SUBJECTS AND METHODS  

Four special schools for mentally retarded children were selected in Bangalore city, one school providing services for the upper socio-economic and other three schools for the middle and lower socio-economic groups. These are day schools with regular teaching staff and offer educational and occupational facilities for the mild, moderate and severe categories of mentally retarded children (Table 1).

Table 2 shows details of 90 children who have been selected for the study satisfying the ICD 9 diagnostic criteria for mental retardation (WHO, 1975). Children of either sex were included, chronological age range being 6-16 years. Children with cerebral palsy, gross neurological problems, physical handicaps, autism, mutism and sensory deficiencies, such as blindness and deafness were excluded from the study. Those with severe behavioural problems like severe hyperkinetic syndrome were also excluded from the study. Amongst those who were included in the study 12 pairs belonged to the mild degree (IQ 50-70), 17 pairs belonged to the moderate degree (IQ 35-50) and 16 pairs belonged to the severe degree (Uma et al., 1988) (IQ 20-34). They were classified into these groups based on Binet Kamat (BK) and Seguin Form Board (SFB) scores. Ten pairs mainly in the severely retarded category who were uncooperative for BK testing were assessed on SFB Vineland Social Maturity Score (VSMS) was used for testing of social age in all three categories. 

The duration of treatment was for one academic year (10 months), 1 hour daily, 5 days a week. 

The experimental yoga group and control group were selected and matched from the same school so that the two groups were subjected to the same socio Environmental background and hence results could be comparable. A one-to-one matching was done with regard to chronological age, sex and IQ. In the 45 matched pairs, one from each pair was randomly selected for training in yoga and the other served as a control (Table 2). The control group was not exposed to yogic practices. Six children dropped out of the study for various reasons.

Table 3 shows the details of the psychological instruments used for assessment of IQ and social behaviour. Both the yoga and control groups were assessed with these tools before the commencement of yoga therapy and one year later after the therapy. Assessments for both the groups were conducted by a trained and qualified psychologist. The psychologist was blind to the matching and was not involved in the training programme. 

All children in the yoga group were taught a specially prepared integrated set of yogic practices consisting of the following: (1) breathing exercises, pranayama (breath slowing techniques) and kapalabhati (a kriya to cleanse the respiratory tract) (10 min); (2) Sithilikarana vyayama (yoga

exercises to loosen the joints) and suryanamaskar (salutations to the sun by 12-count yoga postures) (10 min); (3) yogasanas: simple physical postures (in the standing, sitting, prone and supine positions) with smooth, comfortable bending movements and specific slow breathing procedures; the asana practices were performed with the subject maintaining the final posture with the body relaxed (35 min); savasana is performed last; (4) meditation (5 min). These practices were taught by competent and well-trained yoga instructors for a period of 1 h on every working day at the school premises. The children in the yoga group were taught 5 h of yoga in one week for a period of one year. During this yoga practice hour, the control group was engaged in their usual school routine by one of their regular school staff in a different room within the school premises. Apart from this 1 h of yoga, the yoga group was exposed to the same school curriculum as the control groups.

Attendance was recorded every day for both yoga and control groups and was found satisfactory.