Interrater reliability of mechanical tests for functional classification of transtibial prosthesis components distal to the socket

Abstract

Abstract-Substantial evidence suggests that the design and associated mechanical function of lower-limb prostheses affects user health and mobility, supporting common standards of clinical practice for appropriate matching of prosthesis design and user needs. This matching process is dependent on accurate and reliable methods for the functional classification of prosthetic components. The American Orthotic & Prosthetic Association developed a set of tests for L-code characterization of prosthesis mechanical properties to facilitate functional classification of passive below-knee prosthetic components. The mechanical tests require use of test-specific fixtures to be installed in a materials testing machine by a test administrator. Therefore, the purpose of this study was to assess the interrater reliability of test outcomes between two administrators using the same testing facility. Ten prosthetic components (8 feet and 2 pylons) that spanned the range of commercial designs were subjected to all appropriate tests. Tests with scalar outcomes demonstrated high interrater reliability (intraclass correlation coefficient (2,1) >/= 0.935), and there was no discrepancy in observation-based outcomes between administrators, suggesting that between-administrator variability may not present a significant source of error. These results support the integration of these mechanical tests for prosthesis classification, which will help enhance objectivity and optimization of the prosthesis-patient matching process for maximizing rehabilitation outcomes.

Considering passive mechanical properties and patient user motor performance in lower limb prosthesis design optimization to enhance rehabilitation outcomes

“…Although there are notable exceptions when commercial prostheses characterization is included to correlate mechanical function with user outcomes 42–44 , these studies are constrained within the range of prosthesis properties available through commercial devices. Recently, standardized bench tests were proposed to classify prosthetic feet based on mechanical properties such as stiffness and energy loss 38, 45 , which could enhance objectivity of device classification.…”

The effects of common footwear on stance-phase mechanical properties of the prosthetic foot-shoe system

“…dynamic keel, cushioned heel). 18,24 However, these classifications are based on displacement and energy return that may be problematic if footwear is not considered. For example, all three low mobility prostheses designs (Multiaxial, Single-axis, and SACH) displayed stiffness that allowed for keel displacement at 1230 N to qualify them as rigid per suggestions of the AOPA classification guidelines (<25 mm), but exceeded this threshold when combined with the trainer and hiking boot to be considered flexible (Table 4).…”

“…The setup and mechanical tests used in this study were adapted from those described in the American Orthotic & Prosthetic Association (AOPA) Foot Project Report 18 to characterize prosthesis mechanical behavior, which have been demonstrated to have excellent repeatability, 24 and are modeled after standardized methods for characterizing prosthesis mechanical properties independent of the user. 11,12…”

Effects of Test Socket on Pain, Prosthesis Satisfaction, and Functionality in Patients with Transfemoral and Transtibial Amputations

“…Similarly, although many studies have compared suspension systems in prostheses, types of joints, and different types of sockets [ 10 , 22 , 23 ], there is no any study investigating the effectiveness of socket types. However, most of these studies reported that a test socket was used before the placement of a permanent socket [ 24 , 25 ].…”