Gait assessment during the initial fitting of customized selective laser sintering ankle foot orthoses in subjects with drop foot

Abstract

Background: Recently, additive fabrication has been proposed as a feasible engineering method for manufacturing of customized ankle foot orthoses (AFOs). Consequently, studies on safety, comfort and effectiveness are now carried out to assess the performance of such devices. Objective: Evaluate the clinical performance of customized (selective laser sintering) SLS-AFOs on eight subjects with unilateral drop foot gait and compare to clinically accepted (polypropylene) PP-AFOs. Study Design: Active control trial. Methods: For each subject two customized AFOs were fabricated: one SLS-AFO manufactured following an additive fabrication framework and one thermoplastic PP-AFO manufactured according to the traditional handcraft method. Clinical performance of both AFOs was evaluated during gait analysis. Results: A significant beneficial effect of both custom-moulded PP-AFO and customized SLS-AFO in terms of spatial temporal gait parameters and ankle kinematic parameters compared to barefoot gait of adults with drop foot gait are observed. No statistically significant difference between the effect of PP-AFO and of SLS-AFO was found in terms of spatial temporal gait parameters and ankle kinematic parameters. Conclusion: AFOs manufactured through the SLS technique show performances that are at least equivalent to the handcrafted PP-AFOs commonly prescribed in current clinical practice. Clinical relevanceManufacturing personalized AFOs with selective laser sintering (SLS) in an automated production process results in decreased production time and guarantees the consistency of shape and functional characteristics over different production time points compared to the traditional manufacturing process. Moreover, it reduces the dependency of the appliance on the experience and craftsmanship of the orthopaedic technician.

Selective Laser Sintered Versus Carbon Fiber Passive-Dynamic Ankle-Foot Orthoses: A Comparison of Patient Walking Performance

“…Changes in walking performance that did arise were less than the minimal de tectable change values established within the literature [35], and thus may be of little functional relevance. These results are in agreement with a recent study on subjects with unilateral foot drop that found no significant differences in spatiotemporal parameters and minimal differences in joint kinematics between SLS and polypropylene AFOs [23], However, the AFOs worn in that study were not passive-dynamic [23] and comparisons to the present work are therefore difficult. 3), and although differences were observed in the joint kinematics (Fig.…”

Additive manufacturing of custom orthoses and prostheses—A review

“…Creylman et al [24] tested conventional PP and SLS AFOs (shown in Fig. 9(e)) on eight subjects with unilateral drop foot gait, evaluated gait performance and concluded that SLS AFOs had at least equivalent performances as conventional AFOs.…”

“…9 Examples of AM AFOs, produced by: (a) Faustini et al [21], (b) Mavroidis et al [22], (c) Schrank et al [23], (d) Telfer et al [17], (e) Creylman et al [24], (f) Schrank et al [25], (g) Chen et al [26], and (h) Harper et al [27].…”

The influence of ankle-foot orthosis stiffness on walking performance in individuals with lower-limb impairments

“…An alternative approach is to use advanced additive manufacturing techniques such as selective laser sintering (SLS), which enable more precise control of design characteristics such as stiffness. SLS has recently been used to successfully manufacture PD-AFOs Schrank and Stanhope, 2011), traditional AFOs (Creylman et al, 2013), foot orthoses (Pallari et al, 2010;Salles and Gyi, 2013), prosthetic sockets (Faustini et al, 2006;Rogers et al, 2007Rogers et al, , 2008, prosthetic feet (Fey et al, 2011) and prosthetic ankles (Ventura et al, 2011a,b). Therefore, the overall goal of this study was to use SLSmanufactured PD-AFOs to identify the influence of PD-AFO stiffness on walking performance in individuals with lower-limb neuromuscular and musculoskeletal impairments.…”