Table 2.
Estimate of the conduction velocity in group II afferents in one subject
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
|---|---|---|---|---|---|---|---|---|---|---|
| Nerve-muscle combination | Stim. site-to- motoneurone distance (cm) | I a CV (m s−1) | I a ACT | Extra time: II vs. mono- synaptic I a | I a ACT + extra time | Group I central delay | Group II central delay | IIACT | CV | II CV/I CV |
| Bi→VL | 40 | 68 | 5.9 | 8.2 | 14.1 | 3.9 | 4.9 | 9.2 | 43 | 0.64 |
| CP→VL | 70 | 68 | 10.3 | 9.0 | 19.3 | 3.9 | 4.9 | 14.4 | 48 | 0.68 |
| GM→ST | 70 | 65 | 10.8 | 9.7 | 20.5 | 5.0 | 6.0 | 15.5 | 45 | 0.64 |
| DP→VL | 75 | 68 | 11.0 | 11.7 | 22.7 | 3.9 | 4.9 | 17.8 | 42 | 0.62 |
| DP→Bi | 75 | 68 | 11.0 | 11.5 | 22.5 | 5.0 | 6.0 | 16.5 | 45 | 0.66 |
| SP→ST | 80 | 68 | 11.7 | 12.7 | 24.5 | 5.0 | 6.0 | 18.5 | 43 | 0.63 |
Column 2, distance between site of stimulation and segmental spinal level for the motoneurone; column 3, conduction velocity in I a afferents; column 4, afferent conduction time (ACT) in I a afferents (column 2/column 3); column 5, mean values from different motoneurones for the extra times of group II excitation (over that of heteronymous monosynaptic I a excitation); column 6, delay taken by group II volley to excite motoneurones (column 4 + column 5); column 7, central delay of non-monosynaptic group I excitation (Chaix et al. 1997); column 8, central delay of group II excitation estimated by adding 1 ms to the central delay of non-monosynaptic group I excitation; column 9, ACT of group II volley obtained by subtracting the central delay of group II excitation from the delay taken by group II volley to excite motoneurones (column 6 - column 8); column 10, conduction velocity (CV) in group II afferents (column 2/column 9); column 11, group II CV to group I CV ratio.