Lumbar Injectrode Feasibility Evaluation

The goal of this non-significant risk study is to determine whether stimulation with transcutaneous waveforms applied on the outside of the body and subcutaneously conducted to the lumbar medial branch nerve elicits visible (via ultrasonic imaging) or palpable multifidus muscle activation within the short-term (\<28 day) placement of the Neuronoff PNS Injectrode F1 in healthy volunteers. The main questions it aims to answer are: * Can the PNS Injectrode F1 be safely inserted on the lumbar medial branch nerve for up to 28 days? * Can the PNS Injectrode F1 be safely used to stimulate the lumbar medial branch nerve to activate the multifidus muscle? Participants will * Receive transcutaneous stimulation of the lower back prior to device placement, after device placement, and prior to explant * Insert the PNS Injectrode F1 device on the lumbar medial branch nerve * Have the device inserted for up to 28 days and then explanted * Visit Schedule: Screening/Enrollment, Day 0, Day 2 (email), Day 25, 2 Days Post Explant (email), Day 35