Renato Cocchi M.D., Ph.D. (Sociology) & Marco Favuto M.D.
Italian Journal of Intellective Impairment 7 (1): 31-6 (1995)
Paper presented during the 6th World Down Syndrome Congress, Madrid October 1997
  Reprinted with the permission of Renato Cocchi
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A group of 82 drug treated Down's syndrome subjects aged 10 or more underwent investigation on bike riding with or without support wheels. The group's features were: 46 F + 36 M; average age 12.83 + 2.71 years; chromosomal anomalies: pure trisomy 21 = 75; translocations = 5; mosaicisms = 2. Therapy lasted average 7.07 years + 2.74, and range 2-12.
The results at last checkup showed that 33 Ss (40%) do not ride a bike, 21 (26%) still use support wheels, and 28 (34%) are free biking. When compared with the sample of non drug treated Down Ss (Cocchi R., Favuto M.: Ital. J. Intellect. Impair. 1994, 7: 159-162) this sample significantly differs (<.05), because more Ss ride a bike, either with support wheels or without them.
As for age on which drug treated Downs started biking, it is to be noted that nobody of them could learn it after 15 years of life. Biking remains a difficult task for drug treated Down people too and learning it does not completely match even their better psycho-motor development.

Key words: Down syndrome; drug therapy; bike riding; psycho-motor development.

In our previous research on bike riding in Down children without drug therapy, we pointed up: "Biking seems a difficult task for Downs and it appears that their psycho-motor development does not fully account for it. So we have not clear which causes this behaviour, and we need to assess other variables, both psychological and biological."

Since we had collected the related data, a further investigation on bike riding in drug treated children could give some light on it. To better understand this complex problem, we decide to study how ride a bike the Downs aged 10 or more, who took drug therapy for at least two years.

Materials and method

From 525 records of Down subjects, we checked up those about subjects aged 10 or more at last consultation after at least two years drug therapy. We collected then information on age at last consultation, sex, chromosomal diagnosis, and the use of a bike, from the singled out records.

If such a use had started before, we noted the year the child got to it. For this study a year of life encompasses 6 months before birthday and 6 months after it (Eg. The 11th year ranges from 10 years 7 months to 11 years 6 months). In a similar way we counted up the length of a therapy (Eg. Two years therapy ranges from one year 7 months to 2 years 6 months).

As for bike riding, we summed up this behaviour by seeing about if the child uses a bike, and if yes, whether he has left behind support wheels. We counted in two ways: first we referred them to the total of the sample. Then, we split the sample up into three sub-samples according to years' ranges such as 10-12, 13-15, 16 or more years.

Statistics: Chi Square, when suitable.


We present the results we have obtained as it follows. Eighty and two out of 525 records (15.62%) matched the study criteria and made the sample up. Table 1 shows epidemiological data of the sample and sub-samples 1-3. Tables 2 checks up bike riding and in table 3 we made a comparison with the data of our previous research on this topic (Cocchi & Favuto, 1994). Table 4 shows the age the investigated Downs started to ride a bike.

Table 1: epidemiological data and years of therapy of the sample and 10-12, 13-15, 16 or more years sub-samples.
  Sample Sub-samp.1 Sub-samp.2 Sub-samp.3
No. of Ss 82 50 22 10
" " F 46 27 15 4
" " M 36 23 7 6
F/M *100 128/100 117/100 214/100 43/100
Chromosomal anomalies
Ss with stand. trisomy 21 75 = 91.46% 46 = 92.0% 21 = 95.5% 9 = 90.0%
Ss with translocations 5 = 6.10% 4 = 8.0% 0 0
Ss with mosaicisms 2 = 2.44% 0 1 = 4.5% 1 = 10.0%
Average age (years) ± SD 12.83 ± 2.71 11.08 ± 0.83 14.23 ± 0.87 18.50 ±1.72
Aver. yrs of therapy ± SD 7.07 ± 2.74 6.84 ± 2.66 7.41 ± 3.16 7.50 ± 2.27
Range (years) 2-12 2-11 3-12 3-10
Table 1 shows the prevalence of females on males, in the sample and in 10-12 and 13-15 sub-samples, but a strong reverse in 16 and more years sample. The distribution of chromosomal anomalies of the sample is normal, those of 10-12 and 13-15 samples are fairly correct, but this is not true for 16 or more years sample. Averages of years of therapy differ very little.

Table 2: Down aged 10 years or more and bike riding; total sample and 10-12, 13-15, 16 or more years sub-samples as recorded at last checkup.
Behaviour Sample Sub-samp.1 Sub-samp.2 Sub-samp.3
Ss no. + % Ss no. + % Ss no. + % Ss no + %
Biking w/support wheels 21 = 25.61% 18 = 28.00% 7 = 31.82% 0
Free biking 28 = 34.15% 18 = 36.00% 7 = 31.83% 3 = 30.00%
Sub-totals 49 = 59.76% 32 = 64.00% 14 = 63.63% 3 = 30.00%
Refuses biking 33 = 40.24% 18* = 36.00% 8 = 36.27% 7* = 70.00%
Totals 82 = 100% 50 = 100% 22 = 100% 10 = 100%
(*) In past 2 + 1 subjects rode with support wheels.
Table 2 shows that nearly 60% of the sample currently ride a bike.

Table 3: comparison between non drug treated Downs (NDTD: data from Cocchi & Favuto, 1994) and drug treated Downs (DTD).
Behaviour Sample Sub-samp.1 Sub-samp.2 Sub-samp.3
W/supp. Wheels 16# 21 12 14 3 7 0 0
Free biking 26@ 28 14 18 5 7 4 3
Refuses biking 50$ 33 28 18 17 8 12 7
Chi Square, with 2 df (only for the sample): 6.192, and p < .05.
NB We split the 7 cases found as "non investigated" in our previous paper into the NDTD sample, as it follows: # = 1 case added; @ = 2 cases added; $ = 4 cases adeaddedr> While refusers make up the majority of the sample and sub-samples people among NDTD, the contrary happens for DTD, save 16 and more years sub-sample.

Table 4: Age of starting to ride a bike in Downs aged 10 years or more, treated by drug therapy.
Behaviour Bef. 10 yrs 10-12 yrs 13-15 yrs 16+ years
Ss no. + % Ss no. + % Ss no. + % Ss no + %
With support wheels 7 = 8.54% 13 = 15.85% 1 = 1.21% 0
Free biking 9 = 10.98% 14 = 17.08% 5 = 6.09% 0
Sub-totals 16 = 19.52% 27 = 32.93% 6 = 7.30% 0
Refuses biking   18 = 31.95% 8 = 9.76% 7 = 8.54%
Totals 16 = 19.52% 45 = 54.88% 14 = 17.06% 7 = 8.54%


Although a sample of 82 Down subjects out of 525 had to be representative, the F/M ratio differs very much from about 100/135 expected. On the other hand, the distribution of the chromosomal anomalies of the sample matches the Italian and International distributions. In sub-samples this distribution fails to do it.

Presently we do not know if gender proportion and chromosomal anomalies distribution are crucial for this study too. Therefore, we cannot think out the sample as representative, and we retain ourselves to generalize the results. Nevertheless, by its features the present sample matches better the sample of NDTD we investigated in our previous paper (Cocchi & Favuto, 1994) An overview to the Table 2 shows immediately that nearly 60% of the subjects of this sample currently ride a bike. As we wrote in our previous research, this rate is far from the evidence of nearly 100% of same age normal subjects enjoying bike riding, at least in Italy.

Sub-samples present an increased bike riding in age 10-12 but a decrease in following ages. If not due to a bias, we can think that drug therapy could drive to a wider learning of the bike's use.

We have to note that sub-samples 1 and 3 include among present refusers 3 boys who have left their skill in bike riding.

One of us early described this fact as a part of reduced motor performances in 3 adults Down with mixed demential and pseudodemential problems. (Cocchi & Cordella, 1990)

We noted two cases also in our previous paper on non drug treated Downs (Cocchi & Favuto, 1994). We can think it as a signal of reduced psychomotor skills, by the years going on.

Although less than in NDTD, the number of Downs unable to leave support wheels always appears very high when compared to what same age normal children usually do.

We can speculate on this kind of result, but it seems not easy to give a clear answer.

We need to confirm here our previous suggestion. Surely we had found fearful parents, or others who scarcely had insisted on their child riding a bike, but undoubtedly we have seen also many Down children showing unreasonable refusal, specially when parents urged them to leave the support wheels.

Some Down children fear losing their own balance control, but balance problems do not clearly look as true difficulties when we consider the actual psycho-motor development of the child. To put their feet in a little surface, like pedals are, seems evoke a feeling of being firmless, a kind of empty fear. This suggestion comes only from us because we did not find any Down child who could say why he refused to ride a bike.

Table 4 gives some new information. Fifteen years of age appear a limit in learning to ride a bike in Downs. Iida and coll., 1993 confirmed that 15 years as the age limit for brain plasticity both in normals and even more in Down. Perhaps such a behaviour goes along with this biological event.


The study of biking in a sample of 82 drug treated Down subjects aged 10 years or more showed that about 60% is currently riding a bike. As compared to a sample of non drug treated Down, we found biking increased in a significant degree.

While most non drug treated Downs refused bike riding, in drug treated Downs biking hadhadcome the prevalent behaviour. Among bike riders, nearly 43% did non leave the support wheels, about the same rate we noted in non drug treated Downs.

As we reported for age of walking (Cocchi, 1989) and motor development (Cocchi & Favuto, 1993), drug therapy could account for an increased number of Downs who ride a bike. Nevertheless this complex problem deserves further investigation, and we only hope to have brought some light on it.


Cocchi R.: The anticipation of walking in drug treated Down infants: A controlled study. Ital. J. Intellect. Impair. 1989, 2: 15-19.

Cocchi R., Cordella L.: Evoluzione demenziale in soggetti Down: 3 casi clinici. Atti del III congresso nazionale SIPG. Idelson, Napoli 1990.

Cocchi R., Favuto M.: Miglioramenti motori dopo 3-8 mesi di trattamento con farmaci, nei Down. Riv. Ital. Disturbo Intellet. 1993, 6: 251-258.

Cocchi R., Favuto M.: Study of bike riding in Downs of 10 years or more. It. J. Intellect. Impair. 1994, 7: 159-162.

Iida K., Takashima S., Mito T., Yao R., Onodera K.: Immuno- istochemical and Golgi studies on brain development and aging in patients with Down syndrome. It. J. Intellect. Impair. 1993, 6: 3-11.