Effects of Passive Leg Movement on the Oxygenation Level of Lower Limb Muscle in Chronic Stroke Patients

Objective. To evaluate the effects of passive leg movements on the muscle oxygenation level and electromyographic (EMG) activity in the lower limbs in chronic stroke patients. Methods. With a gait training apparatus, passive movements were imposed on the lower limbs of 15 chronic stroke patients at a frequency of 0.8 Hz for 10 minutes. During the passive leg movements, muscle oxygenation level and muscular EMG activity of the paretic and nonparetic calf muscles were assessed. Results. The passive leg movements caused increases in the EMG activity and muscle oxygenation level in both paretic and nonparetic lower limbs. Although a significant dif-ference was found in the concentration changes of the oxy-genated hemoglobin (Oxy-Hb), both paretic and nonparetic sides of the muscle showed enhancement of the tissue oxy-genation level (TOI). The degree of the changes of the Oxy-Hb depended on the level of motor recovery after stroke; subjects with good motor recovery showed less difference in the Oxy-Hb level between the paretic and nonparetic sides of the muscle. Conclusion. Passive leg movements have the capacity to induce muscular activity and enhance oxygen metabolism, even in the paretic lower limb muscle of chronic stroke patients. This type of exercise might be a useful and efficient method for the prevention of metabolic deterioration in the lower limb paretic muscles of chronic stroke patients. Key Words: Stroke—Hemiplegia—Paretic muscle—Near infrared spectroscopy (NIRS)—Muscle oxygenation