We determined the distribution and sophistication of obstetric technologies in all 80 maternity hospitals in the state of Washington and examined the effect of rural or urban location, birth volume, and physician staffing on technological intensity. Although smaller and more rural hospitals refer most premature and low-birth-weight infants to regional referral centers, sophisticated prenatal and intrapartum technologies are available in the majority of even the smallest and most remote rural units. Rural hospitals have slightly lower obstetrical intervention rates than do their urban counterparts, but the differences are not great.

Lumbar disorders are amongst the major causes of absenteeism in industry. The pain and misery endured, the financial considerations of man hours lost and the understandable difficulty to diagnose and cure the problems make prevention a worthwhile study. Prevention is

This study was concerned with the abdominal and spinal activity during somersaulting and other exercises on the trampoline. During such exercises there are many interrelated factors which if analysed in a skilled performer can contribute to a new understanding of training methods. There are many difficulties in recording several biological parameters simultaneously during gymnastic activities but to achieve an accurate analysis of an exercise it is essential to synchronize the relevant parameters. The present study extends our earlier work, Bevan &Corser, 1969 and Thomas, 1970 by including intratruncal barometry and electro-cardiography. These parameters permit a correlation of the exercise with important changes in intra-truncal pressure and the activity of the heart. METHODSThe records were of four types:(1) 16 mm. cinephotography was linked by a frame synchroniser to a signal marker on an eight channel pen-oscillograph. The camera was set up 5 metres from the performer to allow full coverage of the exercise.(2) Intra-truncal barometry was obtained by using a radio pressure pill calibrated to emit a change of frequency linearly from 0-200 mm.Hg. pressure.The radio-pill (in a suitable thin rubber envelope) was swallowed two hours before the exercise. The radio-receiver input was connected to an aerial worn as a belt by the performer, the output was connected to a channel of the pen oscillograph.(3a) Electrocardiography was obtained from trailing wires from two 1.5 cm. silver disc electrodes placed 2.5 cm. apart immediately inferior to the bulk of the pectoralis muscles and in line with the left nipple. These electrodes were attached to the skin by standard 3M double surfaced adhesive discs. Good electrical contact was achieved by local skin abrasion and filling the electrode cavity with saline electrode jelly. The cardiogram was a direct record using the amplifier and a channel of the pen oscillograph.