Two factors led to this the first was following the breakup of the USSR Russia took on all of the debts/contracts the USSR made. The problem with this was that the USSR depended on the economies provided by all of their member states but especially Poland, the Czech and Slovak republics, and the Baltic nations. The loss of those in the late 80's was a huge blow to the economy that Russia was handed.

The second factor is that the funds created to purchase goods from outside the Warsaw Pact had been underfunded since the late 1960's which made it hard for the USSR to purchase things they needed but could not produce domestically. The lack of these funds meant that all purchases made by the post-USSR Russian government had to be made in their currency which was extremely weak in the early 90's.

Essentially the USSR's collapse was economic in nature as well as political and as Russia was the state that inherited the mantle of the USSR they inherited their problems as well.