G1 active recording electrode
G1: extensor pollicis longus tendon
Place G1 over the extensor pollicis longus tendon.
Table 2 · p.373 ↗
Sensory study
Upper limb
Superficial radial sensory nerve conduction study
Record over the extensor pollicis longus tendon near the anatomical snuffbox and stimulate proximally along the radius.
01 · Placement
G1, G2, stimulation and ground landmarks
G2 reference electrode
G2: base of the thumb
Place G2 at the base of the thumb.
Table 2 · p.373 ↗Stimulation site
Stimulation: along the radius
Stimulate 10 cm proximal to G1 along the radius.
Table 2 · p.373 ↗Ground region
Ground electrode region
AANEM places the ground between the stimulating and recording electrodes. The model shows a usable radial forearm region, not a single mandatory point.
Table 2 · p.373 ↗02 · Reference values
Adult normal limits
| Measure | Reference limit | Basis |
|---|---|---|
| SNAP onset-to-peak | ≥7 µV | 3rd percentile lower limit |
| SNAP peak-to-peak | ≥11 µV | 3rd percentile lower limit |
| Onset latency | ≤2.2 ms | 97th percentile upper limit |
| Peak latency | ≤2.8 ms | 97th percentile upper limit |
| Conduction velocity | ≥50 m/s | Published 3rd percentile |
03 · Technique
Acquisition conditions
Fixed distance
G1 to stimulation site: 10 cm
Sensitivity
5–10 µV/div
Filter
20 Hz–2 kHz
Sweep
1 ms/div
Temperature
Maintain dorsal hand skin temperature >32°C
Ground
Place the ground between the stimulating and recording electrodes
Primary evidence
Method-matched AANEM reference data
Adult superficial radial sensory reference values.