Quantifying accommodation to prosthesis interventions in persons with lower limb loss.

Determining the appropriate amount of accommodation time is an important component of research protocol design in the field of limb prosthetics. Insufficiently short or excessively long accommodation periods may limit the external validity of findings and/or the economic efficiency and ethical innocuousness of a study. However, issuing general recommendations is difficult, as individual accommodation periods are affected by subject characteristics, the nature of the intervention, and possibly a number of environmental factors. We are discussing an approach to determine individual accommodation times based on the assumption that the process of becoming accustomed to a prosthetic intervention follows a similar exponential "learning curve" as many other learning processes that have been previously investigated. Initial data collected with a small subject sample gives some indication that gait cycle symmetry changes along the hypothesized curve trajectory. If those preliminary results can be confirmed it may be possible to extrapolate a subject's eventual level of accommodation based on a small data set that is easily collected during the first twenty minutes after introducing a prosthetic intervention.