P5 for amplitude and velocity · P95 for distal latency
| Nerve / Muscle | Amplitude P5 | Velocity P5 | Distal lat. P95 | Ref. range |
|---|
Pediatric EMG normative values
Nerve conduction values by age band (0–18 years) per Ryan et al. 2019. Amplitudes and velocities change rapidly in childhood — always use the correct age range.
This tool consolidates five independent pediatric normative datasets. EMG/NCS in children presents unique challenges due to ongoing maturation of the nervous system peripheral nervous system and somatic growth, requiring rigorously age-stratified references.
1 · Ryan et al. (2019) - Mayo Clinic
Large-scale retrospective study focused on percentile limits.
- Sample: 1,918 normal studies in 1,849 patients (0 to <18 years). This is the most robust contemporary reference available.
- Methodology: Defines strict normality limits using the 5th percentile (P5) for amplitude and conduction velocity, and the 95th percentile (P95) for distal latency.
- Application: Ideal as daily clinical gold standard for assessment of motor and sensory nerves in the upper and lower limbs.
2 · Parano et al. (1993) - Motor conduction and maturation curve
Classic study on electrophysiological evolution early in life.
- Methodology: Presents mean values (not absolute cutoff limits) for DML, MCV, F wave, and CMAP.
- Application: Essential to understand myelination maturation trajectory (from 7 days to 14 years). Clinically useful to assess whether infant development follows the expected mean for that age band, not only whether it is "abnormal".
3 · Kang (2017) - Sensory conduction
Focused on sensory responses, often difficult to obtain in pediatrics.
- Methodology: Uses the statistically calculated lower limit of normal as the mean minus two standard deviations (mean − 2 SD).
- Application: Provides precise limits for median and ulnar SNAP amplitude and CV ulnar sensory responses, essential to distinguish axonal neuropathies from technical artifacts in non-cooperative children.
4 · Kimura / Miller & Kuntz - F wave in Infants
Assessment of late responses during peak somatic growth.
- Methodology: Defines normality intervals for minimum F-wave latency grouped strictly between 1 and 24 months.
- Application: F-wave latency depends critically on limb length. As infants grow rapidly, these narrow bands avoid overdiagnosis of proximal demyelination proximal (as in polyradiculoneuropathy) in older infants.
5 · Ferrante (2019) - Practical limits (5 to 9 years)
Normative values focused on preschool and school-age children.
- Application: Provides a safe simplified clinical shortcut for children aged 5 to 9 years, where myelination is complete but conduction distances are still significantly shorter than in adults.
Electrophysiological maturation (clinical reminders)
- At term birth: Motor conduction velocity (MCV) is about 50% of adult values (20–25 m/s); in extremely premature infants, it may be <15 m/s.
- 12 months: Reaches approximately 75% of final values.
- 3 to 5 years: Peripheral myelination is complete. From this age, velocities reach the normal adult range (~50 m/s in the upper limb and ~40 m/s in the lower limb).
- Sensory morphology: Sensory action potentials (SNAPs) that are biphasic, polyphasic, or dispersion is a normal finding between 3 months and 5 years due to asynchronous myelination of fibers. They should not be interpreted in isolation as pathology demyelination.
References
References:
1. Ryan CS, Conlee EM, Sharma R, Sorenson EJ, Boon AJ, Laughlin RS. Nerve conduction normal values for
electrodiagnosis in pediatric patients. Muscle Nerve. 2019.
2. Parano E, Uncini A, DeVivo DC, et al. Electrophysiologic correlates of peripheral nervous system
maturation in infancy and childhood. J Child Neurol. 1993;8:336–338.
3. Kang PB. Normal Values Tables. In: McMillan HJ, Kang PB (eds.). Pediatric Electromyography.
Springer, 2017.
4. Kimura J. Electrodiagnosis in Diseases of Nerve and Muscle. (Pediatric tables adapted from
Miller RG & Kuntz NL).
5. Ferrante MA. EMG Lesion Localization and Characterization: A Case Studies Approach. Demos
Medical, 2019.
Frequently asked questions
Why do pediatric values differ from adults?
Progressive myelination, axonal diameter and limb length alter latencies and velocities until skeletal maturity.
Which reference does this calculator use?
Ryan et al. 2019 and age bands declared in the interactive table.
How to cite this page
Vancouver: Eletrodiagnostico. Pediatric EMG normative values [Internet]. São Paulo; 2026 [cited YYYY Mon DD]. Available from: https://eletrodiagnostico.com.br/emgcalculator/pediatric-emg/