Aim: To ascertain the accuracy of partial weight bearing.

Method: 6 healthy volunteers with a below knee plaster cast, 10 patients with uncemented hip replacements and 12 patients with lower limb fractures were trained to partial weight bear. They were asked to place the affected leg on a bathroom scale and to press on it till the prescribed limit. This process was repeated till the subject formed a mental image of the amount of load they must put through the limb. The ability to partial weight bear was tested in a gait lab by making them walk on a walkway incorporating a Bertec force platform. Exact magnitude of weight bearing was calculated from the vertical ground reaction forces produced.

Results: 4 out of 6 volunteers exerted mean weight of 20.3 kg above and the remaining 2 exerted 5.6 kg below that prescribed. Of the 22 patients, 19 exerted mean weight of 24.3 kg above and 3 patients exerted mean weight of 7.5 kg below that prescribed. As per Spearmanñs rank correlation test, the relationship between the prescribed weight bearing and the actual weight bearing was non-signiþcant (p=0.399) i.e., there is little relationship between the prescribed and actual weight bearing.

Conclusions: Neither patients nor healthy volunteers could partial weight bear to the extent required. They were either above or below the prescribed level of partial weight bearing. Current method of teaching partial weight bearing is inaccurate and has poor reproducibility. Such methods use static loading situations whereas walking is a dynamic activity. An inexpensive, easy to use, dynamic device is required to train patients to partial weight bear.