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The limb affected with polio cannot have the same power as the normal limb because the muscles have already undergone paralysis
and degenerative changes ( atrophy ).
However depending on the severity of the affliction ,the muscles uninvolved can be treated to function maximally and Improve the strength of the limb . This can be done by physiotherapy
and occupation therapy . Regarding increasing limb length you should consult an orthopaedic surgeon
for appropriste surgical treatment
of the same .
Wishing you good health.