It is very important to rise this energy in the spine. Open your spine centers and circulate the energy upwards. Align your chakras as well.
When the Serpent energy is activated it will follow the same pattern and will be blocked in the same fashion you feel it now, numbing the leg and the two main nadis.
Do the alternate nostril meditation, hatha yoga. Sun salutation for this is good if you focus on your spine.
The hips are magnetic and hold the disk of the base chakra, the focus should be on the spine and aligning the energies in the right nadi, the spine.
Root lock when rising may help, but beware that the base chakra has also a downward force that should not be changed, so do not do it too much.