Localized 100 Hz vibration improves function and reduces upper limb spasticity: a double-blind controlled study.

BACKGROUND Physical modalities such as vibration has been suggested as possible non-pharmacological way to control spasticity. AIMS The hypotheses tested were: 1) can a selective vibration of the upper limb flexor antagonist, triceps brachii, reduce the spasticity of the flexor biceps brachii muscle; 2) is its association with physiotherapy better than physiotherapy alone in reducing spasticity and improving function, 3) can this possible effect last for longer than the stimulation period. DESIGN Randomized double-blind study. SETTING Rehabilitation Institute, inward patients. POPULATION Thirty hemiplegic patients affected by upper limb spasticity. METHOD (VIB + PT) group received physiotherapy plus vibration by means of a pneumatic vibrator applied over the belly of the triceps brachii of the spastic side (contact surface 2 cm2; frequency 100 Hz; amplitude 2 mm; mean pressure 250 mBar). (SHAM + PT) group received physiotherapy and sham vibration. Both groups had 60 minutes of physiotherapy (Kabat techniques) for 5 days a week (from Monday to Friday) for 2 weeks. MAIN OUTCOME MEASURE Ashworth modified scale for spasticity and robot-aided motor tasks changes for functional modifications were evaluated before starting treatment (T0), 48 hours after the fifth session (T1) and 48 hours after the last session (T2). RESULTS Fisher's exact test showed a statistically significant greater improvements in the (VIB + PT) group (P=0.0001) compared to in the (SHAM + PT) group after 1 week, as well as after 2 weeks of treatment (P=0.0078) at the Ashworth scale. CONCLUSION 1) 100 Hz vibration applied to the triceps brachii of a spastic upper limb in association with physiotherapy is able to reduce the spasticity of the flexor agonist, biceps brachii; 2) this association is better than physiotherapy alone in controlling spasticity and improving function; 3) this clinically perceivable reduction of spasticity and function improvement extends (for at least 48 hours) beyond the period of application of the vibration, supporting its possible role in the rehabilitation of spastic hemiplegia. CLINICAL REHABILITATION IMPACT 100 Hz antagonist muscle vibration, a non-pharmacological treatment, can help physiotherapy to reduce flexors spasticity and improve functions in the rehabilitation of upper limb spasticity.