Comparison of Conventionally Manufactured AFO and Modular Customized AFO (AFO4-0)

Comparison of Conventionally Manufactured Lower Leg Orthoses and Modular Customized Lower Leg Orthoses (AFO 4.0) in Patients With Limited Neuromuscular Foot Function During Overground Walking

The Investigator will investigate the difference in the gait pattern between 2 commercially available ankle foot orthoses (AFO): a) conventionally manufactured AFO and b) modular customized AFO using Industry 4.0 technology. Measurement method: The participants perform an instrumented gait analyses while overground walking at a self - selected speed using a conventionally manufactured AFO or a modular customized AFO.

Cerebral palsy (CP) is the most common movement disorder in children [Stavsky, 2017]. It is frequently accompanied by spasticity [Baker, 2009]. The typical symptoms of spastic cerebral palsy are gait abnormalities such as equinus and drop foot that lead to severe impairments in daily life [Armand, 2016]. As these symptoms will persist in adulthood, an AFO is frequently required in this patient population. Furthermore, other neurological diseases e.g stroke [Choo, 2021], spinal cord injury, and peripheral nerve injury may require the daily use of an AFO. Ankle-foot orthoses (AFO) have been suggested to improve the dynamic efficiency of the gait. In addition, a positive effects on gait kinetics and kinematics have been reported [Figueiredo, 2008]. Recently, modular customized AFO are increasingly proposed as their response can be tuned to the patient's gait characteristics and/or functional maturity [6]. However, the evidence on this topic is still lacking and modular customized AFO are not yet established in clinical routine. The aim of this study is to assess gait parameters with an instrumented gait analysis of the modular customized AFO compared to conventional, untuned AFO in a group of adolescents and a group of adults using for there daily activity an AFO, while over ground walking at self selected speed over a distance of about 10 m.

The primary outcome measure is the gait profile score (GPS), which is an overall score calculated from all kinematic parameters (joint rotation angles) of the affected leg and expressed as the deviation from the normal gait cycle in degrees. The outcome of the GPS will be compared between the conventional AFO, and modular customized AFO for each participant and for each group.

Secondary outcomes are the Movement analysis profile (MAP) and spatial-temporal parameters, both calculated from kinematic parameters and expressed as the deviation from the normal gait cycle in degrees. The MAP consists of individual scores for each joint rotation angle (pelvic tilt, pelvic obliquity, pelvic rotation, hip flexion/extension, hip abduction/adduction, hip rotation, knee flexion/extension, ankle dorsiflexion/extension and foot progression) of the affected leg [2]. Spatial-temporal parameters are walking speed (m/s), cadence (steps/min x 100) and stride length (m) of the affected leg. The above-mentioned parameters will be compared between the conventional AFO, and modular customized AFO for each participant and for each group.

Inclusion Criteria: Participants fulfilling all of the following inclusion criteria are eligible for the study: Patients (11-18 yrs.), who need a new orthosis (visit to an orthopedic technician) Patients (18-65 yrs.), who need a new orthosis (visit to an orthopedic technician) Informed Consent provided as documented by signature Confirmed diagnosis of cerebral palsy Confirmed diagnosis of spastic equinus and/ or drop foot, Gait pathologies treated with conventional AFO Gross Motor Function Classification System (GMFCS) level I or II Exclusion Criteria: Other neuromuscular diseases Surgical intervention lower extremities past 12 months to improve gait pathologies Injections of Botulinum toxin 6 months prior to study inclusion Inability or unwillingness to follow the procedures of the gait analysis in women: pregnancy

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Choo YJ, Chang MC. Effectiveness of an ankle-foot orthosis on walking in patients with stroke: a systematic review and meta-analysis. Sci Rep. 2021 Aug 5;11(1):15879. doi: 10.1038/s41598-021-95449-x.

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