Skip to main content

Table 1 Literature review with respect to the papers reporting on the functional evaluation of custom PD-AFOs. For each paper, when present, it is reported the AFO type(s), the customization criteria, the materials, the functional data/parameters, and the main outcome. Comfort assessment or other subjective scores are also reported

From: Design principles, manufacturing and evaluation techniques of custom dynamic ankle-foot orthoses: a review study

Authors/year Population
(size)
AFO type/ customization criteria Material Motor tasks Functional parameters Other scores Main outcome
Waterval et al. 2021
[56]
unilateral plantar flexor weakness
(9)
dorsal leaf spring AFO
Spring leaf Stiffness customizable
energy cost optimized (Ankle7, OttoBock)
carbon fiber walking spatio-temporal parameters
GRFs
hip, knee, ankle kinematics and kinetics
  peak vertical GRF of the contralateral leg significantly reduced and symmetry improved (AFO vs. no AFO)
Waterval et al. 2021 & 2020
[32, 33]
calf muscle weakness
(34)
dorsal leaf spring AFO
Spring leaf Stiffness customizable
(Ankle7, OttoBock)e
carbon fiber walking spatio-temporal parameters
hip, knee, ankle kinematics and kinetics
energy cost
  reduction in energy cost (AFO optimized stiffness vs. non optimized)
Kerkum et al. 2021
[35]
healthy subjects
(12)
dorsal leaf spring AFO
Spring leaf Stiffness customizable
(Ankle7, OttoBock)
carbon fiber walking Ankle-foot kinematics work and power   Total ankle-foot power increase with increasing footplate stiffness
Lin et al. 2021
[57]
post-stroke drop-foot
(12)
1. energy-Storage 3D Printed AFO
2. anterior-support AFO
PLA + nylon+titanium
thermoplastic
walking spatio-temporal parameters
pelvis, hip, knee, ankle kinematics (sagittal plane)
Evaluation of satisfaction (QUEST) increased gait velocity and stride length (AFO1 vs. AFO2; AFO1 vs. barefoot)
improved satisfaction (AFO1)
Meng et al. 2021 [58] post-stroke drop-foot
(15)
morphology PA2200
Somos NeXt
PA12
NA NA comfort
weight feeling
surface smoothness wearing issues
cleaning issues
Somos NeXt scored better than one or more materials in comfort and surface smoothness
Vasiliauskaite, et al. 2020
[51]
child with unilateral drop-foot
(1)
1. hinged AFO with adjustable ankle stiffness
2. posterior leaf spring
stiffness tuned to achieve the orthotic goals
thermoplastic+metal
polyamide-12
walking spatio-temporal parameters
hip, knee, ankle kinematics and kinetics
NA Despite having the same ankle stiffness, AFO1 and AFO2 did not produce the same gait pattern
Chae et al. 2020 [59] unilateral drop-foot (1) morphology polyurethane walking
stairs ascent/descent
up&go
NA Modified Emory Functional Ambulation Profile improved mEFAP (AFO vs. no-AFO)
Esposito et al. 2020
[22]
unilateral lower limb reconstruction
(12)
IDEO custom AFO (posterior leaf spring)
Stiffness based body mass, load carriage requirements, and range of available pain-free motion
carbon fiber walking COP position
COP velocity
NA ±3 deg in strut flexion/extension strut alignment does not significantly affect the foot-ankle roll-over shape radius
Liu et al. 2019 [11] post-stroke drop-foot (12) morphology PA12 walking spatio-temporal parameters
hip, knee, ankle kinematics
NA improved velocity and stride length (AFO vs.no-AFO)
Waterval et al. 2019
[50]
neuromuscular disorders and non-spastic calf muscle weakness
(37)
dorsal leaf spring AFO (Carbon Ankle Seven, Ottobock, Duderstadt) adjustable stiffness carbon fiber walking energy cost
spatio-temporal parameters
hip, knee, ankle kinematics and kinetics
NA energy cost −20% (optimal AFO vs. no-AFO)
energy cost − 10.7% (optimal AFO vs. non-optimal AFO)
Cha et al. 2017
[44]
unilateral drop-foot
(1)
1. sock-like design with anterior opening and malleoli holes
2. rigid AFO
thermoplastic polyurethane walking spatio-temporal parameters
ankle kinematics
Evaluation of satisfaction (QUEST) insufficient ankle dorsiflexion in swing (AFO1 vs AFO2)
better wearing properties and comfort (AFO1 vs AFO2))
Esposito et al. 2017
[23]
unilateral lower limb reconstruction
(24)
IDEO custom AFO (posterior leaf spring)
Stiffness based body mass, load carriage requirements, and range of available pain-free motion
carbon fiber walking spatio-temporal parameters
hip, knee, ankle kinematics (sagittal plane)
NA limited power capabilities at the ankle, and reduced compensatory strategies at the knee with respect to amputees
Arch & Reisman 2016
[34]
post-stroke
(2)
custom AFOs
Morphology-based, no shoe required
polycarbonate walking spatio-temporal parameters
hip, knee, ankle kinematics and kinetics
NA increased net peak plantarflexion moment and natural ankle pseudo-stiffness.
Whitehead et al. 2016
[60]
unilateral lower limb reconstruction
(13)
normal/healthy
(13)
IDEO custom AFO (posterior leaf spring) carbon fiber stairs ascent/descent spatio-temporal parameters
hip, knee, ankle kinematics and kinetics (sagittal plane)
NA stair ascent: greater bilateral hip power during pull-up and reduced ankle dorsiflexion and knee extensor moment (AFO vs. control)
Ranz et al. 2016
[38]
unilateral ankle muscle weakness
(13)
IDEO custom AFO (posterior leaf spring)
3 bending axis positions
carbon fiber
nylon 11 (strut)
walking sEMG: soleus, gastrocnemius, tibialis ant., rectus fem., biceps fem., vastus med. and gluteus med.
spatio-temporal parameters
hip, knee, ankle kinematics and kinetics
NA hip and knee moments were affected by bending axis position
no difference in spatio-temporal parameters
Arch & Stanhope 2015
[43]
normal/healthy
(2)
passive dynamic AFO (posterior leaf spring)
AFO stiffness according to natural ankle pseudo-stiffness
not reported walking Ankle kinematics and moments (sagittal plane) NA  
Haight at al. 2015
[25]
unilateral lower-limb reconstruction
(12)
IDEO custom AFO (posterior leaf spring)
variable stiffness based on ROM, activity level, types of activities, body mass, load carriage requirements
carbon fiber treadmill uphill walking (10 deg slope) spatio-temporal parameters
hip, knee, ankle kinematics and kinetics
NA AFOs stiffer than nominal increased knee joint flexion
Kerkum et al. 2015 & 2016, Meyns et al. 2020
[27, 28, 61]
children with cerebral palsy
(15; bilateral 14)
ventral shell spring-hinged AFO (vAFO)
variable stiffness/ROM hinge
pre-preg carbon fiber waking energy cost
spatio-temporal parameters
hip, knee, ankle kinematics and kinetics
NA decreased net energy cost (vAFOs vs. no-AFO)
no differences between vAFOs
Harper et al. 2014
[42]
unilateral ankle muscle weakness
(10)
IDEO custom AFO (posterior leaf spring)
clinically prescribed stiffness
carbon fiber
nylon 11 (strut)
walking spatio-temporal parameters
hip, knee, ankle kinematics and kinetics
NA no difference in kinematics/kinetics between the two materials (same AFO stiffness)
Esposito et al. 2014
[24]
unilateral ankle muscle weakness
(13)
healthy controls
(13)
IDEO custom AFO (posterior leaf spring)
variable stiffness based on ROM, activity level, types of activities, body mass, load carriage requirements
carbon fiber
nylon 11 (strut)
walking spatio-temporal parameters
hip, knee, ankle kinematics and kinetics
NA small differences in kinematics and kinetics (nominal stiffness vs. stiffer and more compliant)
Dufek et al. 2014
[29]
Charcot–Marie–Tooth patients
(bilateral 8)
posterior leaf spring AFO
stiffness customization based on prior experience,
visual observations of patient’s gait,
weight and muscle strength, and amount of ankle deformity
carbon-fiber composite walking spatio-temporal parameters
hip, knee, ankle kinematics and kinetics
NA increased walking speed and stride length (custom AFO vs. no-AFO)
AFO energy storage 9.6 ± 6.6 J/kg
Creylman et al. 2013
[8]
unilateral drop foot
(8)
morphology-based posterior leaf spring/shell nylon 12 (AFO1)
polypropylene (AFO2)
walking spatio-temporal parameters
hip, knee, ankle kinematics (sagittal plane)
NA improved spatial temporal gait parameters and ankle kinematics (AFO1 & AF2 vs. no-AFO)
Mavroidis et al. 2011
[7]
normal/healthy
(1)
morphology-based posterior leaf spring/shell (based on Type C-90 Superior Posterior Leaf Spring, AliMed) polypropylene (AFO1, standard)
Accura SI 40 (AFO2)
Somos 9121 (AFO3)
walking spatio-temporal parameters
ankle kinematics and kinetics (sagittal plane)
comfort comparable functional outcome to standard AFO and better comfort (AFO2 and AFO3 vs AFO1)
Lewallen et al. 2010
[62]
post-stroke drop-foot
(13)
solid AFO
vs.
hinged
vs.
posterior leaf spring
thermoplastics walking
walking up/down 10 deg ramp
spatio-temporal parameters NA significantly reduced walking speed and stride length (solid AFO vs. all AFOs and no-AFO)
only one subject preferred solid AFO over the other AFOs
Bartonek et al. 2007
[31]
children with bilateral ankle muscle weakness
(11 AFO; 6 KAFO)
morphology-based posterior leaf spring
patient’s level of functional ambulation and body weight
pre-preg carbon-fiber walking spatio-temporal parameters
hip, knee, ankle kinematics (sagittal plane)
frequency of use
gait
standing function changes
walking velocity
acceptance
ease of putting on and removing
for most children, improved ankle plantarflexion moment (p < 0.001), ankle positive work (p < 0.001), and stride length (p < 0.001)
(custom AFO vs. rigid shell thermoplastic AFO)
Bartonek et al. 2007
[30]
children with bilateral ankle muscle weakness
(2 AFO; 1 KAFO)
morphology-based posterior leaf spring
patient’s level of functional ambulation and body weight
pre-preg carbon-fiber walking spatio-temporal parameters
hip, knee, ankle kinematics (sagittal plane)
frequency of use
gait
standing function changes
walking velocity
acceptance
ease of putting on and removing
increased stride length (2/2; custom AFO vs. rigid shell thermoplastic AFO)
increased walking speed (1/2)
perceived improved gait
Desloovere et al. 2006
[63]
children with hemiplegia
(15)
flexible posterior leaf-springs (PLS)
Dual Carbon Fibre Spring AFO (CFO)
clinical examination and gait analysis
thermoplastic
thermoplastic & carbon and kevlar fibres pre-impregnated with epoxy (strut)
walking spatio-temporal parameters
hip, knee, ankle kinematics
NA increased walking speed and stride length (PLS vs. no-AFO)
larger ankle ROM and ankle velocity during push-off
increased plantar flexion moment and power generation at pre-swing (CFO vs. PLS; p < 0.01).
Gök et al. 2003
[64]
hemiparetic stroke patients
(12)
1. Seattle-type polypropylene AFO
2. metallic AFO
polypropylene
metal
walking spatio-temporal parameters
hip, knee, ankle kinematics
NA increased walking speed (AFO2 vs AFO1 vs. no-AFO)
increased stride length (AFO1 vs. no-AFO; AFO2 vs. no-AFO)
Sienko Thomas et al. 2002
[65]
children spastic hemi-plegia
(19)
morphology-based
1. hinged AFO
2. posterior
leaf spring (PLS)
3. solid AFO
thermoplastic walking
stairs ascent/descent
spatio-temporal parameters
pelvis, hip, knee, ankle kinematics (sagittal plane)
Pediatric Evaluation of Disability Inventory (PEDI) reduced ankle plantarflexion (AFOs vs. barefoot)
Burtner et al. 1999
[66]
children with spastic diplegic cerebral palsy
(4, and 4 healthy control)
1. solid AFO
2. dynamic (spiral) AFO
Polypropylene
graphite
static balance test sEMG: gastrocnemius, tibialis ant.,
hamstrings, quadriceps, paraspinals, abdominals.
hip, knee, ankle kinematics (sagittal plane)
NA decreased activation of gastrocnemius, disorganized muscle-response patterns, decreased use of ankle strategies, increased knee joint angular velocity (AFO1 vs. AFO2 and AFO1 vs no-AFO) without AFOs or with dynamic AFOs.