G1 active recording electrode
G1: center of the EDB
Place G1 over the center of the extensor digitorum brevis.
Table 2 · p.373 ↗
Motor study
Lower limb
Fibular (peroneal) motor nerve conduction study
Place G1 over the center of EDB and stimulate sequentially at the ankle, below the fibular head and above the fibular head.
01 · Placement
G1, G2, stimulation and ground landmarks
G2 reference electrode
G2: distal to the fifth MTP joint
Place G2 distal to the fifth metatarsophalangeal joint.
Table 2 · p.373 ↗Stimulation site
Ankle stimulation: lateral to the tibialis anterior tendon
Stimulate at the ankle lateral to the tibialis anterior tendon, 8 cm from G1.
Table 2 · p.373 ↗Stimulation site
Below fibular head: posteroinferior
Place the below-head stimulation site posteroinferior to the fibular head.
Table 2 · p.373 ↗Stimulation site
Above fibular head: 10 cm proximal
Place the above-head stimulation site 10 cm proximal to the below-head site and just medial to the biceps femoris tendon.
Table 2 · p.373 ↗Ground region
Ground electrode region
AANEM places the ground between the stimulating and recording electrodes. The model shows a usable anterolateral calf region, not a single mandatory point.
Table 2 · p.373 ↗02 · Reference values
Adult normal limits
| Measure | Reference limit | Basis |
|---|---|---|
| Distal CMAP amplitude | ≥1.3 mV | 3rd percentile lower limit |
| CV ankle–below head | ≥38 m/s | 3rd percentile lower limit |
| CV across fibular head | ≥42 m/s | 3rd percentile lower limit |
| Distal motor latency | ≤6.5 ms | 97th percentile upper limit |
| Amplitude drop across head | ≤25% | 97th percentile upper limit |
| CV drop across head | ≤6 m/s or 12% | 97th percentile upper limit |
03 · Technique
Acquisition conditions
Fixed distance
G1 to ankle: 8 cm; across-fibular-head segment: 10 cm
Sensitivity
5 mV/div
Sweep
5 ms/div
Filter
2–3 Hz–10 kHz
Temperature
Maintain dorsal foot skin temperature >31°C
Ground
Place the ground between the stimulating and recording electrodes
Primary evidence
Method-matched AANEM reference data
Adult fibular motor reference values recorded from EDB; see the source table for age- and height-stratified limits.