Control values in the healthy subjects for tibialis anterior (TA) muscle recordings
| MUP analysis | Mean amplitude (μV) | Mean area (μVms) | Mean duration (ms) | Polyphasics (%) | Phases (n) | Turns (n) |
|---|---|---|---|---|---|---|
| Mean+SD | 661.5±92 | 851.5±158.7 | 9.35±0.93 | Range 5–40 | 3.47±0.36 | 3.35±0.52 |
| ULN | 845.5 | 1168.9 | 11.2 | 35% | 4.19 | 4.39 |
| Jitter | Mean jitter μs | % unstable potentials | % blocking | |||
| Mean+SD | 37.0±5.6 | Range 0–20 | 0–10 | |||
| ULN | 48.2 | 20% | 10% | |||
The data for amplitude, area, duration, number of phases and number of turns and mean jitter are normally distributed (Kolmogorov-Smirnov statistic). The % polyphasic potentials; and the number of unstable potentials and number of blocking potentials were not normally distributed. For normally distributed data the upper limit of normal (ULN) was calculated as the mean+2 SD; and for non-normally distributed data the 95% range of the distribution frequency was used as a cut-off. The ULN for neuromuscular jitter in an isolated potential pair was taken as 58 μs, representing the 95% CI in the control population.
MUP, motor unit potential.