Background: Pusher behavior (PB) is a posture disorder due to a subjective bias in verticality perception. However, muscle activity characteristics in this disorder and the effective treatments are not known.
Objective: To investigate electromyographic (EMG) activity and the effect of electrical stimulation (ES) in PB.
Methods: Two PB patients were enrolled. The EMG activity was measured over the upper and lower limb muscles on the non-paretic side, and over the trunk muscles on both sides during sitting. We used a modified ABA single-case design consisting of consecutive baseline, intervention, and follow-up, each phase lasting 2 d. During the intervention, together with conventional treatment, the patient received ES for 5 min/d on the muscle antagonist to the muscle where excessive activity was observed. PB was assessed before and after each phase using the scale for contraversive pushing and the Burke lateropulsion scale. Truncal balance was evaluated using the trunk control test.
Results: In both patients, electromyography of the non-paretic triceps brachii muscle revealed excessive activity. To inhibit the excessive activity, ES was applied to the non-paretic biceps muscle. All scores improved after the intervention and follow-up phases.
Conclusion: ES based on EMG activity is therapeutic for PB.
Keywords: Pusher behavior; electrical stimulation; reciprocal inhibition.