Balance disability after stroke.

Stroke is the third most common cause of death ill the Western Hemisphere and the most common cause of adult disability (1); of the survivors, about 50% will have a significant long-term disability. (2) Balance problems are thought to be common after stroke, and they have been implicated in the poor recovery of activities of daily living (ADL) and mobility and an increased risk of falls. (3-6) Despite these data, there is little detailed information about balance problems. One factor that contributes to this lack of information is a lack of clarity in the language used to describe balance difficulties. The terms "balance," "balance reactions," "postural reactions," "postural control," "posture," and "equilibrium" are used interchangeably, but there are neither commonly accepted definitions for these terms nor any consistency in the way in which they are used. This problem hampers attempts to draw conclusions from the literature or to generalize the findings. Most studies have measured balance impairments (such as postural sway, weight distribution, or related parameters) rather than balance disability (the type of balance task that a subject can perform while maintaining an upright position, such as static or dynamic sitting or standing balance), each of which is reviewed below.

Studies of balance impairments consistently have shown that people with stroke have greater postural sway than age-matched volunteers who are healthy. (7-11) They also have altered weight distribution patterns, so that less weight is taken through the weak leg, and they have smaller excursions when moving their weight around the base of support, especially in the direction of the weaker leg. This pattern is seen in all aspects of balance--static, dynamic, or responses to external perturbations--and even in people with stroke with high levels of function, such as those who are ambulatory in the community. (12-22) The relationship between balance impairments (such as weight distribution or postural sway) and function, whether assessed by balance disability, mobility, or ADL, is less clear. Although some studies have shown that balance impairment measures are related to measures of activity, (15-17,22) other studies have, more frequently, failed to demonstrate a relationship. (8,20,23-30) There are a number of possible reasons for these findings. First, most studies involved small numbers of subjects drawn from a convenience sample with a narrow range of abilities (eg, people who are able to stand with their eyes closed (13,26) or stand on one leg, (13,30) or both (13)), so that the majority of patients with stroke were excluded. Selection of subjects with a narrow range of abilities may result in too small a range of performance to detect a relationship. No descriptive studies of balance impairments used power calculations to determine the number of subjects needed to detect a relationship; therefore, it is possible that there were simply too few subjects. Another possibility is that balance impairments are not related to balance disability or everyday function. This possibility is strengthened by the finding that, although balance disability and function improve during rehabilitation and with time after stroke, balance impairments do not. (8,27,30) This finding suggests either that balance impairments are not related to balance disability and function or that people are able to develop compensation strategies that enable them to become functionally effective despite their balance impairments.

There is even less literature about balance disability after stroke, although this problem, rather than balance impairments, is the locus of physical therapists' assessment and treatment plans. (31-33) The most consistent finding is that a lack of sitting balance in the acute stages alter stroke is a robust indicator of a poor prognosis for recovery of independence in mobility or ADL. (34-39) The other consistent finding is a positive relationship between balance disability and other aspects of function, such as mobility, ADL, and falls. (22,27,30,35-43) However, variability in outcome measures and selection criteria hampers comparison and generalizability and prevents meta-analysis. To date, there have been no detailed descriptive studies of balance disability after stroke. We aimed to repair this deficiency by undertaking a cross-sectional survey of balance disability alter stroke. The specific objectives were to assess the frequency of balance problems, to characterize different degrees of balance disability, and to identify the factors associated with balance disability.

In this study, balance disability was defined as the ability to maintain an upright position within the limits of stability or base of support. (44,45) This definition is operationalized in a newly developed measurement tool, the Brunel Balance Assessment (BBA) (46) (Appendix). There are already many measures of balance after stroke, (47-53) and it may be questioned why a new measure is needed. Although ordinal scales, such as the Berg Balance Scale (47) or the Rivermead Mobility Index, (48) are generally reliable and valid measures of balance disability, they are relatively unresponsive to change. Functional performance measures, such as the Forward Reach Test (49) or the 10-Meter Walk Test, (50) are generally reliable, valid, and sensitive but suitable for use only with people with a narrow range of abilities. For example, the Forward Reach Test is suitable only for people who can stand and reach unaided (ie, have dynamic standing balance) but whose standing balance is not within normal limits. Instrumented measures, such as force plates or postural sway monitors, measure balance impairments rather than disability. For a comprehensive review of balance measurement tools alter stroke and their psychometric properties, see Tyson and DeSouza. (51-53) The BBA is a reliable, valid measure of balance disability after stroke, is suitable for people with a wide range of abilities (from supported sitting balance to an advanced skill such as changing the base of support in a single stance), and is sensitive to change. (46,54) It operationalizes the hierarchy of balance tasks (progressing from sitting to standing and stepping balance) that physical therapists use when assessing balance disability. (31) It combines a 12-point ordinal scale of balance disability with functional performance tests at each level of the ordinal scale. The ordinal scale is arranged into 3 subscales that also can be used individually (Appendix). The sitting balance scale scores 1 to 3 on the main scale, the standing balance scale scores 4 to 6, and the stepping scale scores 7 to 12. In this article, subjects who scored between 1 and 3 on the BBA are referred to as being in the sitting balance group, subjects who scored between 4 and 6 are referred to as being in the standing balance group, and subjects who scored between 7 and 12 are referred to as being in the stepping balance group. Full details of the BBA and how to use it can be found and downloaded from: www. healthcare.salford.ac.uk/crhpr/brunel-balance-assessment. htm.

Method

A prospective cross-sectional hospital-based survey of subjects who had a stroke and who were recruited from 2 British National Health Service trusts was undertaken. Successive subjects with hemiplegia after a first-time anterior circulation stroke were recruited and tested 2 to 4 weeks after the stroke if they were able to give informed consent and were well enough to participate. They were excluded if they had another mobility-limiting neurological condition (such as dementia or Parkinson disease) or bilateral weakness, because their mobility and balance disabilities would be different from those with hemiplegia alone.

Subjects

All people who had a stroke and were admitted to 2 large British National Health Service trusts (N=433) were screened over a 1-year period (January 2003-January 2004). Of these, 75 subjects were recruited. Of the excluded 358 subjects, 132 (37%) were too unwell to participate because they were drowsy or unconscious or had severe comorbidities, 87 (24%) were too aphasic or confused to give consent, 4 (1%) spoke insufficient English to give consent, 77 (21.5%) were discharged within 2 weeks, 49 (14%) had another neurologic condition, and 9 (2.5%) declined to participate.

Of the 75 subjects recruited, 46 (61%) had left hemiplegia and 66 (88%) had ischemic stroke. Twenty (27%) had a total anterior circulation stroke, 24 (32%) had a partial anterior circulation stroke, and 31 (41%) had a lacunar anterior circulation stroke. The mean time since the stroke was 21 days (SD=5). There were 37 men (49%), and the mean age was 71.5 years (SD=12.2, range=34-92). A total of 55 subjects (73%) had no previous disability. The median Motricity Index score was 74.5 (interquartile range=35.5-96), the median Rivermead Assessment of Sensorimotor Performance (RASP) score was 14 (interquartile range=10-18), the median BBA score was 6 (interquartile range=3-10), and the Barthel Index score was 12 (interquartile range=7-17). A total of 21 subjects (28%) had visuospatial neglect. Informed consent was obtained from all participants.

Procedure

Once informed consent was obtained, data were collected in a single measurement session at the hospital bedside or physical therapy treatment gym by 1 of 4 assessors (2 senior neurologic physical therapists and 2 geriatricians). The following data were obtained.

Demographics. Demographic details included age, sex, and prestroke disability (Rankin Scale (55)). The Rankin Scale is a widely used basic measure of disability that is based on mobility and has established reliability and validity for stroke. (55) In this study, it was used to classify prestroke disability. Scores are as follows: 0 indicates no symptoms, 1 indicates no significant disability despite symptoms, 2 indicates slight disability (able to look after own affairs but unable to carry out all previous activities), 3 indicates moderate disability (requires some help but able to walk without assistance), 4 indicates moderately severe disability (unable to walk or attend to bodily needs without assistance), and 5 indicates severe disability (bedridden).

Stroke pathology. Stroke pathology included stroke type (ischemic or hemorrhagic, as determined from computed tomography scan), location (left or right, as determined from computed tomography scan), and severity (Oxford Community Stroke Project [OCSP] classification (56)). The OCSP classification classifies the severity of stroke according to the location of the cerebral insult. It is reliable and valid and is a good prognostic indicator in terms of morbidity and mortality. (56) It is widely used in the United Kingdom to stratify patients tot trials or for treatment. Anterior circulation strokes are classified as total (TACS), partial (PACS), or lacunar (LACS), according to the number of acute impairments on clinical examination.

Neurologic impairments. Neurologic impairments included neglect (as determined by the Star Cancellation Test and the Line Bisection Test (57)), weakness (Motricity Index (58-62)), and sensation (RASP (63)).

The Star Cancellation Test and the Line Bisection Test are part of the Behavioral Inattention Test, which has well-demonstrated reliability, validity, and sensitivity. (57) The Star Cancellation Test consists of an A4 (8.27- x 11.69-in) sheet of paper with large stars, small stars, letters, and short words randomly positioned across the page. The subject is asked to cross out the small stars. There are 54 small stars, and a cutoff point of 51 stars is used to determine the presence of neglect. (57) The Line Bisection Test consists of three 8-in lines across a page. (57) The subject is asked to estimate and mark the center of each line. A template is used to score the subject's mark according to how close it is to the true center of the line. The maximum score is 9, the minimum score is 0, and there is an impairment cutoff at 7. (57) In this study, a subject failing either test was noted to have neglect.

The Motricity Index is a well-established measure of hemiplegic limb strength. The average of the scores for the upper and lower limbs is taken to provide a total score tot the hemiplegic side; the total score was used in this study. A score of 0 indicates complete paralysis, and a maximum score of 100 indicates complete recovery or no weakness. Test-retest reliability, intertester reliability, and validity' for use with people with stroke have been established. (58-62)

The RASP is a measure designed to operationalize the clinical assessment of sensation in neurologic conditions. (63) Proprioception (joint movement and direction) and sensation to light touch (detection of touch and location) of the upper limb (hand, thumb, wrist, and elbow) and lower limb (toot and ankle) are measured. (63) The maximum score is 18. A score of 0 to 6 indicates severely impaired or absent sensation, a score of 7 to 12 indicates impaired sensation, and a score of 12 to 18 indicates mildly impaired or intact sensation. Reliability and validity have been described. (63)

Balance disability. Balance disability was evaluated with the BBA (46,54) (Appendix).

Function. Function (independence in ADL) was evaluated with the modified Barthel Index. (64) The Barthel Index is a widely used measure of independence in ADL. A score of 0 indicates total dependence, and a maximum score of 20 indicates independence in basic ADL. Reliability and validity for use with people with stroke have been demonstrated. (64)

Data Analysis

Descriptive statistics were used to describe the frequency of balance disability (objective 1). To characterize the different balance groups, Kruskal-Wallis tests were used to assess differences between the groups (sitting, standing, or stepping balance); to assess where the differences lie, individual Mann-Whitney U test comparisons (to compare sitting versus standing, sitting versus stepping, and standing versus stepping) were undertaken for the significant parameters (objective 2). To assess which factors affected balance disability, linear regression was used (objective 3). Data for demographics, stroke pathology, and impairments were entered into an individual linear regression model, with balance disability as the dependent variable. Then, to take into account colinearity, the significant factors were loaded into a multifactorial model. The severity of stroke was not entered into the linear regression model because it has obvious colinearity with impairments, as the presence of impairments is used in the OCSP classification. (56)

Results

Thirteen subjects (17%) scored the maximum of 12 on the BBA (step-ups without hand support) and could complete all of the balance tasks. Of the remaining 62 with balance disabilities, 17 (27%) could sit but not stand (BBA scores of 1-3), 25 (40%) could stand but not step and walk (scores of 4-6), and 20 (33%) could step but still had limited balance (scores of 7-11).

There was marked heterogeneity among subjects with different levels of balance ability (Tabs. 1 and 2). There were no differences in the demographic characteristics (age, sex, and previous disability) or the side of stroke for subjects with different levels of balance disability (sitting, standing, or stepping balance). Subjects in the sitting balance group had more severe neurologic impairments, disabilities, and strokes than subjects with limited standing or stepping balance. Conversely, subjects ill the stepping balance group were less severely impaired and disabled and had milder strokes than subjects with limited sitting or standing balance. There were significant differences among the 3 groups for weakness, independence, and severity of stroke. More subjects in the sitting balance group had neglect and sustained a hemorrhage (rather than infarct) than subjects in the standing balance group or the stepping balance group (but there were no differences between the standing balance and stepping balance groups). Subjects in the sitting balance and standing balance groups had worse sensation than subjects in the stepping balance group (but there were no differences between the sitting balance and standing balance groups).

Individual linear regression modeling revealed that none of the demographic or stroke pathology factors (age, sex, premorbid disability, side of stroke, or stroke type) was associated with balance disability. All of the impairments (weakness, sensation, and neglect) were significantly associated with balance disability (Tab. 3). When the significant factors (impairments) were entered into a multifactorial model, weakness and sensation emerged as being independently associated with balance disability, but neglect did not (Tab. 4). This model accounted tot 47% of the variance.

Discussion and Conclusions

Although rehabilitation of balance and mobility often has been identified as an important goal of stroke rehabilitation, this is the first detailed descriptive study of balance disability after stroke. We found that more than 80% of subjects who had first-time strokes, who were admitted to the hospital, and who met the inclusion criteria had balance disability, in the acute phase, with similar numbers of subjects having limited sitting balance, standing balance, and stepping balance. There were marked differences in the severity of stroke, impairments, and disability among subjects with different levels of balance ability. Subjects in the sitting balance group had more severe strokes and impairments and were more dependent than subjects in the standing balance and stepping balance groups, and subjects in the stepping balance group had milder strokes, less impairment, and greater independence than subjects in the other groups. Given the heterogeneity among subjects with different balance abilities, a measure of balance disability may be a useful predictive tool in the clinical setting and for use as a stratification tool for further research. Moreover, level of balance ability (sitting, standing, or stepping balance) is meaningful to clinicians, patients, and their relatives, and a robust measurement tool (BBA (46,54)) that is quick and easy to use has been developed. (46) Further studies including power calculations to ensure a sufficiently large sample are needed to further test the hypothesis that balance level in the acute stages could be a useful, meaningful prognostic indicator of recovery.

Three previous studies (26,40,65) considered which factors may be related to balance disability (as the outcome variable). All 3 studies used a correlational design, rather than the linear regression design used in the present study. Their findings broadly support the results of the present study. A significant positive correlation between strength or lower-limb control and balance disability was found in all 3 studies. (26,40,65) Niam et al (26) and Keenan et al (40) found a positive relationship between balance disability and sensation (as measured by ankle proprioception). As in the present study, Niam et al (26) and Bohannon (65) failed to find a relationship between age, sex, or side of stroke and balance disability.

It is important to know which factors influence a patient's balance abilities most strongly so that they can be targeted during rehabilitation. The present study has indicated that weakness and sensation have the most impact on balance. A surprising finding was that neglect was not associated with balance disability. Although neglect appeared to be significant when it was entered into an individual analysis, the apparent significance was lost when it was entered into a multifactorial model with other significant impairments. This finding indicates that neglect may be related to the severity of balance disability because it is associated with other impairments (weakness and sensory loss); therefore, people with neglect probably have poor balance because they also have severe weakness or sensory, loss, or both, rather than because they have neglect per se. The case for this interpretation is strengthened when people who have neglect and mild weakness (Motricity Index score of <60) are compared with the rest of the sample. If the hypothesis was correct, then people with neglect and mild weakness would have a high balance score. When the data were examined, 7 subjects with neglect and mild weakness were identified. They had better balance scores than the rest of the group (BBA scores of 8.3 [SD=4.23] versus 6.4 [SD=3.5]). These differences did not reach statistical significance (P<.216 for the BBA), however, possibly because of the small number of people with neglect (n=21). Further studies with a power calculation to ensure that sufficient numbers are recruited to detect a difference, should one exist, are needed to investigate this issue.

Although the model that we developed to identify factors associated with balance disability in the acute stages accounted for 47% of the variance in balance disability, 53% of the variance still was unaccounted for. Future studies need to consider which other factors may affect balance disability. Spasticity was not included in the present study because of the lack of a robust measurement tool, (66,67) but many physical therapists believe this to be an important contributor to loss of balance and function alter stroke. (33) Tests of eyesight and cognitive factors, such as speed of information processing, also could be considered, and more subtle measures of neglect or attention may shed more light on otherwise unexplained variance. The relationship between balance impairments and balance disability also needs to be clarified by including measures of balance impairments in future, more detailed studies.

Finally, we chose not to recruit subjects until 2 weeks after stroke. We did this to avoid the first week, when subjects may have been distressed, busy with investigations, or acutely ill or when, in a few cases, the diagnosis was unclear. This strategy was successful in that very few people declined to participate in the study (only 2%), and we did not recruit anyone who was subsequently found not to have had a stroke. However, it did mean that we failed to recruit some people (25%) who had had very mild strokes and who were discharged within 2 weeks of admission. Notwithstanding the above details, it must be emphasized that we included all people who were admitted to 2 trusts over the course of 1 year, who met the inclusion criteria, and who were willing to participate. We therefore believe that our findings have general relevance to the population of people with balance disability alter first-time stroke.

Appendix.
Brunel Balance Assessment (a)

Level of Balance                               Performance Test

1. Static sitting balance with upper-limb      Timed for 30 s (yes/no)
  support

Whether the subject can maintain a sitting
  position for 30 s with upper-limb support
  but without assistance from another person

2. Static sitting balance                      Arm raise

How often the sound arm can be raised and
  lowered (to the subject's full range) in
  15 s; minimum score to pass this level = 3
  lifts

3. Dynamic sitting balance                     Forward reach

Distance the subject can reach beyond arm's
  length; minimum score to pass this
  level = 11 cm

4. Static standing balance with upper-limb     Timed for 30 s (yes/no)
  support

Whether the subject can maintain a standing
  position for 30 s with upper-limb support
  but without assistance from another person

5. Static standing balance                     Arm raise

How often the sound arm can be raised and
  lowered (to the subject's full range) in
  15 s; minimum score to pass this level = 3
  lifts

6. Dynamic standing balance                    Forward reach

Distance the subject can reach beyond arm's
  length; minimum score to pass this
  level = 7 cm

7. Static double stance (stride-standing)      Timed for 30 s (yes/no)

Whether the subject can maintain
  stride-standing position for 30 s without
  holding onto or assistance from another
  person

8. Supported single stance                     Timed 5-m walk without
                                                 an aid
Time taken to walk 5 m with a walking stick;
  minimum score to pass this level = 0.43 s

9. Dynamic double stance (stride-standing)     Weight shift

How often the subject con transfer weight
  on and off the weak leg while in
  stride-standing position in 15 s; minimum
  score to pass this level = 3 shifts

10. Change of the base of support (between     Timed 5-m walk without
  double stance and single stance)               an aid

Time taken to walk 5 m without a walking
  aid; minimum score to pass this level =
  0.7 s

11. Maintaining static single stance           Tap

How often the subject con tap the sound leg
  on and off a 10-cm box in 15 s; minimum
  score to pass this level = 2 taps

12. Advanced change of the base of support     Step-up

How often the subject can step up onto and
  off of a 10cm box, leading with the weak
  leg; minimum score to pass this level = 1
  step-up

(a) The Brunel Balance Assessment is the copyrighted property
of Sarah Tyson.

This article was received December 10, 2004, and was accepted June 6, 2005.

References

(1) Secretary of State for Health. Saving Lives: Our Healthier Nation. London, United Kingdom: The Stationer), Office; 1999.

(2) Wolfe CD. The impact of stroke. Br Med Bull. 2000;56:275-286.

(3) Loewen SC, Anderson BA. Predictors of stroke outcome using objective measurement scales. Stroke. 1990;21:78-81.

(4) Kwakkel G, Wagenaar RC, Kollen BJ, Lankhorst GJ. Predicting disability in stroke: a critical review of the literature. Age Ageing. 1996:25:476-489.

(5) Lamb SE, Ferrucci L, Volapto S, et al. Risk factors for falling in home-dwelling older women with stroke. Stroke. 2003;34:494-501.

(6) Lofgren B, Nyberg L, Osterlind O, Gustafson Y. In-patient rehabilitation after stroke: outcome and factors associated with improvement. Disabil Rehabil. 1998;20:55-61.

(7) Corriveau H, Hebert R, Raiche M, Prince F. Evaluation of postural stability in the elderly with stroke. Arch Phys Med Rehabil. 2004;85: 1095-1101.

(8) De Haart M, Geurts A, Huidekoper S, et al. Recovery of standing balance in post-acute stroke patients: a rehabilitation cohort study. Arch Phys Med Rehabil. 2004;85:886-895.

(9) Lamontagne A, Paquet N, Fung J. Postural adjustments to voluntary head motions during standing are modified following stroke. Clin Biomech. 2003; 18:832- 842.

(10) Ikai T, Kamikubo T, Takehara I, et al. Dynamic postural control of patients with hemiparesis. Am J Phys Med Rehabil. 2003;82:463-469.

(11) Mizrahi J, Solzi R, Ring H, Nisell R. Postural stability in stroke patients: vectorial expression of asymmetry, sway, activity and relative sequence of reactive forces. Med Biol Eng Comput. 1989;27:181-190.

(12) Eng J, Chu K. Reliability and comparison of weight-bearing ability during standing tasks for individuals with chronic stroke. Arch Phys Med Rehabil. 2002;83:1138-1144.

(13) Goldie P, Matyas T, Evans O, et al. Maximum voluntary weight-bearing by the affected and unaffected legs in standing following stroke. Clin Biomech. 1996;11:333-342.

(14) Turnbull G, Charteris J, Wall J. Deficiencies in standing weight shifts by ambulant hemiplegic subjects. Arch Phys Med Rehabil. 1996;77: 356-362.

(15) Titanova E, Tarkka I. Asymmetry in walking performance and postural sway in patients with chronic unilateral, cerebral infarction. J Rehabil Res Dev. 1995;32:236-244.

(16) Sackley C. Falls, sway and symmetry of weight-bearing after stroke. International Disability Studies. 1991;13:1-4.

(17) Di Fabio RP, Badke MB. Extraneous movement associated with hemiplegic postural sway during dynamic goal-directed weight redistribution. Arch Phys Med Rehabil. 1990;71:365-371.

(18) Gruendel T. Relationship between weight-bearing characteristics in standing and ambulatory independence in hemiplegia. Physiother Can. 1992;44:16-17.

(19) Rogers MW, Hedntan L, Pai Y. Kinetic analysis of dynamic transitions in stance support accompanying voluntary leg flexion movements in hemiparetic adults. Arch Phys Med Rehabil. 1993;74:19-25.

(20) Pai Y, Rogers M, Hedman L, Hanke T. Alterations in weight-transfer capabilities in adults with hemiparesis. Phys Ther. 1994;7:647-659.

(21) Di Fabio RP, Badke MB. Relationship of sensory organization to balance function in patients with hemiplegia. Phys Ther. 1990;70: 542-548.

(22) Au-Yeung S, Ng J, Lo S. Does balance or motor impairment discriminate the ambulatory status of stroke survivors? Am J Phys Med Rehabil. 2003;82:279-283.

(23) Laufer Y, Sivan D, Schwarzmann R, Sprecher E. Standing balance and functional recovery of patients with right and left hemiparesis in the early stages of rehabilitation. Neurorehabil Neural Repair. 2003;17: 207-213.

(24) Fishman M, Colby L, Sachs L, Nichols D. Comparison of upper-extremity balance tasks and force platform testing in persons with hemiparesis. Phys Then 1997;77:1052-1062.

(25) Stevenson T, Garland S. Standing balance during internally produced perturbations in subjects with hemiplegia: validation of the balance scale. Arch Phys Med Rehabil. 1996;77:656-662.

(26) Niam S, Cheung W, Sullivan P. et al. Balance and physical impairment after stroke. Arch Phys Med Rehabil. 1999:80:1227-1233.

(27) Garland S, Willems D, Ivanova T, Miller K. Recovery of standing balance and functional mobility after stroke. Arch Phys Med Rehabil. 2003;84:1753-1759.

(28) Shehon F, Volpe B, Reding M. Motor impairment as a predictor of functional recovery and guide to rehabilitation treatment after stroke. Neurorehabil Neural Repair. 2001 ; 15:229-237.

(29) Sackley C. The relationship between weight-hearing symmetry after stroke, motor function and activities of daily living. Physiother Theory Pract. 1990;6:179-185.

(30) Isakov E, Mendelevich I, Ring H, Mizhari J. Balance recovery and relationship with ambulation distance in recent hemiparetic adults. Europa Medicophysica. 1998;43:5-9.

(31) Tyson S, DeSouza L. A clinical model for the assessment of posture and balance post-stroke. Disabil Rehabil. 2002;25:120-127.

(32) Ballinger C, Ashburn A, Low J, Roderick P. Unpacking the black box of therapy: a pilot study to describe occupational therapy and physiotherapy interventions for people with stroke. Clin Rehabil. 1999; 13:301-309.

(33) Lennon S, Baxter D, Ashburn A. Physiotherapy based on the Bobath concept in stroke rehabilitation: a survey within the UK. Disabil Rehabil. 2001;23:254-262.

(34) Nichols DS, Miller L, Colby LA, Pease WS. Sitting balance: its relation to function in individuals with hemiparesis. Arch Phys Med Rehabil. 1996;77:865-869.

(35) Morgan P. The relationship between sitting balance and mobility outcome. Aust J Physiother. 1994:40:91-96.

(36) Feigin L, Sharon B, Czaczkes B, Rosin A. Sitting equilibrium two weeks after a stroke call predict walking ability, at six months. Gerontology. 1996;42:348-353.

(37) Tsang Y, Mak M. Sit-and-reach test can predict mobility of patients recovering from acute stroke. Arch Phys Med Rehabil. 2004;85:94-98.

(38) Nitz J, Gage A. Post-stroke recovery of balance sitting and ambulation ability. Aust J Physiother. 1995;41:263-267.

(39) Broussean L, Phillipe P, Potvin L, Boulanger Y. Post-stroke inpatient rehabilitation, 1: predicting length of stay. Am J Phys Med Rehabil. 1996;75:6422-6430.

(40) Keenan M, Perry J, Jordan C. Factors affecting balance and ambulation following stroke. Clin Orthop. 1984;182:165-171.

(41) Pohl P, Duncan P, Perera S, et al. Influence of stroke-related impairments on performance in the 6-minute walk test. J Rehabil Res Dev. 2002;39:439-444.

(42) Nilsson L, Carlsson J, Grimby G, Nordholm L. Assessment of walking balance and sensorimotor performance of hemiparetic patients in the acute stages after stroke. Physiother Theory Pract. 1998; 14:149-157.

(43) DeQuervain I, Simon S, Leurgans S, et al. Gait patterns in the early recover, period after stroke. J Bone Joint Surg. 1996:78:1506-1514.

(44) Bronstein A, Brandt T, Woollacott M. Clinical Disorders of Balance. Posture and Gait. London, United Kingdom: Arnold Publications; 1996.

(45) Shumway-Cook A, Woollacott M. Motor Control: Theory and Practical Applications. 2nd ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2001.

(46) Tyson S, DeSouza L. Development of the Brunel Balance Assessment: a new measure of balance disability post-stroke. Clin Rehabil. 2004;18:801-810.

(47) Berg K, Wood-Dauphinee S, Williams J. The Balance Scale: reliability assessment with elderly residents and patients with acute stroke. Scand J Rehabil Med. 1995;27:27-36.

(48) Collen F, Wade D, Robb G, Bradshaw C. The Rivermead Mobility Index: a further development of the Rivermead Motor Assessment. Int Disabil Stud. 1991;13:50-54.

(49) Duncan PW, Weiner DK, Chandler J, et al, Functional Reach: a new clinical measure of balance. J Gerontol. 1990;45:M192-M197.

(50) Collen F, Wade DT, Bradshaw C. Mobility after stroke: reliability of measures of impairment and disability. Int Disabil Stud. 1990;12:6-9.

(51) Tyson S, DeSouza L. Measurement of balance and walking post-stroke, part 1: ordinal scales. Physical Therapy Reviews. 2002;7:177-185.

(52) Tyson S, DeSouza L. Measurement of balance and walking post-stroke, part 2: functional performance tests. Physical Therapy Reviews. 2002;7:87-91.

(53) Tyson S, DeSouza L. Measurement of balance post-stroke, part 3: instrumented measurement tools. Physical Therapy Reviews. 2002;7: 231-241.

(54) Tyson S, DeSouza L. Reliability and validity of functional balance tests post-stroke. Clin Rehabil. 2004;18:916-923.

(55) Rankin J. Cerebral vascular accidents in patients over the age of 60, 2: prognosis. Scott Med J. 1057;2:200-215.

(56) Bamford J, Sandercock P, Dennis D, et al. A prospective study of acute cerebrovascular disease in the community--the Oxfordshire Community Stroke Project 1981-86, 1: methodology, demography and incident cases of first-ever stroke. J Neurol Neurosug Psychiatry. 1988;51: 1373-1380.

(57) Wilson B, Cockburn J, Halligan P. Development of a behavioral test of visuo-spatial neglect. Arch Phys Med Rehabil. 1087;68:98-102.

(58) Demeurrisse G, Demol O, Robaye E. Motor evaluation in vascular hemiplegia. Eur Neurol. 1980;19:382-389.

(59) Collin C, Wade D. Assessing motor impairment after stroke: a pilot study. J Neurol Neurosurg Psychiatry. 1990;53:576-599.

(60) Collen F, Wade D, Bradshaw C. Mobility after stroke: reliability of measures of impairment and disability. Int Disabil Stud. 1990;12:6-9.

(61) Bohannon RW. Motricity Index scores are valid indicators of paretic upper extremity strength following stroke. Journal of Physical Therapy Science. 1999;11:59-61.

(62) Cameron D, Bohannon RW. Criterion validity of lower extremity Motricity Index scores. Clin Rehabil. 2000;14:208-211.

(63) Winward CE, Halligan PW, Wade DT. The Rivermead Assessment of Somatosensory Performance (RASP): standardisation and reliability data. Clin Rehabil. 2002;16:523-533.

(64) Collin C, Wade DT, Davis S, Horne V. The Barthel ADL Index: a reliability study. Int Disabil Stud. 1988;10:61-63.

(65) Bohannon RW. Correlation of lower limb strengths and other variables with standing performance in stroke patients. Physiother Can. 1989:41:198-202.

(66) Pandyan AD, Price C, Curless RH, et al. A review of the properties anti limitations of the Ashworth and modified Ashworth Scales as measures of spasticity. Clin Rehabil. 1999:13:373-383.

(67) Pomeroy V, Dean D, Sykes L, et al. The unreliability of clinical measures of muscle tone: implications for stroke therapy. Age Ageing. 2000:29:229-233.

SF Tyson is Senior Research Fellow, Centre for Rehabilitation and Human Performance Research, University of Salford. Address all correspondence to Dr Tyson at: Frederick Rd Campus, University of Salford. Salford, M6 6PU United Kingdom ([e-mail]).

M. Hanley, MBChB, MRCP, is Consultant Geriatrician, Stockport NHS Trust, Stockport, United Kingdom.

J. Chillala, MBChB, MRCP, is Consultant Geriatrician, Trafford NHS Trust, Manchester, United Kingdom.

A. Selley, MSc, MCSP, is Senior Physiotherapist, North Manchester PCT, Manchester, United Kingdom.

R.C. Tallis, MA, MRCP, FRCP, F MedSci, DLitt, is Professor of Geriatric Medicine, University of Manchester, Manchester, United Kingdom.

All authors provided concept/idea/research design. Dr Tyson, Ms Selley, and Prof Tallis provided writing. Dr Hanley, Dr Chillala, and Ms Selley provided data collection, and Dr Tyson and Ms Selley provided data analysis. Dr Tyson and Prof Tallis provided project management. Prof Tallis provided tired procurement.

Ethical approval tot the study was obtained from the following Local Research Ethics Committee: Salford, Trafford, and Bolton.

This study was funded by the Stroke Association and Humphrey Booth Charities.

This research was presented to the Society of Research in Rehabilitation, The University of Nottingham, Nottingham, United Kingdom, June 30-July 1, 2003.

Table 1.
Kruskal-Wallis Test Comparisons to Identify Differences Among
Balance Groups (a)

                                  Sitting (BBA        Standing (BBA
                                  Score = 1-3)        Score = 4-6)
Parameter                         (n = 17)            (n = 25)

Stroke pathology
  Side of stroke--no. (%) with    11 (65)             14 (56)
    left hemiplegia
  Type-no. (%) with infarcts      12 (70)             24 (96)
  Stroke severity--no. (%) of     9/8/0 (53/47/0)     7/9/9 (28/36/36)
    TACS/PACS/LACS

Demographics
  Age (y)--median (IQR)           76.0 (68, 81.5)     75 (70, 80)
  Sex--no. (%) of men              8  (47)            11 (44)
  Premorbid disability--no. (%)   11 (65)             21 (84)
    symptom free

Neurologic impairments
  Neglect--no. (%) of subjects    11 (65)              4 (16)
    with neglect
  Sensation--median (IQR)         10 (8, 14)          14 (8.5, 18)
  Weakness--median (IQR)          12.5 (1, 33.5)      55 (43.25, 89.5)

Disability
  Independence in ADL--median      6.5 (4.5, 10.75)   16 (12.5, 17)
    (IQR)

                                  Stepping (BBA
                                  Score = 7-11)
Parameter                         (n = 33)            P

Stroke pathology
  Side of stroke--no. (%) with    21 (64)             .051
    left hemiplegia
  Type-no. (%) with infarcts      30 (91)             .000 (b)
  Stroke severity--no. (%) of     4/7/22 (12/21/67)   .000 (b)
    TACS/PACS/LACS

Demographics
  Age (y)--median (IQR)           74 (61, 80)         .896
  Sex--no. (%) of men             18 (54)             .908
  Premorbid disability--no. (%)   23 (70)             .381
    symptom free

Neurologic impairments
  Neglect--no. (%) of subjects     6 (18)             .000 (b)
    with neglect
  Sensation--median (IQR)         18 (14, 18)         .000 (b)
  Weakness--median (IQR)          88 (76.5, 100)      .000 (b)

Disability
  Independence in ADL--median     18 (16.25, 19)      .000 (b)
    (IQR)

(a) BBA = Brunel Balance Assessment, which assesses balance
disability. Stroke severity was assessed by the Oxford Community
Stroke Project in which TACS = total anterior circulation stroke.
PACS = partial anterior circulation stroke, and LACS = lacunar
anterior circulation stroke. IQR = interquartile range. ADL =
activities of daily living. Premorbid disability was evaluated with
the Rankin Scale. Neglect was evaluated with the Star Cancellation
Test and the Line Bisection Test. Sensation was evaluated with the
Rivermead Assessment of Sensorimotor Performance. Weakness was
evaluated with the Motricity Index. Independence in ADL was
evaluated with the Barthel Index.

(b) Significant at P < .05.

Table 2.
Individual Mann-Whitney U Test Comparisons to Identify Where
Differences Among Balance Groups Lie 9a)

                        Balance Group
Parameter               Comparison                P

Type of stroke          Sitting and standing      .022
                        Sitting and stepping      .066
                        Standing and stepping     .453

Severity of stroke      Sitting and standing      .014
                        Sitting and stepping      .000
                        Standing and stepping     .000

Neglect                 Sitting and standing      .001
                        Sitting and stepping      .001
                        Standing and stepping     .829

Sensation               Sitting and standing      .137
                        Sitting and stepping      .000
                        Standing and stepping     .016

Weakness                Sitting and standing      .000
                        Sitting and stepping      .000
                        Standing and stepping     .001

Independence in ADL     Sitting and standing      .000
                        Sitting and stepping      .000
                        Standing and stepping     .000

(a) ADL = activities of daily living.

Table 3.
Results of Individual Linear Regressions to Identify
Which Factors Predict Balance Disability

Factor                                       P

Stroke pathology
  Side of stroke                             .937
  Type of stroke (infarct or hemorrhage)     .086

Demographics
  Age                                        .23
  Sex                                        .365
  Premorbid disability                       .981

Neurologic impairments
  Neglect                                    .015 (a)
  Sensation                                  .0001 (a)
  Weakness                                   .0001 (a)

(a) Significance was sct at P < .05.

Table 4.
Multiple Regression of Significant Factors Identified in Table 3.

                       Partial         Standardized
Adjusted [R.sup.2]     Correlation     Beta
Change = 0.468         Coefficient     Coefficient      P

Neglect                -0.066          -0.034           .714
Sensation              -0.569           0.206           .036 (a)
Weakness               -0.258           0.555           .000 (a)

(a) Significance was set at P < .05.