it is caused by a complex interplay of 
 motor , sensory , and cognitive impairments2 .
these neurological deficits are the prime cause of reduced quality of 
 life and social participation3 .
thus , gait 
 and balance recovery is regarded as a chief goal in stroke rehabilitation4 . until now
, various exercise programs such as progressive exercise5 , 6 , muscle strength 
 exercise7 , rhythmic pattern 
 exercise8 , 9 , and virtual training10 have been used to regain the balance , mobility , and endurance of 
 stroke patients in clinical and research settings . among these interventions ,
repetitive 
 motor training can alter brain representation maps and is mainly and basically used for 
 managing the motor function recovery in stroke patients11 .
skilled activity is necessary to drive brain changes that might lead to improvements in 
 functional activities such as gait12 . 

stationary cycling , which requires less balance capability , has been used for training 
 patients with or without nervous system disorders who have difficulty in maintaining balance 
 and independent gait13 .
cycling and 
 walking share similar locomotor patterns of reciprocal flexion and extension movements and 
 alternating muscle activation of antagonists14 .
cycling can improve functional mobility and acts as a pseudo 
 walking task - oriented exercise2 .
besides 
 improving muscle strength , cycling exercise also facilitates muscle control of the lower 
 limbs , which may allow putting more weight on the affected leg while standing . for this 
 reason
, stationary cycling exercise has been used with various other interventions in the 
 clinical environments15 .
however , the 
 pure effect of cycling exercise is uncertain in chronic stroke patients .
therefore , this 
 study investigated the effects of stationary cycling exercise on the balance and gait 
 abilities of chronic stroke patients .
this study was designed as a randomized , double - blind , pretest - posttest controlled trial . 
 in this study ,
all 
 experimental procedures and contents were explained to each participant , who provided 
 written informed consent thereafter .
all of the experimental procedures were approved by the 
 institutional review board of sahmyook university .
the inclusion criteria were as follows : 
 presence of hemiparesis secondary to stroke that had occurred in the past 6 months ; ability 
 to walk 10  m independently with or without an assistive device ; ability to communicate and 
 understand , with a mini - mental status examination score of more than 21 points ; no visual 
 disorders or visual field deficit ; and no known musculoskeletal conditions that would affect 
 the ability to walk safely .
the 6 subjects who refused to participate in the present program 
 or did not meet the inclusion criteria were excluded from the study .
the subjects were randomly assigned to the following 2 groups by using a table of random 
 sampling numbers : the experimental and the control group .
both the subjects and the therapist were blinded 
 to group assignments of the patients .
all of the participants were evaluated before training 
 and at the end of the 4-week training period .
the patients in the experimental group 
 performed the cycling exercise 30 minutes a day , 5 times a week for 4 weeks .
both groups 
 received traditional therapy for 30 minutes per session , 5 times a week for 4 weeks . 

stationary bicycle training has been used in order to improve the balance and walking 
 abilities of stroke patients . in this study , only the lower extremity part of a 
 dual - extremity ergometer ( super dynamic 3000 , shingwang medical ) was used . to perform the exercise ,
the patient mounted a stationary bicycle safely under supervision , 
 and the therapist adjusted the position of the seat and tied the ankles and calf to the 
 pedals .
the therapist was fully aware of the order and method of the stationary bicycle 
 training , and the patients performed the exercise after receiving instructions and 
 familiarizing themselves with the ergometers , including test runs .
the resistance was set at 
 1 of 4 , which corresponded to 2530  w on the stationary bicycle .
the patient was riding the 
 bicycle at 5060  rpm without stopping , for 30 min , 5 times a week for 6 weeks .
the subjects balancing skills were rated using the berg balance scale ( bbs ; range , 056 ) , 
 and the timed up - and - go ( tug ) test was used to evaluate dynamic balance abilities .
the 
 patients were asked to stand up , walk at a comfortable speed to a point marked 3  m away from 
 their chair , turn around , walk back , and sit down in the chair .
the cut - off tug test score that indicated normal versus below normal 
 performance was 12 seconds . the intra - rater ( r = 0.99 ) and inter - rater 
 ( r = 0.98 ) reliability values were high16 .
the bbs and tug test scores were obtained by an experienced 
 physical therapist blinded to the group assignment .
gait ability was measured by using the timed 10-m walking test ( 10mwt ) . for the 10mwt , 10 
m 
 was measured on the floor by using a tape measure , and the start and end points were marked 
 with tape . in order to provide sufficient distance for acceleration and deceleration , 
 intervals of 2  m were added before the start and after the end marks .
the 10-m walking time was measured with 
 a stopwatch for the period from the moment the subject s feet passed the starting line to 
 the moment they crossed the finish line . the subjects practiced once , and all measurements 
 were made 3 times , using the average value of the 3 measurements in the analysis . .
for the 
 10mwt , the test - retest and inter - rater reliability have been reported to be 0.95 and 0.90 , 
 respectively ; both of these values are very high17 .
the statistical package for the social sciences ( spss ) ver . 18.0 was used for data 
 analysis .
descriptive statistics was used to analyze the general characteristics of the 
 subjects . in order to examine the effects of the intervention in each group , a paired t test 
 was conducted . in order to investigate differences between the groups ,
the demographic characteristics of the participants are shown in the table 1table 1.general characteristics of the subjectsexperimental group(n = 16)control group(n = 16)gender ( male / female)12/413/3age ( years)65.2  6.461.7  6.1height ( cm)165.0  7.9169.0  6.1weight ( kg)69.5  10.466.8  10.0lesion side ( right / left)7/910/6mmse ( score)26.10  1.7425.80  2.12data are expressed as mean  sd .
mmse : mini - mental state examination as shown in table 2table 2.changes in balance and gait abilitiesexperimental groupcontrol groupbbs scorepretest36.15  5.9837.06  5.61posttest37.90  5.65 * 37.44  5.62postpre1.75  1.520.40  0.88tug ( sec)pretest25.11  5.4024.19  3.47posttest16.74  3.07 * 19.48  3.90*postpre8.4  4.354.71  4.86 * 10mwt ( sec)pretest44.75  18.4045.93  13.22posttest37.74  15.70 * 43.96  12.04*postpre7.02  7.021.96  3.13*bbs : berg balance scale ; tug : timed up - and - go ; 10mwt : 10-m walking test .
significant 
 difference , paired t test : * p < 0.05 ; significant difference , independent t test : 
 p < 0.05 , the experimental group showed significant improvements in bbs , tug test , and 
 10mwt scores after the intervention ( p < 0.05 ) , whereas the control group showed 
 significant improvements in their tug test and 10mwt scores , but not in their bbs score ( p 
 < 0.05 ) . moreover , the experimental group showed greater improvement than the control 
 group in 3 outcome measurements ( p < 0.05 ) .
bbs : berg balance scale ; tug : timed up - and - go ; 10mwt : 10-m walking test
. significant 
 difference , paired t test : * p < 0.05 ; significant difference , independent t test : 
 p < 0.05
the aim of this study was to test the effects of cycling exercise on the balance and gait 
 abilities of chronic stroke patients .
the results demonstrated that the stationary cycling 
 exercise supplemented with conventional therapy led to better balance and gait abilities 
 than the conventional therapy alone .
first , the stationary cycling training was found to have a positive effect on dynamic 
 balance as measured by using the tug test .
the results are similar to those obtained in a 
 previous study by kim et al . , who compared ergometer bicycle training with treadmill walking 
 training in stroke patients and reported significant improvement in tug test scores in both 
 groups , although the differences between the groups were not significant18 .
this suggests that the effectiveness of 
 cycling training in improving locomotor function is similar to the effectiveness of 
 treadmill exercise in stroke patients .
preliminary evidence suggests that cycling training 
 programs reduce musculoskeletal impairment after stroke . in terms of muscle strength , 

a study by kuo 
 and zajak suggested that the muscles that may be particularly important for this purpose are 
 the hamstrings , rectus femoris , gastrocnemius , and tibialis anterior .
these were all 
 activated during the cycling task , which requires reciprocal flexion and extension movements 
 of the hip , knee , and ankle19 .
it is 
 interesting that lustosa et al . reported a significant correlation between muscle strength 
 and improvement in tug test score .
therefore , we assumed that in this study the mechanism of 
 tug test score improvement in stroke patients was muscle strengthening20 .
repetitive bilateral training and treadmill walking 
 with or without suspension have a positive effect on walking ability21 .
repetitive practice is known to be important for motor 
 learning , as the repetitions enable the system to coordinate muscle synergies5 .
cycling and walking share similar locomotor 
 patterns of repetitive reciprocal flexion and extension movements . hence , stationary cycling 
 exercise , which employs reciprocal movement of the lower limbs and requires coordination of 
 corresponding muscles , effectively increased the gait ability .
cycling training stimulates motor regions in the central nervous system and activates the 
 cerebral cortex which eventually improves motor learning and balance .
based on the results , stationary cycling training can be 
 effective in rehabilitation of stroke patients with gait and dynamic balance deficits .
this study has the following limitations that we plan to address in future studies , 
 including the small sample size and relatively short intervention duration .
further 
 large - scale , long - term controlled clinical studies are required to verify the clinical 
 benefits of stationary cycling exercise training .
 [ purpose ] the objective of this study was to investigate the effects of stationary 
 cycling exercise on the balance and gait abilities of chronic stroke patients . [ subjects ] 
 thirty - two chronic stroke patients were randomly assigned to an experimental group ( n=16 ) 
 or a control group ( n=16 ) . 
 [ methods ] all of the subjects received the standard 
 rehabilitation program for 30 minutes , while the experimental group additionally 
 participated in a daily session of stationary cycling exercise for 30 minutes , 5 times per 
 week for 6 weeks . to assess balance function , the berg balance scale and timed up - and - go 
 test were used . 
 the 10-m walking test was conducted to assess gait function . 
 [ results ] 
 both groups showed significant improvements in balance and gait abilities . 
 the 
 improvements in the berg balance scale and timed up - and - go test scores ( balance ) , and 10-m 
 walking test score ( gait ) in the stationary cycling exercise group were significantly 
 greater than those in the control group . 
 [ conclusion ] this study demonstrated that 
 stationary cycling exercise training is an effective intervention for increasing the 
 balance and gait abilities of chronic stroke patients . 
 therefore , we suggest that 
 stationary cycling training is suitable for stroke rehabilitation and may be used in 
 clinical practice . 