Vacuum casting will be performed using the Ottobock vacuum casting system. For our vacuum casting procedures, we will be following the protocols outlined in the Harmony Fabrication Quick Guide

For the aqua casting system, we will be using an in-house manufactured device. This device will be created following guidelines from the PCAST Technical Manual

Participants will be cast using vacuum casting (Ottobock Harmony) method. The method of casting will be randomized via RNG. Participants will be fitted with both sockets and dynamic alignment procedures will be performed. This 15-minute fitting and alignment period will address any extreme gait deviations and initial socket discomforts. After fitting, the participant will then be given a 15-minute adjustment period to wear the device. We will then begin the assessment phase, beginning with the timed Get-Up and Go test and followed by the 6-Minute Walk test. Each patient will perform 3 rounds of each test and patient order will be determined at random. The participants will be given a 10 min break between each series of tests. At the end, a questionnaire will be given.

Participants will walk in a 100-ft hallway on a flat, hard surface in a period of 6 minutes.

The Ohio Willow Wood Omega Tracer 3-dimensional image capture device and associated Omega shape capture software will be used to determine the volumes of each socket type, comparing the vacuum and aqua casting volume metrics. The scanning variables of width, depth, and length will determine the total displacement of each socket type. It has been determined that laser scanning is a valid and reliable method for accurately measuring volume fluctuations between casting methods.