***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: The authors examined sources of variance in  self-reported physical activity  in a cohort of healthy adults ( n = 580 ) from Worcester , Massachusetts ( the Seasonal Variation of Blood Cholesterol Study , 1994 - 1998 ) . Fifteen 24-hour physical activity recalls of total , occupational , and nonoccupational activity ( metabolic equivalent-hours/day ) were obtained over 12 months . R and om effects models were employed to estimate variance components for subject , season , day of the week , and residual error , from which the number of days of assessment required to achieve 80 % reliability was estimated . The largest proportional source of variance in total and nonoccupational activity was within-subject variance ( 50 - 60 % of the total ) . Differences between subjects accounted for 20 - 30 % of the overall variance in total activity , and seasonal and day-of-the-week effects accounted for 6 % and 15 % , respectively . For total activity , 7 - 10 days of assessment in men and 14 - 21 days of assessment in women were required to achieve 80 % reliability . For nonoccupational activity , 21 - 28 days of assessment were required . This study is among the first to have examined the sources of variance in daily physical activity levels in a large population of adults using 24-hour physical activity recall .  These findings provide insight for underst and ing the strengths and limitations of short term and long term physical activity assessment s employed in epidemiologic studies Background and Purpose — More than 70 % of individuals who have a stroke experience upper limb deficits that impact daily activities . Increased amount of upper limb therapy has positive effects ; however , practical and inexpensive methods of therapy are needed to deliver this increase in therapy . Methods — This was a multi-site single blind r and omized controlled trial to determine the effectiveness of a 4-week self-administered grade d repetitive upper limb supplementary program ( GRASP ) on arm recovery in stroke . 103 in patients with stroke were r and omized to the experimental group ( GRASP group , n=53 ) or the control group ( education protocol , n=50 ) . The primary outcome measure was the Chedoke Arm and H and Activity Inventory ( CAHAI ) , a measure of upper limb function in activities of daily living . Secondary measures were used to evaluate grip strength and paretic upper limb use outside of therapy time . Intention-to-treat analysis was performed . Group differences were tested using analysis of covariance . Results — At the end of the 4-week intervention ( approximately 7 weeks poststroke ) , the GRASP group showed greater improvement in upper limb function ( CAHAI ) compared to the control group ( mean difference 6.2 ; 95 % CI : 3.4 to 9.0 ; P<0.001 ) . The GRASP group maintained this significant gain at 5 months poststroke . Significant differences were also found in favor of the GRASP protocol for grip strength and paretic upper limb use . No serious adverse effects were experienced . Conclusion — A self-administered homework exercise program provides a cost- , time- , and treatment-effective delivery model for improving upper limb recovery in subacute stroke Objective : To compare the outcome of robot-assisted therapy with dose-matched active control therapy by using accelerometers to study functional recovery in chronic stroke patients . Design : Prospect i ve , r and omized , controlled trial . Setting : Stroke units in three medical centres . Subjects : Twenty patients post stroke for a mean of 22 months . Intervention : Robot-assisted therapy ( n = 10 ) or dose-matched active control therapy ( n = 10 ) . All patients received either of these two therapies for 90–105 minutes each day , 5 days per week , for four weeks . Main measures : Outcome measures included arm activity ratio ( the ratio of mean activity between the impaired and unimpaired arm ) and scores on the Fugl-Meyer Assessment Scale , Functional Independence Measure , Motor Activity Log and ABILH AND question naire . Results : The robot-assisted therapy group significantly increased motor function , hemiplegic arm activity and bilateral arm coordination ( Fugl-Meyer Assessment Scale : 51.20 ± 8.82 , P = 0.002 ; mean arm activity ratio : 0.76 ± 0.10 , P = 0.026 ; ABILH AND question naire : 1.24 ± 0.28 , P = 0.043 ) compared with the dose-matched active control group ( Fugl-Meyer Assessment Scale : 40.90 ± 13.14 ; mean arm movement ratio : 0.69 ± 0.11 ; ABILH AND question naire : 0.95 ± 0.43 ) . Conclusions : Symmetrical and bilateral robotic practice , combined with functional task training , can significantly improve motor function , arm activity , and self-perceived bilateral arm ability in patients late after stroke OBJECTIVE To examine the psychometric properties of an objective method for assessing real-world arm activity in a large sample with subacute stroke . DESIGN Validation study . SETTING Community . PARTICIPANTS Persons 3 to 9 months poststroke ( N=169 ) with mild to moderate motor impairment of their hemiparetic arm enrolled in a multisite , r and omized clinical trial of constraint-induced movement therapy .  INTERVENTIONS Not applicable . MAIN OUTCOME MEASURES Participants wore an accelerometer on each arm outside the laboratory for 3 days before and after treatment or an equivalent no-treatment period . They also completed the Actual Amount of Use Test ( AAUT ) , which is an observational measure of spontaneous more-impaired arm use , and the Motor Activity Log ( MAL ) , which is an interview assessing more-impaired arm use in daily life . RESULTS Low-pass-filtered accelerometer recordings were reliable ( r range , > .8 ) and stable ( P range , > .48 ) . Their validity was also supported . Correlations calculated across all participants at baseline between the ratio of more-impaired to less-impaired arm accelerometer recordings and AAUT and MAL scores were .60 and .52 , respectively . CONCLUSIONS Accelerometry provides an objective , real-world index of more-impaired arm activity with good psychometric properties Aim : The aim of the present study was the evaluation of actigraphy as a tool to objectify the recovery process after motor paresis due to stroke . Methods : The motor activity of both arms of patients suffering from stroke was actigraphically recorded at four different time points during the course of rehabilitation : 24–36 h , 5–7 days , 3 months , and 6 months after stroke . Results : Motor activity monitored by wrist-worn actigraphs located at the impaired side revealed an increase in activity between the first two time points and the subsequent ones . Additionally , actigraphic recordings showed lower total motor activity at the impaired side as compared to the nonimpaired side . A significant positive correlation was found between the actigraphically recorded motor activity and the results of the Sc and inavian Stroke scale , the Barthel Index , the Rankin Scale Score and with the Motoricity Index during the 1st week , which corresponds to the time when neurological deficits were most pronounced . Conclusion : Our results suggest that actigraphy is a useful tool in the objective evaluation of motor activity after stroke . Moreover , actigraphy covers additional aspects that are not reflected by the usual stroke scales in a clinical situation 
    Output:
    
The efficacy of a rehabilitation intervention was assessed using accelerometry by three studies : in two studies both accelerometry and clinical test scores detected a post-treatment difference but in one study accelerometry data did not change despite clinical test scores showing motor and functional improvements .