Characteristics and course of lower extremity muscle activity in a patient with body lateropulsion due to pontine infarction: a case report.

Background: Body lateropulsion (BL) is a phenomenon in which the body involuntarily falls to one side; however, its detailed postural control characteristics remain unclear.

Objective: This case report aimed to measure the surface electromyography (EMG) of the lower limbs while standing in a patient with severe BL on the affected side due to pontine infarction and to investigate the characteristics of postural control.

Case description: We evaluated a patient with severe BL due to pontine infarction at two-time points, 6 and 20 days after onset, to assess static standing balance under open and closed eye conditions and measure the center of pressure (COP) and lower extremity EMG during these tasks.

Outcomes: There were minimal changes in COP position and total locus length during the eyes closed condition compared to the eyes open condition. However, the head and trunk to the non-BL side of the tilt and bilateral medial hamstring muscle activity tended to be higher when the eyes were closed. At the final evaluation, head and trunk tilt and EMG changes were reduced during the eyes-closed condition compared to the eyes-open condition. The initial postural response was considered to reflect a compensatory postural strategy for BL, characterized by the body involuntarily tilting to one side.

Conclusion: The change in posture over time may indicate a reduction in the compensatory postural response as the condition improves. In this case, characteristic postural findings were identified through EMG measurements, suggesting the possibility of future studies involving multiple cases.