Background and Objectives. Current methods of assessing lower limb mot
or function using low-dose epidural analgesia are either too insensiti
ve (Bromage scale) or too cumbersome for use during labor. Accordingly
, we have designed a force meter that quantitatively measures isometri
c muscle power of the lower limbs during peak voluntary exertion. Meth
ods. The force meter was tested for linearity using calibrated referen
ce weights. Measurements were made on two occasions (separated by an i
nterval of approximately 5 years), and differences in response were as
sessed by regression analysis. Departure from linearity was examined b
y a lack of fit test. Results. There was no significant nonlinearity i
n response over the range 0-15 kg, nor was there any significant diffe
rence in slope between the two functional modes of this device. The de
vice overread slightly at the higher weights. Conclusions. The force m
eter described was found to be sufficiently accurate and suitable for
the quantitative assessment of lower limb motor function after epidura
l analgesia during labor.