, we compare their versatility, specifically what parameters can be measured, controlled, and varied. This approach reveals critical trade-offs of bioadhesion measurement techniques. Beyond stimulating future studies on evolutionary and physicochemical aspects of bioadhesion, understanding the fundamentals of biological attachment is key to the development of biomimetic technologies, from soft robotic grippers to gentle surgical tools.

Multi-Time and Multi-Band CSP Motor Imagery EEG Feature Classification Algorithm

The effective decoding of motor imagination EEG signals depends on significant temporal, spatial, and frequency features. For example, the motor imagination of the single limbs is embodied in the μ (8–13 Hz) rhythm and β (13–30 Hz) rhythm in frequency features. However, the significant temporal features are not necessarily manifested in the whole motor imagination process. This paper proposes a Multi-Time and Frequency band Common Space Pattern (MTF-CSP)-based feature extraction and EEG decoding method. The MTF-CSP learns effective motor imagination features from a weak Electroencephalogram (EEG), extracts the most effective time and frequency features, and identifies the motor imagination patterns. Specifically, multiple sliding window signals are cropped from the original signals. The multi-frequency band Common Space Pattern (CSP) features extracted from each sliding window signal are fed into multiple Support Vector Machine (SVM) classifiers with the same parameters. The Effective Duration (ED) algorithm and the Average Score (AS) algorithm are proposed to identify the recognition results of multiple time windows. The proposed method is trained and evaluated on the EEG data of nine subjects in the 2008 BCI-2a competition dataset, including a train dataset and a test dataset collected in other sessions. As a result, the average cross-session recognition accuracy of 78.7% was obtained on nine subjects, with a sliding window length of 1 s, a step length of 0.4 s, and the six windows. Experimental results showed the proposed MTF-CSP outperforming the compared machine learning and CSP-based methods using the original signals or other features such as time-frequency picture features in terms of accuracy. Further, it is shown that the performance of the AS algorithm is significantly better than that of the Max Voting algorithm adopted in other studies.

Verification and Regularization Method for 3D-Human Body Pose Estimation based on Prior Knowledge

Applications used in human-centered scene analysis often rely on AI processes that provide the 3D data of human bodies. The applications are limited by the accuracy and reliability of the detection. In case of safety applications, an almost perfect detection rate is required. The presented approach gives a confidence measure for the likelihood that detected human bodies are real persons. It measures the consistency of the estimated 3D pose information of body joints with prior knowledge about the physiologically possible spatial sizes and proportions. Therefore, a detailed analysis was done which lead to the development of an error metric that allows the quantitative evaluation of single limbs and in summary of the complete body. For a given dataset an error threshold has been derived that verifies 97% persons correctly and can be used for the identification of false detections, so-called ghosts. Additionally, the 3D-data of single joints could be rated successfully. The results are usable for relabeling and retraining of underlying 2D and 3D pose estimators and provides a quantitative and comparable verification method, which improves significantly a reliable 3D-recognition of real persons and increases hereby the possibilities of high-standard applications of 3D human-centered technologies.

Robotic tests for position sense and movement discrimination in the upper limb reveal that they each are highly reproducible but not correlated in healthy individuals

BackgroundRobotic technologies for neurological assessment provide sensitive, objective measures of behavioural impairments associated with injuries or disease such as stroke. Previous robotic tasks to assess proprioception typically involve single limbs or in some cases both limbs. The challenge with these approaches is that they often rely on intact motor function and/or working memory to remember/reproduce limb position, both of which can be impaired following stroke. Here, we examine the feasibility of a single-arm Movement Discrimination Threshold (MDT) task to assess proprioception by quantifying thresholds for sensing passive limb movement without vision. We use a staircase method to adjust movement magnitude based on subject performance throughout the task in order to reduce assessment time. We compare MDT task performance to our previously-designed Arm Position Matching (APM) task. Critically, we determine test-retest reliability of each task in the same population of healthy controls.MethodHealthy participants (N = 21, age = 18–22 years) completed both tasks in the End-Point Kinarm robot. In the MDT task the robot moved the dominant arm left or right and participants indicated the direction moved. Movement displacement was systematically adjusted (decreased after correct answers, increased after incorrect) until the Discrimination Threshold was found. In the APM task, the robot moved the dominant arm and participants “mirror-matched” with the non-dominant arm.ResultsDiscrimination Threshold for direction of arm displacement in the MDT task ranged from 0.1–1.3 cm. Displacement Variability ranged from 0.11–0.71 cm. Test-retest reliability of Discrimination Threshold based on ICC confidence intervals was moderate to excellent (range, ICC = 0.78 [0.52–0.90]). Interestingly, ICC values for Discrimination Threshold increased to 0.90 [0.77–0.96] (good to excellent) when the number of trials was reduced to the first 50. Most APM parameters had ICC’s above 0.80, (range, ICC = [0.86–0.88]) with the exception of variability (ICC = 0.30). Importantly, no parameters were significantly correlated across tasks as Spearman rank correlations across parameter-pairings ranged from − 0.27 to 0.30.ConclusionsThe MDT task is a feasible and reliable task, assessing movement discrimination threshold in ~ 17 min. Lack of correlation between the MDT and a position-matching task (APM) indicates that these tasks assess unique aspects of proprioception that are not strongly related in young, healthy individuals.

Treatment of displacement-type lumbar intervertebral disc protrusion on L2-L5 with percutaneous endoscopic interlaminar discectomy

To evaluate the operative characteristic, safety, clinical effect of percutaneous endoscopic interlaminar discectomy (PEID) in treating displacement-type lumbar intervertebral disc protrusion on L₂-L₅. Form November 2015 to October 2016, 15 patients with displacement-type lumbar intervertebral disc protrusion were treated with percutaneous endoscopic interlaminar discectomy. There were 9 males and 6 females, aged from 19 to 63 years old with an average of 42 years. All the patients with single-segment displacement-type lumbar intervertebral disc protrusion were diagnosed by clinical and iconography data, and complicated with low back pain and single lower limbs radioactivity pain. Lesion occurred in L₄,₅ of 8 cases, L₃,₄ of 4 cases, L₂,₃ of 3 cases. The patients were divided into 4 regions according to Lee standard (displaced nucleus pulposus location on spinal canal), I region was 2 cases, II region was 3 cases, III region was 5 cases, IV region was 5 cases.Preoperative, postoperative 3 months, final follow-up, lumbago-leg pain and lumbar function were assessed by VAS, JOA scores;at final follow-up, MacNab was used to evaluate the clinical effect;postoperative 3 months, rechecked lumbar MRI to observe discectomy condition. All the operations were successfully complete under local anesthesia, and no complications such as injuries of nerve root and dural sac, postoperative hemorrhage, local infection were found. Operative time was 45 to 90 min with an average of 54.8 min;and hospitalization time was 3 to 4 days with an average of 3 days. All 15 cases were followed up for 12 to 13 months with an average of 12.2 months, no recurrence was found. Preoperation, postoperative 3, 12 months, VAS scores were 8.2±1.4, 3.0±0.6, 1.7±0.5, JOA scores were 8.76±3.32, 23.61±2.14, 24.82±3.43, respectively. Postoperative VAS, JOA scores were obviously improved(P<0.05). According to MacNab standard to evaluate the clinical effect, 9 cases obtained excellent results, 5 good, 1 fair. PEID is a micro-trauma surgical method and has advantage of safe and effective in treating displacement-type lumbar intervertebral disc protrusion on L₂-L₅, but requires laminoplasty during operation, and under local anesthesia to operation maybe can induce neurostimulation.

Comparison of Endovascular Stent Grafts for Abdominal Aortic Aneurysm Repair in Medicare Beneficiaries

Increased renal complications have been suggested with suprarenal stent grafts, but long-term analyses have been limited. Therefore, the purpose of this study was to evaluate the effect of endograft choice on perioperative and long-term outcomes. We compared Medicare beneficiaries undergoing endovascular abdominal aortic aneurysms repair from 2005 to 2008 with endografts with infrarenal fixation and a single docking limb (AneuRx, Excluder) to those with suprarenal fixation and 2 docking limbs (Zenith), or a unibody configuration (Powerlink). Propensity score weighting accounted for differences in patient characteristics among the different graft formations, and perioperative mortality, complications, and length of stay and 4-year rates of survival, rupture, and reintervention were compared. Forty-six thousand one hundred seventy-one Medicare beneficiaries were identified including 11,002 (24%) with suprarenal fixation, 32,909 (71%) with infrarenal fixation, and 2,260 (5%) with a unibody graft. After propensity score weighting, there were no significant differences in patients' baseline clinical and demographic characteristics. The suprarenal fixation patients had higher rates of perioperative mortality (1.7% vs. 1.3%, P<0.01), renal failure (6.0% vs. 4.7%, P<0.001), and mesenteric ischemia (0.7% vs. 0.4%, P<0.01) and longer length of stay (3.4days vs. 3.0days, P<0.001) compared with patients with infrarenal fixation. Unibody grafts had higher rates of renal failure (5.9% vs. 4.7%, P<0.001), mesenteric ischemia (1.0% vs. 0.4%, P<0.001), and conversion to open repair (0.7% vs. 0.1%, P<0.001) compared to those with infrarenal fixation and single docking limbs. At 4 years, mortality remained slightly higher with suprarenal compared to infrarenal fixation (30% vs. 29%, P=0.047), although these patients had fewer conversions to open repair (0.6% vs. 0.9%, P=0.03) and aneurysm-related reinterventions (10% vs. 12%, P<0.01). At 4 years, unibody grafts had more aneurysm-related interventions compared to infrarenal fixation grafts (15% vs. 12%, P<0.01) but fewer conversions to open repair (0.4% vs. 0.9%, P=0.02). Late rupture did not differ among the groups. Compared to infrarenal fixation devices, patients who underwent EVAR with suprarenal fixation had higher perioperative mortality and renal complications but fewer reinterventions including conversion, while the unibody graft had more perioperative complications and aneurysm-related reinterventions, but fewer conversions to open repair. Although these differences could be explained by selection bias, these data suggest that further comparative effectiveness analyses should be performed to understand the outcomes following EVAR with suprarenal fixation and unibody grafts.

施工升降机单肢稳定性计算校核

施工升降机导轨架设计中普遍存在对单肢稳定性校核计算重视程度不足的问题，导致在设计时只确保导轨架整体稳定性应力值小于许用应力，在使用过程中仍会出现导轨架失稳现象。文章依据GB26557-2011《吊笼有垂直导向的人货两用施工升降机》中的相关规定，通过分析比较导轨架在各工况下应计算的不同载荷组合，提出了异常情况下安全装置作用工况为单肢受力最危险的工况，分析比较了最危险工况下导轨架所有危险截面，确定了在吊笼分别位于导轨架上端和底架与最下附墙架中间时，底架与最下层附墙架中间导轨架截面为最危险截面，给出了最危险工况下最危险截面处单肢稳定性计算校核方法。以SC200/200施工升降机为例，对其单肢稳定性进行了校核，解释了目前广泛使用的施工升降机，在受到较大冲击后导轨架产生失稳的原因。 In the design of the construction elevator, the problem of insufficient attention to the calculation of the stability of the single limbs is found, which leads to the fact that only the stability stress of the rail frame is less than the allowable stress in the design. In the course of use, stable phenomenon, according to GB26557-2011 “hanging cage with vertical guide the dual-use construction of the lift,” the relevant provisions of the comparison through the rails under the conditions of the load should be calculated under different load combinations, put forward the exception of the safety device. The most dangerous working conditions of the single limb are analyzed and compared with all the dangerous sections of the rail frame under the most dangerous conditions. It is determined that the cage is located in the middle of the guide rail frame and the bottom frame and the bottom. The cross section of the middle section of the middle frame is the most dangerous section, and the verification method of the single limb stability calculation under the most dangerous cross section of the most dangerous condition is given. Taking the SC200/200 construction lifts as an example, the stability of the single limbs is checked, which explains the reason why the construction lifts are widely used and the instability of the rails after the impact is large.

Early experience of transilluminated cryosurgery for varicose vein with saphenofemoral reflux: review of 84 patients (131 limbs).

PurposeVaricose veins with great saphenous vein (GSV) insufficiency is prevalent. Among various surgical treatments for varicose veins, cryosurgery of GSV is an alternative minimally invasive technique that could leave fewer scars and replace conventional stripping with ambulatory phlebectomy. This study sought to assess outcomes including efficacy and safety of cryosurgery for varicose veins.MethodsOne hundred thirty-one limbs in 84 patients (37 male, 47 female; mean age, 53.3 years) with varicose veins were treated with cryosurgery over a 2-year period. The patients were followed for postoperative complication with surveillance of recurrence. The analyzed variables included age, sex, symptom, operative time (from skin incision to the application of elastic bandages on the legs for compression purposes), and postoperative complications including bruising, hematoma, superficial thrombophlebitis, cellulitis, seroma, cutaneous nerve damage, and wound complication.ResultsThe mean operative time was 64.7 minutes for both limbs and 44 minutes for single limbs. The median number of incisions was 2. For stripping of GSV, one incision at the groin was necessary. Postoperative complications included an episode of hematoma in 3 limbs (2.3%), cutaneous nerve damage in 3 limbs (2.3%), cellulitis in 2 patients (1.5%), and seroma in 1 limb (0.8%). No wound infection, thrombophlebitis or deep venous thrombosis was observed. During follow-up (mean follow-up period, 13.5 months; range, 3–28 months), there was no recurrence.ConclusionCryosurgery to treat varicose veins is an effective and safe treatment modality in terms of postoperative complication, cosmetic result, and recurrence.

MAGNETIC RESONANCE IMAGING, GROSS POSTMORTEM, AND HISTOLOGICAL FINDINGS FOR SOFT TISSUES OF THE PLANTAR ASPECT OF THE TARSUS AND PROXIMAL METATARSAL REGION IN NON-LAME HORSES.

Injuries of the plantar soft tissues of the tarsus and proximal metatarsus can be a source of lameness in horses, however published information is lacking on high field MRI characteristics of these tissues. Objectives of the current anatomic study were to (1) describe high-field MRI features of the plantar tarsal and proximal metatarsal soft tissues; and (2) compare MRI findings with gross and histological appearances of selected structures for a sample of cadaver limbs from non-lame horses. Single hindlimbs for 42 horses, and right and left hindlimbs for eight horses were scanned using high-field MRI. The MRI findings were described for the 50 single limbs; and the MRI, gross postmortem and histological findings were compared for the eight pairs of hindlimbs. The superficial digital flexor tendon had uniform low signal intensity, surrounded by the flexor retinaculum of intermediate to high signal intensity on all sequences. The lateral digital flexor tendon had slightly higher signal intensity, enclosed on the plantaromedial aspects by the low signal intensity metatarsocalcaneal ligament. The accessory ligament of the deep digital flexor tendon varied in size and signal intensity. The proximal and distal plantar ligaments, accessory ligament of the suspensory ligament, and calcaneoquartal ligament had low signal intensity. The long plantar ligament comprised a number of related parts, separated by lines of high signal intensity corresponding with fibrous septae seen in gross anatomical specimens. The plantar aspect of the ligament had uniform low signal intensity in all sequences, but the dorsal half was more heterogeneous with multifocal spots or lines of higher signal intensity.

The effect of myofascial neck pain on postural control: Visual deprivation

The aim of this study was to investigate the standing balance (with open and closed eyes) on rigid surface in women with myofascial neck pain syndromes. This study was carried out in single and double limbs stances, open versus closed eyes, and the results were compared with control group. Forty subjects (20 in each group) were tested on a force-platform, during 30 seconds. The mean velocity (cm/s), surface area (cm2), antero-posterior and medio-lateral displacements (cm) of center of foot pressure (COP) were determined. There were significant differences between two groups regarding the mean velocity and area of COP displacements. In addition, significant differences were observed in respect to eye and limb conditions (open versus closed; single versus double limbs stances; respectively) on mean velocity, area, antero-posterior (AP) and medio-lateral (ML) displacements of COP. Our results showed that myofascial neck pain syndrome might be one of the disturbing factors on standing balance.

Rescue of dystrophic skeletal muscle by PGC-1α involves restored expression of dystrophin-associated protein complex components and satellite cell signaling

Duchenne muscular dystrophy is typically diagnosed in the preschool years because of locomotor defects, indicative of muscle damage. Thus, effective therapies must be able to rescue muscle from further decline. We have established that peroxisome proliferator-activated receptor gamma coactivator 1-alpha (Pgc-1α) gene transfer will prevent many aspects of dystrophic pathology, likely through upregulation of utrophin and increased oxidative capacity; however, the extent to which it will rescue muscle with disease manifestations has not been determined. Our hypothesis is that gene transfer of Pgc-1α into declining muscle will reduce muscle injury compared with control muscle. To test our hypothesis, adeno-associated virus 6 (AAV6) driving expression of Pgc-1α was injected into single hind limbs of 3-wk-old mdx mice, while the contralateral limb was given a sham injection. At 6 wk of age, treated solei had 37% less muscle injury compared with sham-treated muscles (P < 0.05). Resistance to contraction-induced injury was improved 10% (P < 0.05), likely driven by the five-fold (P < 0.05) increase in utrophin protein expression and increase in dystrophin-associated complex members. Treated muscles were more resistant to fatigue, which was likely caused by the corresponding increase in oxidative markers. Pgc-1α overexpressing limbs also exhibited increased expression of genes related to muscle repair and autophagy. These data indicate that the Pgc-1α pathway remains a good therapeutic target, as it reduced muscle injury and improved function using a rescue paradigm. Further, these data also indicate that the beneficial effects of Pgc-1α gene transfer are more complex than increased utrophin expression and oxidative gene expression.

A neuromechanical model for the neuronal basis of curve walking in the stick insect

The coordination of the movement of single and multiple limbs is essential for the generation of locomotion. Movement about single joints and the resulting stepping patterns are usually generated by the activity of antagonistic muscle pairs. In the stick insect, the three major muscle pairs of a leg are the protractor and retractor coxae, the levator and depressor trochanteris, and the flexor and extensor tibiae. The protractor and retractor move the coxa, and thereby the leg, forward and backward. The levator and depressor move the femur up and down. The flexor flexes, and the extensor extends the tibia about the femur-tibia joint. The underlying neuronal mechanisms for a forward stepping middle leg have been thoroughly investigated in experimental and theoretical studies. However, the details of the neuronal and mechanical mechanisms driving a stepping single leg in situations other than forward walking remain largely unknown. Here, we present a neuromechanical model of the coupled three joint control system of the stick insect's middle leg. The model can generate forward, backward, or sideward stepping. Switching between them is achieved by changing only a few central signals controlling the neuromechanical model. In kinematic simulations, we are able to generate curve walking with two different mechanisms. In the first, the inner middle leg is switched from forward to sideward and in the second to backward stepping. Both are observed in the behaving animal, and in the model and animal alike, backward stepping of the inner middle leg produces tighter turns than sideward stepping.

Improved single-limb balance after total knee arthroplasty

Unsteady ambulation shortly after total knee arthroplasty (TKA) may cause falling. Postural sway may predict the risk of falling. This prospective single-blinded observational study therefore evaluated the effects of TKA on single-limb standing balance (SLSB) and factors related to change in SLSB. Patients with varus deformity and medial compartment degeneration were evaluated between September and December 2010. The Western Ontario and McMaster Universities Osteoarthritis Index and Kellgren/Lawrence scale were assessed, as were varus angle, number of painful knees, isometric peak torque of the quadriceps femoris, balance index of double limbs, and postural sway of single limbs. Twelve patients were enrolled and 11 were analysed. The mean ± SD postural sway of single limbs (i.e., SLSB) was reduced significantly after TKA, from 30.3 ± 20.8 cm to 18.5 ± 9.3 cm (p = 0.02). Amelioration was in proportion to pre-operative postural sway (β = 0.92). SLSB in patients with varus knees with osteoarthritis was improved significantly 11 days after TKA. Poorer pre-operative SLSB was associated with better post-operative SLSB. TKA may be useful for the immediate reduction of falling in patients with osteoarthritis.

Lower limb pain caused by insufficient muscular microcirculation.

Lumbar spinal surgery is a common procedure to treat low back pain. To remark that lower limb perfusion insufficiency may induce the similar syndrome as neuropathic pain, 1,076 cases of postspinal surgery was surveyed within 5years, in which 51 cases had no obvious improvement 3months after surgery; 27 cases received second operation because of instability, inadequate decompression, and wrong level; and the other 27 cases including 3 cases after twice spinal surgeries were enrolled. Physical examinations were presented with atypical neuropathic pain and muscle wasting at single lower limbs which deteriorated with long-distance walking. Computed tomography or magnetic resonance imaging scan was studied including the neural structure and lower limb angiography. The report showed degenerative change without definite neural structural compression or vascular occlusion. There was also no significant finding of electrodiagnostic study. The rest radionuclide study of lower limb muscle and myocardium was performed in these 27 cases using Thallium-201. All patients presented 9-24% (~14%) muscle perfusion difference compared with two legs. Most of peripheral arterial occlusion disease cases presented the symptoms with ischemic pain and vascular claudication. In the study, the patients presented not only ischemic limb but also the bizarre symptoms, such as low back pain with or without radiating root pain and sensory disturbance. Physicians should be aware of the possibility of lower limb pain caused by lower perfusion syndrome.

Outcome of transilluminated powered phlebectomy for varicose vein: review of 299 patients (447 limbs)

Varicose vein incompetence in the legs is very prevalent in the Korean population. New technologies and improvements in established methods have changed the treatment of varicose veins. Transilluminated powered phlebectomy is an alternative surgical technique that combines endoscopic powered vein resection and ablation of superficial varicosities with tumescent anesthesia and irrigated illumination. The present study sought to determine the clinical efficacy and safety of transilluminated powered phlebectomy from clinical data. Four hundred and forty-seven limbs in 299 patients (157 male, 142 female; mean age 50.6 years) with varicose veins were treated with transilluminated powered phlebectomy over a 7-year period. The patients were followed for 1 year postoperatively. The analyzed data included sex, age, body mass index, operative time (from skin incision to the application of elastic bandages on the legs for compression purposes), and postoperative complications. The mean operative time was 87.2 min for both limbs and 57.3 min for single limbs. The median number of incisions was five. Postoperative complications included an episode of cellulitis in 10 patients (2.2%), wound abscess in two patients (0.4%), hematoma in 15 patients (3.4%), residual veins in five patients (1.1%), cutaneous nerve damage in 10 patients (2.2%), and seroma in 13 patients (2.9%). No skin perforation and deep venous thrombosis were observed at the 1-year follow-up. Transilluminated powered phlebectomy is an effective and safe method for the excision of varicosities.

From Part- to Whole-Body Ownership in the Multisensory Brain

The question of how we experience ownership of an entire body distinct from the external world is a fundamental problem in psychology and neuroscience [1-6]. Earlier studies suggest that integration of visual, tactile, and proprioceptive information in multisensory areas [7-11] mediates self-attribution of single limbs. However, it is still unknown how ownership of individual body parts translates into the unitary experience of owning a whole body. Here, we used a "body-swap" illusion [12], in which people experienced an artificial body to be their own, in combination with functional magnetic resonance imaging to reveal a coupling between the experience of full-body ownership and neural responses in bilateral ventral premotor and left intraparietal cortices, and left putamen. Importantly, activity in the ventral premotor cortex reflected the construction of ownership of a whole body from the parts, because it was stronger when the stimulated body part was attached to a body, was present irrespective of whether the illusion was triggered by stimulation of the hand or the abdomen, and displayed multivoxel patterns carrying information about full-body ownership. These findings suggest that the unitary experience of owning an entire body is produced by neuronal populations that integrate multisensory information across body segments.