Shock wave therapy (SWT) has shown some effectiveness in the spasticity treatment. However, few randomized controlled trials remained available, particularly in long-term spasticity, and the effect of a single session of treatment has poorly been assessed.

Sixteen adults with a long-term stroke (4.3±6 years post-stroke) and presenting a spasticity of the triceps surae were included. Patients were submitted to two sessions of shock wave therapy: one session (real-SWT) of 6000 real shocks (8Hz; 1.6bar) applied on the triceps surae, and one session (sham-SWT) of 6000 sham shocks. Both sessions were separated by a one week interval, and allocated in a random order. Patients were assessed immediately before and after each session of SWT. Assessment was carried out by a blind assessor, and included the Modified Ashworth Scale (MAS) and the Tardieu scale (TS) of the triceps surae (assessed with knee flexed and knee extended), as well as a ten-meter walking test (10MWT).

The MAS score (knee flexed) and the TS score (knee extended) improved significantly after real-SWT, but not after sham-SWT (P=0.007 and 0.01, respectively). The median improvement was 0.5[0;1] on the MAS and 1[0;2] on TS. However, the 10MWT remained unchanged.

A single session of shock wave therapy can be effective to improve spasticity, but not walking ability, in long-term spasticity. Larger studies are needed to confirm this hypothesis.