Fig. 5.

Motor-evoked and lumbar-evoked potentials during static position, passive shortening, and lengthening in soleus and tibialis anterior. a, b Averaged representative traces in response to electrical stimulation of the lumbar spinous processes (black line) and single-pulse transcranial magnetic stimulation (dashed grey line) during static position (left panel), passive shortening (centre panel) and passive lengthening (right panel) in soleus (a) and tibialis anterior (b). Each representative trace is an average of ten waveforms. c, d Amplitude of lumbar-evoked potential (left panel) and motor-evoked potential (right panel) expressed as a percentage of the amplitude of maximal compound action potential (LEP/M_max and MEP/M_max, respectively) during static position (STAT), passive shortening (SHO), and passive lengthening (LEN) in soleus (c) and tibialis anterior (d). Open squares and full lines represent the sample mean, whilst open circles and dashed lines denote individual responses (n = 11). *p < 0.005 compared to static position and passive lengthening