Interlimb coupling in children with hemiplegic cerebral palsy during reaching and grasping at speed

This investigation examined reaching and grasping at speed in children with hemiplegic cerebral palsy. Of particular interest was the effect of the movement of the less affected limb on the more affected one. Using 3D kinematic analysis and standard video recordings, 11 children with hemiplegia of varying degrees of severity were examined performing three reaching tasks at speed. The data were analysed and the extent and nature of the interlimb coupling occurring in each child were assessed using a number of different variables. The results are discussed in terms of spatial, temporal, and postural coupling. All children coupled to some degree but differed in the degree and type of coupling. Speed facilitated coupling which was stronger during the first part of the movement in all three tasks. The variables affecting coupling included the type of coupling, the nature of the task, the importance of context, and the stage in the movement.     

A novel functional electrical stimulation-control system for restoring motor function of post-stroke hemiplegic patients

Hemiparesis is one of the most common consequences of stroke. Advanced rehabilitation techniques are essential for restoring motor function in hemiplegic patients. Functional electrical stimulation applied to the affected limb based on myoelectric signal from the unaffected limb is a promising therapy for hemiplegia. In this study, we developed a prototype system for evaluating this novel functional electrical stimulation-control strategy. Based on surface electromyography and a vector machine model, a self-administered, muki-movement, force-modulation functional electrical stimulation-prototype system for hemiplegia was implemented. This paper discusses the hardware design, the algorithm of the system, and key points of the self-oscillation-prone system. The experimental results demonstrate the feasibility of the prototype system for further clinical trials, which is being conducted to evaluate the efficacy of the proposed rehabilitation technique.     

功能性电刺激结合重复经颅磁刺激用于缺血性脑卒中偏瘫患者步行障碍恢复的临床观察

目的 观察功能性电刺激结合重复经颅磁刺激用于缺血性脑卒中偏瘫患者步行障碍恢复的临床疗效。方法 将53例缺血性脑卒中偏瘫患者随机分为对照组、治疗组、假治疗组3组,在均接受常规康复训练的基础上对照组接受功能性电刺激治疗,治疗组接受功能性电刺激及重复经颅磁刺激治疗,假治疗组接受功能性电刺激及假重复经颅磁刺激治疗; 治疗前及治疗8周后采用步态运动学参数、时间参数、距离参数及Amer-Lindholm分级对3组患者的下肢综合运动功能进行评定。结果 治疗前3组患者步态运动学参数、时间参数、距离参数及Amer-Lindholm分级评分均无显著差异(P>0.05),治疗8周后3组患者上述指标明显改善且治疗组改善幅度明显优于其余2组(P<0.05)。结论 功能性电刺激联合重复经颅磁刺激治疗有利于改善缺血性脑卒中偏瘫患者的步行运动功能。     

Changes in neuromuscular function after training by functional electrical stimulation

We examined whether the neuromuscular function of rectus femoris (RF) and flexor digitorum brevis (FDB) in humans was modified after a 6-week training period of functional electrical stimulation (FES), and whether any effects persisted at the end of a 6-week post-FES recovery period. In both the stimulated and contralateral nonstimulated muscles, we recorded the muscle force, surface electromyogram, and M wave, and also measured the root mean square (RMS) and the median frequency (MF) during static contraction sustained until exhaustion at 60% of maximal voluntary contraction (MVC). FES was performed with symmetric biphasic pulses, with a ramp modulation of both the stimulation frequency and pulse duration. No changes in MCV and endurance time to exhaustion occurred in nonstimulated muscles, whereas a significant MVC increase occurred immediately after FES in RF (+14 +/- 5%) and FDB (+13 +/- 5%), these effects persisting 6 weeks after the end of FES. In FDB, FES also elicited a significant increase in endurance time to exhaustion (+18 +/- 7%). The M-wave characteristics never varied after FES, but a marked attenuation occurred in the MF decrease and the RMS increase measured at endurance time to sustained 60% MVC, especially in FDB, which contains the higher proportion of type II fibers. These data indicate that FES improves muscle function and elicits changes in central muscle activation. The benefits of FES were greater in FDB, which is highly fatigable, and persisted for at least a 6-week period.     

The effects of electromyography-controlled functional electrical stimulation on upper extremity function and cortical perfusion in stroke patients

Objective

The relation was investigated between hemiparetic arm function improvement and brain cortical perfusion (BCP) change during voluntary muscle contraction (VOL), EMG-controlled FES (EMG-FES) and simple electrical muscle stimulation (ES) before and after EMG-FES therapy in chronic stroke patients.

Methods

Sixteen chronic stroke patients with moderate residual hemiparesis underwent 5 months of task-orientated EMG-FES therapy of the paretic arm once or twice a week. Before and after treatment, arm function was clinically evaluated and BCP during VOL, ES and EMG-FES were assessed using multi-channel near-infrared spectroscopy.

Results

BCP in the ipsilesional sensory-motor cortex (SMC) was greater during EMG-FES than during VOL or ES; therefore, EMG-FES caused a shift in the dominant BCP from the contralesional to ipsilesional SMC. After EMG-FES therapy, arm function improved in most patients, with some individual variability, and there was significant improvement in Fugl–Meyer (FM) score and maximal grip strength (GS). Clinical improvement was accompanied by an increase in ipsilesional SMC activation during VOL and EMG-FES condition.

Conclusion

The EMG-FES may have more influence on ipsilesional BCP than VOL or ES alone.

Significance

The sensory motor integration during EMG-FES therapy might facilitate BCP of the ipsilesional SMC and result in functional improvement of hemiparetic upper extremity.     

Ambulation using the reciprocating gait orthosis and functional electrical stimulation.

Until recently, rehabilitation engineering offered 2 different methods to improve daily living independence for spinal cord paralyzed subjects. One, the use of various orthotics and the other, the application of functional electrical stimulation. In the present work we chose to combine reciprocating gait orthosis (RGO) with functional electrical stimulation (FES) into one hybrid system. A detailed biomechanical and clinical instruction for the use of this system is given. Results obtained from application of the hybrid system on a complete T4 paraplegic patient demonstrate that the most significant contribution was the reduced invested energy cost required for stand-up and for ambulation.     

Posture switching for prolonging functional electrical stimulation standing in paraplegic patients

The presently employed posture for Functional Electrical Stimulation (FES) assisted standing in spinal cord injury (SCI) patients utilises the active locking of knee joints by tetanically stimulating the quadriceps muscle. The hip joints are in hyperextension and the ankle joints remain free. The upper limbs are used for balancing. This posture requires minimal corrective forces exerted by the hands, the weight is transferred across the legs, while very limited forward-backward sway is permitted. Knee jack-knifing may occur in the instance when the gravity knee bending moment exceeds the moment generated by the quadriceps muscle. Because of these effects and fatiguing of the M. quadriceps the standing time is short, lasting from several minutes up to an hour, depending on the condition of the patient's muscles. Cyclical FES with a duty cycle of 10-20 seconds (on/off) fatigues muscle considerably less. The use of different postures for standing requiring activation of different muscles permits the application of cyclical FES. The cyclic FES results in prolonging standing times by a factor of two to five. Utilising this improvement some patients can stand for up to five hours at a time. This functional achievement is comparable to the standing time of a normal man. The incorporation of the principle of posture switching also prolongs standing in patients with weak muscles, because of the possibility of cyclical coactivation of different synergistic muscle assemblies. It is shown that posture switching can be carried out automatically and that patients adapt quickly to it. In addition using co-contraction of two or three muscles with posture switching does further expand the range of suitable patients and improves standing with an increased permissible range of body sway. Also, the FES antigravity action obtained raises hopes for substantially improving FES induced reciprocal gait.     

Rebuilding motor function of the spinal cord based on functional electrical stimulation

Rebuilding the damaged motor function caused by spinal cord injury is one of the most serious challenges in clinical neuroscience. The function of the neural pathway under the damaged sites can be rebuilt using functional electrical stimulation technology. In this study, the locations of motor function sites in the lumbosacral spinal cord were determined with functional electrical stimulation technology. A three-dimensional map of the lumbosacral spinal cord comprising the relationship between the motor function sites and the correspond-ing muscle was drawn. Based on the individual experimental parameters and normalized coordinates of the motor function sites, the motor function sites that control a certain muscle were calculated. Phasing pulse sequences were delivered to the determined motor function sites in the spinal cord and hip extension, hip lfexion, ankle plantarlfexion, and ankle dorsilfexion movements were successfully achieved. The results show that the map of the spinal cord motor function sites was valid. This map can provide guidance for the selection of electrical stimulation sites during the rebuilding of motor function after spinal cord injury.     

高压氧及右正中神经电刺激对重型颅脑外伤患者的术后催醒作用

目的 探讨高压氧(HBO)及右正中神经电刺激(RMNS)对重型颅脑损伤患者术后催醒的影响. 方法 选择83例术后恢复期重型颅脑损伤患者,按随机数字表法分为治疗组(n=42)和对照组(n=41),其中对照组患者接受常规及对症治疗,治疗组在此基础上同时进行高压氧(HBO)及右正中神经电刺激(RMNS)治疗.3个月后比较2组患者的格拉斯哥昏迷评分(GCS)、格拉斯哥预后评分(GOS)、日常生活能力评分(ADL)、神经功能缺损评定(ESS)和远期生活质量评分(KPS),采用经颅三维多普勒彩色超声(TCD)和脑地形图(BEAM)分别评定脑血流量和脑电活动的变化. 结果与对照组比较,治疗组患者治疗1、3个月时各项评分均有改善,差异有统计学意义(P＜0.05);TCD检查显示治疗组患者病灶局部脑血流量明显提高,对照组仅有17例患者病灶局部脑血流量较前有所提高;与对照组比较,BEAM显示治疗组患者治疗后弥漫性慢波明显减少. 结论 高压氧及右正中神经电刺激治疗能促进重型颅脑损伤患者脑组织和脑神经功能的恢复,促进意识水平的改善.     

Real-time and wearable functional electrical stimulation system for volitional hand motor function control using the electromyography bridge method

Voluntary participation of hemiplegic patients is crucial for functional electrical stimulation therapy. A wearable functional electrical stim-ulation system has been proposed for real-time volitional hand motor function control using the electromyography bridge method. hTrough a series of novel design concepts, including the integration of a detecting circuit and an analog-to-digital converter, a miniaturized functional electrical stimulation circuit technique, a low-power super-regeneration chip for wireless receiving, and two wearable armbands, a pro-totype system has been established with reduced size, power, and overall cost. Based on wrist joint torque reproduction and classiifcation experiments performed on six healthy subjects, the optimized surface electromyography thresholds and trained logistic regression classiifer parameters were statistically chosen to establish wrist and hand motion control with high accuracy. Test results showed that wrist lfexion/extension, hand grasp, and ifnger extension could be reproduced with high accuracy and low latency. hTis system can build a bridge of in-formation transmission between healthy limbs and paralyzed limbs, effectively improve voluntary participation of hemiplegic patients, and elevate effciency of rehabilitation training.     

A clinical exercise system for paraplegics using functional electrical stimulation.

A low cost clinical exercise system was developed for the spinal cord injured, based on a bicycle ergometer and electrical stimulation. A pilot project was conducted, using the system, to examine the effects of stimulation induced cycling in long term paraplegics. The project comprised 2 phases of exercise, a strengthening phase involving a 12 week programme of electrical stimulation to the quadriceps and hamstrings and a 12 week cycling phase. Physiological, morphological and biochemical parameters were measured for each subject, at the beginning of the programme and following each phase. Results showed that a programme of stimulation induced lower limb exercise increased the exercise tolerance of all patients, as determined by a progressive increase in exercise time, cycling rate and exercise load. The enhanced exercise tolerance was a result of increases in local muscle strength and endurance. Increases in thigh muscle area and joint range of motion were recorded and all incomplete subjects reported an improvement in functional capabilities and general wellbeing.     

Hand kinematics during reaching and grasping in the macaque monkey

In this paper, we develop an animal model of prehension movements by examining the kinematics of reaching and grasping in monkeys and by comparing the results to published data on humans. Hand movements were recorded in three dimensions in monkeys who were trained to either point at visual targets under unperturbed and perturbed conditions, or to reach and grasp 3-D objects. The results revealed the following three similarities in the hand kinematics of monkey and man. (1) Pointing movements showed an asymmetry depending on target location relative to the hand used; in particular, movements to an ipsilateral target took longer than those to a contralateral one. (2) Perturbation of target location decreased the magnitude of the velocity peak and increased the duration of pointing movements. (3) Reaching to grasp movements displayed a bell-shaped wrist velocity profile and the maximum grip aperture was correlated with object size. These similarities indicate that the macaque monkey can be a useful model for understanding human motor control.     

Development of reaching and grasping skills in infants with Down syndrome

Reaching and grasping skills have been described to emerge from a dynamic interaction between intrinsic and extrinsic factors. The aims of the study were to investigate the effect of such intrinsic factors as age and Down syndrome on the development of reaching and grasping skills and on overall gross motor skill, and to test the influence of the overall level of gross motor skill on the development of reaching and grasping. Seven infants with Down syndrome (DS) and seven infants with typical development were assessed at the ages of 4, 5 and 6 months. The following variables were analyzed: straightness index, mean velocity, movement units and deceleration time (for reaching movements), grasping frequency and AIMS scores. Intrinsic factors such as age and DS were found to influence the development of reaching, grasping, and of the overall level of gross motor skill. The overall level of gross motor skill was observed to influence grasping.     

Electrophysiological characterization of pre- and postoperative facial nerve function in patients with acoustic neuroma using electrical and magnetic stimulation techniques

Facial nerve function was examined in patients who underwent posterior fossa surgery for unilateral acoustic neuroma. Examinations took place prior to surgery (n = 47 patients), early after surgery (0–12 days, n = 16 of 47 patients), and late after surgery (187–1505 days, n = 29 of 47 patients). Clinical signs of facial palsy were present to a variable extent in 13 of 47 patients before, in 12 of 16 patients early, and in 18 of 29 patients later after surgery. Electrophysiologically, the facial nerve was stimulated electrically at the stylomastoid fossa and magnetically at its proximal intracanalicular segment. In addition, the faceassociated motor cortex was stimulated magnetically. In patients with facial palsy, any of these stimulation methods resulted in a decreased amplitude of the response in the nasalis muscle. The decrease showed a linear relationship to the clinical grade of palsy, pre- and postoperatively. Corticomuscular latencies remained unchanged. We conclude that: (i) the electrophysiological characteristics of facial nerve lesions due to compression by acoustic neuromas or due to a complication of neuroma removal are those of a purely axonal neuropathy; (ii) the three stimulation techniques have a similar diagnostic yield, thus making the use of all three of them redundant; and (iii) the electrophysiological techniques allowed no prediction of the final facial nerve function. © 1994 John Wiley & Sons, Inc.     

三级康复训练对脑卒中偏瘫患者肢体功能恢复及生活质量的影晌

目的探讨三级康复训练对脑卒中偏瘫患者肢体功能恢复及生活质量的影响。方法选择我院2010一08—2012—10收治的116例脑卒中偏瘫患者,观察组58例采用三级康复训练措施,对照组58例采用常规护理措施,比较2组患者的肢体功能恢复情况和生活质量改善情况。结果治疗前、治疗1个月与3个月后,2组患者的上肢和下肢FMA评分、MBI评分均基本相当,组问差异无统计学意义;而6个月后,2组患者的上肢和下肢FMA评分、MBI评分均出现明显提高,且观察组改善程度更为显著,2组比较差异具有统计学意义（P〈O．05）。结论三级康复训练措施通过循序渐进的护理措施指导脑卒中患者进行机体的康复联系,有利于患者的肢体功能恢复,并在一定程度上提高患者的生活质量,有利于患者的预后恢复,值得临床应用。     

New functional electrical stimulation approaches to standing and walking

Spinal cord injury (SCI) is a devastating neurological trauma that is prevalent predominantly in young individuals. Several interventions in the areas of neuroregeneration, pharmacology and rehabilitation engineering/neuroscience are currently under investigation for restoring function after SCI. In this paper, we focus on the use of neuroprosthetic devices for restoring standing and ambulation as well as improving general health and wellness after SCI. Four neuroprosthetic approaches are discussed along with their demonstrated advantages and their future needs for improved clinical applicability. We first introduce surface functional electrical stimulation (FES) devices for restoring ambulation and highlight the importance of these devices for facilitating exercise activities and systemic physiological activation. Implanted muscle-based FES devices for restoring standing and walking that are currently undergoing clinical trials are then presented. The use of implanted peripheral nerve intraneural arrays of multi-site microelectrodes for providing fine and graded control of force during sit-to-stand maneuvers is subsequently demonstrated. Finally, intraspinal microstimulation (ISMS) of the lumbosacral spinal cord for restoring standing and walking is introduced and its results to date are presented. We conclude with a general discussion of the common needs of the neuroprosthetic devices presented in this paper and the improvements that may be incorporated in the future to advance their clinical utility and user satisfaction.     

Stochastically-modulated stimulation to slow down muscle fatigue at stimulated sites in paraplegics using functional electrical stimulation for leg extension

This short communication is a preliminary report on a study concerning slowing down the rate of muscle fatigue when FES (Functional Electrical Stimulation) is applied for standing and walking by complete (traumatic) thoracic-level paraplegics. It is shown that randomly modulating the inter-pulse interval between FES pulses (which serve to trigger action potentials in the peripheral nerves concerned) results in a significantly lower rate of muscle fatigue, as tested in a series of leg extensions, when FES was applied at the quadriceps. Specifically, we report that the best results (longest durations of leg extension prior to onset of muscle-fatigue) were achieved with a +/- 5 msec uniformly-distributed (pseudo-) white-noise modulation at a 42 msec inter-pulse interval (24 pulses per sec). These resulted in an average increase in duration of leg extension of approximately 37% in this pilot study, as compared with unmodulated (fixed-rate) trains of FES pulses. This significant increase, even in a very preliminary study appears to merit careful further examination, since it may allow a possibly significant increase in standing duration and in walking range of paraplegics using FES for ambulation.