SITTING, A PREREQUISITE FOR most functional activities, Sit-and-Reach Test Can Predict Mobility of Patients Recovering From Acute Stroke

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1 94 Sit-and-Reach Test Can Predict Mobility of Patients Recovering From Acute Stroke Yuk Lan Tsang, MSc, Margaret Kit Mak, PhD ABSTRACT. Tsang YL, Mak MK. Sit-and-reach test can predict mobility of patients recovering from acute stroke. Arch Phys Med Rehabil 2004;85:94-8. Objectives: To establish the test-retest reliability of the sitand-reach test (SRT) and to determine the capacity of the SRT to predict mobility of patients recovering from acute stroke. Design: Study 1 consisted of repeating the SRT to examine its reliability over trials (same day) and sessions (alternate days). Study 2 consisted of measuring performance in the SRT 7 to 10 days poststroke and measuring mobility at discharge for prospective analysis. Setting: Medical and rehabilitation wards in hospital in Hong Kong. Participants: Thirty-six subjects with acute stroke (study 1, n 10; study 2, n 26). Interventions: Not applicable. Main Outcome Measures: Between 7 and 10 days of stroke onset, distance reached on the SRT was measured. Mobility at discharge was assessed using the transfer and locomotion scale of the FIM instrument (FIM mobility) and a timed walk test. Results: The intertrial and intersession reliability of the SRT were rated good, with intraclass correlation coefficients of.98 and.79, respectively. Distance reached on the SRT correlated with the FIM mobility score on discharge (r.572, P.002) and the distance achieved on the timed walk test (r.524, P.006). Distance reached on the SRT accounted for 32.7% and 27.5% of the variance in the FIM mobility score at discharge and the distance achieved on the timed walk test, respectively. Conclusions: Performance in the SRT is reliable and can significantly predict the mobility of patients with acute stroke at discharge. Key Words: Balance; Cerebrovascular accident; Rehabilitation; Walking by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation SITTING, A PREREQUISITE FOR most functional activities, such as dressing, transferring, and eating in a seated position, 1,2 is the first posture to be restored after stroke. 3,4 Ninety-three percent of patients in the stroke population can achieve 1-minute independent sitting balance within 6 days of stroke onset. 4 Sitting balance has been reported to correlate with mobility and functional outcomes after stroke. 1,5-8 Morgan 6 showed a correlation (r.49) in patients with stroke From the Department of Physiotherapy, Caritas Medical Center, Hong Kong (Tsang); and Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hong Kong, (Mak) ROC. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated. Reprint requests to Margaret K. Mak, PhD, Dept of Rehabilitation Sciences, Hong Kong Polytechnic University, Hung Hom, Hong Kong, ROC, rsmmak@ polyu.edu.hk /04/ $30.00/0 doi: /s (03) between the ability to maintain 15-second static sitting within the first 3 days of stroke onset and gait outcomes at 6 weeks poststroke. Nitz and Gage 7 reported a significant relationship between independent sitting balance within the first 10 days of stroke onset and independent ambulation on discharge. Loewen and Anderson 5 further reported that sitting balance on day 7 poststroke correlated better than that within 3 days of stroke onset with mobility and function on discharge. Within 3 days of stroke onset, patients may be disoriented in hospital; therefore, they might not perform the test well. Despite its association with mobility and functional outcomes, sitting balance has not been reported as a sole predictor for mobility and function in patients with stroke. 5,9-12 Juneja et al 9 demonstrated that Berg Balance Scale score at admission accounted for 22% of the variance in FIM instrument efficiency score when demographic factors were controlled. Wade et al 10 identified 5 variables urinary incontinence, arm motor deficit, sitting balance, hemianopia, and age that accounted for 38% of the total variance of Barthel Index score at 6 months after acute stroke. To use sitting balance as an outcome predictor, a precise measurement of sitting balance during the acute phase of stroke is essential. However, there is no widely accepted or standardized measurement of sitting balance. Measurement techniques include the assessment of trunk movements, perturbations, and a variety of subjective ratings. 1,6,8,13-15 Reaching distance in the Functional Reach Test (FRT) is a reliable and well-validated test for measuring postural control in reaching forward during standing. 16,17 It has the predictive power to screen potential fallers among frail elderly. 17,18 In addition to objectively assessing standing balance, investigators have objectively measured sitting balance. Dean et al 19,20 reported that a forward-reach distance in sitting was positively associated with the magnitude of trunk and upper-arm segmental motion, as well as the active contribution of the lower limbs in healthy persons. Therefore, reaching forward in sitting is a challenge to a person s postural control; hence, it is suggested to be an indicator of sitting balance. Nichols et al 2 used the Balance System to measure force distribution under the buttocks during forward and sideways reaching in patients with stroke during rehabilitation. Results showed a significant correlation between the forces registered during forward reach in sitting and FIM score in these patients. Lynch et al 21 used an FRT in sitting for subjects with spinal cord injury (SCI) and found good test-retest reliability (.85.94) with a single rater. Because a large percentage of patients with acute stroke could achieve independent sitting, 4 and because forward reach in sitting is a relatively simple action, we anticipated that the sit-and-reach test (SRT) would be useful in patients during the early acute phase of stroke. The purposes of our investigation were to standardize the procedures of the SRT, to establish its test-retest reliability in patients with acute stroke, and to examine the ability of the SRT to predict mobility in patients recovering from acute stroke. METHODS Two related studies were performed. Study 1 established the test-retest reliability of the SRT. Study 2 evaluated the predictive validity of SRT on mobility at discharge by a prospective data collection method.

2 MOBILITY OUTCOME PREDICTION IN STROKE, Tsang 95 Table 1: Characteristics of Subjects in Studies 1 and 2 Study 1 (n 10) Study 2 (n 26) Mean SD Range Mean SD Range Age (y) AMT* Gender Male 5 16 Female 5 10 Diagnosis L hemiplegia 6 17 R hemiplegia 4 9 First incidence of stroke 9 23 Premorbid independent walker some of the subjects were unable to walk independently and hence could not perform this test. Details of the conversion of the timed walk into the 7-point scale are found in appendix 1. Ten seconds were used at each level to easily show changes in the ambulation status. Performance on the SRT was measured using a tape measure secured to a wall at the level of the subject s acromial process Abbreviations: L, left; R, right; SD, standard deviation. *One subject in each group was unable to perform the AMT because of expressive dysphasia. Participants Patients with stroke who were transferred to the subacute medical and rehabilitation wards of a local hospital were recruited for the studies. The inclusion criteria were (1) recent hemiparesis secondary to stroke 7 to 10 days after onset; (2) medically stable for rehabilitation; (3) preserved cognitive and communicative ability with an Abbreviated Mental Test (AMT) score 7; and (4) ability to sit unsupported for 1 minute to allow performance of the SRT. The exclusion criteria were (1) confirmed or suspected subarachnoid or intercerebral hemorrhage, which could receive different medical management; (2) preexisting neurologic disorders, such as Parkinson s disease, which could cause motor deficits in addition to those resulting from recent stroke; (3) vestibular or orthopedic disorders, which could affect sitting balance or a stroke rehabilitation program; and (4) the nonparetic upper limb with shoulder flexion less than 110, which could affect performance on the SRT. The study was approved by the ethics committees of the hospital and university, and all subjects provided signed informed consent. During the study, subjects received the same medical and rehabilitation management as other patients. Interventions included physiotherapy, occupational therapy, speech therapy, clinical psychology counseling, and medical social support on an individual referral basis. Ten subjects participated and completed study 1. Thirty-two subjects were recruited for study 2, but 6 did not complete the study. Five subjects were discharged without notice to the investigator, and 1 subject was transferred back to the acute medical ward. The subjects characteristics are shown in table 1. On discharge from hospital, 21 of 26 subjects in study 2 were able to walk with or without supervision. Their average length of stay standard deviation (SD) was days (range, 10 48d). Instrumentation The assessment tools used in our study included the SRT, FIM transfer and locomotion scales (FIM mobility), and the timed walk test (appendix 1), all of which are well established and reliable. FIM mobility includes 3 items reflecting the performance mobility transfer (from bed to chair), locomotion (walking), and locomotion (stairs). Each item is scored from 1 (complete dependence) to 7 (complete independence). By adding the scores of the 3 items, FIM mobility scores can range from 3 to 21 points. The timed walk test measures the time taken to walk 6m at a self-selected speed. Stand-by supervision was provided during the timed walk test, and no physical assistance was given. The timed walk, measured in seconds, was transformed into a 7-point scale for data analysis, because Fig 1. Subject s (A) initial and (B) final position during the SRT.

3 96 MOBILITY OUTCOME PREDICTION IN STROKE, Tsang Table 2: Test-Retest Reliability of the SRT for Intertrial Reliability Within a Testing Session and Intersession Reliability Intertrial Reliability SRT (cm) Trial 1 Trial 2 Trial 3 ICC 1,k 95% CI SE Session Session Intersession Reliability SRT (cm) Session 1 Session 2 ICC 1,k 95% CI SE NOTE. Values are mean SD. of the nonparetic upper limb while he/she was sitting on an adjustable plinth (fig 1). The height of the plinth was adjusted so that the subject s hips, knees, and ankles were positioned at 90 of flexion, with the feet positioned flat on the floor. Each subject made a fist with the nonparetic upper limb, straightened the elbow, and flexed the shoulder to 90. The placement of the end of the third metacarpal along the tape was recorded as the initial position (fig 1). The subject then reached as far forward as possible without rotating the trunk or losing balance. Placement of the end of the third metacarpal was recorded as the final position (fig 1). If the subject touched the wall or lost balance during the test, the trial was repeated. The investigator sat beside the subject to record the measurements, monitor performance, and prevent falling. Each subject practiced twice before performing the 3 test trials of the SRT. All subjects completed the 3 test trials without a mistrial due to loss of balance. Distance achieved on the SRT was defined as the difference between the initial and final positions. The mean of the 3 test trials was used for analysis. Procedures In study 1, subjects performed the SRT 7 to 10 days after stroke onset. The investigator repeated the test in 2 sessions during consecutive days at the same time of the day. Study 2 included an initial and a predischarge follow-up assessment. All subjects were tested 7 to 10 days after stroke onset using the SRT during the initial assessment session. A predischarge follow-up assessment was performed within 5 days of discharge from the hospital (mean, d). FIM mobility and timed walk test were measured as the mobility outcomes. Statistical Analysis The SPSS, version 10.0, a for Windows, was used in the data analysis. A significance level ( ) of.05 was used for all statistical comparisons. The test-retest reliability of the SRT was studied using the intraclass correlation coefficient (ICC I,k ), which is based on the 1-way random analysis of variance model. Intertrial and intersession reliability was examined. Multiple linear regression was used to evaluate the degree to which the SRT that was performed in the early stage of stroke and age-predicted mobility at discharge. RESULTS Test-Retest Reliability The SRT has a good response stability, as illustrated by the small standard error (SE) of measurement (table 2). The ICC value for the intertrial reliability of the SRT score was.98 in sessions 1 and 2, respectively (table 2). The results indicated that performance in the repeated trials of the SRT was highly reproducible within the same session. On examining the intersession reliability, the ICC of the SRT scores between 2 testing sessions performed on different days was.79 (table 2). These results indicated strong test-retest reliability for SRT performance of subjects with acute stroke. Predictive Validity of the SRT on Discharge Mobility Outcomes The results of linear regression analysis showed that SRT could predict discharge FIM mobility and timed walk scores (table 3). Residual analysis showed that the regression models followed the assumptions for regression analysis. SRT performance significantly accounted for 32.7% of the variance of discharge FIM mobility score (P.002), the remaining 67.3% being unexplained by this model. The standard error of the estimate (SEE) for this predictive model was 3.47, which was small. SRT performance significantly accounted for 27.5% of the variance in discharge timed walk (P.006), the remaining 72.5% being unexplained by this model. The SEE for this predictive model was small (SEE 1.86). The relationships of SRT performance with FIM mobility and timed walk test at discharge were further developed by the actual equation showed in table 3. Age, however, was not a significant predictive variable in our study. Age was excluded from the regression models with P values of.669 and.420 in predicting discharge FIM mobility and timed walk scores, respectively. DISCUSSION Test-Retest Reliability Ours is the first study to investigate the test-retest reliability on the SRT in people with acute stroke. A consistent objective *P.01. Table 3: Linear Regression Equations Predicting Discharge FIM Mobility and Timed Walk Equations SEE R r 2 P Discharge FIM mobility (SRT) * Discharge timed walk (SRT) *

4 MOBILITY OUTCOME PREDICTION IN STROKE, Tsang 97 measure of sitting balance is essential to evaluate changes in this activity in patients with acute stroke. The intertrial reliability of the SRT in both sessions 1 and 2 was marked by an excellent ICC of.98 and a narrow range of confidence interval (CI) (table 2A). The high ICC indicates that performance of the SRT is repeatable within a single session, provided that subjects are allowed 2 practice trials. Because of the high consistency among test trials, we propose that 1 test trial of the SRT would be adequate during clinical application to save time. For intersession reliability, a 1-day interval was used because no significant change in sitting ability was to be expected within such a short period. However, the SRT was performed slightly better in session 2 than in session 1. Practice, learning effects, or improvement in patients with acute stroke could contribute to the slight performance difference between the 2 sessions. The ICC for SRT score was.79 in our study, which is considered good. 22 When compared with previous findings, the ICC for the test-retest reliability of FRT in standing was.92 in healthy subjects. 16 The ICCs for the test-retest reliability of the modified SRT were.94,.85, and.93 in patients with chronic SCI, each ICC corresponding to an injury at a different spinal cord level. 21 Because healthy subjects and patients with chronic SCI were recruited for these studies, their performance might have been more stable than that of patients with acute stroke examined in our study. Our study also found that SRT scores had a wider range of 95% CI for test-retest reliability between the 2 test sessions. This may be explained by the variable performance of 2 subjects. Both subjects had a 10-cm difference between the testing sessions. One subject improved greatly in session 2, and another performed poorly in session 2 because of his deteriorating conditions. To improve the test-retest reliability, further study is needed to examine healthy subjects and patients with chronic stroke. Predictive Validity of Performance of SRT on Discharge Mobility The SRT is a significant predictor of mobility at discharge from a rehabilitation program. The SRT score accounts for 32.7% of the variance in the discharge FIM mobility score and for 27.5% of the variance in discharge timed walk score (table 3). It is difficult to compare our results with the predictive power with other studies, because the number of subjects, conditions of subjects, and the measurement interval differed. Nevertheless, the sole use of the SRT in our study appeared to have a predictive power comparable to 14-item Berg Balance Scale 9 and to that reported by Wade et al, 10 who used 5 variables for prediction. Therefore, we conclude that the SRT is a good predictor of mobility at discharge in patients stroke. Subject age was also used in the analysis, because another study reported that age was among the variables that could predict mobility at discharge. 10 However, in our study, age was not significant, probably because of the small sample size and a small age range, as reflected by the SD. The SRT is a reliable and easy-to-use clinical tool; only a simple, inexpensive tape measure is needed. The SRT requires patients who can follow simple instructions, are able to sit unsupported for 1 minute, and can actively flex the nonparetic shoulder to 90. The patient is required only to perform a very simple forward reaching action in a sitting position. In our study, all patients completed the test without a mistrial due to loss of balance. Therefore, the SRT can be used as a quick screening tool for patients with acute stroke. Although the SRT is a significant predictor of performance of FIM, mobility and timed walk at discharge, it could not provide all prediction. No single factor was found to be a high predictor of mobility level at discharge, which may be because of patients other physical, mental, and social factors. Efforts to predict functional recovery from stroke can lead only to approximate results, because such efforts rely on physiopathologic factors in the brain, the background pathology of the patient, and emotional status. 8 Further studies on multiple regression may provide more evidence of the importance of the SRT compared with other predictive factors such as urinary incontinence, arm motor defect, proprioception, admission activities of daily living score, and level of social support. It is possible to advance out study by establishing the cutoff points for the SRT at different mobility levels, and by evaluating its sensitivity and specificity in the stroke population. Doing so will provide more information on the use of the SRT in predicting mobility outcomes in patients with acute stroke. CONCLUSIONS Use of the SRT in the assessment of patients with acute stroke has not been previously reported. The SRT is a reliable, simple, and useful clinical tool for quick screening of mobility in patients with acute stroke. We found that the performance of the SRT had high intertrial and intersession reliability. By determining that the SRT is a good predictor of the discharge FIM, transfer and locomotion, and timed walk test, we have provided more evidence for clinicians in choosing variables for predicting mobility outcomes in patients with stroke. With this information, more appropriate treatment interventions can be tailored to meet different needs of patients. Acknowledgments: We acknowledge the Caritas Medical Center for their permission to conduct the research, Professor Sing Kai Lo for his statistical advice, and Professor Elizabeth Dean and Dr. Leonard Li for their valuable comments. APPENDIX 1: ASSESSMENT GUIDELINE FOR FIM MOBILITY FIM transferring scale: bed, chair Includes all aspects of transferring to and from a bed and chair, coming to a standing position if walking is the typical mode of locomotion. Performs safely. FIM locomotion scale: walk Includes walking, once in a standing position, on a level surface. Performs safely. FIM locomotion scale: stairs Goes up and down 12 to 14 stairs (1 flight) indoors. Performs safely. General Assessment Scoring for Each FIM Item No help 7 Complete independence 6 Modified independence Helper 5 Supervision or setup 4 Minimal contact assistance 3 Moderate assistance 2 Maximal assistance 1 Total assistance Assessment Scores for Timed Walk 0 Cannot walk s s s s s s

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