Developmental Changes in Associated Movements

Develop. Med. Child Neurol. 1968, 10, 49-56

Developmental Changes in Associated Movements Kevin Connolly Peter Stratton

ASSOCIATED, or synkinetic, movements are movements accompanying a motor or intended motor function but not necessary for its performance. Indeed, from the point of view of effective adaptation they are often superfluous. They are usually contralateral and symmetrical to that limb or part of the body which is voluntarily active-for example, the involuntary clos- ure of the second eyelid while trying to keep one closed.

These movements also appear in patho- logical states such as result from the break- down of pyramidal motor control. Their assessment may therefore be of value in clinical diagnosis, particularly perhaps in cases on minimal cerebral dysfunction, in assessing neurological maturity and, as suggested by Abercrombie et al. (1964), in providing a more precise description of the brain-damaged child.

Fog and Fog (1963) have used these movements to study cerebral inhibition, the development of which, they argue, is necessary for the acquisition of detailed, discriminative motor activity. The results of their study of children show a steady fall in the incidence of associated movements with increase in age. This they attribute to the fact that excitatory mechanisms develop earlier than inhibitory ones. Two tests were used-one bilateral, from feet to hands ; and one crossed, from one hand to

the other-on 265 normal and 184 mentally retarded children. They found that these movements became inhibited in the course of childhood and more so in the normal than in the retarded group. When the retarded children who were also sus- pected of being brain-damaged were com- pared with the normal group the disparity was greater.

Zazzo (1960) and his collaborators have investigated several of these synkinetic movements and devised a test on the basis of finger movements. Using Zazzo’s finger- lifting test and the Fogs’ clip-pinching test, Abercrombie et al. (1964) investigated the responses of 23 normal children with a mean age of 9 years 1 month, and 50 physically handicapped children, including 26 with cerebral palsy. On the whole the cerebral palsied children were found to be outside the normal range, though with the small discontinuous sample of normal children used it is difficult to establish a normal range with any degree of pre- cision.

These movements have also been in- corporated into tests of motor impairment (Stott 1966), though data on a large continuous sample of normal children are again not yet available.

The aims of the study reported here were :

(1) To administer the three tests norm-

Department of Psychology, Sheffield University, Sheffield, 10.

49

DEVELOPMENTAL MEDICINE AND CHILD NEUROLOGY. 1968, 10

ally used and a new one to a large continuous sample of children.

(2) To modify the tests so that they can be easily and rapidly administered.

(3) To examine the inter-relationship of the several tests used.

Subjects 658 children were drawn from 3 schools :

one infant, one junior and one secondary. The schools were all in the same district of Sheffield, their catchment area being very largely a new housing estate. The ages of the children ranged from 4 years 9 months to 1 5 years 8 months.

Procedure Children were tested in group$ of 5.

With the younger children the examiner drew a circle and a square on a sheet of paper. He then placed the pencil on the table and asked each child to pick it up and draw a square and a circle. The hand used for drawing was taken to be the dominant hand. Older children were simply asked which hand they wrote with and whether they always used that hand for writing, throwing a ball, etc.

The tests were administered in a standard order as follows : clip-pinching, Fogs’ feet- to-hands, finger-spreading, finger-lifting. All the children in a group were given the clip-pinching test, then all were given the feet-to-hands test, and so on.

Clip- Piiichitig Test In their test, Fog and Fog (1963) used

three degrees of pressure-a spring clothes- peg and 2 spring (bulldog) paper-clips. In this study only one bulldog clip, too strong for the subject to open completely, u.as used. The child‘s hands in pronation were placed on a table with the fingers hooked and the thumbs spread. The clip was placed between the thumb and the side of the first finger and the child was told : ‘See how far you can open the clip’. If the thumb on

the contralateral hand closed (Fig. la) a score of 1 (failure) was assigned. If it did not close (Fig. Ib) the score was 0 (pass). In the Fogs’ study both homolateral and

/ ,

Fig. 1. Diagram of clip-pinching test. (a) Failure, thumb on contralateral hand shows

( h ) Pass, no associated movement of thumb on associated movement.

cont ralateral hand,

contralateral movements were recorded. I t is, however, difficult to be certain of homolateral movements since they might easily be artefacts of arm or shoulder movements. The test was performed in the same way on dominant and non-dominant hands.

Feet- to- Halids Test This test (Fog and Fog 1963) requires

the subject to invert his feet and walk on the outside edges of them. This was demonstrated to the children and then each child in turn was asked to invert his feet and walk towards the examiner. They were also instructed to ‘Try and keep your arms down by your sides’. If there was supina- tion, pronation or marked extension in the

50

KEVIN CONNOLLY PETER STRATTON

arms a score of 1 (failure) was assigned; otherwise 0 (pass).

Finger-Spreading Test This we believe to be a new test of

associated movement. The experimenter demonstrated to the children the spreading of the third (middle) from the fourth (ring) fingers of each hand in turn. The subject was asked: ‘Hold both hands out with your fingers together and then try to separate these fingers as I do while keeping the rest together’.

If the child succeeded in spreading the fingers indicated without other fingers on the hand spreading and without a spread on the contralateral hand (Fig. 2a), a score of 0 (pass) was given. If the child was unable to spread only the third and fourth fingers (Fig. 2b) or if there was an associated response on the other hand, a score of 1 (fail) was assigned. In cases where the child seemed capable of passing the test but failed a second test was given and this scored instead of the first. The test was performed on both dominant and non- dominant hands.

Finger-Lifting Test This test, described by Zazzo (1960), was

modified to make its administration simpler and less time-consuming. In Zazzo’s test the child is required to lift independently and in random order all the fingers of both hands. He reported that the fourth finger (ring) was the most difficult, while the easiest was the second (fore) fingei of the right hand. He did not, however, distinguish between dominant and non-dominant hands. In this investigation two fingers were examined, the third (middle) finger on the dominant and the fourth (ring) finger on the non-dominant hand. The subject was told: ‘Place both hands flat on the table and try to lift just the fingers I point tQ without moving the others’. Following a demonstration the

(b) Fig. 2. Diagram of finger-spreading test.

(a) Pass, fingers spread with no associated

(b) Failure, all the fingers on the hand are movement.

spread.

test was carried out on the third finger of the dominant hand and the fourth finger of the non-dominant hand.

In the three tests which were administered to both hands, the first hand to be tested was alternated randomly between dominant and non-dominant.

Results A dichotomous measure, pass or fail,

was used for each test; the data for each subject therefore consisted of 7 binary digits followed by the child’s date of birth. The data for boys and girls were separated and each was arranged in ascending order of age, giving two sets of scores of 305 girls and 353 boys respectively. These groups were then further divided, again in ascending order of age, into blocks of 40 subjects. This technique was used to avoid the unreliability which would have arisen from grouping into years; if this had been

51


I 2 ' -: -- . _ _ _

i I , - . ta;?',?-r%,

Fig. 3. Perccntage o f children at various ages 4 i ( ~ tiig no associated niovement on clip-pinching !wt. Broken line s h o w girls' performance, solid

I i ne boys'.

done the numbers in the various age ranges ti ouid hat^ differed considerably. The fact tha t age is a continuous and not a discrete wriable provides further justification for this method. Because the total numbers of boys and girls is not equally dit.isible by 40, the last block for boys has only 33 subjects \t,hile that for girls has only 25.

A preliminary analysis of the data using Xi fiiiled to reveal any differences between dominant and non-dominant hands on either the clip-pinching or finger-spreading tests. Accordingly. the data for the two hands for each test were combined.

The percentage of passes in each block of 40 subjects for both girls and boys was plotted against the mean age for that block. Figs. 3, 4, 5 and 6 show the results f o r the various tests. It should be noted thnt the last point on each graph represents a smaller number of subjects and is therefore less reliable. Each test shows a decrease in the occurrence of associated movements as a function of increasing age. The different tests, however, show their most rapid changes at different ages. Successes (no associated movements) on

43e lyeorsl

Fig. 4. Percentage of children at different ages showing no associated movement on feet-to-hands

test. Broken line girl$, solid line boys.

the clip-pinching test show a steady increase with age throughout the whole age-range investigated. By the age of 14 only some 22 per cent of the subjects fail the test. The test therefore is not likely to be a sensitive instrument beyond the 15- year level. The feet-to-hands test appears to be maximally sensitive between 8 and 13 years. A test is defined as being sensitive for a given age-range if it is passed by more than 20 but less than 80 per cent of the children in that age-range. This 20 per cent criterion for test sensitivity indicates that the finger-spreading test becomes useful only at the 10-year level and probably

Fig. 5. Percentage of children at different ages showing no associated movements on finger- spreading test. Broken line girls, solid line boys.

52

KEVIN CONNOLLY

Finger- Spreading D

PETER STRATTON

Finger- ~ Zazzo

I D Spreading N D

differentiates well beyond the age-range tested. The upper pair of lines on Fig. 6 shows the percentage of boys and girls who succeeded in raising the third (middle) finger of their dominant hand. This test is obviously most appropriate for children below or at the bottom of the age-range investigated. At approximately the 8-year level almost all the children performed this test successfully. The test therefore does not differentiate between. children of 8 years or above. The lower pair of lines refers to performance with the third finger of the non-dominant hand; this test becomes sensitive for boys at the 9-year level and for girls at the 6-year level.

To examine the degree to which these tests are related, and so might be considered as measuring the same set of variables, each test was examined against every other test for each child. In this way it was possible to discover whether passing or failing any one test was a predictor of success or failure on the others, failure being taken as the occurrence of an associated movement.

Tetrachoric correlation coefficients were computed and the intercorrelation matrix is shown in Table I. Each value given in the table is based on the age-range where the two tests being correlated are sensitive, as defined above. The Zazzo test on the

: ) . . , ~ ! , , . , 5 6 7 8 9 10 I / 12 13 14 1;

Age(years.1

Fig. 6. Percentage of children at different ages showing no associated movement on finger-lifting test. Upper pair of lines refers to third finger on dominant hand, lower pair to fourth finger on non- dominant hand. Broken line girls, solid line boys.

dominant hand failed to overlap with any of the others since it was passed by 80 per cent of the children before any other test was passed by 20 per cent of them, and therefore no reliable correlations could be computed for it.

Reliability of Judgments To assess the reliability of the examiner’s

judgment regarding the presence or absence of associated movements accord-

TABLE I Intercorrelations of All Tests except Zazzo’s Test on Dominant Hand

ClipND .. .. Hands/Feet . . . . Finger-Spreading D . . Finger-Spreading ND . . Zazzo D . . . . Zazzo ND . . . .

Clip D

0.78*

0,197

0.33

0.32*

-

0.28*

Clip N D

0.15t

0.18t

0.28*

0.20

Hands/ Feet

____

0.207

0.17*

0.25*

, -

~ i 0.50* 0.62* I

I

* Significant at 0.01 level. t Significant at 0.05 level.

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ing to the criteria adopted, a further investigation was conducted. Thirty judges were each given a set of instructions regarding the scoring system and the criteria to be applied. This information was discussed with them and they were shown a cine film of 5 children of various ages performing the tests. This was followed by a second film of 5 children which was scored independently by each of the judges and the examiner. The percentage of the judges whose score agreed with that of the examiner for each child was calculated and is gi\ren in Table 11.

On the whole agreement is high. In view of the use of filmed sequence (which led to reduced visibility and some loss of control over the test situation, in as much as ambiguous performances could not be repeated) this was considered very satisfactory. In two cases the film sequence was particularly short and the associated movement slight. This resulted in one near chance score, finger-lifting test on the non- dominant hand for subject 1 ; and one case where a majority disagreed with the examiner, finger-spreading test on the dominant hand for subject 5.

Discussion The fact that all correlations between

pairs of tests are positive suggests that there is some common factor underlying the different kinds of performance which were examined. The correlations between dominant and non-dominant hands on both the clip-pinching and finger-spreading tests are high. Similarly, Zazzo reports no reliable differences between left and right hands for a given finger. This would suggest that any consistent difference between the two hands may be an important diagnostic feature. It has been suggested (Paine and Oppe 1966) that such differences may accompany some abnormality at the level of the pyramidal decussation in the medulla.

Though most of the correlations are significant the feet-to-hands test correlated significantly with only two of the other tests. This suggests that the feet-to-hands test is affected, to a greater degree than the other tests, by factors other than simple maturation. A further point is that this test shows a less consistent difference between the sexes than any of the others.

It is clear from examining the changes in

TABLE I1 Percentage Agreement between Tester and Panel of Judges on Presence of Associated

Movements in 5 Subjects of Different Ages

S, S? S3 S4 s5 ______ - ~ ~- - ~ _ _ -

I D 100 70 93 93 80

ND 100 77 90 100 80

Hand-Feet 87 73 73 1 90 77

D 100 100 97 100 27

N D 93 97 100 67 97

CllP

I Finger-Spreading

D 90 80 93 1 0 0 100

ND 57 97 100 80 80 Zavo

I I

D = dominant hand ND = non-dominant hand

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KEVIN CONNOLLY PETER STRATTON

the percentage of children showing associated movements at different ages that the tests are maximally sensitive at different stages in development. T h s is particularly interesting and important if the presence of associated movements is to be used as an index of neural maturity or in some test of motor impairment-for example, that being prepared by Stott and his collaborators (1967)-since the test used in any screening process must b’e sensitive for the age-range in question. In this connection the sensitivity of the modified finger-lifting tests might be extended by introducing a third test of intermediate difficulty. Zazzo’s results suggest that the fourth (little) finger remains a sensitive test up to the age of 12 years; this would provide an overlap with the other two finger-lifting tests. It might also be profitable to introduce a further finger-spreading test, between the first (fore) and second (middle) fingers, which would be sensitive at the lower age- ranges.

Abercrombie et al. (1964) found no evidence of a sex difference in their relatively small sample of normal children. The data reported above, however, show that there is a significant sex difference over the age-range studied. Girls show a consistent superiority during all the periods when each test may be regarded as an informative measure. There is only one point at which the boys are more successful than the girls, this is on the feet-to-hands test at the 10-year level. That this sex difference is more marked on some of the tests can be seen in Figs. 3-6.

Abercrombie el al. also report a significant difference between their 6- and 9-year- old groups on the clip-pinching and feet- to-hands tests. The data reported here confirm this and further show continued changes with increasing age. A direct comparison with Zazzo’s findings is more difficult since he distinguished only between left and right hands, whereas in this study

the distinction was made between dominant and non-dominant hands. However, by matching right hand with dominant hand and left hand with non-dominant hand a satisfactory agreement was obtained from the fingers tested (Fig. 7 )

” 5 6 7 R 9 I 0 I1 I2 I3 14 I5

Ar;z’yea-:l

Fig. 7. Coniparrson of Zazzo’s data (broken line) with data obtained in present study (solid line) on

finger-lifting test for comparable fingers.

Part of the sample of children studied had been separated into different classes on their learning capacity and there appeared to be some relationship between being in the upper stream and success on the battery of tests. The information available does not permit us to decide whether this is due to an underlying relationship with intelligence or whether other factors, such as clumsiness, poor handwriting and so forth, which might be expected to relate to these tests, may also have influenced the streaming. Both the Fogs’ and Aber- crombie et a/., working respectively with mentally retarded and physically handicapped children, found evidence suggestive of a connection with intelligence. Children who were singled out by their teacher as performing particularly well at manual tasks did not appear to score consistently above their age norms, but again the information relating manual dexterity to

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associated movements is too inadequate to permit a definite statement. Further studies are being planned to examine the ship of these and other variables to the occurrence of associated movements.

Acknowledgements: This work was supported by a research grant from the Spastics Society. The authors wish to acknowledge the co-operation of the Director of Education for Sheffield, the Heads of the Schools involved in the investigation and particularly the children for playing the games.

SUMMARY Four tests of associated movement-modified version of Zazzo‘s finger-lifting test, the

Fogs’ clip-pinching test, the feet-to-hands test and a new finger-spreading test-were given to 658 normal children whose age ranged from 4 years 9 months to 15 years 8 months. The incidence of associated movements shows marked changes with age. The various tests are maximally sensitive at different stages in development as follows : clip-pinching 5-1 3 years, feet-to-hands 8-13 years, finger-spreading 10 years to beyond the age range studied, finger- lifting from 5 onwards depending on the finger examined. The correlations between the test< were all positive and largely significant, indicating some common factor underlying the different kinds of performance which were examined.

RESUME

On a essay6 sur 658 enfants normaux dont les 2ges variaient de 4 ans 9 mois a 15 ans 8 mois. les quatre tests de mouvement associl suivants: une version modifiee du test d’tlevation des doigts de Zazzo, le pieds a mains, et un nouveau test d’lcartement des doigts. L’incidence des mouvements associis change de faqon Cvidente avec l‘2ge. Les differents tests atteignent leur maximum de sensibilite A des stades diffirents du developpe- ment de la maniere suivante: test de Fogs 5-13 ans; pieds a mains 8-13 am; Ccartement des doigts de 10 ans jusqu’apres 1’5ge Ctudit; ClCvation des doigts, a partir de 5 ans et variable doigt examine. Les corrtlations entre les tests ltaient toutes positives et trts significatives, selon le indiquant I’existence d’un facteur commun a la base des diffirentes sortes de examinees.

RESUMEN

Se administraron cuatro tests de movimientos asociados a 658 niiios sanos de 4 aiios y 9 meses hasta 15 aiios y 8 meses. Estqs tests comprendian : una versidn modificada del test de Zazzo de levantar un dedo, el test de Fogs de apretar una pinza, tests ‘pies a manos’, > un nuevo test de extender y separar 10s dedos. La frecuencia de movimientos asociados cambia mucho a medida que el niiio agrandece. Cada test tiene una sensitividad maxima durante una fase distinta del desarrollo, a saber: el de apretar una pinza de 5 a 13 aiios, ‘pies a manos’ de 8 a 13 aiios, separacion de 10s dedos de 10 aiios hasta una edad mayor que las que se estudiaban, y levantar un dedo de 5 aRos en adelante, segun el dedo de que se trata. Las correlaciones entre 10s tests eran todas positivas y casi todas significantes, lo que indica un factor comun que explique 10s tipos distintos de funcionamiento que se estudiaban.

REFERENCES Abercrombie, M. L. J., Lindon, R. L., Tyson, M. C. (1964) ‘Associated movements in normal and physically

handicapped children.’ Develop. Med. Child Nerirol., 6 , 573. Fog, E., Fog, M. (1963) ‘Cerebral inhibition examined by associated movements.’ In Bax, M., Mac Keith,

R. C. (Eds.) Minimal Cerebral Dysfunction. London : Spastics Society/Heinemann, p. 52. Paine, R. S., Oppe, T. E. (1966) Neurological Examination of Children. London: Spastics Society/

Heinemann. Stott, D. H. (1966) ‘A general test of motor impairment for children.’ Develop. Med. Child Neurol., 8, 523.

~ -

Zazzo, R. (Ed.) (1960) Manuel pour 1’Examination Psychologique de 1’Enfant. Neuchatel: Delachaux and Moyes, F. A., Headridge, S. H. (1967) ’Test of motor impairment.’ Personal communication.

Niestle.

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Developmental Changes in Associated Movements