Abstract
Seiza is one of the most commonly used sitting postures in various enrichment lessons of Japanese origin. Because Seiza blocks blood flow in lower limbs and induces sensory palaysis, it may results in a staggered walk or a fall accident. This study aimed to examine the influence of Seiza on tissue oxygenation kinetics in the lower limbs, the proprioceptive sensation threshold, and gait.
Ten male and 10 female healthy young adults were asked to walk before and after sitting in a Seiza position. Participants walked on a level and straight 10m-walkway before Seiza, just after increasing their proprioceptive sensaion threshold of their plantar muscles due to Seiza, 5 min and 10 min after Seiza.
Tissue oxygenation in the lateral soleus muscle and plantar proprioceptive sensation threshold were measured during Seiza. Oxygenated hemoglobin(Hb)/myoglobin(Mb) decreased and deoxygenated Hb/Mb increased just after the onset of Seiza and reached a plateau within about 3 – 5 min. After blood stasis in the lower limbs was maintained for about 18 min, the proprioceptive sensation threshold of plantar muscles increased. Just after and 5min after the Seiza, stride and gait velocity decreased compared with before assuming the Seiza posture.
About 10 min rest may be necessary to decrease a risk of falling due to abnormal gait induced by Seiza.
