Statistical analyses were performed for the mean BBS and GMFM scores using the groups based on functional classification. The ANOVA for mean BBS scores was significant (F = 59.53, df = 3, p ≤ 0.01), as was the ANOVA for mean GMFM scores (F = 135.32, df = 3, p ≤ 0.01). Post-hoc analysis for the mean BBS scores revealed significant pair-wise differences among all groups of children except between children in Level I and children with no motor impairment. Post-hoc analysis performed for the mean GMFM scores also revealed significant differences among all groups of children except those children in Level I and those with no motor impairment. Thus, the ability to use scores attained on both the BBS and the GMFM to distinguish among groups of children with varying balance abilities was greater when using functional classification than when using medical diagnosis. Figure 2 provides a summary of the findings using both traditional medical diagnosis and functional classification using the GMFCS.
The purpose of the study was to evaluate the use of the BBS to assess the balance abilities of children with cerebral palsy. When the children were classified using medical diagnostic categories, the ability to use scores on the GMFM to distinguish among groups of children with differing balance abilities was slightly better than that of scores on the BBS, showing one more significant pair-wise difference. This difference was between the children with spastic diplegia who ambulated without aids and the children with no motor impairment (Fig. 2). When functional classification was used to categorize the children, the ability to use scores on both tests to distinguish among the groups improved and was identical. These results suggest that both test characteristics and the method of classification influenced the ability to use the tests to distinguish among groups of children with different balance abilities.
When using diagnostic classification, the ability to use scores on the GMFM to distinguish among the groups was greater than when using scores on the BBS. This result was most likely because the GMFM has more items at a higher level of difficulty than the BBS. For example, there are more items in Dimension E of the GMFM that require single-leg stance, such as hopping on one leg in a circle. Administration of these items distinguished between the balance abilities of children with no motor impairment and children with spastic diplegia who did not use aids to ambulate. The most challenging items on the BBS include such items as reaching forward with an outstretched arm (No. 8), turning in a full circle in both directions (No. 11), alternately lifting each foot to touch a stool (No. 12), standing in tandem stance (No. 13), and standing on one leg (No. 14). During the initial development of the BBS, Berg stated that, “the lack of an item that requires a postural response to an external stimulus or uneven support surface…will likely limit the utility of the scale when assessing very active persons with minimal deficits.”8 Items on the GMFM could be considered as more challenging than items on the BBS. However, items on the BBS and the GMFM were not discrete enough to enable a therapist to distinguish between the balance abilities of children with no motor impairment and children with spastic hemiplegia by using test scores.
After functional classification using the GMFCS, the ability to use scores on both the BBS and the GMFM to distinguish among the groups was identical. Functional classification resulted in more homogeneous groups in terms of balance abilities. Despite an improved ability to distinguish among the groups, it was still not possible to differentiate between children in Level I and children with no motor impairment by using test scores. This finding may be due to a lack of items on either test that are discrete enough to identify subtle deficits in balance in children who have a mild motor impairment. Items that are more challenging to balance, such as items requiring speed, or movement over uneven terrain, may distinguish between children in Level I and children with no motor impairment. Neither test has such items.
The inability to use scores on the BBS to distinguish between children with no motor impairment and children with mild balance deficits may also have been influenced by the method of administration of the BBS. The BBS does not specify which side the subject must use when performing items such as single leg stance. Thus, the children with spastic hemiplegia were able to use the non–involved side to perform these activities. The administration protocol, as recommended by Berg, may have masked their balance deficits.
These results suggest that neither the BBS nor the GMFM are appropriate tests to measure balance deficits in children with mild functional limitations. The results also indicate that classification of children clearly affects the ability to use scores on the BBS and the GMFM to differentiate among groups of children with differing balance abilities. This finding contributes to the growing belief that the traditional classification of cerebral palsy by tonus and distribution provides an incomplete reflection of a child’s functional abilities.
Using the International Classification of Functioning and Disability (ICIDH 2) drafted by the World Health Organization (WHO), 18 traditional classification of children with cerebral palsy is at the level of impairment. Traditional classification using medical diagnosis provides an incomplete indication of the child’s gross motor abilities, except that it is assumed that the more severe the impairment, the more limited the child’s function. Because rehabilitation professionals should be addressing client issues at the functional level of activity, clients should be classified in terms of function. Only then will measurement of treatment intervention truly capture the effect of intervention on aspects of function. 19
Classification schemes based more on function than on impairment in cerebral palsy have only recently been developed. The GMFCS, developed by Palisano et al. 14 is a major departure of philosophy in the classification of children with cerebral palsy. This classification scheme is based on self-initiated movements, emphasizing sitting and walking. 14 The system includes descriptors of function at various ages, and children can change from one functional level to another as they mature. Researchers in Sweden have found that the GMFCS correlates highly with the ICIDH handicap code, with the highest correlation being with the dimension of mobility (r = 0.95, P < 0.0001). 20
Clinically, these results suggest that the BBS has limited use with children who have minimal motor deficits or mild balance impairments. There is a danger of a ceiling effect when the BBS is used with this population of children. This preliminary evaluation suggests that the BBS has potential to be used with ambulatory children with a diagnosis of cerebral palsy with moderate balance impairments, for example, children who were classified in either Levels II or III of the GMFCS. The test-retest and interrater reliability of the BBS needs to be examined in a pediatric population before it can be used widely with this population. The results do, however, suggest that by using test scores on the BBS, a therapist has the ability to distinguish balance abilities in children with cerebral palsy who are classified in Levels II or III of the GMFCS. The ability to use the GMFM and the BBS to distinguish among groups of children with differing functional abilities were identical when the GMFCS classification scheme was used. The BBS has fewer items and requires less time to administer than Dimensions D and E of the GMFM, and thus, may be more appealing to use in a clinical setting.
Test characteristics and issues of client classification affect the use of the BBS and the GMFM to distinguish among groups of children with differing balance abilities. Children with spastic diplegia who ambulated independently demonstrated more variability of balance abilities than the other diagnostic groups. Children with this diagnosis seemed to be grouped more homogeneously when the functional classification scheme was used.
The BBS has potential for use with children as a measure of functional balance. Its ease of use makes it an appealing clinical measure. More research is needed to evaluate its reliability with a pediatric population and its use with a younger age group. Because it would be valuable to use as an evaluative index with children with cerebral palsy, future research should also include evaluation of its responsiveness with a pediatric population.
This research was conducted in partial fulfillment of the requirements for a Master of Science degree in Physical Therapy at the University of Alberta for the first author. We would like to thank the children and their families who participated in the study, and the physical therapists at the Glenrose Hospital who assisted with recruitment of subjects and data collection.
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BERG BALANCE SCALE WORKSHEET AND INSTRUCTIONS
Please demonstrate each task and/or give instructions as written. When scoring, please record the lowest response category that applies for each item.
In most items, the subject is asked to maintain a given position for a specific time. Progressively more points are deducted if the time or distance requirements are not met, if the subject’s performance warrants supervision, or if the subject touches an external support or receives assistance from the examiner. Subjects should understand that they must maintain their balance while attempting the tasks. The choices of which leg to stand on or how far to reach are left to the subject. Poor judgment will adversely influence the performance and the scoring.
Equipment required for the testing are a stopwatch or watch with a second hand, and a ruler or other indicator of 2, 5, and 10 inches. Chairs used during testing should be of reasonable height. Either a step or a stool (of average step height) may be used for item # 12.
1. SITTING TO STANDINGINSTRUCTIONS: Please stand up. Try not to use your hands for support.
( ) 4 able to stand without using hands and stabilize independently
( ) 3 able to stand independently using hand
( ) 2 able to stand using hands after several tries
( ) 1 needs minimal aid to stand or to stabilize
( ) 0 needs moderate or maximal assist to stand
2. STANDING UNSUPPORTEDINSTRUCTIONS: Please stand for 2 minutes without holding.
( ) 4 able to stand safely 2 minutes
( ) 3 able to stand 2 minutes with supervision
( ) 2 able to stand 30 seconds unsupported
( ) 1 needs several tries to stand 30 seconds unsupported
( ) 0 unable to stand 30 seconds unsupportedIf a subject is able to stand 2 minutes unsupported, score full points for sitting unsupported. Proceed to item # 4.
3. SITTING WITH BACK UNSUPPORTED BUT FEET SUPPORTED ON FLOOR OR ON A STOOLINSTRUCTIONS: Please sit with arms folded for 2 minutes.
( ) 4 able to sit safely and securely 2 minutes
( ) 3 able to sit 2 minutes under supervision
( ) 2 able to sit 30 seconds
( ) 1 able to sit 10 seconds
( ) 0 unable to sit without support 10 seconds
4. STANDING TO SITTINGINSTRUCTIONS: Please sit down.
( ) 4 sits safely with minimal use of hands
( ) 3 controls descent by using hands
( ) 2 uses back of legs against chair to control descent
( ) 1 sits independently but has uncontrolled descent
( ) 0 needs assistance to sit
5. TRANSFERSINSTRUCTIONS: Arrange chair(s) for a pivot transfer. Ask subject to transfer one way toward a seat with armrests and one way toward a seat without armrests. You may use two chairs (one with and one without armrests) or a bed and a chair.
( ) 4 able to transfer safely with minor use of hands
( ) 3 able to transfer safely definite need of hands
( ) 2 able to transfer with verbal cueing and/or supervision
( ) 1 needs one person to assist
( ) 0 need two people to assist or supervise to be safe
6. STANDING UNSUPPORTED WITH EYES CLOSEDINSTRUCTIONS: Please close your eyes and stand still for 10 seconds.
( ) 4 able to stand 10 seconds safely
( ) 3 able to stand 10 seconds with supervision
( ) 2 able to stand 3 seconds
( ) 1 unable to keep eyes closed 3 seconds but stays steady
( ) 0 needs help to keep from falling
7. STANDING UNSUPPORTED WITH FEET TOGETHERINSTRUCTIONS: Place your feet together and stand without holding.
( ) 4 able to place feet together independently and stand 1 minute safely
( ) 3 able to place feet together independently and stand for 1 minute with supervision
( ) 2 able to place feet together independently but unable to hold for 30 seconds
( ) 1 needs help to attain position but able to stand 15 seconds feet together
( ) 0 needs help to attain position and unable to hold for 15 seconds
8. REACHING FORWARD WITH OUTSTRETCHED ARM WHILE STANDINGINSTRUCTIONS: Lift arm 90°. Stretch out your fingers and reach forward as far as you can. (Examiner places a ruler at end of fingertips when arm in at 90°. Fingers should not touch the ruler while reaching forward. The recorded measure is the distance forward that the fingers reach while the subject is in the most forward lean position. When possible, ask subject to use both arms when reaching to avoid rotation of the trunk.)
( ) 4 can reach forward confidently > 10 inches
( ) 3 can reach forward > 5 inches safely
( ) 2 can reach forward > 2 inches safely
( ) 1 reaches forward but needs supervision
( ) 0 loses balance while trying/requires external support
9. PICK UP OBJECT FROM THE FLOOR FROM A STANDING POSITIONINSTRUCTIONS: Pick up the shoe/slipper which is placed in front of your feet.
( ) 4 able to pick up slipper safely and easily
( ) 3 able to pick up slipper but needs supervision
( ) 2 unable to pick up but reaches 1–2 inches from slipper and keeps balance independently
( ) 1 unable to pick up and needs supervision while trying
( ) 0 unable to try/needs assist to keep from losing balance or falling
10. TURNING TO LOOK BEHIND OVER LEFT AND RIGHT SHOULDERS WHILE STANDINGINSTRUCTIONS: Turn to look directly behind you over your left shoulder. Repeat to the right. Examiner may pick an object to look at directly behind the subject to encourage a better twist turn.
( ) 4 looks behind from both sides and weight shifts well
( ) 3 looks behind one side only other sides shows less weight shift
( ) 2 turns sideways only but maintains balance
( ) 1 needs supervision when turning
( ) 0 needs assistance while turning
11. TURNS 360 DEGREESINSTRUCTIONS: Turn completely around in a full circle. Then turn a full circle in the other direction.
( ) 4 able to turn 360° safely in 4 seconds or less
( ) 3 able to turn 360° safely one side only in 4 seconds or less
( ) 2 able to turn 360° safely but slowly
( ) 1 needs close supervision or verbal cueing
( ) 0 needs assistance while turning
12. 12.PLACING ALTERNATE FOOT ON THE STEP OR STOOL WHILE STANDING UNSUPPORTEDINSTRUCTIONS: Place each foot alternately on the step/stool. Continue until each foot has touched the step/stool 4 times.
( ) 4 able to stand independently and safely and complete 8 steps in 20 seconds
( ) 3 able to stand independently and complete 8 steps > 20 seconds
( ) 2 able to complete 4 steps without aid with supervision
( ) 1 able to complete > 2 steps needs minimal assist
( ) 0 needs assistance to keep from falling/unable to try
13. STANDING UNSUPPORTED ONE FOOT IN FRONTINSTRUCTIONS: (DEMONSTRATE TO SUBJECT) Place one foot directly in front of the other. If you feel that you cannot place your foot directly in front try to step far enough ahead that the heel of your forward foot is ahead of the toes of the other foot. (To score 3 points, the length of the step should exceed the length of the other foot and the width of the stance should approximate the subject’s normal stride width.)
( ) 4 able to place foot tandem independently and hold 30 seconds
( ) 3 able to place foot ahead of other independently and hold 30 seconds
( ) 2 able to take small step independently and hold 30 seconds
( ) 1 needs help to step but can hold 15 seconds
( ) 0 loses balance while stepping or standing
14. STANDING ON ONE LEGINSTRUCTIONS: Stand on one leg as long as you can without holding.
( ) 4 able to lift leg independently and hold > 10 seconds
( ) 3 able to lift leg independently and hold 5 – 10 seconds
( ) 2 able to lift leg independently and hold = or > 3 seconds
( ) 1 tries to lift leg unable to hold 3 seconds but remains standing independently
( ) 0 unable to try or needs assist to prevent fall ( ) TOTAL SCORE (Maximum 56)