Bidirectional Tuning of the AFO Stiffness

ConditionNeuromuscular Disorders

Trial statusRecruiting

Trial phaseNot applicable

Trial typeInterventional

Biological sexAll

Age18+

SponsorAcademisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)

About this trial

The goal of this pilot study with a pre-post design is to investigate the effects of separate individualization of the AFO stiffness towards plantar- and dorsiflexion in a spring-hinged AFO on walking compared to a spring-like AFO (3 types) having the same stiffness in both directions.

People with a neuromuscular disease or nerve injury causing at least plantarflexor weakness (determined as the inability to perform 3 single heel rises), with an indication for or using an AFO, will be fitted with a new, custom-made spring-hinged AFO with the NEURO SWING® system ankle joint (Fior\& Gentz, Lüneburg, Germany), of which the stiffness of ventral and dorsal compartment of this spring-hinged AFO will be individualized. For comparison, measurements will be performed with three different prefab spring-like AFOs with different stiffness levels (but which have a similar stiffness towards plantar and dorsiflexion), and the participants' current AFO if applicable, and shoes-only at baseline.

The main outcome parameters will be the maximal ankle plantarflexion angle, ankle angular velocity and knee flexion angle during the loading response, which will be measured using a 3D gait analysis. Secondary outcomes include other gait biomechanics, walking energy cost, walking speed, standing balance, perceived physical functioning and perceived walking ability.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

Age 18 years or older;

Presence of plantar flexor weakness in at least one leg, determined as a score lower than 5 on the manual muscle testing scale (Medical Research Council- MRC) and/or inability to perform three single heel rises, with or without dorsiflexion weakness;

Indicated for or using an AFO;

Ability to walk 6-minutes consecutively (with assistive device, if necessary).

Disqualifiers

When wearing the AFO, not able to walk short bouts of 10m without walking aids, such as a walker;

Foot deformities that do not fit in prefab spring-like AFOs;

Weakness of the knee extensor muscles, for which a knee-ankle-foot orthosis is indicated.

Trial design

Design model

Single group

Treatments tested in this trial

NEURO SWING AFO (Fior& Gentz, Lüneburg, Germany)
Device
stiffness-optimized custom-made spring-hinged AFO with the NEURO SWING® system ankle joint build in
WalkOn Reaction® (Ottobock, Duderstadt)
Device
comparator: prefab spring-like AFO without hinge with a predefined stiffness (2.8 Nm/degree).
Matrix Max2® (TruLife, Dublin, Ireland)
Device
comparator: prefab spring-like AFO without hinge with a predefined stiffness (1.4 Nm/degree)
Matrix® (TruLife, Dublin, Ireland)
Device
comparator: prefab spring-like AFO without hinge with a predefined stiffness (0.6 Nm/degree)

Treatment groups

10 Participants

are divided into 1 treatment group

Group A: NEURO SWING AFOExperimental treatment 4 interventions