DISCUSSION

The present study has shown that following yoga practice adult and child volunteers and patients with rheumatoid arthritis show significant increases in hand grip strength. At baseline, as expected, adults show higher values than children, and males compared to females (4). The magnitude of increase in grip strength following yoga was maximum for female patients (about thrice the percentage increase observed in male patients, even though the yoga program and the duration were the same), followed by female volunteers whose percentage increase was about double that of male volunteers.

Yoga practice has already been shown to improve grip strength in adult male volunteers trained in physical education (9), in children whose yoga program emphasized pranayama (8), and in patients with rheumatoid arthritis who practiced yoga as a single session per day (2). The improvement in hand grip strength after yoga practices, emphasizing pranayama, was ascribed to the oxygen requirement-reducing effect of pranayama, as the availability of energy and oxidation of glucose is believed to influence the hand grip strength proportionately (5). However, the increase in hand grip strength following other yoga practices, including pranayama could be due to different factors including cognitive components and non-specific arousal (7).

Rheumatoid arthritis patients of the present study showed significant improvement in hand grip strength, whereas patients of an earlier study (2), showed a non-significant trend of improvement. This difference could be related to the fact that the patients of the present study had an intensive, though short duration program. These results may also suggest that improvement may be more rapid following a short-term intensive yoga training program (i.e., in this case 15 days), as opposed to a longer duration (i.e., 8 weeks followed by 3 months), much less intensive program, as described earlier (2). The present study has also shown differences in the percentage increase of improvement in hand grip strength after yoga, related to hand dominance, age, and gender. Right hand values were greater then left hand values, and females showed greater percentage improvement then adult males both for normal volunteers and patients. The exact reason for this difference is not known.

 Hence the present results have shown that yoga practice increases hand grip strength, with different magnitudes of percent change depending on gender and age. However it should also be noted that the results, especially the magnitude of change in grip strength following yoga, may have been related to the fact that the values at baseline were lower than for the control group, hence there was greater scope for improvement in the yoga group, to begin with.