Bidirectional Tuning of the AFO Stiffness

Summary

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.

Conditions

• Neuromuscular Disorders

Interventions

DEVICE

NEURO SWING AFO (Fior& Gentz, Lüneburg, Germany)

stiffness-optimized custom-made spring-hinged AFO with the NEURO SWING® system ankle joint build in

DEVICE

WalkOn Reaction® (Ottobock, Duderstadt)

comparator: prefab spring-like AFO without hinge with a predefined stiffness (2.8 Nm/degree).

DEVICE

Matrix Max2® (TruLife, Dublin, Ireland)

comparator: prefab spring-like AFO without hinge with a predefined stiffness (1.4 Nm/degree)

DEVICE

Matrix® (TruLife, Dublin, Ireland)

comparator: prefab spring-like AFO without hinge with a predefined stiffness (0.6 Nm/degree)

Sponsors & Collaborators

• FIOR & GENTZ

  collaborator UNKNOWN

• Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)

  lead OTHER

Principal Investigators

• Frans Nollet, MD PhD · Amsterdam UMC, location AMC

Study Design

Allocation

NA

Purpose

TREATMENT

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2024-05-15

Primary Completion

2025-02-01

Completion

2025-02-01

Countries

• Netherlands

Study Locations