Toe curl in the affected weak calf muscle leg is common. Your brain tries to recruit all muscles that flex the foot when you attempt a heel raise adn the toe flexors are some of these muscles.
The lack of pain is probably not a great sign in the face of weakness after an epidural steroid injection. The nerve can be too damaged to send signals but on the other hand, damaged nerves tend to send chronic pain signals. Coupling the loss of sensation of the back of your thigh with no pain means that this nerve is not functioning well.
Surgery is necessary in my opinion.