Effects of physiotherapy on F-wave-amplitudes in spasticity.

F-wave amplitudes have been used to demonstrate changes of motor neuron excitability in spasticity and pharmacological antispastic therapy. In this study it is shown that F-wave amplitudes can also be used to document changes of motor neuron excitability as an effect of physiotherapy. Ten F-waves were recorded immediately before and after physiotherapy in 42 legs of 21 patients with spastic paraparesis due to multiple sclerosis. Mean F-wave amplitude, maximum F-wave amplitude, mean F-wave/M-response ratio and maximum F-wave/M-response ratio were significantly lower after physiotherapy than before. Therefore the antispastic effect of physiotherapy is documented by a decrease of F-wave-amplitude parameters.