Dear student,
The social backwardness was mainly due to the social inequality among the working class. The workers were divided based on their jobs. A skilled and trained worker considered him superior to the untrained workers.
Russia was economically backward because of overpopulation. Adding to that was the schemes of industrialization which resulted in the exploitation of the working class and worsening of the living conditions.
Russia was politically backward because all the political parties were considered illegal in Russia before 1905. Even though the Russian peasants formed a Socialist Revolutionary Party in 1900, they were not considered to be a part of the socialist movement due to the divisions in the party.
Regards