METHOD

Subjects

The subjects were 130 school children of 11 and 18 years of age. They attended a 10 day residential yoga training camp during the school vacation. The children were all from a similar social and academic background. For all the subjects the right hand was dominant.

Design

The hand grip of both hands was assessed in all subjects, in the same manner. The subjects were then randomly assigned to five groups. All five groups had the same basic yoga training. In addition each of the five groups practised a specific yoga exercise, viz., [i] sav, surya anuloma viloma pranayama or right nostril breathing, [ii] cav, chandra anuloma viloma pranayama or left nostril breathing, [iii] nds,- nadisuddhi or alternate nostril breathing, [iv] baw or breath awareness without nostril manipulation, since breath awareness is a part of the first three practices, and [v] mdr with specific mudras. The first four groups had 30 subjects each, while the fifth group had 10 Subjects. The group average age (in years) ± SD for the five groups was as follows: sav - 14.1 + 1.2, cav - 14.0 ± 1.1, nds 13.9 ± 1.2, baw 14.9 ± 1.8, and mdr- 14.4 ± 2.6. The assessments were made at the beginning and end of the 10 day camp.

Assessment procedure

Hand grip strength was assessed using a grip dynamometer (Anand Agencies, Pune, India). Subjects were tested in 6 trials, 3 for each hand alternately with 10 seconds gap between trials. During the assessment subjects were asked to keep their arm extended at shoulder level, horizontal to the ground as has been described earlier (6), The maximum value obtained during the three trials was used for analysis.

Yoga training

The subjects of all five groups practised asanas, pranayama practices (excluding the group-specific practices), meditation, lectures, and kriyas. Each of the specific practices have been described in detail elsewhere (7), and are mentioned briefly here. All five practices involved sitting cross legged with eyes closed. (i) Surya anuloma viloma pranayama (sav) involves inhalation and exhalation through the right nostril alone. (ii) Chandra anuloma viloma pranayama (cav) involves inhalation and exhalation through the left nostril alone. (iii) Nadisuddhi pranayama (nds) begins with exhalation (both nostrils) followed by inhalation through the left, then exhalation through the right nostril, inhalation again through the right, and exhalation through the left nostril, to complete the round. These specific pranayamas were practised as 27 rounds, four times a day. All 3 practices were accompanied by the practice of specific mudras or hand gestures. These have been described under the fifth group. (iv) Breath awareness or baw, involved being aware of the breath without manipulating the nostrils. (v) Mudra or mdr involved keeping the fingers in specific positions. For example, the right hand was used to manipulate the nostrils. The index and middle fingers were flexed, while other fingers were extended and used to gently close the nostrils. The left nostril with the ring finger and the right nostril with the thumb. The left hand was kept resting on the left knee with the tips of the thumb and index finger in contact and other fingers extended.

Data analysis

The data obtained for each of the four groups at the beginning and end of the camp were compared with separate two tailed 't' - tests for paired data.