To determine whether AFOs optimized for stiffness in patients with calf muscle weakness are superior to standard AFOs in reducing walking effort, as measured by energy cost of walking (ECW, in Jkg-1m-1), and 2) to build a model to predict required…
ID
Source
Brief title
Condition
- Neuromuscular disorders
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
The main study endpoint will be walking effort (ECW), which will be measured
during a 6-minute walk test (6MWT) with simultaneous gas-analysis.
Secondary outcome
Secondary study endpoints will include: joint angles and net joint moments
during gait (measured by 3D gait analysis); walking speed (assessed with a
6MWT); perceived physical functioning (assessed with the 36-Item Short-Form
Health Survey questionnaire); perceived fatigue (measured with the Fatigue
Severity Scale); daily step activity (measured with the StepWatch3TM Activity
Monitor 3.0 + a motivation dairy); and satisfaction (evaluated on a 10-point
Numeric Rating Scale). Additional endpoints will include isometric strength and
passive stiffness characteristics of the calf muscles; visualization of the
fiber architecture of the calf muscles, assessed with diffusion-tensor magnetic
resonance imaging; the AFO stiffness and treatment adherence.
Background summary
Patients with paretic calf muscles due to neuromuscular diseases walk unstable
at a reduced speed and an increased walking effort. To overcome these gait
problems, a carbon-fiber ankle-foot orthosis (AFO) can be prescribed. This AFO
acts as a spring with high resistance around the ankle, providing stability
during stance and augmenting push-off by releasing stored energy. While both
mechanisms aim to reduce walking effort, their effectiveness depends on the
stiffness of the AFO. This is a delicate issue: if the AFO is too stiff, it
will impede push-off, while a too compliant AFO won*t provide stability.
Optimal AFO stiffness is key to the energetic benefit that can be obtained from
it, and depends on patient characteristics. However, its relationship with the
most favorable AFO stiffness that maximally reduces walking effort is unclear.
This lack of knowledge limits optimal AFO provision in patients with
neuromuscular diseases.
Study objective
To determine whether AFOs optimized for stiffness in patients with calf muscle
weakness are superior to standard AFOs in reducing walking effort, as measured
by energy cost of walking (ECW, in Jkg-1m-1), and 2) to build a model to
predict required AFO stiffness to maximally reduce walking effort.
Study design
The study design includes a nonrandomized self-controlled experimental study,
with three repeated measurements, i.e. at baseline, walking with the current
old AFO (pre-treatment, T1); directly after supplying the new AFO in each of
five stiffness (K) configurations (T2K1 -T2K5); and after a 3-month follow-up
(T3Kopt), walking with the selected optimal AFO configuration. The total
duration of the study will be approximately 18-20 weeks. The study will be
performed at the Department of Rehabilitation of the Academic Medical Center
Amsterdam.
Intervention
Participants will receive a new AFO that will be adjusted into five stiffness
configurations (range: very flexible - very stiff). For each individual
patient, the optimal AFO configuration will be selected, which will be
evaluated 12 weeks later.
Study burden and risks
Visits for baseline measurements (n=3, ±1 to 2.5 hours per visit) will be
scheduled simultaneously with the regular consultancies for AFO treatment
(casting and fitting), to limit the number of visits to the medical centre.
Optimization measurements at T2 (n=2 visits) will be performed for five AFO
stiffness configurations (±2.5 hours per visit). The 3-month follow up
measurement at T3 (n=1 visit) will be performed for the selected optimal AFO
(±2.5 hours).
Measurements are non-invasive. It is possible that the orthosis causes pressure
sores or pain during walking, which is common in orthotic care. The risk of
pain will be marginal and subjects can quit the measurements if pain occurs.
Risks for the subjects undergoing a MRI examination are also minimal, provided
precautions have been made to prevent examining individuals with
contraindications. For this purpose, the routine MRI contra indications form of
the AMC will be used.
Meibergdreef 9
Amsterdam 1105 AZ
NL
Meibergdreef 9
Amsterdam 1105 AZ
NL
Listed location countries
Age
Inclusion criteria
-age between 18 and 80 years;
-weakness of the calf muscles (i.e. a MRC score <5 or unable to perform >3 heel rises);
-using an AFO or orthopedic boot (one or both sided);
-able to walk for 5 minutes, with or without walking aids;
-able to walk for 10m barefoot without assistive devices.
Exclusion criteria
-presence of pes equinus under weight-bearing (dorsiflexion * 0º);
-severe deformity of the ankle/foot that cannot be fitted with a custom-made AFO;
-severe weakness of the upper legs requiring a knee-ankle-foot orthosis;
-body weight > 120 kg.
Design
Recruitment
Medical products/devices used
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
In other registers
| Register | ID |
|---|---|
| CCMO | NL50511.018.14 |
| OMON | NL-OMON22379 |