NCV FIELD ATLAS Nerve conduction placement guide
17 complete protocols 0 documented gaps
Atlas Upper limb Superficial radial sensory
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Anatomy & placement

Superficial radial sensory

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Isolated left upper limb Mirror for the opposite side S1 · standardized stimulation site shown
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G1 active G2 reference S1 stimulation site Ground region Selected nerve course
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Placement guide

Sensory study

Superficial radial sensory

G1 active recording electrode G1: extensor pollicis longus tendon

Place G1 in the anatomical snuffbox on the dorsolateral wrist, directly over the superficial radial nerve as it crosses the thumb extensor tendons.

Table 2 · p.373 ↗
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All placements & reference values

Superficial radial sensory nerve conduction study

Record over the extensor pollicis longus tendon near the anatomical snuffbox and stimulate proximally along the radius.

One side shown; mirror the placement for the opposite limb

01

Placement and evidence

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G1: extensor pollicis longus tendon Place G1 in the anatomical snuffbox on the dorsolateral wrist, directly over the superficial radial nerve as it crosses the thumb extensor tendons. Table 2 · p.373
G2: base of the thumb Place G2 on the dorsal thumb 3–4 cm distal to G1, continuing along the same line over the thumb extensor tendons. Distance · 3–4 cm distal to G1 Superficial radial sensory technique · p.19
Stimulation: along the radius Stimulate over the distal mid-radius, 10 cm proximal to G1 along the radial border of the forearm; orient the cathode toward G1. Distance · 10 cm proximal to G1 Table 2 · p.373
Ground electrode region Place the ground on the dorsal radial wrist or distal forearm between S1 and G1, clear of the recording electrodes. Table 2 · p.373
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Normal waveform schematic

Normal SNAP waveform schematic with a 2.2 ms onset-latency reference limit.

Educational SNAP schematic. The dashed line marks this protocol's latency reference limit; this is not a patient waveform.

03

Adult reference values

Use only when the test method matches
SNAP onset-to-peak≥7 µV3rd percentile lower limit
SNAP peak-to-peak≥11 µV3rd percentile lower limit
Onset latency≤2.2 ms97th percentile upper limit
Peak latency≤2.8 ms97th percentile upper limit
Conduction velocity≥50 m/sPublished 3rd percentile
04

Technical conditions

Fixed distanceG1 to stimulation site: 10 cm
Sensitivity5–10 µV/div
Filter20 Hz–2 kHz
Sweep1 ms/div
TemperatureMaintain dorsal hand skin temperature >32°C
GroundBetween the stimulating and recording electrodes

Primary evidence

Every marker is tied to a published table

The 3D coordinates project AANEM's written anatomical landmarks onto an educational model. Clinical testing still requires palpation of the patient's anatomy, measured distances and laboratory-validated reference values.

Open the original AANEM table Table 3 · p.374 · Muscle & Nerve, 2016

Nerve conduction study learning resource

Evidence-based electrode placement, waveforms and adult reference values

NCV Field Atlas is a free, no-login reference for learning common sensory and motor nerve conduction techniques. It combines an interactive 3D body model with G1 active-electrode placement, G2 reference-electrode placement, stimulation landmarks, ground regions, technical settings and method-matched adult limits.

Superficial radial sensory Median sensory Ulnar sensory Dorsal ulnar cutaneous sensory MABC sensory LABC sensory Median motor Ulnar motor Radial motor to EIP Sural sensory Superficial fibular sensory Fibular motor Fibular motor to tibialis anterior Tibial motor Saphenous sensory Medial plantar mixed Lateral plantar mixed

Primary references: AANEM Normative Data Task Force, Muscle & Nerve (2016) and AANEM Upper and Lower Extremity NCS handout (2023) .