Bidirectional Tuning of the AFO Stiffness
- Conditions
- Neuromuscular Disorders
- Interventions
- Device: NEURO SWING AFO (Fior& Gentz, Lüneburg In Duderstadt, Germany)Device: WalkOn Reaction® (Ottobock, Duderstadt)Device: Matrix Max2® (TruLife, Dublin, Ireland)Device: Matrix® (TruLife, Dublin, Ireland)
- Registration Number
- NCT06412055
- Brief 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.
- Detailed Description
Many neuromuscular diseases cause weakness of the ankle dorsiflexors and plantarflexors, resulting in an altered gait pattern. In particular, weakness of the plantar flexors leads to a reduced walking ability as it hampers safety in both standing and walking. The primary treatment to improve walking ability and safety during standing and walking in dorsiflexor and/or plantarflexor weakness is the provision of ankle-foot orthoses (AFOs). To maximize treatment outcomes in case of lower leg weakness, the optimal AFO stiffness needs to be individually determined. Individual optimization of the stiffness can be performed with a spring-like AFO or with a spring-hinged AFO. With a spring-like AFO, the stiffness towards plantar- and dorsiflexion is similar, oftentimes resulting in a higher than necessary stiffness towards plantarflexion. An advantage of spring-hinged AFOs is that, unlike spring-like AFOs, the stiffness can be separately optimized in the directions of dorsiflexion and plantarflexion.
The objective of this pilot study is to evaluate the effects of separate individualization of the AFO stiffness towards plantar- and dorsiflexion in a spring-hinged AFO compared to three types of spring-like AFO having the same stiffness in both directions on gait biomechanics, walking energy cost, walking speed, and standing balance. Additionally, effects will be evaluated of the optimal spring-hinged AFO 6 weeks after delivery of the AFO on perceived physical functioning, walking ability and satisfaction in daily life compared to the participants' AFO used at baseline if applicable or walking with shoes-only.
In this pilot study with a pre-post design, people with a neuromuscular disease or nerve injury causing at least plantarflexor weakness 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). The stiffness of ventral and dorsal compartment of this spring-hinged AFO will be individualized using a previously developed optimization algorithm. The spring-hinged AFO with optimal stiffness settings will be used at home for 6-weeks. For comparison, the investigators will test the direct effects of three different prefab spring-like AFOs with different stiffness levels (but which have a similar stiffness towards plantar and dorsiflexion) of 2.8, 1.4 and 0.6 Nm/degrees respectively in a randomized order, and the participants' current AFO if applicable, and shoes-only at baseline.
Recruitment & Eligibility
- Status
- RECRUITING
- Sex
- All
- Target Recruitment
- 10
- 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).
- 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.
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- SINGLE_GROUP
- Arm && Interventions
Group Intervention Description NEURO SWING AFO Matrix® (TruLife, Dublin, Ireland) Participants will be fitted with a new custom-made spring-hinged AFO with the NEURO SWING® system ankle joint. Following a previously developed algorithm, the stiffness will be individually selected from six different configurations tested during an optimization measurement directly after delivery of the new AFO. Thereafter, participants will use the optimized AFO with individualized stiffness at home for six weeks during the course of the study. NEURO SWING AFO NEURO SWING AFO (Fior& Gentz, Lüneburg In Duderstadt, Germany) Participants will be fitted with a new custom-made spring-hinged AFO with the NEURO SWING® system ankle joint. Following a previously developed algorithm, the stiffness will be individually selected from six different configurations tested during an optimization measurement directly after delivery of the new AFO. Thereafter, participants will use the optimized AFO with individualized stiffness at home for six weeks during the course of the study. NEURO SWING AFO WalkOn Reaction® (Ottobock, Duderstadt) Participants will be fitted with a new custom-made spring-hinged AFO with the NEURO SWING® system ankle joint. Following a previously developed algorithm, the stiffness will be individually selected from six different configurations tested during an optimization measurement directly after delivery of the new AFO. Thereafter, participants will use the optimized AFO with individualized stiffness at home for six weeks during the course of the study. NEURO SWING AFO Matrix Max2® (TruLife, Dublin, Ireland) Participants will be fitted with a new custom-made spring-hinged AFO with the NEURO SWING® system ankle joint. Following a previously developed algorithm, the stiffness will be individually selected from six different configurations tested during an optimization measurement directly after delivery of the new AFO. Thereafter, participants will use the optimized AFO with individualized stiffness at home for six weeks during the course of the study.
- Primary Outcome Measures
Name Time Method maximal ankle angular velocity in loading response in degrees day 0 (directly post-delivery) measured during a 3D gait analysis
- Secondary Outcome Measures
Name Time Method minimal ankle angle in loading response in degrees day 0 (directly post-delivery) and 6 weeks post-delivery for the stiffness-optimized NEURO SWING AFO only measured during a 3D gait analysis
maximal ankle push-off power in Watt/kg day 0 (directly post-delivery) and 6 weeks post-delivery for the stiffness-optimized NEURO SWING AFO only measured during a 3D gait analysis
maximal ankle angular velocity in loading response 6 weeks post-delivery for the stiffness-optimized NEURO SWING AFO measured during a 3D gait analysis
minimal knee flexion angle during the stance phase in degrees day 0 (directly post-delivery) and 6 weeks post-delivery for the stiffness-optimized NEURO SWING AFO only measured during a 3D gait analysis
maximal external knee flexion moment in loading response in degrees day 0 (directly post-delivery) and 6 weeks post-delivery for the stiffness-optimized NEURO SWING AFO only measured during a 3D gait analysis
ankle angle during midstance in degrees day 0 (directly post-delivery) and 6 weeks post-delivery for the stiffness-optimized NEURO SWING AFO only measured during a 3D gait analysis
maximal ankle angle during the stance phase in degrees day 0 (directly post-delivery) and 6 weeks post-delivery for the stiffness-optimized NEURO SWING AFO only measured during a 3D gait analysis
maximal ankle moment in Nm/kg day 0 (directly post-delivery) and 6 weeks post-delivery for the stiffness-optimized NEURO SWING AFO only measured during a 3D gait analysis
minimal external knee flexion moment during the stance phase in Nm/kg day 0 (directly post-delivery) and 6 weeks post-delivery for the stiffness-optimized NEURO SWING AFO only measured during a 3D gait analysis
maximal hip power during loading response in Watt/kg day 0 (directly post-delivery) and 6 weeks post-delivery for the stiffness-optimized NEURO SWING AFO only measured during a 3D gait analysis
walking speed in m/s day 0 (directly post-delivery) and 6 weeks post-delivery for the stiffness-optimized NEURO SWING AFO only Walking speed will be measured during a 6-minute walk test (6MWT) at a self-selected comfortable speed.
Perceived walking ability baseline and 6 weeks post-delivery of the stiffness-optimized NEURO SWING AFO Perceived walking ability in terms of satisfaction, intensity, safety and stability during walking will be measured on a 10-point Numerical Rating Scale (NRS) ranging from 0 (worst possible score) to 10 (best possible score).
maximal knee flexion angle in loading response in degrees day 0 (directly post-delivery) and 6 weeks post-delivery for the stiffness-optimized NEURO SWING AFO only measured during a 3D gait analysis
maximal hip power during ankle push-off in Watt/kg day 0 (directly post-delivery) and 6 weeks post-delivery for the stiffness-optimized NEURO SWING AFO only measured during a 3D gait analysis
center-of-pressure displacement in mm day 0 (directly post-delivery) and 6 weeks post-delivery for the stiffness-optimized NEURO SWING AFO only During the 3D gait analysis, a standing balance test will be performed. Participants will stand on one force plate with a standardised distance of 10 cm between the medial borders of the feet for 30 seconds. Standing posture, in terms of joint angles, will be determined using the markers placed according to the Plug-in-Gait model. Postural sway will be calculated as the Center-of-Pressure displacement during the last 15 seconds of the test.
Perceived physical functioning baseline and 6 weeks post-delivery of the stiffness-optimized NEURO SWING AFO Physical functioning will be measured using the physical functioning scale of the 36-item short form health survey (SF-36), with range 0-100 (a higher score means a better functioning).
walking energy cost in J/kg/m day 0 (directly post-delivery) and 6 weeks post-delivery for the stiffness-optimized NEURO SWING AFO only During a 6-minute walk test (6MWT) at comfortable speed, oxygen uptake (VO2) and carbon dioxide production (VCO2) will be measured using a breath-by-breath gas analysis system (K5, Cosmed, Rome, Italy) worn on the patient's back. Over at least one minute during the last three minutes of the test, walking energy cost will be calculated from these measured parameters and the comfortable walking speed.
velocity of center-of-pressure displacement in mm/s day 0 (directly post-delivery) and 6 weeks post-delivery for the stiffness-optimized NEURO SWING AFO only During the 3D gait analysis, a standing balance test will be performed. Participants will stand on one force plate with a standardised distance of 10 cm between the medial borders of the feet for 30 seconds. Standing posture, in terms of joint angles, will be determined using the markers placed according to the Plug-in-Gait model. Postural sway will be calculated as the Center-of-Pressure displacement during the last 15 seconds of the test.
Trial Locations
- Locations (1)
Department of rehabilitation medicine Amsterdam UMC, location AMC
🇳🇱Amsterdam, Netherlands