The face of the pro-Western Orange Revolution in 2004, who suffers from herniated discs, started medical examinations on Saturday morning, said Karl-Max Einhaupl, director of the Charite University Hospital, Berlin.
No decision on whether she will need an operation has yet been taken, Einhaupl added.
"On Sunday and Monday, we will continue our diagnosis to see what can be done," he said during a televised press conference.
He stressed that it was impossible to predict how long Tymoshenko will remain in care, stressing that the hernias caused her "severe pain".
"We have confidence that she will be able to walk freely again," he said.
Tymoshenko, 53, was freed from prison on February 23rd, having served three years of a seven year sentence for abuse of power, charges she always denied.
Immediately after her release, she appeared in a wheelchair in Kiev's Independence Square to address protesters in Ukraine's capital.
Tymoshenko's relationship with the Berlin hospital goes back several years. A team of its doctors were given permission to examine her in April 2012 while she was imprisoned, although their recommendation to treat her in Germany was never accepted by Kiev.
Tymoshenko also met with German Chancellor Angela Merkel over the weekend on the sidelines of the European People's Party congress in Dublin.