Reliability of concentric and eccentric torque during isokinetic knee extension in post-stroke hemiparesis. Muscle Weakness and Cocontraction in Upper Limb Hemiparesis: Relationship to Motor Impairment and Physical Disability Reliability of isokinetic normalized peak torque assessments for knee muscles in post-stroke hemiparesis. Muscle strengthening and physical conditioning to reduce impairment and disability in chronic stroke survivors. Comparison of Bilateral and Unilateral Training for Upper Extremity Hemiparesis in Stroke Time and magnitude of torque generation is impaired in both arms following stroke. Trunk Muscle Strength in Relation to Balance and Functional Disability in Unihemispheric Stroke Patients A pilot study of respiratory muscle training to improve cough effectiveness and reduce the incidence of pneumonia in acute stroke: study protocol for a randomized controlled trial Determinants of improvement in walking capacity among individuals with chronic stroke following a multi-dimensional exercise program. Reliability of Dynamic Muscle Performance in the Hemiparetic Upper Limb Muscle strength of trunk flexion-extension in post-stroke hemiplegic patients. Electroacupuncture may help motor recovery in chronic stroke survivors: a pilot study. Circuit training in community-living "younger" men after stroke. Physical Complications in Acute Lung Injury Survivors: A Two-Year Longitudinal Prospective Study Robotic unilateral and bilateral upper-limb movement training for stroke survivors afflicted by chronic hemiparesis Mechanisms of Chronic Muscle Wasting and Dysfunction after an Intensive Care Unit Stay. A Pilot Study. Isokinetic strength training of the hemiparetic knee: effects on function and spasticity. Training of Reaching in Stroke Survivors With Severe and Chronic Upper Limb Paresis Using a Novel Nonrobotic Device: A Randomized Clinical Trial Examination of motor unit control properties in stroke survivors using surface EMG decomposition: A preliminary report Chronic stroke motor recovery: duration of active neuromuscular stimulation Low resonance frequency vibration affects strength of paretic and non-paretic leg differently in patients with stroke. Functional electrical stimulation of dorsiflexor muscle: effects on dorsiflexor strength, plantarflexor spasticity, and motor recovery in stroke patients. The relation between Ashworth scores and neuromechanical measurements of spasticity following stroke
BACKGROUND Emerging evidence on the velocity-dependent nature of force impairment in post-stroke hemiparesis has emphasized the complexity of strength and motor performance assessment s in this clinical population . The need to establish reliability and responsiveness of muscle performance measures across a broad range of concentric and eccentric movement speeds is therefore clear , as these metrics will provide benchmarks both for making clinical inference and evaluating meaningful clinical change following interventions . METHODS Isokinetic knee extensor strength was tested at 14 angular velocities in 17 adults with chronic post-stroke hemiparesis ( > 18 months ) , and 13 non-disabled controls . Identical tests were conducted on two occasions separated by two days . Test-retest reliability of maximal isokinetic torque was evaluated using intraclass correlation . Absolute reliability was assessed using st and ard error of measurement from which smallest real differences were derived . FINDINGS Overall , intraclass correlation coefficients were excellent for both hemiparetic ( 0.891 ) and control ( 0.937 ) groups . Intraclass correlation coefficients for each criterion speed were also high for both groups ( > 0.86 ) . Measurement error relative to the mean torque varied between 14.1 % and 26.3 % for hemiparetic subjects and 6.0 - 18.1 % for controls . The smallest real difference relative to mean torque was 39.0 - 72.7 % and 16.6 - 50.2 % for hemiparetic and control subjects , respectively . INTERPRETATION Isokinetic knee extension torque can be measured reliably in persons with chronic post-stroke hemiparesis and in non-disabled controls across a full functional range of concentric and eccentric speeds . Established measurement error and smallest real differences will aid interpretation of longitudinal observations of muscle performance in this clinical population The purpose of this article is to describe the relationship between poststroke upper limb muscle weakness and cocontraction , and clinical measures of upper limb motor impairment and physical disability .  Electromyographic ( EMG ) activity of the  paretic and nonparetic wrist flexors and extensors of 26 chronic stroke survivors were recorded during isometric wrist flexion and extension . The root mean square ( RMS ) of the EMG signal was used as a measure of strength of contraction . A ratio of RMS of antagonist and agonist muscles was used as a measure of cocontraction . Upper limb motor impairment and physical disability were assessed with the Fugl-Meyer motor assessment ( FMA ) and the  arm motor ability test ( AMAT ) , respectively . The strength of muscle contraction was significantly stronger in the nonparetic limb ( P < 0.001 ) . The degree of cocontraction was significantly greater in the paretic limb ( P < 0.001 ) . The strength of muscle contraction in the paretic limb correlated significantly with FMA ( r = 0.62 to 0.87,P ≤ 0.001 ) and AMAT ( r = 0.66 to 0.80 , P ≤ 0.001 ) scores . Similarly , the degree of cocontraction correlated significantly with FMA ( r = -0.70 to -0.64 , P ≤ 0.001 ) and AMAT ( r = -0.72 to -0.62 , P ≤ 0.001 ) scores . Muscle weakness and degree of cocontraction correlate significantly with motor impairment and physical disability in upper limb hemiplegia . This relationship may provide insights toward development of specific interventions . However , additional studies are needed to demonstrate a cause and effect relationship The purpose of this study was to establish test-retest reliability of measurement procedures for quantifying isokinetic concentric peak torque ( PT ) at the knee using normalization methods post-stroke . A second aim was to estimate the change required to show clinical ly significant improvements in knee muscles strength .  The isokinetic normalized PT ( NPT ) values for the knee extensors and flexors were measured in each participant at two different angular velocities during two sessions 1 day apart . Thirty participants with mild to moderate hemiparesis after stroke who were able to walk were tested . The normalized PT measures for the knee muscles of the affected lower extremity were highly reliable ( intraclass correlation coefficients ranged from 0.85 to 0.98 ; p<0.05 ) . Size of relative changes ( the percent smallest real difference , SRD% ) for extensors NPT ( ranged from 22.35 % to 25.68 % ) were lower than flexors NPT ( ranged from 74.01 % to 76.31 % ) , indicating that the affected isokinetic knee flexors had more r and om variation than the knee extensors . This study supports the use of isokinetic dynamometers for the assessment of knee muscle strength in participants with chronic mild to moderate post-stroke hemiparesis and to measure clinical improvements . Established measurement error and smallest real differences in normalized PT will aid interpretation of real changes in muscle strength in this clinical population OBJECTIVE To evaluate the impact of a program of muscle strengthening and physical conditioning on  impairment and disability in chronic stroke subjects . DESIGN A r and omized pretest and posttest control group , followed by a single-group pretest and posttest design . SUBJECTS Thirteen community-dwelling stroke survivors of at least 9 months . INTERVENTION A 10-week ( 3 days/week ) program consisting of a warm-up , aerobic exercises , lower extremity muscle strengthening , and a cool-down . MAIN OUTCOME MEASURES Peak isokinetic torque of the major muscle groups of the affected lower limb , quadriceps and ankle plantarflexor spasticity , gait speed , rate of stair climbing , the Human Activity Profile ( HAP ) , and the Nottingham Health Profile ( NHP ) were recorded twice for the treatment group and three times for the control group . RESULTS Significant improvements were found for all the selected outcome measures ( HAP , NHP , and gait speed ) for the treatment group ( p < .001 ) . In terms of overall training effects , the 13 subjects demonstrated increases in strength of the affected major muscle groups , in HAP and NHP profiles , and in gait speed and rate of stair climbing without concomitant increases in either quadriceps or ankle plantarflexor spasticity . CONCLUSIONS The 10-week combined program of muscle strengthening and physical conditioning result ed in gains in all measures of impairment and disability . These gains were not associated with measurable changes of spasticity in either quadriceps or ankle plantarflexors Background . Upper extremity hemiparesis is the most common poststroke disability . Longitudinal studies have indicated that 30 % to 66 % of stroke survivors do not have full arm function 6 months poststroke . One promising treatment approach is bilateral training . To date , no r and omized , blinded study of efficacy comparing 2 groups ( bilateral training vs unilateral training ) using analogous tasks has been performed in chronic stroke survivors with moderate upper extremity impairment . Objective . To compare the effectiveness of bilateral training with unilateral training for individuals with moderate upper limb hemiparesis . The authors hypothesized that bilateral training would be superior to unilateral training in the proximal extremity but not the distal one . Methods . Twenty-four subjects participated in a r and omized , single-blind training study . Subjects in the bilateral group ( n = 12 ) practice d bilateral symmetrical activities , whereas the unilateral group ( n = 12 ) performed the same activity with the affected arm only . The activities consisted of reaching-based tasks that were both rhythmic and discrete . The Motor Assessment Scale ( MAS ) , Motor Status Scale ( MSS ) , and muscle strength were used as outcome measures . Assessment s were administered at baseline and posttraining by a rater blinded to group assignment . Results . Both groups had significant improvements on the MSS and measures of strength . The bilateral group had significantly greater improvement on the Upper Arm Function scale ( a subscale of the MAS-Upper Limb Items ) . Conclusion . Both bilateral and unilateral training are efficacious for moderately impaired chronic stroke survivors .  Bilateral training may be more advantageous for proximal arm function Muscle strength , usually measured as the peak torque during maximal contraction , is impaired in persons with stroke . Time-dependent properties of muscle contraction may also be altered but have not been quantified . We quantified both magnitude ( peak torque ) and time-dependent parameters ( times to develop and reduce torque ) in eight different isometric joint actions . Parameters were compared among the more and less affected arms of 20 persons with chronic stroke and the nondominant arms of 10 similarly aged healthy persons .  Torque-generation parameters were independent from one another ( i.e. , low correlations ) and highly reliable between trials and days . All parameters were impaired in the more affected arm , whereas peak torque and time to develop torque were impaired in the less affected arm . Following stroke , torque-generation impairments include both magnitude and time-dependent properties and exist not only in the more affected but also in the less affected arm . Clinicians attempting to improve upper-extremity function should employ therapeutic exercises that challenge patients to improve both their strength and speed of muscle contraction Karatas M , Çetin N , Bayramoglu M , Dilek A : Trunk muscle strength in relation to balance and functional disability in unihemispheric stroke patients . Am J Phys Med Rehabil 2004;83:81–87 . Objective To evaluate trunk muscle strength in unihemispheric stroke patients and to assess how it relates to body balance and functional disability in this patient group . Design This prospect i ve case-comparison study investigated isometric and isokinetic reciprocal trunk flexion and extension strength at angular velocities in 38 unihemispheric stroke patients and 40 healthy volunteers .  The Berg balance scale was used to assess balance and stability , and the  FIM ™ instrument was used to evaluate functional disability in the patient group . Patients were evaluated as soon as they were able to st and long enough for testing . Results Peak torque values for trunk flexion and extension were lower in the stroke patients than in the controls . The differences were significant for trunk flexion and for trunk extension . In both groups , peak torque values for trunk flexors were greater than peak torque values for trunk extensors . There was a significant positive correlation between trunk muscle strength and Berg balance scale score at discharge . Trunk muscle strength was not correlated with FIM total score or FIM motor score , but the locomotion-transfers FIM subscore at discharge was positively correlated with trunk muscle torque values , except for isometric extension . Conclusion The findings indicate trunk flexion and extension muscle weakness in unihemispheric stroke patients , which can interfere with balance , stability , and functional disability Background After stroke , pneumonia is a relevant medical complication that can be precipitated by aspiration of saliva , liquids , or solid food . Swallowing difficulty and aspiration occur in a significant proportion of stroke survivors . Cough , an important mechanism protecting the lungs from inhaled material s , can be impaired in stroke survivors , and the likely cause for this impairment is central weakness of the respiratory musculature . Thus , respiratory muscle training in acute stroke may be useful in the recovery of respiratory muscle and cough function , and may thereby reduce the risk of pneumonia . The present study is a pilot study , aim ed at investigating the validity and feasibility of this approach by exploring effect size , safety , and patient acceptability of the intervention . Methods / design Adults with moderate to severe stroke impairment ( National Institutes of Health Stroke Scale ( NIHSS ) score 5 to 25 at the time of admission ) are recruited within 2 weeks of stroke onset . Participants must be able to perform voluntary respiratory maneuvers . Excluded are patients with increased intracranial pressure , uncontrolled hypertension , neuromuscular conditions other than stroke , medical history of asthma or chronic obstructive pulmonary disease , and recent cardiac events . Participants are r and omized to receive inspiratory , expiratory , or sham respiratory training over a 4-week period , by using commercially available threshold resistance devices . Participants and caregivers , but not study investigators , are blind to treatment allocation . All participants receive medical care and stroke rehabilitation according to the usual st and ard of care . The following assessment s are conducted at baseline , 4 weeks , and 12 weeks : Voluntary and reflex cough flow measurements , forced spirometry , respiratory muscle strength tests , incidence of pneumonia , assessment s of safety parameters , and self-reported activity of daily living . The primary outcome is peak expiratory cough flow of voluntary cough , a parameter indicating the effectiveness of cough . Secondary outcomes are incidence of pneumonia , peak expiratory cough flow of reflex cough , and maximum inspiratory and expiratory mouth pressures . Discussion Various novel pharmacologic and nonpharmacologic approaches for preventing stroke-associated pneumonia are currently being research ed . This study investigates a novel strategy based on an exercise intervention for cough rehabilitation . Trial registration Current Controlled Trials IS RCT OBJECTIVE To identify the determinants of improvement in walking capacity following therapeutic exercise in chronic stroke survivors . DESIGN A secondary analysis of data obtained from a prospect i ve , single-blind , r and omized controlled intervention trial . SUBJECTS Sixty-three community-dwelling individuals ( mean age = 65 years , age range = 50 - 87 years ) with a chronic stroke ( post-stroke duration : mean = 5.5 years , range = 1 - 28 years ) . METHODS Subjects were r and omized into a leg exercise group ( n = 32 ) or an arm exercise group ( n = 31 ) . Subjects in each group underwent 3 1-hour exercise sessions per week for 19 weeks . Walking capacity , cardiorespiratory fitness , isometric knee extensor muscle strength , balance ability , and balance confidence were evaluated before and after the interventions . Multiple regression analysis was performed to identify the determinants of improvement in walking capacity . RESULTS After controlling for age , gender , post-stroke duration , and baseline walking capacity , gain in paretic leg muscle strength and peak oxygen consumption remained independently associated with gain in walking capacity ( R2 = 0.229 ) . CONCLUSION Enhancement of cardiorespiratory fitness and paretic leg muscle strength are both significant determinants in improving walking capacity among chronic stroke survivors . However , the rather weak relationship ( R2 = 0.229 ) indicates that other factors not measured in this study may also contribute to the improvement in walking capacity We established reliability of upper-limb muscle performance in adults with post-stroke hemiparesis . Ten adults with post-stroke hemiparesis ( 51.5 ± 34 . 5 months ) performed isokinetic concentric shoulder flexion , elbow flexion , and extension at 3 criterion speeds ( 30 ° /s , 75 ° /s , and 120 ° /s ) on 3 separate occasions ( Days 1,7 , and 49 ) . As several participants were unable to reach criterion speeds , actual speed and power were also analyzed . Relative reliability ( intr-aclass correlation coefficient-ICC ) was excellent for torque and power ( 0.82 to 0.98 ) but less consistent for speed ( 0.63 to 0.99 ) . Absolute reliability ( st and ard error of measurement-%SEM ) ranged between 0 % to 34 % . No systematic errors were observed across sessions . Smallest real differences ( SRD ) ranged between 4–11Nm for torque and 3–24W for power . Shoulder flexion , elbow flexion , and elbow extension torque , speed , and power can be measured reliably following stroke . Given that many of these individuals demonstrate inability to generate torque at preselected speeds , power may be a more valid indicator of muscle performance This study was undertaken to determine muscle strength of trunk flexion-extension in hemiplegic patients after stroke compared with that of normal controls . The design consisted of a nonr and omized control trial in a secondary care setting ( a rehabilitation unit at a hospital facility ) . The subjects included 25 post-stroke male hemiplegic patients and 25 male healthy controls . The maximal peak torques of trunk flexion-extension  at angular velocities of 0 degrees ( isometric contraction ) , 60 degrees , 120 degrees , and 150 degrees/s were measured by using an isokinetic dynamometer ( Cybex Trunk Extension-Flexion Unit , Cybex , Ronkonkoma , NY ) . Peak torque of trunk flexion and extension in hemiplegic patients was significantly smaller than that of healthy controls ( P < 0.05 ) , except isometric trunk flexion ( P > 0.05 ) . The weakness of trunk flexion-extension muscles in hemiplegic patients might be accounted for by the bilateral innervation from the motor cortex , the insufficient use of high threshold motor units , and disuse atrophy Past studies have suggested that acupuncture may reduce spasticity in stroke survivors . We do not know , however , whether acupuncture may enhance the effect of  strength training on motor function . This study compared upper-limb motor functional improvement in chronic stroke survivors who received a combination of  acupuncture and strength training with that of subjects who received strength training alone .  A total of 10 chronic stroke patients with moderate or severe wrist muscle spasticity were recruited for this study . The study used a crossover design with a r and om order of either combined electroacupuncture and strength training or strength training alone . Each subject received one of the two types of treatment twice a week for the first 6 weeks and switched to the other for another 6 weeks . Quantitative measurements of wrist spasticity , active wrist extension range of motion , isometric wrist strength , and clinical evaluation with Fugl-Meyer ( FM ) upper-limb motor scores were conducted before and after either treatment . After the combined treatment , the quantitative spasticity level , active wrist extension range of motion ( increased by a mean of 16.3 degrees ) , and FM upper-limb motor score ( increased by a mean of 4.9 points ) changed significantly ( p < 0.01 ) but no significant changes were noted in isometric wrist strength . The strength training alone result ed in no significant changes to any measured variable . The results of the current study indicate that the combined acupuncture and strength training treatment reduced muscle spasticity and may have improved motor function for chronic stroke survivors with moderate or severe muscle spasticity OBJECTIVES We sought to assess a training program focused on muscle strength and endurance in persons with prior stroke . METHODS Thirty men with a slight hemiparesis caused by a first occurrence of stroke at least 6 months earlier were included with an average age of 54 years . The following was assessed before and after an 8-week period : muscle strength , endurance , work capacity , and activity level . The training group consisted of 21 persons and 9 served as control subjects . There were no differences between the groups in the various assessment s from the start . The training was set up as circuit training with 5 stations aim ing to strengthen the muscles and increase endurance in the bilateral lower limbs . The session lasted for 45 minutes , 3 times per week , for 8 weeks . On eligible persons in the training group , double-sided muscle biopsies were also performed before and after . RESULTS There was significance in improved muscle strength and improved peak oxygen uptake for the paretic leg , which was reflected in the muscle enzymes . The nonparetic side also showed improvement , but to a lesser extent . The control group remained unchanged . CONCLUSIONS Stroke survivors can improve muscle strength , endurance , and work capacity in both the paretic and nonparetic leg with a circuit training program Objective : Survivors of severe critical illness frequently develop substantial and persistent physical complications , including muscle weakness , impaired physical function , and decreased health-related quality of life . Our objective was to determine the longitudinal epidemiology of muscle weakness , physical function , and health-related quality of life and their associations with critical illness and ICU exposures . Design : A multisite prospect i ve study with longitudinal follow-up at 3 , 6 , 12 , and 24 months after acute lung injury . Setting : Thirteen ICUs from four academic teaching hospitals . Patients : Two hundred twenty-two survivors of acute lung injury . Interventions : None . Measurements and Main Results : At each time point , patients underwent st and ardized clinical evaluations of extremity , h and grip , and respiratory muscle strength ; anthropometrics ( height , weight , mid-arm circumference , and triceps skin fold thickness ) ; 6-minute walk distance , and the Medical Outcomes Short-Form 36 health-related quality of life survey . During their hospitalization , survivors also had detailed daily evaluation of critical illness and related treatment variables . Over one third of survivors had objective evidence of muscle weakness at hospital discharge , with most improving within 12 months . This weakness was associated with substantial impairments in physical function and health-related quality of life that persisted at 24 months . The duration of bed rest during critical illness was consistently associated with weakness throughout 24-month follow-up . The cumulative dose of systematic corticosteroids and use of neuromuscular blockers in the ICU were not associated with weakness . Conclusions : Muscle weakness is common after acute lung injury , usually recovering within 12 months . This weakness is associated with substantial impairments in physical function and health-related quality of life that continue beyond 24 months . These results provide valuable prognostic information regarding physical recovery after acute lung injury . Evidence -based methods to reduce the duration of bed rest during critical illness may be important for improving these long-term impairments Stroke is the leading cause of long-term neurological disability and the principle reason for seeking rehabilitative services in the US . Learning based rehabilitation training enables independent mobility in the majority of patients post stroke , however , restoration of fine manipulation , motor function and task specific functions of the hemiplegic arm and h and is noted in fewer than 15 % of the stroke patients . Brain plasticity is the innate mechanism enabling the recovery of motor skills through neurological reorganization of the brain as a response to limbs ' manipulation . The objective of this research was to evaluate the therapeutic efficacy for the upper limbs with a dual arm exoskeleton system ( EXO-UL7 ) using three different modalities : bilateral mirror image with symmetric movements of both arms , unilateral movement of the affected arm and st and ard care .  Five hemiparetic subjects were r and omly assigned to each therapy modality . An upper limb exoskeleton was used to provide bilateral and unilateral treatments . St and ard care was provided by a licensed physical therapist . Subjects were evaluated before and after the interventions using 13 different clinical measures . Following these treatments all of the subjects demonstrated significant improved of their fine motor control and gross control across all the treatment modalities . Subjects exhibited significant improvements in range of motion of the shoulder , and improved muscle strength for bilateral training and st and ard care , but not for unilateral training . In conclusion , a synergetic approach in which robotic treatments ( unilateral and bilateral depending on the level of the motor control ) are supplemented by the st and ard of care may maximize the outcome of the motor control recover following stroke RATIONALE Critical illness survivors often experience permanent functional disability due to intensive care unit (ICU)-acquired weakness . The mechanisms responsible for long-term weakness persistence versus resolution are unknown . OBJECTIVES To delineate cellular mechanisms underlying long-term weakness persistence in ICU survivors . METHODS We conducted a nested , prospect i ve study of critically ill patients mechanically ventilated for 7 days or longer . The patients were recruited from the RECOVER program  and serially assessed over 6 months after ICU discharge . Twenty-seven of 82 patients consented to participate ; 15 and 11 patients were assessed at 7 days and 6 months after ICU discharge , respectively . MEASUREMENTS AND MAIN RESULTS We assessed motor functional capacity , quadriceps size , strength , and voluntary contractile capacity and performed electromyography , nerve conduction studies , and vastus lateralis biopsies  for histologic , cellular , and molecular analyses . Strength and quadriceps cross-sectional areas were decreased 7 days after ICU discharge . Weakness persisted to 6 months and correlated with decreased function . Quadriceps atrophy resolved in 27 % patients at 6 months . Muscle mass reconstitution did not correlate with resolution of weakness , owing to persistent impaired voluntary contractile capacity . Compared with Day 7 , increased ubiquitin-proteasome system-mediated muscle proteolysis , inflammation , and decreased mitochondrial content all normalized at 6 months . Autophagy markers were normal at 6 months . Patients with sustained atrophy had decreased muscle progenitor ( satellite ) cell content . CONCLUSIONS Long-term weakness in ICU survivors results from heterogeneous muscle pathophysiology with variable combinations of muscle atrophy and impaired contractile capacity . These findings are not explained by ongoing muscle proteolysis , inflammation , or diminished mitochondrial content . Sustained muscle atrophy is associated with decreased satellite cell content and compromised muscle regrowth , suggesting impaired regenerative capacity PURPOSE To determine whether isokinetic training can improve the strength of the hemiparetic knee musculature , functional mobility , and physical activity and to evaluate its effect on spasticity in long-term stroke survivors . DESIGN Nonr and omized self-controlled trial . SUBJECTS A volunteer sample of 15 community-dwelling stroke survivors of at least 6 months . INTERVENTION A 6-week ( 3 days/week , 40 minutes/day ) program consisting of warm-up , stretches , reciprocal knee extension and flexion isokinetic strengthening , and cool-down for the paretic limb . MAIN OUTCOME MEASURES Peak isokinetic hamstring and quadriceps torque , quadriceps spasticity , gait velocity , timed Up and Go , timed stair climb , and the Human Activity Profile ( HAP ) scores were recorded at baseline , after training , and 4 weeks after training cessation ( follow-up ) . RESULTS Paretic muscle strength improved after training ( p < .05 ) while tone remained consistent ( p > .87 ) . Gait velocity increased after training ( p < .05 ) and at follow-up ( p < .05 ) . Changes in stair climbing and timed Up and Go were not significant ( p > .37 ; p > .91 ) , although subjects perceived gains in their physical abilities at follow-up ( p < .01 ) . CONCLUSIONS Gains in strength and gait velocity without concomitant increases in muscle tone are possible after a short-term strengthening program for stroke survivors . The psychological benefit associated with physical activity is significant Background and Purpose — Severe upper limb paresis is a major contributor to disability after stroke . This study investigated the efficacy of a new nonrobotic training device , the Sensorimotor Active Rehabilitation Training ( SMART ) Arm , that was used with or without electromyography-triggered electrical stimulation of triceps brachii to augment elbow extension , permitting stroke survivors with severe paresis to practice a constrained reaching task . Methods — A single-blind , r and omized clinical trial was conducted with 42 stroke survivors with severe and chronic paresis . Thirty-three participants completed the study , of whom 10 received training using the SMART Arm with electromyography-triggered electrical stimulation , 13 received training using the SMART Arm alone , and 10 received no intervention ( control ) . Training consisted of 12 1-hour sessions over 4 weeks . The primary outcome measure was “ upper arm function , ” item 6 of the Motor Assessment Scale . Secondary outcome measures included impairment measures ; triceps muscle strength , reaching force , modified Ashworth scale ; and activity measures : reaching distance and Motor Assessment Scale . Assessment s were administered before ( 0 weeks ) and after training ( 4 weeks ) and at 2 months follow-up ( 12 weeks ) . Results — Both SMART Arm groups demonstrated significant improvements in all impairment and activity measures after training and at follow-up . There was no significant difference between these 2 groups . There was no change in the control group . Conclusions — Our findings indicate that training of reaching using the SMART Arm can reduce impairment and improve activity in stroke survivors with severe and chronic upper limb paresis , highlighting the benefits of intensive task-oriented practice , even in the context of severe paresis The objective of this pilot study was to examine alterations in motor unit ( MU ) control properties , ( i.e. MU recruitment and firing rate ) after stroke utilizing a recently developed high-yield surface electromyogram ( EMG ) decomposition technique . Two stroke subjects participated in this study .  A sensor array was used to record surface EMG signals from the first dorsal interosseous ( FDI ) muscle during voluntary isometric contraction at varying force levels . The recording was performed in both paretic and contralateral muscles using a matched force protocol . Single motor unit activity was extracted using the  surface EMG decomposition  software from Delsys Inc. The results from the two stroke subjects indicate a reduction in the mean motor unit firing rate and a compression of motor unit recruitment range in paretic muscle as compared with the contralateral muscles . These findings provide further evidence of spinal motoneuron involvement after a hemispheric brain lesion , and help us to underst and the complex origins of stroke induced muscle weakness Active neuromuscular stimulation is an effective behavioral intervention for motor recovery improvements after a stroke . However , the most effective active neuromuscular stimulation duration s have not been determined . The present experiment investigated active stimulation duration s ( 0 , 5 , and 10 s ) coupled with bilateral movements on progress toward motor recovery in wrist and finger extension . Twenty-six stroke survivors with chronic hemiparesis were r and omly assigned to the stimulation duration groups , and subjects completed 4 days of rehabilitation training over a 2-week period . Mixed design analyses of variance on the Box and Block scores , chronometric reaction times , and force modulation of the sustained muscle contraction task revealed distinct motor recovery improvements for both the 5 and 10 s stimulation duration groups in comparison to the 0 s duration control group . Further , the number of blocks moved by the 10-s duration group exceeded those moved by the 5-s duration group . In conclusion , the 5 and 10 s duration active stimulation/bilateral movement groups decreased residual motor dysfunctions that persisted beyond 12 months post stroke The objective of the study was to investigate the chronic effect of low frequency whole body vibration ( WBV ) on isometric and eccentric strength of knee extensors with different force exertion capacity . It was hypothesized that ( 1 ) four-week WBV intervention with the low frequency domain would enhance muscle strength and ( 2 ) the improvement would be more pronounced in the weaker muscle . To test our hypothesis twenty patients with acute stroke were recruited . Ten patients were r and omly assigned to vibration and the remaining ten patients served for control . The patients in the vibration group received WBV with 20 Hz frequency three times per week st and ing on a vibration platform in half squat position meanwhile flexing and extending the joints and placing the weight from one leg to the other . Knee extensor strength was determined under isometric and eccentric contraction before and after WBV intervention . Myoelectrical activity ( EMG ) of the vastus lateralis muscle was also measured . Significant improvement was revealed in the vibration group only . The maximum isometric torque and EMG activity increased significantly for both paretic and non-paretic leg , but the improvement was threefold greater in the vibration group . No significant alteration was found in rate of torque development . Maximum eccentric torque and EMG increased significantly for the paretic leg only . Mechanical work enhanced significantly in the paretic side only . The results of our study indicate that the selection of the effective vibration frequency depends upon the physical condition of neuromuscular system . Low vibration frequency intervention can increase the strength in weak muscles due to neuromuscular impairment and restricted physical activity OBJECTIVE To evaluate the therapeutic effects of Functional Electrical Stimulation ( FES ) of the tibialis anterior muscle on plantarflexor spasticity , dorsiflexor strength , voluntary ankle dorsiflexion , and lower extremity motor recovery with stroke survivors . DESIGN We conducted a prospect i ve interventional study . SETTING Rehabilitation ward , physiotherapy unit and gait analysis laboratory . PARTICIPANTS Fifty-one patients with foot drop result ing from stroke . INTERVENTION The functional electrical stimulation ( FES ) group ( n=27 ) received 20 - 30 minutes of electrical stimulation to the peroneal nerve and anterior tibial muscle of the paretic limb along with conventional rehabilitation program ( CRP ) . The control group ( n=24 ) treated with CRP only . The subjects were treated 1 hr per day , 5 days a week , for 12 weeks . MAIN OUTCOME MEASURES Plantarflexor spasticity measured by modified ashworth scale ( MAS ) , dorsiflexion strength measured by manual muscle test ( MMT ) , active/passive ankle joint dorsiflexion range of motion , and lower-extremity motor recovery by Fugl-Meyer assessment ( FMA ) scale . RESULTS After 12 weeks of treatment , there was a significant reduction in a plantarflexor spasticity by 38.3 % in the FES group and 21.2 % in control group ( P < 0.05 ) , between the beginning and end of the trial . Dorsiflexor muscle strength was increased significantly by 56.6 % and 27.7 % in the FES group and control group , respectively . Similarly , voluntary ankle dorsiflexion and lower-extremity motor function improved significantly in both the groups . No significant differences were found in the baseline measurements among groups . When compared with control group , a significant improvement ( p < 0.05 ) was measured in all assessed parameters in the FES group at post-treatment assessment , thus FES therapy has better effect on recovery process in post-stroke rehabilitation . CONCLUSIONS Therapy combining FES and conventional rehabilitation program was superior to a conventional rehabilitation program alone , in terms of reducing spasticity , improving dorsiflexor strength and lower extremity motor recovery in stroke patients Background Spasticity is a common impairment that follows stroke , and it results typically in functional loss . For this reason , accurate quantification of spasticity has both diagnostic and therapeutic significance . The most widely used clinical assessment of spasticity is the modified Ashworth scale ( MAS ) , an ordinal scale , but its validity , reliability and sensitivity have often been challenged . The present study addresses this deficit by examining whether quantitative measures of neural and muscular components of spasticity are valid , and whether they are strongly correlated with the MAS . Methods We applied abrupt small amplitude joint stretches and Pseudor and om Binary Sequence ( PRBS ) perturbations to both paretic and non-paretic elbow and ankle joints of stroke survivors . Using advanced system identification techniques , we quantified the dynamic stiffness of these joints , and separated its muscular ( intrinsic ) and reflex components . The correlations between these quantitative measures and the MAS were investigated . Results We showed that our system identification technique is valid in characterizing the intrinsic and reflex stiffness and predicting the overall net torque . Conversely , our results reveal that there is no significant correlation between muscular and reflex torque/stiffness and the MAS magnitude . We also demonstrate that the slope and intercept of reflex and intrinsic stiffnesses plotted against the joint angle are not correlated with the MAS . Conclusion Lack of significant correlation between our quantitative measures of stroke effects on spastic joints and the clinical assessment of muscle tone , as reflected in the MAS suggests that the MAS does not provide reliable information about the origins of the torque change associated with spasticity , or about its contributing components
Conclusion :  Objective muscle strength assessment  can be reliably used in lower and upper extremities in post-stroke patients with chronic hemiparesis
Background : Muscle weakness is the main cause of motor impairment among stroke survivors and is associated with reduced peak muscle torque .
Objective : To systematic ally investigate and organize the evidence of the reliability of muscle strength evaluation measures in post-stroke survivors with chronic hemiparesis .