these upper 
 limb impairments include difficulty moving and coordinating the arms , hands , and fingers , 
 often resulting in difficulty carrying out daily activities such as eating , dressing , and 
 washing1 . more than half of the people 
 with upper limb impairment will still have problems many months to years after their 
 stroke2 . improving arm function is a 
 core element of occupational performance for quality of life . many possible interventions 
 have been suggested such as repetitive task practice , constraint - induced movement therapy 
 ( cimt ) , mental practice , mirror therapy , interventions for sensory impairment , virtual 
 reality , repetitive task practice , and action observation3 . action observation ( ao ) is defined as a dynamic state during which an observer can 
 understand what other people are doing by simulating the actions and the outcomes that are 
 likely to follow from the observed motor act4 . this phenomenon is supposed to occur via the activation of the 
 mirror neuron system ( involving the inferior parietal lobule , the premotor cortex , and the 
 superior frontal gyrus)5 . recent studies 
 have reported the effectiveness of action observation for motor skill learning and 
 performance improvement in stroke patients6 , 7 . it is important for the ao used in the clinic to be supported by evidence - based research . the aim of this review was to provide evidenced information about ao and bring together all 
 systematic reviews of action observation provided to improve upper limb function after 
 stroke . the search terms used were ( action observation or action observation therapy ) and ( stroke 
 or cerebrovascular accident or hemiplegia ) and ( limb or arm or upper extremity ) . electronic 
 databases were searched , including medline , cinah , and the physiotherapy evidence database 
 ( pedro ) , for articles published between 2000 and 2014 . following completion of the searches , two reviewers independently 
 assessed the trials and extracted data using a data extraction form and independently 
 documented the methodological quality of the trials using the pedro scale . disagreements 
 concerning whether a study met the inclusion criteria , level of evidence , or quality ratings 
 were resolved by consensus . the inclusion criteria were as follows : the subject s primary 
 diagnosis was stroke , action observation was used as a main intervention , and ao was used to 
 reduce upper - extremity impairment or improve upper - extremity function . from the 164 titles 
 and abstracts retrieved , after reading the full articles , 9 of these 14 articles were excluded , and the remaining 5 
 articles met the inclusion criteria ( fig . 1fig . the methodological quality 
 scores of the 5 randomized controlled trials ( rcts ) , which ranged between 6 and 9 points are 
 shown in table 1table 1.analysis of studies with action observation interventionstudypedro scorepatientinterventioncomparisonoutcomenmean agetype of aointensityoutcome measure(s)findingscowles et al . , 2013962878ao with intention - to - imitate followed by physical practice15 sessions , 3 times / week , two 30-min / dayconventional physical therapymi and arateg : significant improvements for the mi , cg : significant 
 improvement for arat , between - group difference was not statistically 
 significantertelt et al . , 2012106188<30ao and immediate imitation of common daily hand and arm actions 
 with household objectsdaily , lasting 90 minutes / day for 6 weeksplacebo group and a group receiving usual rehabilitationwmftimprovement of the experimental group in a standardized motor 
 function test relative to control groups.franceschini et al . , 2012771026720 different daily routine tasks20 sessions , 5 times / week , for 4 weeksconventional otfm , frenchay arm test , bbt , mas , and fim motor itemsan improvement over time was appreciated on all measures of 
 impairmentlee et al . , 20131153363ao ( picking up a cup , bring it to the mouth , and returning it to 
 the starting position)observe the task video for 5minutes and practiced the action for 
 5 minutesaction practice group , combined action observation - action 
 practice group , and control groupdrinking behavior functionssignificant improvements compared to the controlsale et al . , 20141296766.520 different daily routine tasks20 sessions , 5 times / week , for 4 weekssham aobbt and fmsignificant difference within groups and between two groups at 
 the end of treatment and follow - up ( 45 months)ao : action observation ; eg : experimental group ; cg : control group ; bbt : box and block 
 test ; fm : fugl - meyer assessment ; wmft : wolf motor function test ; mi : motricity index ; 
 arat : action research arm test ; mas : modified ashworth scale ; fim : functional 
 independence measure . flowchart of the article search and study selection ao : action observation ; eg : experimental group ; cg : control group ; bbt : box and block 
 test ; fm : fugl - meyer assessment ; wmft : wolf motor function test ; mi : motricity index ; 
 arat : action research arm test ; mas : modified ashworth scale ; fim : functional 
 independence measure table 1 shows the main characteristics 
 of the 5 eligible studies included in the present systematic review . two studies7 , 12 
 used the fugl - meyer assessment ( fm ) and the box and block test ( bbt ) , one study9 used the motricity index ( mi ) and the action 
 research arm test ( arat ) , and one article10 used the wolf motor function test ( wmft ) as the outcome parameter , 
 whereas the study of lee et al.11 
 evaluated outcome with an analysis of drinking behavior . four7 , 10,11,12 of the rcts reported 
 statistically significant effects for motor recovery of upper limb , whereas 1 rcts9 did not find significant differences between 
 groups . the experimental group received an ao intervention 30 to 60 minutes per day , 3 to 5 
 times per week , for a total of 15 to 20 sessions . the present review involving 5 articles that shows a positive trend toward action 
 observation intervention for the upper limb when compared with conventional or sham 
 interventions with regard to motor recovery when measured with the fm or wmft or drinking 
 behavior functions . when considering the impact of intensity of intervention on stroke outcome , it should be 
 realized that the intensity of rehabilitation programs is often limited13 . in this review , action observation may be achieved by 
 applying the actions were observed from a first - person perspective with the videos that 
 tasks were based on some relevant adls except one study9 . two7 , 12 of the five studies used ao with 20 different daily 
 routine tasks , starting from the easiest and ending with the most complex action throughout 
 20 sessions in the same way . ertelt et al.10 reported that ao had 
 a significant effect of patients with chronic stroke , and franceschini et al.7 investigated the effect of ao on patient 
 with acute stroke . future systematic review or meta - analysis with pooled 
 data analysis would prove useful in determining the effectiveness of the conditions ( acute 
 and chronic ) after stroke and duration of intervention . this review assessed the quality of rcts using the pedro score and considered any trial 
 with a score greater than or equal to 4 to be of  high quality  . high 
 quality  took into consideration criteria such as the level of evidence and heterogeneity of 
 pooled data2 . first , the trials included in the review 
 had different intervention goals , treatment contents in the experimental and control groups , 
 patient selection criteria , and outcome measures . this means we may have missed relevant studies published in other 
 languages . the key difference between our overview and other reviews that has based 
 assessments of the evidence on rcts . in summary , the present systematic review revealed that 
 there is strong evidence confirming that action observation has the potential to elicit 
 improvements in upper limb function .
[ purpose ] the purpose of this study was to suggest evidenced information about action 
 observation to improve upper limb function after stroke . 
 [ methods ] a systematic review of 
 randomized controlled trials involving adults aged 18  years or over and including 
 descriptions of action observation for improving upper limb function was undertaken . 
 electronic databases were searched , including medline , cinahl , and pedro ( the 
 physiotherapy evidence database ) , for articles published between 2000 to 2014 . following 
 completion of the searches , two reviewers independently assessed the trials and extracted 
 data using a data extraction form . 
 the same two reviewers independently documented the 
 methodological quality of the trials by using the pedro scale . 
 [ results ] five randomized 
 controlled trials were ultimately included in this review , and four of them ( 80% ) reported 
 statistically significant effects for motor recovery of upper limb using action 
 observation intervention in between groups . 
 [ conclusion ] this review of the literature 
 presents evidence attesting to the benefits conferred on stroke patints resulting from 
 participation in an action observation intervention . 
 the body of literature in this field 
 is growing steadily . 
 further work needs to be done to evaluate the evidence for different 
 conditions after stroke and different duration of intervention .