Development and preliminary evaluation of a new anatomically based prosthetic alignment method for below-knee prosthesis

Abstract

The objectives of current study were to a) assess similarities and relationships between anatomical landmark-based angles and distances of lower limbs in unilateral transtibial amputees and b) develop and evaluate a new anatomically based static prosthetic alignment method. First substudy assessed the anthropometrical differences and relationships between the lower limbs in the photographs taken from amputees. Data were analyzed via paired t-test and regression analysis. Results show no significant differences in frontal and transverse planes. In the sagittal plane, the anthropometric parameters of the amputated limb were significantly correlated to the corresponding variables of the sound limb. The results served as bases for the development of a new prosthetic alignment method. The method was evaluated on a single-subject study. Prosthetic alignment carried out by an experienced prosthetist was compared with such alignment adjusted by an inexperienced prosthetist but with the use of the developed method. In sagittal and frontal planes, the socket angle was tuned with respect to the shin angle, and the position of the prosthetic foot was tuned in relation to the pelvic landmarks. Further study is needed to assess the proposed method on a larger sample of amputees and prosthetists.

A systematic review of methods used to assist transtibial prosthetic alignment decision-making

“…24 In the primary studies, although 10 m of self-selected walking speed for amputees to adapt alignment changes between trials was considered, adaptation time for 19 studies was not reported. The rest of the studies offered an adaptation time ranging from 5 to 30 min, 25,26,29 one study checked the prosthetic alignment after 1 month, 21 and another followed up monthly for 2 years. 24 A qualitative measure that assists prosthetists throughout the alignment process was not found.…”

Transtibial prosthetic socket fitting: Australian prosthetist perspectives on primary challenges, management strategies, and opportunities for workflow and technological innovation

“…There were also reports of issues relating to access to prosthetic components, which prevented the prosthetist from testing and trialing a range of liners, for example. (12). "Other" items included rough alignment, review of fit and alignment, inspection of stump/palpation, funding, ordering componentry, and additional consultations (initial and follow-up after fitting).…”

“…11 Others may also indirectly exacerbate fit problems later in the process, for example, suboptimal alignment, which may lead to unintended forces being transferred to the limb. 12 Prosthetists' experiences of the prosthetic manufacturing workflow, common management strategies, and their perceptions of how various steps may contribute to socket fit problems are currently undocumented. Furthermore, innovative technologies to assist in these processes and improve the socket fitting process are emerging all the time 7 but few studies have sought to explore prosthetistidentified priorities for future workflow intervention (eg, via improved methods, assessment tools, or technologies).…”

“…11 Others may also indirectly exacerbate fit problems later in the process, for example, suboptimal alignment, which may lead to unintended forces being transferred to the limb. 12…”

“…Both the number of respondents who identified they experienced challenges with socket fit, and the availability of a strategy to address these challenges are indicated. (b) Stages where a challenge was indicated in A are ranked from most challenging (1) to least challenging(12). "Other" items included rough alignment, review of fit and alignment, inspection of stump/palpation, funding, ordering componentry, and additional consultations (initial and follow-up after fitting).…”