Brief Answer:
Peroneal nerve affected most likely.

Detailed Answer:
Hello and thanks for using HealthcareMagic.

I have read your question and understand your concerns.

Numbness is mainly an attribute of the sensory nerves dysfunction, in your case peroneal nerve seems to be affected.

This nerve could be pinched/compressed at the lumbar spine exit or during its pathway.

First stages of peripheral neuropathy may also debut with only numbness.

A nerve conduction study is necessary to understand better your condition.

Please discuss with your Doctor about these issues.

Hope you found the answer helpful.

Take care.

---