An understandmg of the historical development of the
traction illustrates that accurate traction application and
maintenance are crucial in ensurmg successful treatment
on Hamilton Russell traction Failure to mamtam the traction
The dependent variable was the position and magnitude
of the resultant traction force The independent variables
were the angle of hip fiexion (angle A), angle B, angle C,
the extent of bed elevation and the amotmt of weight (W)
in the system (Figure 2)
An instrument capable of measurmg the required angles
was designed based on a goniometer, which has been used
to measure joint motion A manufactured goniometer was
unavailable and so it was necessary to construct one for
the purposes of this research A 15 cm semi-circle and
60 cm by 3 cm extension were cut out of 2 mm thick clear
perspex m one piece A separate 50 cm by 3 cm extension
was cut out of similar perspex and a straight lme scored
m the middle along its length A small perspex protractor