Influence of prior activity on residual limb volume and shape measured using plaster casting: results from individuals with transtibial limb loss.

The purpose of this research was to determine whether prior activity affected the shape of a plaster cast taken of a transtibial residual limb. Plaster casts were taken twice on one day in 24 participants with transtibial limb loss, with 5 s between doffing and casting in one trial (PDI-5s) and 20 min in the other trial (PDI-20m). The ordering of the trials was randomized. The mean +/- standard deviation radial difference between PDI-20m and PDI-5s was 0.34 +/- 0.21 mm when PDI-5s was conducted first and -0.02 +/- 0.20 mm when PDI-20m was conducted first. Ordering of the trials had a statistically significant influence on the mean radial difference between the two shapes (p = 0.008). The result shows that prior activity influenced the residual limb cast shape. Practitioners should be mindful of prior activity and doffing history when casting an individual's limb for socket design and prosthetic fitting.