***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Objective : To compare the effect of the Chignon ankle-foot orthosis on gait versus a st and ard ankle-foot orthosis . Method : A multicentre r and omized study was conducted in seven rehabilitation centres . Hemiplegic patients were recruited after unilateral stroke lasting less than six months . Exclusion criteria were : impossibility to st and for 10 seconds ; ankle passive dorsiflexion < 5 degrees with knee flexed to 90 degrees ; triceps spasticity ≥3/4 on the Ashworth modified scale ; diseases that might impair active participation in the study . Thirteen patients were r and omized to the Chignon group and 15 to the control group . Included patients were given a st and ard ankle-foot orthosis or Chignon ankle-foot orthosis . The Chignon ankle-foot orthosis is an articulated double-stopped custom-made orthosis with elements to assist dorsiflexion and plantar flexion . Gait speed improvement ( ten-metre test ) , kinematic assessment , and functional scales were assessed . Results : Gain ratio of walking speed with the  orthosis increased significantly more in the Chignon group than in the control group at day 0 ( 27.2 ± 36 % versus −0.8 ± 17 % ; P = 0.006 ) , day 30 ( 39.9 ± 19 % versus 7.5 ± 17 % ; P = 0.0004 ) and day 90 ( 44.6 ± 27 % versus 17.1 ± 0.3 % ; P = 0.04 ) . There was also a significant improvement in kinematic parameters and spasticity in the Chignon group . Conclusion : Early compensation of distal motor deficiency by the Chignon ankle-foot orthosis improves the immediate gait of hemiplegics more than the st and ard ankle-foot orthosis and seems to modify motor recovery processes in the legs after stroke Objective : To investigate the short- and long-term effects of dynamic ankle foot orthoses on functional ambulation activities in chronic hemiparetic patients . Design : R and omized controlled trial . Setting : University ’s neurological rehabilitation outpatient clinic and orthotics department . Subjects : Twenty-eight chronic hemiparetic patients of level 3–5 according to Functional Ambulation Classification and with a maximum spasticity level of 3 according to Modified Ashworth Scale , were r and omly assigned to the study and control groups . Interventions : The control group ( n = 14 ) was assessed with tennis shoes whereas the study group ( n = 14 ) was assessed initially with tennis shoes and after three months with dynamic ankle foot orthosis . Measures : Functional Reach , Timed Up and Go , Timed Up Stairs , Timed Down Stairs , gait velocity and Physiological Cost Index . Results : In the initial assessment no difference was found between the groups for any of the measured parameters ( P > 0.05 ) . After three months , intergroup comparisons while the patients in the study group were wearing dynamic ankle-foot orthosis showed a significant difference in favour of the study group for Timed Up Stairs 12.00 ( 10.21 ) seconds study versus 15.00 ( 7.29 ) seconds control group ; for gait velocity 0.99 ( 0.45 ) m/s study versus 0.72 ( 0.20 ) m/s control group and for Physiological Cost Index 0.12 ( 0.06 ) beats/min study versus 0.28 ( 0.13 ) beats/min control group ( P < 0.05 ) . No difference was found between the groups for Functional Reach , Timed Up and Go , Timed Down Stairs ( P > 0.05 ) . Conclusion : Chronic hemiparetic patients may benefit from using dynamic ankle-foot orthosis Objective : To examine the effects of an ankle-foot orthosis ( AFO ) on balance performance in patients with hemiparesis of short and long duration . Design : Within-subject r and om order of intervention , cross-sectional study design . Setting s : Medical centres and district hospitals . Subjects : Forty-two subjects with hemiparesis of short duration ( B = six months ) and 61 subjects of long duration ( = 12 months ) . Measurements : The balance and gait ability of subjects were evaluated both with an AFO and without . The static and dynamic balance activities were evaluated by the Balance Master System , whereas the functional balance was assessed with the Berg Balance Scale . The speed and cadence were also measured during a 10-metre walk . Paired t-test was used to determine the effect of the AFO . Results : In subjects with hemiparesis of short duration , we found that subjects wearing an AFO showed significant improvements in ( 1 ) weight-bearing distribution during quiet st and ing ( p / 0.042 , 95 % confidence interval ( CI ) 0.521 , 7.325 ) , ( 2 ) body sway during st and ing on foam surface with eyes open ( p / 0.020 , 95 % CI 0.020 , 0.680 ) and eyes closed ( p / 0.041 , 95 % CI 0.023 , 0.921 ) , ( 3 ) movement velocity during limit of stability test ( LOS ) / toward the affected side ( p / 0.037 , 95 % Cl / 0.978 , / 0.042 ) and nonaffected side ( p / 0.008 , 95 % CI / 2.223 , / 0.377 ) , ( 4 ) maximal excursion toward the affected side ( p / 0.042 , 95 % CI / 19.546,=0.071 ) , and ( 5 ) speed ( p / 0.028 , 95 % CI / 0.204 , / 0.017 ) and cadence ( p / 0.021 , 95 % CI / 22.983 , / 1.864 ) . Such effects were not observed in subjects with hemiparesis of long duration . Conclusions : For the subjects with hemiparesis of short duration , the AFO improves the symmetry in quiet and dynamic st and ing balances . It also increases speed and cadence . However , its effectiveness is minimal for patients of long duration OBJECTIVE To evaluate the kinematic features of rear-foot motion during gait in hemiplegic stroke patients , using anterior ankle-foot orthoses ( AFOs ) , posterior AFOs , and no orthotic assistance . DESIGN Crossover design with r and omization for the interventions . SETTING A rehabilitation center for adults with neurologic disorders . PARTICIPANTS Patients with hemiplegia due to stroke ( n=14 ) and able-bodied subjects ( n=11 ) . INTERVENTIONS Subjects with hemiplegia were measured walking under 3 conditions with r and omized sequences : ( 1 ) with an anterior AFO , ( 2 ) with a posterior AFO , and ( 3 ) without an AFO . Control subjects were measured walking without an AFO to provide a normative reference . MAIN OUTCOME MEASURES Rear-foot kinematic change in the sagittal , coronal , and transverse planes . RESULTS In the sagittal plane , compared with walking with an anterior AFO or without an AFO , the posterior AFO significantly decreased plantar flexion to neutral at initial heel contact ( P=.001 ) and the swing phase ( P<.001 ) , and increased dorsiflexion at the stance phase ( P=.002 ) . In the coronal plane , the anterior AFO significantly increased maximal eversion to neutral ( less inversion ) at the stance phase ( P=.025 ) , and decreased the maximal inversion angle at the swing phase when compared with using no AFO ( P=.005 ) . The posterior AFO also decreased the maximal inversion angle at the swing phase as compared with no AFO ( P=.005 ) . In the transverse plane , when compared with walking without an AFO , the anterior AFO and posterior AFO decreased the adduction angle significantly at initial heel contact ( P=.004 ) . CONCLUSIONS For poststroke hemiplegic gait , the posterior AFO is better than the anterior AFO in enhancing rear-foot dorsiflexion during a whole gait cycle . The anterior AFO decreases rear-foot inversion in both the stance and swing phases , and the posterior AFO decreases the rear-foot inversion in the swing phase when compared with using no AFO BACKGROUND Ankle-foot orthoses are often provided to improve walking in stroke patients , although the evidence of effects on walking and balance control is still inconsistent . This could be caused by a lack of insight into the influence of orthoses on the underlying impairments . These impairments can be assessed with dual plate posturography to determine the relative contribution of each lower limb to balance control and weight-bearing . This study examined the effects of ankle-foot orthoses on functional balance , static and dynamic weight-bearing asymmetry and dynamic balance control of the paretic and non-paretic lower limbs . METHODS Twenty stroke subjects ( time since stroke 5 - 127 months ) completed the study . Subjects were assessed with and without ankle-foot orthosis .  Functional balance was assessed using the Berg Balance Scale , Timed Up & Go test , Timed Balance Test , 10-m walking test and Functional Ambulation Categories . Weight-bearing asymmetry and dynamic balance control were assessed with force plates on a movable platform . FINDINGS No significant effects of ankle-foot orthoses were found for weight-bearing asymmetry and dynamic balance control , but significant differences in favour of ankle-foot orthosis use were found for most functional tests . INTERPRETATION Although ankle-foot orthoses had no effect on weight-bearing asymmetry or dynamic balance contribution of the paretic lower limb , functional tests were performed significantly better with orthoses . Apparently , improvements at functional level can not be readily attributed to a greater contribution of the paretic lower limb to weight-bearing or balance control . This finding suggests that ankle-foot orthoses influence compensatory mechanisms Objective : Regaining walking ability is a major goal during the rehabilitation of stroke patients . To support this process an ankle-foot orthosis ( AFO ) is often prescribed . The aim of this study is to investigate the effect of an AFO on walking ability in chronic stroke patients . Design : Cross-over design with r and omization for the interventions . Methods : Twenty chronic stroke patients , wearing an AFO for at least six months , were included .  Walking ability was operationalized as comfortable walking speed , scores on the timed up and go ( TUG ) test and stairs test .  Patients were measured with and without their AFO , the sequence of which was r and omized . Additionally , subjective impressions of self-confidence and difficulty of the tasks were scored . Clinical ly relevant differences based on literature were defined for walking speed ( 20 cm/s ) , the TUG test ( 10 s ) . Gathered data were statistically analysed using a paired t-test . Results : The mean difference in favour of the AFO in walking speed was 4.8 cm/s ( 95 % CI 0.85–8.7 ) , in the TUG test 3.6 s ( 95 % CI 2.4 4.8 ) and in the stairs test 8.6 s ( 95 % CI 3.1 –14.1 ) . Sixty-five per cent of the patients experienced less difficulty and 70 % of the patients felt more self-confident while wearing the AFO . Conclusions : The effect of an AFO on walking ability is statistically significant , but compared with the a priori defined differences it is too small to be clinical ly relevant . The effect on self-confidence suggests that other factors might play an important role in the motivation to use an AFO 
    Output:
    
Conclusion ] While the findings suggest the benefits of an AFO regarding gait velocity , the impact of this type of orthosis on cadence remains inconclusive .