NeuroRehabilitation

Stroke is a leading cause of disability worldwide. Many survivors of stroke remain with residual disabilities, even years later. Advances in technology have led to the development of a variety of robotic devices for use in rehabilitation. The integration of robotics in the delivery of neurorehabilitation is promising, but still not widely used in clinical settings.

The aim of this review is to discuss the general design of three typical upper limb robotic devices, and examine the practical considerations for their use in a clinical environment.

Each device is described, the available clinical literature is reviewed and a clinical perspective is given on the usefulness of these robotic devices in rehabilitation of this population.

Current literature supports the use of robotics in the clinical environment. However, claims that robotic therapy is more effective than traditional treatment is not substantially supported. The majority of clinical trials reported are small, and lack the use of a control group for comparison treatment.

The use of robotics in stroke rehabilitation is still a relatively new treatment platform, and still evolving. As technological advances are made, there is much potential for growth in this field.

Good motor outcome after stroke has been found to correlate with increased activity in a dorsal premotor (PMd) brain circuit, suggesting that therapeutic strategies targeting this circuit might have a favorable, causal influence on motor status.

This study addressed the hypothesis that a Premotor Therapy that exercises normal PMd functions would provide greater behavioral gains than would standard Motor Therapy; and that Premotor Therapy benefits would be greatest in patients with greater preservation of PMd circuit elements.

Patients with chronic hemiparetic stroke (n = 15) were randomized to 2-weeks of Premotor Therapy or Motor Therapy, implemented through a robotic device.

Overall, gains were modest but significant (change in FM score, 2.1 ± 2.8 points, p < 0.02) and did not differ by treatment assignment. However, a difference between Therapies was apparent when injury to the PMd circuit was considered, as the interaction between treatment assignment and degree of corticospinal tract injury was significantly related to the change in FM score (p = 0.018): the more the corticospinal tract was spared, the greater the gains provided by Premotor Therapy. Similar results were obtained when looking at the interaction between treatment assignment and PMd function (p = 0.03).

Targeted engagement of a brain circuit is a feasible strategy for stroke rehabilitation. This approach has maximum impact when there is less stroke injury to key elements of the targeted circuit.

Robot assisted upper extremity therapy has been shown to be effective in adult stroke patients and in children with cerebral palsy (CP) and other acquired brain injuries (ABI). The patient's active involvement is a factor in its efficacy. However, this demands focused attention during training sessions, which can be a challenge for children.

To compare results of training requiring two different levels of focused attention. Differences in short term performance and retention of gains as a function of training protocol as measured by the Fugl-Meyer (FM) were predicted.

Thirty-one children with CP or ABI were randomly divided into two groups. All received 16 one hour sessions of robot-assisted therapy (twice a week for 8 weeks) where they moved a robot handle to direct a cursor on the screen toward designated targets. One group had targets presented sequentially in clockwise fashion, the other presented in random order. Thus, one group could anticipate the position of each target, the other could not.

Both groups showed significant functional improvement after therapy, but no significant difference between groups was observed.

Assist-as-needed robotic training is effective in children with CP or ABI with small non-significant differences attributed to attentional demand.

To evaluate the effects of add-on distal upper limb robot-assisted treatment on the outcome of proximal regions.

64 chronic stroke patients divided into two groups participated in the study. Group A was assigned to the proximal robot-assisted rehabilitation, Group B to the proximal and distal. Shoulder/elbow subsection of Fugl-Meyer Assessment scale was collected for Group A, whereas for Group B wrist subsection was also collected. Motricity Index was used and a set of kinematic parameters was computed for both groups.

A decrease in impairment after the treatment in both groups of patients (Group A: Shoulder/elbow FM p < 0.001 and MI p < 0.001; Group B: Shoulder/elbow FM p < 0.001 and MI p < 0.001) was found. In the Group B wrist subsection of FM showed an improvement as well (p < 0.001). No difference between groups was found in changes of clinical scales. Movement velocity and accuracy increased after the robot-assisted treatment in both groups; group B showed a greater improvement in velocity.

Robotic treatment is effective to reduce motor impairment in chronic stroke patients even if distal training added to proximal segments in the Group B does not provide any incremental benefit to the proximal segments. It remains unclear if the effectiveness of robot-assisted treatment is directly related to the upper limb segment specifically treated and which order may lead to better outcome. Our study suggests that kinematic parameters should be computed in order to better clarify the role of distal training (wrist) on proximal segments (shoulder/elbow) as well.

High intensity and early initiation of rehabilitation have been extensively demonstrated to enhance neural plasticity and motor recovery after stroke. However, the optimal duration of rehabilitation programs in order to have the highest impact on motor outcomes has not been established.

To evaluate motor outcomes in subacute stroke survivors with moderate to severe upper limb paresis over an extended period of rehabilitation consisting of usual care augmented with a large number of upper limb robot-assisted sessions (54 ± 13 sessions).

Retrospective study in 10 inpatients.

The results showed a gradual decrease in motor and functional impairments throughout the training period with a clinically meaningful increase in the Fugl-Meyer Assessment scores and in the Motor Status Scores (1st vs 37th day of the training, FMA,+ 48%, p = 0.018, MSS,+ 64%, p = 0.012; 37th vs. 79th day, FMA,+ 23%, p = 0.012, MSS,+ 30%, p = 0.017). In addition, there were improvements in hand kinematics recorded by the robot during a pointing task, with quantitative improvement (1st vs 40th day, movement efficacy,+ 97%, p = 0.0499; hand velocity,+ 335%, p = 0.013) prior to qualitative improvement (1st vs 80th day, number of hand trajectory reversals, −50%, p = 0.028; root mean square error of the trajectory/linear displacement, −52%, p = 0.059).

Although this study was a retrospective analysis of a small sample of patients, the results suggested that a prolonged period of intensive upper limb rehabilitation, including robot-assisted training incorporated into a multidisciplinary program throughout the subacute phase after stroke resulted in significant improvements in patients with moderate to severe motor impairments.

Combining tDCS with robotic therapy is a new and promising form of neurorehabilitation after stroke, however the effectiveness of this approach is likely to be influenced by the relative timing of the brain stimulation and the therapy.

To measure the kinematic and neurophysiological effects of delivering tDCS before, during and after a single session of robotic motor practice (wrist extension).

We used a within-subjects repeated-measurement design in 12 chronic (>6 months) stroke survivors. Twenty minutes of anodal tDCS was delivered to the affected hemisphere before, during, or after a 20-minute session of robotic practice. Sham tDCS was also applied during motor practice. Robotic motor performance and corticomotor excitability, assessed through transcranial magnetic stimulation (TMS), were evaluated pre- and post-intervention.

Movement speed was increased after motor training (sham tDCS) by ∼20%. Movement smoothness was improved when tDCS was delivered before motor practice (∼15%). TDCS delivered during practice did not offer any benefit, whereas it reduced speed when delivered after practice (∼10%). MEPs were present in ∼50% of patients at baseline; in these subjects motor practice increased corticomotor excitability to the trained muscle.

In a cohort of stroke survivors, motor performance kinematics improved when tDCS was delivered prior to robotic training, but not when delivered during or after training. The temporal relationship between non-invasive brain stimulation and neurorehabilitation is important in determining the efficacy and outcome of this combined therapy.

Recovering upper-limb motor function has important implications for improving independence of patients with tetraplegia after traumatic spinal cord injury (SCI).

To evaluate the feasibility, safety and effectiveness of robotic-assisted training of upper limb in a chronic SCI population.

A total of 10 chronic tetraplegic SCI patients (C4 to C6 level of injury, American Spinal Injury Association Impairment Scale, A to D) participated in a 6-week wrist-robot training protocol (1 hour/day 3 times/week). The following outcome measures were recorded at baseline and after the robotic training: a) motor performance, assessed by robot-measured kinematics, b) corticospinal excitability measured by transcranial magnetic stimulation (TMS), and c) changes in clinical scales: motor strength (Upper extremity motor score), pain level (Visual Analog Scale) and spasticity (Modified Ashworth scale).

No adverse effects were observed during or after the robotic training. Statistically significant improvements were found in motor performance kinematics: aim (pre 1.17 ± 0.11 raduans, post 1.03 ± 0.08 raduans, p = 0.03) and smoothness of movement (pre 0.26 ± 0.03, post 0.31 ± 0.02, p = 0.03). These changes were not accompanied by changes in upper-extremity muscle strength or corticospinal excitability. No changes in pain or spasticity were found.

Robotic-assisted training of the upper limb over six weeks is a feasible and safe intervention that can enhance movement kinematics without negatively affecting pain or spasticity in chronic SCI. In addition, robot-assisted devices are an excellent tool to quantify motor performance (kinematics) and can be used to sensitively measure changes after a given rehabilitative intervention.

1) To investigate the feasibility of combining transcranial direct current stimulation (tDCS) to the lower extremity (LE) motor cortex with novel locomotor training to facilitate gait in subjects with chronic stroke and low ambulatory status, and 2) to obtain insight from study subjects and their caregivers to inform future trial design.

Double-blind, randomized controlled study with additional qualitative exploratory descriptive design. One-month follow-up.10 subjects with stroke were recruited and randomized to active tDCS or sham tDCS for 12 sessions. Both groups participated in identical locomotor training with a robotic gait orthosis (RGO) following each tDCS session. RGO training protocol was designed to harness cortical neuroplasticity. Data analysis included assessment of functional and participation outcome measures and qualitative thematic analysis.

Eight subjects completed the study. Both groups demonstrated trends toward improvement, but the active tDCS group showed greater improvement than the sham group. Qualitative analyses indicated beneficial effects of this combined intervention.

It is feasible to combine tDCS targeting the LE motor cortex with our novel locomotor training. It appears that tDCS has the potential to enhance the effectiveness of gait training in chronic stroke. Insights from participants provide additional guidance in designing future trials.

A task-specific repetitive approach in gait rehabilitation after CNS lesion is well accepted nowadays. To ease the therapists' and patients' physical effort, the past two decades have seen the introduction of gait machines to intensify the amount of gait practice. Two principles have emerged, an exoskeleton- and an endeffector-based approach. Both systems share the harness and the body weight support. With the end-effector-based devices, the patients' feet are positioned on two foot plates, whose movements simulate stance and swing phase.

This article provides an overview on the end-effector based machine's effectiveness regarding the restoration of gait.

For the electromechanical gait trainer GT I, a meta analysis identified nine controlled trials (RCT) in stroke subjects (n = 568) and were analyzed to detect differences between end-effector-based locomotion + physiotherapy and physiotherapy alone.

Patients practising with the machine effected in a superior gait ability (210 out of 319 patients, 65.8% vs. 96 out of 249 patients, 38.6%, respectively, Z = 2.29, p = 0.020), due to a larger training intensity. Only single RCTs have been reported for other devices and etiologies.

The introduction of end-effector based gait machines has opened a new succesful chapter in gait rehabilitation after CNS lesion.

Advances in our understanding of neuroplasticity and motor learning post-stroke are now being leveraged with the use of robotics technology to enhance physical rehabilitation strategies. Major advances have been made with upper extremity robotics, which have been tested for efficacy in multi-site trials across the subacute and chronic phases of stroke. In contrast, use of lower extremity robotics to promote locomotor re-learning has been more recent and presents unique challenges by virtue of the complex multi-segmental mechanics of gait.

Here we review a programmatic effort to develop and apply the concept of joint-specific modular robotics to the paretic ankle as a means to improve underlying impairments in distal motor control that may have a significant impact on gait biomechanics and balance.

An impedance controlled ankle robot module (anklebot) is described as a platform to test the idea that a modular approach can be used to modify training and measure the time profile of treatment response.

Pilot studies using seated visuomotor anklebot training with chronic patients are reviewed, along with results from initial efforts to evaluate the anklebot's utility as a clinical tool for assessing intrinsic ankle stiffness. The review includes a brief discussion of future directions for using the seated anklebot training in the earliest phases of sub-acute therapy, and to incorporate neurophysiological measures of cerebro-cortical activity as a means to reveal underlying mechanistic processes of motor learning and brain plasticity associated with robotic training.

Finally we conclude with an initial control systems strategy for utilizing the anklebot as a gait training tool that includes integrating an Internal Model-based adaptive controller to both accommodate individual deficit severities and adapt to changes in patient performance.

Due to physical and psychosocial issues associated with long-term sitting in a wheelchair, devising new ways to facilitate upright mobility is a key issue in rehabilitation medicine. Wearable Power-Assist Locomotor (WPAL) is a motorized orthosis and is developed for providing independent and comfortable walking for paraplegic patients.

The WPAL consists of a wearable robotic orthosis and custom walker. To facilitate alternate usage with a wheelchair, the wearable robotic orthosis is based on a medial system with motors located at the bilateral hip, knee and ankle joints to reduce the increase in heart rate during gait. The gait parameters include stride length, toe clearance height, swing time, double support time, etc. (gait speed: up to 1.3 km/h). Independent gait with the walker can be learned through a five-stage gait exercise sequence. The first two stages are stepping and gait exercises with parallel bars. The third stage is gait exercise on treadmill. The subsequent two stages are gait exercise with walker.

Seven motor-complete paraplegic patients (spinal cord functional levels: T6-T12) participated. Through a series of exercises, all users achieved independent gait on a level floor (Functional Ambulation Categories: 4). The mean duration and distance of consecutively walking were 14.1 ± 11.4 minutes and 165.6 ± 202.6 m, respectively. The most competent user was able to walk continuously for as long as 40 minutes and 640 m whereas only for 6 minutes and 107 m with a conventional orthosis.

These results suggest that WPAL might be useful device for supporting upright walking in persons with paraplegia.

Evaluate the efficacy of outcome measures routinely used in a physical therapy service for Multiple Sclerosis (MS).

We performed a retrospective review of 500 medical records of MS patients from the outpatients service of AISM Rehabilitation Centre, Genova, Italy.

All records of outpatients followed by AISM Rehabilitation Centre who underwent physical therapy from 2006 to 2008 were evaluated.

Modified Fatigue Impact Scale (MFIS) and Ambulation Index (AI) were reviewed for all records at the begin and at the end of the rehabilitation treatment.

The number of assessments recorded was 295 in 209 patients. Out of the 209 patients, 133 were female and 76 were male. The mean age was 51.6 ± 11.68 years, the mean Expanded Disability Status Scale (EDSS) score was 4.98 ± 1.79, and 185 patients were ambulatory. In nonambulatory patients neither scale showed a significant increase. In ambulatory patients (275 assessments) significant changes were observed in AI, MFIS total score and subscores.

Physical therapy has a positive impact on fatigue, and the MFIS seems to be a good outcome measure in ambulatory patients. The AI and MFIS seem to be not indicated for use in non-ambulatory patients.

To measure heart rate (HR) and heart rate variability (HRV) at rest, during and after walking among children with cerebral palsy (CP) as compared to age matched typically developed (TD) controls. The second aim was to describe the association between HRV and motor performance in children with CP.

Twenty six children with CP (age 8–14 years) and sixteen TD children matched for age assessed during rest, walking and after walking. HR and HRV parameters include: time domain parameters: standard deviation of the R-R interval (SDNN), square root of the mean squared differences of successive R-R differences (RMSSD).

Children with CP demonstrated higher mean HR values at rest; 98.4 ± 13.9 bpm vs 83.0 ± 11.5 bpm in controls, (p < 0.05) and significantly lower time domain measures of HRV; RMSSD was 52.0 ± 19.1 ms and 87.0 ± 39.8 ms respectively (p < 0.05). Significant interaction effects were noted for HR and time domain HRV parameters. HR increased and SDNN and RMSSD decreased when children change their activity level from rest to walking and HR decreased and SDNN and RMSSD increased again after walking for TD children but not for children with CP (p < 0.05). No association was noted between HRV and motor performance in children with CP.

The findings of this study suggest that among children with CP, the cardiac autonomic mechanism is less efficient at rest and less adaptive to exercise and activity as compared to TD children.

Gorham's disease of the spine is very rare and usually associated with poor prognosis. Till date very few cases have been reported in the literature. It is characterized by osseous invasion by angiomatous vascular mass without skip areas, eventually causing lysis of affected bone. Morbidity and mortality are high in those with spinal and/or visceral involvement. Neurological complications increase the mortality to 33% whereas with chylothorax, mortality increases to more than 50%.

To describe the clinical course and the challenges in planning and implementing effective rehabilitation services for management of patients with Gorham's disease of the spine.

We report two patients with Gorham's disease who had neurological deficits secondary to spinal cord involvement, and their rehabilitation perspectives.

Both patients achieved satisfactory ambulation and functional outcomes.

Multiple revision surgeries may be required to ensure spinal stability. When working with these patients, one must remain vigilant about spinal stability as well as about possible serious pulmonary complications, and be prepared to make appropriate management decisions when necessary.

Muscle weakness in the lower limbs and impeded gait performance are common in persons with late effects of polio.

To assess self-reported walking ability in persons with late effects of polio and determine the relationship with objectively assessed gait performance.

One-hundred and twenty-two individuals with prior polio (65 women and 57 men, mean age 65 [SD ± 9] years) participated in the study. The main outcome measures were: Walk-12 (Swedish version) to assess self-reported walking ability, and Timed “Up & Go”, Comfortable Gait Speed, Fast Gait Speed and 6-Minute Walk Tests to assess gait performance objectively.

More than 50% of the participants reported limitations (moderately or quite a bit) related to standing or walking, climbing stairs, walking speed and distance, concentration and effort, and gait quality aspects. Half of the participants reported no need to use support when walking indoors or outdoors, but 58% reported that their ability to run was extremely limited. Significant correlations (P < 0.01) were found between the Walk-12 and the four gait performance tests (rho −0.66 to 0.63).

The strength of the relationship implies that Walk-12 reflects broader dimensions than the objective gait performance tests and can be a complement when the walking ability in persons with late effects of polio is evaluated.

To describe adaptations in power output, quadriceps muscle strength, and fatigability that occur during a 13-week regimen of Functional Electrical Stimulation Leg Cycle Ergometry (FES-LCE) in Spinal Cord Injury (SCI). To identify differences in outcomes between individuals with complete and incomplete motor impairment.

Observational and longitudinal. SETTING: Rehabilitation and biomechanics research laboratory.

Eleven (N = 11) individuals with SCI and no previous FES-LCE experience.

40 sessions of FES-LCE at a rate of three sessions per week. Continuous exercise was performed at a pedal cadence of 45 RPM against a constant resistance for up to 60 minutes.

Mean power output was recorded for each session. Before and after the training regimen, each subject performed a fatigue test in which electrically stimulated knee extension torque and Fatigue Index were measured.

Participants demonstrated significant increases in mean power output (9.0 to 20.3 W; p < 0.001), peak isometric knee extension torque (3.8 to 16.9 Nm; p = 0.006) and sustainable isometric knee extension torque (4.9 to 14.4 Nm; p = 0.001) after FES-LCE training (95% confidence intervals). Participants with incomplete motor impairment demonstrated a decrease in Fatigue Index (p = 0.021), and improved mean power output more than those with complete motor impairment (p = 0.037).

Significant improvements in muscle conditioning and exercise performance are possible following the 13-week regimen of FES-LCE described in this article. Individuals with incomplete motor impairment experience greater improvements in mean power output than individuals with complete motor impairment.

To explore the etiology of exercise intolerance in patients with MS, it is analyzed whether a disturbed cardiac autonomic control could be observed during exercise testing in patients with MS, and is related to exercise tolerance.

From 26 MS patients and 15 healthy subjects, exercise-onset (first 20 and 60 seconds) and –offset (1-minute recovery) HR change was determined during a 6-minute constant-load exercise bout on bike. Blood lactate, HR, oxygen uptake, expiratory volume and perceived exertion were assessed during exercise, and compared between groups. In 15 MS patients, a 6-min walking test was executed.

Twenty-second exercise-onset HR increase was significantly smaller in MS patients (14 ± 7 bts/min) vs. healthy subjects (20 ± 8 bts/min, p < 0.05), and independently related to MS and age in total group (p < 0.05). Sixty-second exercise-onset and –offset HR changes were not different between groups, nor independently related to MS presence (p > 0.05). A significant correlation was found between 20-second exercise-onset HR increase and walking capacity in MS patients (r = 0.64, p < 0.01).

In MS patients, the early increase in heart rate during endurance exercise is significantly slowed, indicating a disturbed cardiac autonomic control, and is related to exercise tolerance.

A Pretest –Posttest Experimental Design.

Patients with incomplete spinal cord injury (ISCI) retain or regain the ability to walk, but due to limitations in gait parameters, walking may not be the practical method of mobility in the community. Specific muscle training plays an important role in gait training. The purpose of this study was to determine the effect of EMG Biofeedback training of gluteus maximus muscle on gait parameters in ISCI patients.

Indian Spinal Injury Center, New Delhi, India.

30 incomplete spinal cord injured (ISCI) patients were included and randomly assigned to two groups. Group 1 received EMG Biofeedback (EMG BF), Traditional Rehabilitation and Gait Training. Group 2 received Traditional Rehabilitation and Gait Training.

Gait parameters were measured prior to the intervention for all 30 ISCI patients. EMG Biofeedback was given specifically over gluteus maximus muscle along with traditional rehabilitation and gait training to Group 1 for 5 days/week for 4 weeks. Group 2 received traditional rehabilitation and gait training for 5 days/week for 4 weeks. The results were interpreted on the basis of: EMG amplitude, step length, walking velocity and cadence.

Results showed significant difference between two groups for EMG amplitude (t = 6.06, p = 0.001), walking velocity (t = 2.12, p = 0.043), cadence (t = 1.96, p = 0.05). Step length did not show any significant difference (t = 0.66, p = 0.512).

The study concluded that EMG BF when given specifically over gluteus maximus resulted in improvement of EMG amplitude and various gait parameters (walking velocity, cadence).

We investigated the hypothesis that ADL tests dependent on cortical functions could be used to assess outcome in stroke patients.

27 right-handed stroke patients were evaluated on National Institute of Health Stroke Scale (NIHSS), Barthel Index (BI), Instrumental Activities of Daily Living (IADL) Scale and thinking process items of Loewenstein Occupational Therapy Cognitive Assessment (LOTCA).

Correlations between thinking process subtests of LOTCA and different items of NIHSS such as consciousness, arm movement, aphasia, ataxia and inattention was significant. Spearman correlation of thinking process and BI tasks showed no relationship, although Structured Riska of thinking process evaluation was correlated to both self-care and mobility areas of the BI. Thinking process was strongly related to IADL total score (p = 0.004). The total NIHSS correlated significantly with BI and IADL total scores.

Higher-order functions, such as categorization, sorting and reasoning, are related to IADL performance which depends on complicated cognitive abilities. In contrast, the BI depends heavily on motoric function, and does not correlate with higher-order functions. Further confirmation is needed, but our data suggest that commonly used IADL tests could serve to as valid, reliable tests of cognitive impairment and recovery in stroke victims.

To investigate the effects of regional thigh composition that result in different responses to current amplitude among individuals with spinal cord injury (SCI) during applications of surface neuromuscular electrical stimulation (NMES) to evoke dynamic leg extension.

Cross-sectional.

Academic Settings.

Five males with chronic motor complete SCI completed 3 visits of NMES to determine the current amplitude required to evoke full knee extension. The participants underwent magnetic resonance imaging of both thighs to measure skeletal muscle cross-sectional area (CSA), thigh subcutaneous adipose tissue (SAT) and intramuscular fat (IMF). Applicants were classified into high (n = 3) and low-responders (n = 2) based on the determined current amplitude.

The low-responders required 48–59% greater current amplitude to complete the same task as the high-responders. Low-responders had greater thigh SAT CSA (51–56%) than the high-responders with SCI. After adjusting to whole thigh CSA, IMF CSA was significantly greater in the low- responders; whereas skeletal muscle CSA was lower compared to the high-responders.

The findings suggest that thigh SAT and IMF act as insulation against propagation of current during surface NMES applications in individuals with SCI.

It is unclear whether mental simulation without actual muscle contraction associated with actual motion can increase the excitability of the spinal neural function.

To determine the best method for mental simulation without actual muscle contraction, we analyzed the F-wave of thenar muscles after stimulating the median nerve by motor imagery whilst holding the sensor of a pinch meter between the thumb and index finger and without holding the sensor.

Healthy volunteers (n = 11; mean age, 34 years) participated in this study after providing informed consent. We examined the F-wave of the left thenar muscles after stimulating the left median nerve at the wrist at rest and under holding and motor imagery conditions. For the motor imagery condition, the subjects were asked to establish 50% maximal voluntary contraction (MVC) of isometric contraction while holding the sensor between the thumb and index finger (motor imagery with the sensor condition) and without holding the sensor on another day (motor imagery without the sensor condition).

The persistence and amplitude ratio of F/M during motor imagery with or without the sensor was better than that during relaxation. In particular, this ratio was significantly higher under the with sensor condition than under the without sensor condition.

Movement preparation for a motor imagery task involving 50% MVC isometric contraction of the opponens pollicis is important.

The major contributors to physical disability after stroke are the negative impairments related to loss of functional ability and muscle strength. The aim of this study was to examine the effects of close kinetic chain (CKC) exercise and open kinetic chain (OKC) exercise on muscle activation of the paretic lower limb and balance in chronic stroke subjects.

Thirty-three patients with chronic stroke of over 6 months were enrolled. They were randomly allocated to three groups: CKC exercise group (n = 11), OKC exercise group (n = 11), and control group (n = 11). CKC and OKC exercise groups were trained 5 times per week for 6 weeks. The control group maintained routine activities and did not participate in any regular exercise program. All subjects were measured on muscle activation of the paretic lower limb and balance.

Muscle activation of rectus femoris (RF) and biceps femoris (BF) was significantly increased in both CKC exercise and OKC exercise groups, compared to the control group. However, muscle activation of gastrocnemius (GC) and tibialis anterior (TA) was significantly increased in only the CKC exercise group. Antero-posterior (A-P) andmedio-lateral (M-L) sway velocities (both with EO and EC) were decreased with the application of CKC exercise.

These findings indicate that the CKC exercise can improve lower limb muscle strength, and balance in chronic stroke, and it may carry over into an improvement in functional performance.