Work and workload of nursing personnel in a nursery school and two institutions for handicapped children.

Work-related low back pain and cervicobrachial disorders have become increasingly common among nursing personnel with the increase in the number of social welfare institutions and workers. The aim of this study is to assess the burden on the low backs of personnel caring for children. We measured work content, working time, posture and muscular activity in 16 nursery workers in three different types of institutions for healthy and handicapped children. The working time and posture of 7 nursery teachers in a public nursery school for healthy children (A school), 7 nursing workers (4 nursery teachers and 3 nursery instructors) in a public daycare center for mentally and physically handicapped children (B center), and 2 nursery instructors in a private home for severely handicapped children (C home) were analyzed. The muscular activity of the erectores spinae muscle of three subjects was measured using a newly developed EMG monitor (portable EMG monitor, PEMM). The following results were obtained. The average length of a lesson or activity in A school was greater than that in B center and C home. The time required by care for meals was longest in C home. The arrangement and rearrangement times were longest in the classes of children aged 3-5 in A school. The time occupied for clerical work and other work was relatively longer, while recess including lunch time was approximately one hour. The most commonly observed posture was sitting on the floor in all kinds of classes, with this occurring most often in C home. Hazardous postures such as bending forward, squatting, and kneeling appeared in 11-18% (48-81 min) of a day's working time. The average muscular activity of the erectores spinae muscle of three subjects throughout a day was approximately 10% of the maximum isometric contraction (% maximum work load, %MWL), when muscular activities were measured by PEMM. The relatively high %MWL values (19-27%MWL) were obtained at a slightly bending posture and a kneeling posture, while lower (1-9%MWL) values were observed at a sitting posture. The %MWL values at a sitting posture varied according to such conditions as duration of sitting, back rest, weight on the arms, twisting of the trunk, and hip movement. The risky nature of the sitting posture are also discussed.