A systematic review to determine best practice reporting guidelines for AFO interventions in studies involving children with cerebral palsy

The effect of carbon fiber custom dynamic orthosis use and design on center of pressure progression and perceived smoothness in individuals with lower limb trauma

BACKGROUND

Carbon-fiber custom dynamic orthoses are used to improve gait and limb function following lower limb trauma in specialty centers. However, the effects of commercially available orthoses on center of pressure progression and patient perception of orthosis smoothness during walking are poorly understood.

METHODS

In total, 16 participants with a unilateral lower extremity traumatic injury underwent gait analysis when walking without an orthosis, and while wearing monolithic and modular devices, in a randomized order. Device alignment, stiffness, participant rating of perceived device smoothness, center of pressure velocity, and ankle zero moment crossing were assessed.

FINDINGS

The modular device was approximately twice as stiff as the monolithic device. Alignment, smoothness ratings, peak magnitude of center of pressure velocity, and zero moment crossing were not different between study devices. The time to peak center of pressure velocity occurred significantly later for the modular device compared to the monolithic and no orthosis conditions, with large effect sizes observed.

INTERPRETATION

Commercially available orthoses commonly used to treat limb trauma affect the timing of center of pressure progression relative to walking without an orthosis. Despite multiple design differences, monolithic and modular orthoses included in this study did not differ with respect to other measures of center of pressure progression. Perceived smoothness ratings were approximately 40% greater with the study orthoses as compared to previous studies in specialty centers, which may be due to a more gradual center of pressure progression, as indicted by lower peak magnitude of center of pressure velocity with both study orthoses.

Exploring the rationale for prescribing ankle-foot orthoses and supramalleolar orthoses in children with cerebral palsy: A narrative synthesis of rationale statements

BACKGROUND

To help improve outcomes for children with cerebral palsy (CP), ankle-foot orthoses (AFOs) and supramalleolar orthoses (SMOs) are prescribed. However, it is not clear why one intervention is prescribed over the other.

OBJECTIVES

To explore the rationale for prescribing AFOs and SMOs in children with CP and its link to the choice of outcome measure used.

STUDY DESIGN

Narrative review.

METHODS

Six databases were searched (eg, Medline) and data extracted from articles that met the inclusion criteria. Data describing the participant demographics, type of orthosis, and outcome measures used were summarized to provide context for the different rationale for orthotic prescription that were thematically analyzed.

DISCUSSION

Forty-seven articles were included. Participants were aged 9 ± 2 years, 59% were male, 79% had diplegia, and 38% were classified as Gross Motor Function Classification System level I. All studies included a rationale for prescribing AFOs that, in most cases, reflected the outcome measures used. These rationale statements were synthesized into 5 specific themes (e.g., reduced energy expenditure and metabolic costs). By comparison, 5 of these studies described the rationale for providing SMOs, and of those that did, most of the rationale statements were nonspecific.

CONCLUSIONS

A large and contemporary body of literature describes the rationale for prescribing AFOs for children with CP. There are opportunities for future research that clearly articulates the rationale for prescribing SMOs for children living with CP and to focus the rational for orthotic intervention on the real-world challenges that are most important to children living with CP, such as the ability to participate among peers.

Design and characterization of a variable-stiffness ankle-foot orthosis

BACKGROUND

Ankle-foot orthoses (AFOs) are a type of assistive device that can improve the walking ability of individuals with neurological disorders. Adjusting stiffness is a common way to customize settings according to individuals' impairment.

OBJECTIVE

This study aims to design a variable-stiffness AFO by stiffness module and characterize the AFO stiffness range to provide subject-specific settings for the users.

METHODS

We modeled AFO using bending beams with varying fulcrum positions to adjust the stiffness. To characterize the stiffness range and profile, we used the superposition method to generate the theoretical model to analyze the AFO numerically. The intrinsic deformation of the bending beam in the AFO is considered a combination of 2 bending deformations to replicate actual bending conditions. The corresponding experiments in different fulcrum positions were performed to compare with and optimize the theoretical model. The curve fitting method was applied to tune the theoretical model by adding a fulcrum position-related coefficient.

RESULTS

The AFO stiffness increased as the fulcrum moved to the proximal position. The maximum stiffness obtained was 1.77 Nm/° at a 6-cm fulcrum position, and the minimum stiffness was 0.82 Nm/° at a 0.5-cm fulcrum position with a 0.43-cm thick fiberglass beam. The corresponding theoretical model had maximum and minimum stiffness of 1.71 and 0.80 Nm/°, respectively. The theoretical model had a 4.08% difference compared with experimental values.

CONCLUSIONS

The stiffness module can provide adjustable stiffness with the fulcrum position and different kinds of fiberglass bars, especially the thickness and material of the beam. The theoretical model with different fulcrum positions can be used to profile the real-time stiffness of the AFO in a dynamic motion and to determine the appropriate dimensions of the bending beam.

Carbon fiber ankle-foot orthoses in impaired populations: A systematic review

BACKGROUND

Carbon fiber is increasingly being used in ankle-foot orthoses (AFOs). Orthotic devices and carbon fiber-containing devices have been shown to reduce pain and improve function in multiple patient populations. Although the number of publications and interest in carbon fiber AFOs is growing, a systematic evaluation of their effects is lacking.

OBJECTIVES

To characterize the effects of carbon fiber AFOs in impaired individuals.

STUDY DESIGN

Qualitative systematic review.

METHODS

Systematic searches in PubMed, Embase, CINAHL, and Cochrane Library were completed in July 2020. The results were deduplicated, screened, and assessed for quality by independent reviewers. Articles were excluded if they had nonhuman subjects, only healthy subjects, or included active control systems, motors, or other power sources.

RESULTS

Seventy-eight articles were included in the qualitative synthesis. Most articles were of low to moderate methodological quality. Five commonly used devices were identified: the Intrepid Dynamic Exoskeletal Orthosis, ToeOff, WalkOn, Neuro Swing, and Chignon. The devices have unique designs and are associated with specific populations. The Intrepid Dynamic Exoskeletal Orthosis was used in individuals with lower-limb trauma, the Neuro Swing and ToeOff in individuals with neurological disorders, the Chignon in individuals with hemiplegia and stroke, and the WalkOn in people with hemiplegia and cerebral palsy. Each device produced favorable outcomes in their respective populations of interest, such as increased walking speed, reduced pain, or improved balance.

CONCLUSIONS

The mechanical characteristics and designs of carbon fiber AFOs improve outcomes in the populations in which they are most studied. Future literature should diligently report patient population, device used, and fitting procedures.

Standardised classification system for bespoke thermoplastic ankle foot orthoses

PURPOSE

To validate a new classification system for bespoke thermoplastic ankle foot orthoses (AFOs).

METHODS

Inter- and intra-observer reliability study. A classification system based on the design and function of AFOs was created. Sixty-three independent observers classified thirty-six photographs of different AFOs, according to the proposed classification system via an online questionnaire. Approximately two weeks later, the same AFOs were classified again by fifty-three of the same participants. All participants were health care professionals, researchers, or technicians with experience in referring for, prescribing, fitting, reviewing, researching or manufacturing AFOs.

RESULTS

The mean inter- and intra-observer agreement Fleiss' kappa was 0.932 and 0.944, respectively. 98.3% of participants reported that the classification system was very easy or moderately easy to use, with 85.7% reporting they would use the classification system. 90.5% of participants reported that the proposed AFO classification system was clear, with 84% stating it was useful.

CONCLUSION

The proposed classification system for bespoke thermoplastic AFOs, has an excellent inter- and intra-observer agreement. It will reduce the ambiguity of the description of the type of AFOs used in clinical practice and research. Furthermore, it makes reproducible comparisons between groups possible, which are essential for future evaluations of evidence-based orthotic care.

How does a systematic tuning protocol for ankle foot orthosis-footwear combinations affect gait in children in cerebral palsy?

PURPOSE

To investigate the effects of a systematic tuning protocol for ankle foot orthosis footwear combinations (AFO-FC) using incrementing heel height on gait in children with cerebral palsy (CP).

METHODS

Eighteen children with CP (10.8 ± 3 years, Gross Motor Function Classification System (GMFCS) I-II) underwent 3D gait analysis on a treadmill, while the AFO heel surface was systematically incremented with wedges. Children were subdivided based on their gait pattern, i.e., knee hyperextension (EXT) and excessive knee flexion (FLEX). Outcome measures included sagittal hip and knee angles and moments, shank to vertical angle (SVA), foot to horizontal angle, and gait profile score (GPS).

RESULTS

For both groups, incrementing heel height resulted in increased knee flexion, more inclined SVA, and increased knee extension moments. This resulted in gait improvements for some children of the EXT-group, but not in FLEX. High variation was found between individuals and within-subject effects were not always consistent for kinematic and kinetics.

CONCLUSIONS

A systematic AFO-FC tuning protocol using incremented heel height can be effective to improve gait in children with CP walking with EXT. The current results emphasise the importance of including kinematics as well as kinetics of multiple instances throughout the gait cycle for reliable interpretation of the effect of AFO tuning on gait.Implications for rehabilitationA systematic ankle foot orthosis footwear combinations (AFO-FC) tuning protocol using incremented heel height can improve gait in children walking with knee hyperextension.Tuning results in changes throughout the gait cycle.Little evidence is found for an optimal SVA of 10-12° at midstance.For clinical interpretation, both joint kinematic and kinetic parameters should be considered throughout the gait cycle and evaluation should not be based on SVA only.

Moderate effect of ankle foot orthosis versus ground reaction ankle foot orthosis on balance in children with diplegic cerebral palsy

BACKGROUND

The children with diplegic cerebral palsy (CP) commonly have abnormal alignment of lower extremities affecting their abilities of keeping balance. Orthoses are one of the many approaches that can be prescribed to improve balance and walking in diplegic children.

OBJECTIVE

This study was conducted to assess the moderate effect of solid ankle foot orthosis (AFO) vs. the ground reaction ankle foot orthosis (GRAFO) on balance in children with diplegic CP.

STUDY DESIGN

A randomized controlled trial.

METHODS

Thirty children with spastic diplegic CP from both genders participated in this study; their ages were between 6 and 9 years. They were divided randomly into two study groups of equal numbers; the first study group A received the regular physical therapy program besides wearing the AFO for successive three months. The second study group B received the regular physical therapy program besides wearing the GRAFO for successive 3 months. All childrens' balance was evaluated before starting the treatment program and after 3 months by using the Biodex balance system (anteroposterior and mediolateral stability indices).

RESULTS

There were significant improvement of all stability indices in both groups (P < 0.05), with significant difference between groups when comparing post-treatment mean values of the measured indices in favor to study group B (P < 0.05).

CONCLUSION

The GRAFO achieved more balance control in children with spastic diplegic CP compared with solid AFO.

Multiplanar Stiffness of Commercial Carbon Composite Ankle-Foot Orthoses

The mechanical properties of an ankle-foot orthosis (AFO) can impact how a user's movement is either restricted or augmented by the device. However, standardized methods for assessing stiffness properties of AFOs are lacking, posing a challenge for comparing between devices and across vendors. Therefore, the purpose of this study was to quantify the rotational stiffness of thirteen commercial, nonarticulated, carbon composite ankle-foot orthoses. A custom, instrumented test fixture, for evaluating mechanical properties in rotating exoskeletons (EMPIRE), deflected an AFO through 20 deg of plantar/dorsiflexion motion about a specified, but adjustable, ankle axis. Sagittal, frontal, and transverse plane rotational stiffness were calculated, and reliability was assessed between cycles, sessions, and testers. The EMPIRE demonstrated good-to-excellent reliability between testers, sessions, and cycles (intraclass correlation coefficients all ≥0.95 for sagittal plane stiffness measures). Sagittal plane AFO stiffness ranged from 0.58 N·m/deg to 3.66 N·m/deg. AFOs with a lateral strut demonstrated frontal plane stiffnesses up to 0.71 N·m/deg of eversion while those with a medial strut demonstrated frontal plane stiffnesses up to 0.53 N·m/deg of inversion. Transverse plane stiffnesses were less than 0.30 N·m/deg of internal or external rotation. These results directly compare AFOs of different models and from different manufacturers using consistent methodology and are intended as a resource for clinicians in identifying a device with stiffness properties for individual patients.

Prefabricated ankle-foot orthoses for children with cerebral palsy to overcome spastic drop-foot: does orthotic ankle stiffness matter?

BACKGROUND

Spastic drop-foot is a common problem in children with cerebral palsy that may lead to tripping and falling. To improve ankle dorsiflexion in swing phase, prefabricated carbon-composite ankle-foot orthoses are commonly prescribed; by increasing ankle stiffness, these orthoses may also improve knee extension in stance.

OBJECTIVES

To compare the effect of a stiff vs. flexible prefabricated ankle-foot orthosis on sagittal plane ankle and knee kinematics and kinetics during walking.

STUDY DESIGN

Cross-sectional, repeated-measures, interventional study.

METHODS

Twenty-seven children and adolescents with cerebral palsy who had drop-foot in swing were included. Gait analysis was conducted under four conditions: barefoot, shod, with a stiff, and with a flexible orthosis. Participants were divided into two groups including children and adolescents who have a flexed knee during stance (KF, N = 12) and without flexed knee during stance (KE, N = 15).

RESULTS

Ankle dorsiflexion in swing phase was significantly improved compared with the shod condition by 6.3 degrees (SD = 3.3 degrees) only in the KE group when using the flexible orthosis. For the stiff orthosis, knee extension in stance was significantly increased by 2.4 degrees (SD = 3.3 degrees) in the KE group compared with the shod condition. No significant improvements were observed for the KF group. Further analysis indicated that only seven patients in the KF group with weak ankle plantarflexors improved knee extension while using the stiff orthosis.

CONCLUSIONS

Our results suggested that in the KE group, the flexible orthosis was best suited for patients with drop-foot without a knee extension deficit. The stiff orthosis was not suitable in this group as it caused a hyperextended knee without improving dorsiflexion in swing phase. Therefore, stiffness should be considered when prefabricated orthoses are prescribed.

Alternative methods for measuring ankle-foot orthosis alignment in clinical care

BACKGROUND

Changes in gait due to an ankle foot orthosis (AFO) have been shown to be impacted by the sagittal plane alignment of the AFO, but there is variability in practice and lack of consensus as to how this alignment should be measured. The neutral angle is a measure of AFO alignment that has the potential to be used by various specialties that prescribe, provide, and analyze AFOs. Currently, a lack of validated measurement methods prevents the neutral angle from being used in various clinical settings. Two experimental neutral angle measurement methods are proposed to address this shortcoming: a portable low-cost method for use during AFO fabrication and fitting, and a laboratory-based method for use during dynamic three-dimensional gait analysis (3DGA).

RESEARCH QUESTION

What is the concurrent validity of the two experimental neutral angle measurement methods against the gold standard?

METHODS

The gold standard neutral angle measurement (NA_GOLD) was prospectively collected during a static 3DGA trial for 19 pediatric AFOs from 10 individuals. While NA_GOLD was being collected, the neutral angle was simultaneously measured using digital differential inclinometers (NA_INCL). Within the same 3DGA session, the neutral angle was also measured during the swing phase of gait (NA_SWING). The NA_INCL and NA_SWING measurements were compared to NA_GOLD using repeated measures ANOVA, ICC, and bootstrapped errors-in-variables regressions.

RESULTS

Repeated measures ANOVA indicated no differences between measurement methods (p = 0.43) and ICC analysis indicated good absolute agreement (ICC(A-1) = 0.85). Mean absolute deviations between the NA_INCL and NA_SWING with NA_GOLD measurements were 2.4 ° and 1.9 °, with standard deviations of 2.9 ° and 2.7 °, respectively. Maximum observed differences were less than 7 °. The NA_INCL and NA_SWING methods explained 74 % and 81 % of the variance in NA_GOLD, respectively.

SIGNIFICANCE

The concurrent validity of two new neutral angle measurement methods provides alternative means to assess AFO alignment in the clinic.

Ankle Foot Orthoses: Standardisation of terminology

The term Ankle Foot Orthosis (AFO) has been standardised and defined by the International Organization for Standardisation which offers general terms for external orthoses, describing terms relating to external orthoses including the abbreviation AFO. These standards relate to functional deficiencies including a description of the person to be treated with an orthosis, clinical objectives of treatment, and functional requirements of the orthosis and offers categorisation and description of external orthoses and orthotic components using the aforementioned standards. However, it is important to point out that these definitions and standardisations only apply to the term "AFO". Yet the terms used to describe the different types of AFOs have not been standardised and defined.

Crouch gait or flexed-knee gait in cerebral palsy: Is there a difference? A systematic review

BACKGROUND

Crouch or flexed-knee gait is one of the most common pathological gait patterns in cerebral palsy (CP). Differences exist in definitions used; the degree of knee flexion, inclusion of hip or ankle position, and timing in the gait cycle. This ambiguity may be responsible for variations in prevalence rates and difficulty comparing data across studies.

RESEARCH QUESTION

What are the kinematic parameters used to define crouch or flexed-knee gait in CP gait? A secondary aim was to examine the quality of data reporting, focusing on the sample characteristics, inclusion/exclusion criteria and the choice of limb included for analysis.

METHODS

Articles included in this review reported on a specified cohort of adults or children with crouch or flexed-knee gait assessed with 3-dimensional gait analysis. A customised data extraction and quality assessment table was designed specific to the research question.

RESULTS

The majority (75 %) of included studies used the term crouch gait. Where the pattern was defined, 80 % of crouch papers and 94 % of flexed-knee gait papers based this solely on knee position. Kinematic parameters were clearly defined when they provided objective values of knee flexion, supported this with rationale and provided a reference point in the gait cycle. Only 22 % of crouch papers and 19 % of flexed-knee gait papers provided this information. The majority of studies (67 % crouch; 90 % flexed-knee) specified which limb(s) were included for analysis with the majority including both limbs. Objective values of knee flexion ranged from 8 o to 30 o.

SIGNIFICANCE

This review highlights that crouch and flexed knee are synonymous and ambiguity exists in the kinematic definition making it difficult to make compare data amongst study cohorts. Future research should provide detailed definitions including the threshold value of knee flexion, how it was derived, the timing in the gait cycle and the limb(s) included in analysis.

The effect of tuning ankle foot orthoses-footwear combinations on gait kinematics of children with cerebral palsy: A case series

STUDY DESIGN

Case series.

BACKGROUND

AFOs are a commonly prescribed medical device given to children with cerebral palsy (CP) in an attempt to improve their gait. The current literature is equivocal on the effects AFOs have on the gait of children with CP. The vast majority of AFOs issued are not subject to AFO-FC tuning. There are emerging studies investigating the effects tuning AFO-FCs has on the gait of children with CP. However, the research is limited, and there is a lack of quantitative data.

OBJECTIVE

To compare the kinematics of tuned versus non-tuned gait in children with CP.

METHODS

Gait analysis assessment of five children aged between 7-11 years with a diagnosis of CP (one hemiplegic and four diplegic participants, two female, three male, with a Gross Motor Functional Classification System (GMFCS) of 2) at a Gait Analysis Laboratory.

RESULTS

In comparison to barefoot and non-tuned gait, walking with a tuned AFO-FC produced improvements in several key gait parameters. Including hip flexion and extension, posterior pelvic tilt and knee extension. Results also indicated that the type of gait pattern demonstrated by the participant affected the outcomes of tuning.

CONCLUSIONS

Tuning the AFO-FC of children with CP has the potential to improve hip function, pelvic function, knee extension in stance phase and knee flexion during swing phase and that a non-tuned AFO-FC can potentially decrease hip function, posterior pelvic tilt and increase knee extension.

CLINICAL RELEVANCE

Whilst AFO-FC tuning has been recommended for routine clinical practice, there still remains a paucity of research on the kinematic effects of using a tuned AFO-FC compared to a non-tuned. This paper provides a comparison of kinematics on children with CP, during barefoot, non-tuned and tuned AFO-FC walking with a view to inform clinical practice.

An Unsupervised Data-Driven Model to Classify Gait Patterns in Children with Cerebral Palsy

Ankle and foot orthoses are commonly prescribed to children with cerebral palsy (CP). It is unclear whether 3D gait analysis (3DGA) provides sufficient and reliable information for clinicians to be consistent when prescribing orthoses. Data-driven modeling can probe such questions by revealing non-intuitive relationships between variables such as 3DGA parameters and gait outcomes of orthoses use. The purpose of this study was to (1) develop a data-driven model to classify children with CP according to their gait biomechanics and (2) identify relationships between orthotics types and gait patterns. 3DGA data were acquired from walking trials of 25 typically developed children and 98 children with CP with additional prescribed orthoses. An unsupervised self-organizing map followed by k-means clustering was developed to group different gait patterns based on children's 3DGA. Model inputs were gait variable scores (GVSs) extracted from the gait profile score, measuring root mean square differences from TD children's gait cycle. The model identified five pathological gait patterns with statistical differences in GVSs. Only 43% of children improved their gait pattern when wearing an orthosis. Orthotics prescriptions were variable even in children with similar gait patterns. This study suggests that quantitative data-driven approaches may provide more clarity and specificity to support orthotics prescription.

RESULTS OF ORTHOSES USED ON AMBULATORY PATIENTS WITH BILATERAL CEREBRAL PALSY

Objective:

To investigate the impact of ankle-foot orthoses (AFO) on subjects diagnosed with bilateral cerebral palsy (CP) using the gait index and temporal data parameters.

Methods:

Twenty-four subjects, 14 male and 10 female, with a mean age of 11 (5-17 years old), underwent a comprehensive gait analysis under both barefoot (BF) and braced walking conditions. All children had been wearing the orthoses for at least 2 months before the gait analysis.

Results:

The overall values for the left and right Gait Profile Scores (GPS) did not show statistically significant variations when comparing the same individuals with and without orthoses. Gait velocity increased by 19.5% (p < 0.001), while the cadence decreased by 4% with use of orthosis, although it was not statistically significant (p > 0.05). The stride and the step lengths on both the right and left sides, however, resulted in statistically significant increases, when wearing AFO.

Conclusion:

AFO, prescribed for assistance by professionals without using gait data, did not significantly affect the gait index (GPS), but improved temporal data. The determination of quantitative clinical parameters for the prescription of orthotics in patients with bilateral CP, as well as orthotics that meet the specific requirements are points to be addressed in the future to obtain more significant effects. Level of evidence III, Case control study.

Impact of Ankle-Foot Orthosis on Gait Efficiency in Ambulatory Children With Cerebral Palsy: A Systematic Review and Meta-analysis

OBJECTIVE

Children with cerebral palsy experience functional limitations because of excessive muscle weakness, spasticity, and impaired motor control. They are prescribed ankle-foot orthoses to assist with ambulation. Our objective was to analyze stride length and dorsiflexion data comparing the effectiveness of "ankle-foot orthoses" with "barefoot or shoes only" on ambulatory children with cerebral palsy.

DESIGN

An electronic literature search was conducted. Studies were screened by two reviewers based on our inclusion criteria: prospective cohort study or randomized clinical trial, participants younger than 18 yrs with a primary diagnosis of cerebral palsy, ankle-foot orthoses with a control group, 20 combined participants in the experimental and control groups for cohort studies, and 10 participants for randomized clinical trials.

RESULTS

Seventeen studies were selected. Pooled results of the meta-analyses showed that stride length was significantly better in the ankle-foot orthoses group as compared with the control group (mean difference between groups = 0.05 m (95% confidence interval = 0.04-0.06). The dorsiflexion angle (5 studies, 124 participants) was improved in patients with ankle-foot orthoses as compared with barefoot or shoes only (mean difference between groups = 8.62 degrees (95% confidence interval = 8.05-9.2).

CONCLUSIONS

Children with cerebral palsy using ankle-foot orthoses had improved stride length and dorsiflexion angle during gait in a pooled meta-analyses of cohort studies and clinical trials.

Effects of solid ankle-foot orthoses with individualized ankle angles on gait for children with cerebral palsy and equinus

PURPOSE

For children with cerebral palsy (CP) and equinus, the conventional practice of setting the ankle angle in an ankle-foot orthosis (AA-AFO) at 90∘ may not adequately accommodate gastrocnemius length/stiffness. Therefore, this study compared the effects of statically-optimized solid AFOs with individualized AA-AFOs (iAA-AFOs) and conventionally-prescribed AFOs on gait for children with CP and equinus.

METHODS

Ten children with CP and equinus (15 limbs with AFOs), and 15 typically-developing (TD) children participated. For the children with CP, solid AFOs with iAA-AFOs (range = 5∘-25∘ plantarflexion) were compared with their usual AFOs using three-dimensional gait analysis. TD children walked in shoes only. Peak values and Gait Variable Scores (GVS) for joint and segment variables were calculated for stance phase. Responses were categorized using 90% confidence intervals relative to TD data, for each affected leg.

RESULTS

Net responses to iAA-AFOs were positive for 60% of limbs and negative for 40%. Knee variables (GVS and peak extension, flexion, and midstance moment) were most positively affected, and foot-floor angle and vertical ground reaction force were most negatively impacted.

CONCLUSION

Individualized AFO prescription and iAA-AFOs can impact gait biomechanics for some children with equinus, compared to conventionally-prescribed AFOs. Optimizing dynamic alignment for walking may further improve outcomes.

Improved motor function in a pre-ambulatory child with spastic bilateral cerebral palsy, using a custom rigid ankle-foot orthosis-footwear combination: A case report

BACKGROUND

Ankle-foot orthoses may be used in pre-ambulatory children with cerebral palsy; however, their effect on the acquisition of walking is unknown. This case report aims to evaluate the effect of an ankle-foot orthosis-footwear combination on the acquisition of walking in a single subject with cerebral palsy.

CASE DESCRIPTION AND METHODS

This study reports the orthotic management of a single child with spastic bilateral cerebral palsy over a 15-month period, during which time the ability to independently stand and walk was acquired. Custom rigid ankle-foot orthoses were prescribed. Gait speed and Edinburgh Visual Gait Score were assessed with and without the orthoses.

FINDINGS AND OUTCOMES

The subject developed the ability to stand and walk using an ankle-foot orthosis-footwear combination with a walker frame, and to a limited extent without a walker frame. The subject remained unable to take independent steps unless wearing the ankle-foot orthosis-footwear combination. Clinically significant differences in gait speed and Edinburgh Visual Gait Score were observed.

CONCLUSION

An ankle-foot orthosis-footwear combination may aid the development of independent walking in some children with cerebral palsy. Further research on the effects of orthoses on the acquisition of walking ability in children with cerebral palsy is needed.

CLINICAL RELEVANCE

Custom rigid ankle-foot orthoses combined with footwear may aid the development of independent standing and walking in some children with bilateral spastic cerebral palsy. This intervention may be considered in clinical practice and future research in this patient group.

Ankle foot orthoses for young children with cerebral palsy: a scoping review

AIM

To describe research on outcomes associated with early Ankle Foot Orthosis (AFO) use, AFO use patterns, and parent and clinician perspectives on AFO use among young children with cerebral palsy.

METHOD

Arksey and O'Malley's five-stage method was used to conduct a scoping review. MEDLINE (Ovid), PubMed, CINAHL, Cochrane Database of Systematic Reviews, EMBASE, PEDro, Web of Science and Scopus were searched for studies evaluating AFO use with children under the age of six years. Descriptive information was extracted and outcomes categorized according to the International Classification of Functioning, Disability and Health (ICF). Quality assessments were conducted to evaluate methodological rigor.

RESULTS

Nineteen articles were included in the review; 14 focused on body functions and structures, seven on activity level outcomes and no studies addressed participation outcomes. Evaluations of the effects of AFOs on gross motor skills other than gait were limited. Overall, the body of evidence is comprised of methodologically weak studies with common threats to validity including inadequate descriptions of study protocols, AFO construction, and comparison interventions.

CONCLUSION

Research evaluating the effects of AFOs on age-appropriate, functional outcomes including transitional movements, floor mobility and participation in early childhood settings is needed to inform practice regarding early orthotic prescription. Implications for rehabilitationLack of rigorous evidence about the effects of AFOs in young children limits the ability of research to guide practice in pediatric rehabilitation.More rigorous research that evaluates a broader range of age-appropriate outcomes, including those focused on participation in meaningful activities, could further inform clinical practice.While clinicians often discuss expectations and goals with individual families, qualitative research that provides more insight into the experiences of families could guide AFO prescription and monitoring practices.

Comparison of gait with and without ankle-foot orthoses after lower limb surgery in children with unilateral cerebral palsy

PURPOSE

Children with spastic unilateral cerebral palsy (SUCP) frequently undergo lower limb surgery to improve gait. Postoperatively, ankle-foot orthoses (AFOs) are used to maintain the surgical corrections and provide adequate mechanical support. Our aim was to evaluate changes in gait and impacts of AFOs one-year postoperatively.

METHODS

In all, 33 children with SUCP, 17 girls and 16 boys, mean age 9.2 years (5 to 16.5) were measured by 3D gait analysis walking barefoot preoperatively and walking barefoot and with AFOs one-year postoperatively. Changes in Gait Profile Scores (GPS), kinematic, kinetic and temporal spatial variables were examined using linear mixed models, with gender, gross motor function and AFO type as fixed effects.

RESULTS

The results confirm significant gait improvements in the GPS, kinematics and kinetics walking barefoot one year after surgery. Comparing AFOs with barefoot walking postoperatively, there was additionally reduced ankle plantarflexion by an average of 5.1° and knee flexion by 4.7° at initial contact, enhanced ankle moments during loading response, increased velocity, longer steps and inhibited push-off power generation. Stance and swing phase dorsiflexion increased in children walking with hinged AFOs versus children walking with ground reaction AFOs. Changes in the non-affected limbs indicated less compensatory gait postoperatively.

CONCLUSION

Major changes were found between pre- and postoperative barefoot conditions. The main impact of AFOs was correction of residual drop foot and improved prepositioning for initial contact, which could be considered as indications for continued use after the one-year follow-up.

LEVEL OF EVIDENCE

Level II - Therapeutic.

Impact of ankle-foot orthoses on gait 1 year after lower limb surgery in children with bilateral cerebral palsy

BACKGROUND:

Different types of ankle-foot orthoses are commonly used following lower limb surgery in children with bilateral spastic cerebral palsy. After three-dimensional gait analysis 1 year postoperatively, many children are recommended continued use of ankle-foot orthoses.

OBJECTIVES:

Our aims were to quantify the impact of ankle-foot orthoses on gait 1 year postoperatively and evaluate predictors for clinically important improvement.

STUDY DESIGN:

Prospective cohort study.

METHODS:

A total of 34 ambulating children with bilateral cerebral palsy, with mean age 11 years (range 6-17), comprising 12 girls and 22 boys, were measured with three-dimensional gait analysis preoperatively (barefoot) and 1 year postoperatively (barefoot and with ankle-foot orthoses). Outcome was evaluated using gait profile score, key kinematic, kinetic and temporal-spatial variables in paired sample comparisons. Logistic regression was used to evaluate predictors for clinically important improvement with orthoses (⩾1.6° change in gait profile score).

RESULTS:

Walking barefoot 1 year postoperatively, major improvements were seen in gait profile score and key variables. With ankle-foot orthoses, there were significantly improved step length and velocity, additional moderate reduction/improvement in gait profile score and knee moments and decreased stance ankle dorsiflexion compared to barefoot. Children using ground reaction ankle-foot orthoses ( n = 14) decreased stance knee flexion from 13.9° walking barefoot to 8.2° with orthoses. High gait profile score and more gait dysfunction preoperatively were significant predictors of clinically important improvement walking with orthoses.

CONCLUSION:

The results indicate improved gait function walking with ankle-foot orthoses versus barefoot 1 year after lower limb surgery. Stronger impact of ankle-foot orthoses was found in children with more pronounced gait dysfunction preoperatively.

CLINICAL RELEVANCE

The 1-year postoperative three-dimensional gait analysis is a useful method to assess treatment outcome after lower limb surgery in children with bilateral cerebral palsy and could also guide clinicians whether further treatment with ankle-foot orthoses is indicated, using clinically important differences as thresholds to evaluate their impact on gait.

The added value of orthotic management in the context of multi-level surgery in children with cerebral palsy

BACKGROUND

Treatment of cerebral palsy includes an interdisciplinary concept and in more severe cases the well-established multi-level surgery (MLS). Different kinds of orthoses are typically part of postoperative treatment but there is a lack of knowledge about their additional benefit.

RESEARCH QUESTION

Do ankle foot orthoses lead to an additional, measurable improvement of gait after MLS?

METHODS

20 children with bilateral spastic cerebral palsy (9 retrospective, 11 in a postoperative clinical routine) were included. All had a preoperative gait analysis before MLS. Postoperatively, they were fitted with different ankle foot orthoses (AFO), depending on their individual needs. Dynamic ankle foot orthoses (DAFO), combined DAFO with additional dynamic, elastic shank adaptation (DESA) and ground reaction force AFOs (GRAFO) were used. Patients underwent a second gait analysis 1.5 (± 0.6) years postoperatively barefoot and with orthoses. Data analysis included testing for normal distribution (Shapiro-Wilk-Test) and further nonparametric statistical testing on basis of a Wilcoxon Single-Rank Test.

RESULTS

The operation produced changes in the hip, knee and ankle joint, and the pelvis. Spatiotemporal parameters showed significant changes due to additional use of the orthoses. Further, additional kinematic changes occurred at the hip, knee and ankle joint as well as the foot. The Gillette Gait Index (GGI) improved significantly by supplementary orthoses, but not by surgery alone. The Gait Profile Score (GPS) and Gait Deviation Index (GDI) rather showed changes due to the surgery.

SIGNIFICANCE

MLS significantly improves GPS and GDI more than a year after surgery, which can be interpreted as an improvement in gait pattern. In contrast, the GGI is improved by additional postoperative orthotic treatment, which implies that walking ability itself has improved, rather than the gait pattern. Orthoses show a positive additional effect on surgical results at different anatomical levels. Spatiotemporal parameters are positively influenced solely by additional orthotic support.

Physical Therapists' Use of Evaluation Measures to Inform the Prescription of Ankle-Foot Orthoses for Children with Cerebral Palsy

Aims: To examine how physical therapists (PTs) use evaluation measures to guide prescription and re-assessment of ankle-foot orthoses (AFOs) for children with CP. Methods: PTs in Canada who work with children with CP were invited to complete an online survey. Survey questions examined PT evaluation and interpretation of findings at initial AFO prescription and re-assessment. Closed-ended responses were analyzed using descriptive statistics, and a conventional content analysis examined responses to open-ended questions. Results: Sixty responses from ten provinces were analyzed. Three themes emerged from the open-ended responses, which were supported by closed-ended responses. (1) Focus on impairment-level measures. Although evaluation primarily involved observational, non-standardized measures of impairments and gait pattern, most respondents also considered participation-level constructs. (2) Lack of confidence/knowledge. Respondents reported a moderate level of confidence concerning decision-making about AFO type and characteristics. 3) Inconsistent practices between therapists, possibly reflecting the paucity of available evidence or individualization of the prescription. Conclusions: Non-standardized, observational assessment methods, and impairment-level constructs appear to guide AFO prescription decisions. Integrating current knowledge into practice, developing best practice guidelines, and developing standardized tools to assess the effects of AFOs on participation may promote confidence, consistency, and improved outcomes.

Efficacy of prefabricated carbon-composite ankle foot orthoses for children with unilateral spastic cerebral palsy exhibiting a drop foot pattern

PURPOSE

This study aims to evaluate the effectiveness of a prefabricated carbon-composite ankle foot orthoses (c-AFOs) on gait parameters in children with unilateral spastic cerebral palsy (USCP) exhibiting a drop foot pattern.

METHODS

Sixteen ambulatory children with USCP and a drop foot pattern were included (mean age: 9 years; gross motor function classification system: I = 14, II = 2) and three-dimensional gait analysis was applied under randomly assigned conditions (barefoot; shoe; c-AFO). Kinematics, kinetics, time-distance parameters and gait indices were investigated.

RESULTS

Effects on the drop foot pattern were investigated while the children walked in shoes only. The shoes already increased the maximum ankle dorsiflexion in swing (p= 0.004) and initiated more knee flexion during single support (p⩽ 0.013). Compared to shoe walking, the c-AFO led to additional benefits regarding further ankle dorsiflexion during swing (p⩽ 0.001) and initial contact (p< 0.001), ankle movement during loading response (p= 0.002), improved the sole angle during initial contact (p< 0.001) and during mid stance (p= 0.015). Plantarflexion and ankle power generation during push-off decreased when wearing the c-AFO (p⩽ 0.008).

CONCLUSION

Investigated c-AFOs are beneficial for improving drop foot patterns in children with USCP. Significant effects on pathological barefoot pattern were already achieved with the child's regular shoes. This could be considered in clinical decision processes. In comparison to shoe walking, c-AFO additionally improved foot clearance and normalized initial heel contact. The third rocker deteriorates with the c-AFO. Since kinematics improved with the orthoses during swing and early stance phase, c-AFOs might reduce tripping and falling caused by a drop foot during long distance walking.

Effect of floor reaction ankle-foot orthosis on crouch gait in patients with cerebral palsy: What can be expected?

BACKGROUND

Floor reaction ankle-foot orthoses are commonly prescribed to improve knee extension of children with cerebral palsy having crouch gait. Their effectiveness is debated. Therefore, the objective of this study is to optimize current prescription criteria for the improvement of crouch gait.

STUDY DESIGN

Cross-sectional interventional study.

METHODS

A total of 22 patients with bilateral spastic cerebral palsy, between 6 and 17 years, Gross Motor Function Classification System II-IV participated in this study. Instrumented gait analysis was done under three conditions: barefoot, shoed, and with orthotics. Patients were divided into two groups: good and non-responders with more and less than 8.8° improvement of knee extension during walking, respectively. A multiple predictor analysis was done on parameters that were different between groups.

RESULTS

In total, 12 of 22 patients showed good response in knee extension with a mean change of 17° (standard deviation = 5°). Good responders showed a significantly smaller walking velocity, knee extension strength, ankle plantarflexion strength, and greater external foot progression angle compared to non-responders. Foot progression angle together with ankle plantarflexion strength explained 37% of the variance in improvement of knee extension.

CONCLUSION

With appropriate patient selection, an improvement of crouch gait by ankle-foot orthoses of 17° (standard deviation = 5°) can be expected. Patients with slow velocity, weak plantarflexors, and external foot progression benefit most. Joint contractures were no contraindications. Clinical relevance This study showed that gait in patients with low functional level benefit most from ankle-foot orthoses. Unlike in patients with higher functional status, contractures of hip, knee, and ankle did not reduce the positive effects on gait. The suggested prescription criteria may help to better select appropriate patients for orthotics.

Effect of ankle-foot orthoses on gait, balance and gross motor function in children with cerebral palsy: a systematic review and meta-analysis

Objective:

To determine the effects of ankle-foot orthoses (AFOs) on gait, balance, gross motor function and activities of daily living in children with cerebral palsy.

Data sources:

Five databases were searched (Pubmed, Psycinfo, Web of Science, Academic Search Premier and Cochrane Library) before January 2018.

Review methods:

Studies of the effect of AFOs on gait, balance, gross motor function and activities of daily living in children with cerebral palsy were included. Articles with a modified PEDRO score ≥ 5/9 were selected. Data regarding population, AFO, interventions and outcomes were extracted. When possible, standardized mean differences (SMDs) were calculated from the outcomes.

Results:

Thirty-two articles, corresponding to 56 studies (884 children) were included. Fifty-one studies included children with spastic cerebral palsy. AFOs increased stride length (SMD = 0.88, P < 0.001) and gait speed (SMD = 0.28, P < 0.001), and decreased cadence (SMD = –0.72, P < 0.001). Gross motor function scores improved (Gross Motor Function Measure (GMFM) D (SMD = 0.30, P = 0.004), E (SMD = 0.28, P = 0.02), Pediatric Evaluation of Disability Inventory (PEDI) (SMD = 0.57, P < 0.001)). Data relating to balance and activities of daily living were insufficient to conclude. Posterior AFOs (solid, hinged, supra-malleolar, dynamic) increased ankle dorsiflexion at initial contact (SMD = 1.65, P < 0.001) and during swing (SMD = 1.34, P < 0.001), and decreased ankle power generation in stance (SMD = –0.72, P < 0.001) in children with equinus gait.

Conclusion:

In children with spastic cerebral palsy, there is strong evidence that AFOs induce small improvements in gait speed and moderate evidence that AFOs have a small to moderate effect on gross motor function. In children with equinus gait, there is strong evidence that posterior AFOs induce large changes in distal kinematics.

The influence of the use of ankle-foot orthoses on thorax, spine, and pelvis kinematics during walking in children with cerebral palsy

BACKGROUND

To improve gait function in children with cerebral palsy, ankle-foot orthoses are often prescribed. However, until now, little attention has been devoted to the effect of ankle-foot orthoses on the postural control during walking in children with cerebral palsy.

OBJECTIVES

The aim was to compare the differences in thorax, spine, and pelvis movements in children with cerebral palsy during walking barefoot and walking with ankle-foot orthoses.

STUDY DESIGN

Clinical study with an intra subject design.

METHODS

A total of 15 children (12 boys and 3 girls; mean age, 8 ± 2 years) with bilateral spastic cerebral palsy (12 with Gross Motor Function Classification System I and 3 with Gross Motor Function Classification System II) performed a full-body three-dimensional gait analysis. Differences in the range of motion of the thorax, spine, and pelvis during walking barefoot and walking with bilateral ankle-foot orthoses were analyzed (SPSS v20, paired-samples t-test).

RESULTS

Children with cerebral palsy showed a significantly larger range of motion of the thorax (flexion/extension, lateral bending, and rotation) and the spine (lateral bending) during walking with ankle-foot orthoses compared to walking barefoot. No significant differences were found in the range of motion of the pelvis between these two conditions.

CONCLUSION

It can be concluded that wearing ankle-foot orthoses influences the postural control during walking in children with bilateral spastic cerebral palsy. Due to the increased range of motions, the movement pattern of the trunk diverges from the typically developing children. Clinical relevance Wearing ankle-foot orthoses not only gives more stability at the pelvis and ankle joint but also influences trunk motion. In order of the level of core stability of the child, compensations can be either seen in the lower back or the upper trunk. Clinicians should be aware of these compensations and should evaluate postural control in a more detailed evaluation.

A systematic review of approaches to modelling lower limb muscle forces during gait: Applicability to clinical gait analyses

Computational methods to estimate muscle forces during walking are becoming more common in biomechanical research but not yet in clinical gait analysis. This systematic review aims to identify the current state-of-the-art, examine the differences between approaches, and consider applicability of the current approaches in clinical gait analysis. A systematic database search identified studies including estimated muscle force profiles of the lower limb during healthy walking. These were rated for quality and the muscle force profiles digitised for comparison. From 13.449 identified studies, 22 were finally included which used four modelling approaches: static optimisation, enhanced static optimisation, forward dynamics and EMG-driven. These used a range of different musculoskeletal models, muscle-tendon characteristics and cost functions. There is visually broad agreement between and within approaches about when muscles are active throughout the gait cycle. There remain, considerable differences (CV 7%-151%, range of timing of peak forces in gait cycle 1%-31%) in patterns and magnitudes of force between and within modelling approaches. The main source of this variability is not clear. Different musculoskeletal models, experimental protocols, and modelling approaches will clearly have an effect as will the variability of joint kinetics between healthy individuals. Limited validation of modelling approaches, particularly at the level of individual participants, makes it difficult to conclude if any of the approaches give consistently better estimates than others. While muscle force modelling has clear potential to enhance clinical gait analyses future research is needed to improve validation, accuracy and feasibility of implementation in clinical practice.

Clinician perspectives and experiences in the prescription of ankle-foot orthoses for children with cerebral palsy

PURPOSE

Physiotherapists, orthotists, and physicians are involved in the prescription of ankle-foot orthoses (AFOs) for children with cerebral palsy (CP); however, little is known about how prescription decisions are made in practice. Therefore, the study objective was to identify current AFO prescription and clinical decision-making practices for children with CP in Canada.

METHODS

Focus groups were conducted in five pediatric rehabilitation facilities, with 32 clinicians. Semi-structured interviews focused on the goals and types of AFOs used, referral and follow-up processes, and clinical evaluation measures. Interpretive Description was used as a framework for analysis. Transcribed dialogue was imported into NVivo 11 for data coding and analysis. Three researchers participated in coding to establish categories and themes.

RESULTS

Categories included: what is made, how it is used, and factors that either support or challenge outcomes. Strengths and challenges of the current prescription process were discussed, including funding, communication, and technology to enhance clinical evaluation. Throughout the interviews, the theme of prescription as a collaborative, iterative, and individualized process emerged.

CONCLUSIONS

Processes, strengths, and challenges associated with AFO prescription in Canada were identified. This is a first step toward the development of guidelines to help clinicians improve AFO prescription for children with CP.

Testing Gait with Ankle-Foot Orthoses in Children with Cerebral Palsy by Using Functional Mixed-Effects Analysis of Variance

Existing statistical methods extract insufficient information from 3-dimensional gait data, rendering clinical interpretation of impaired movement patterns sub-optimal. We propose an alternative approach based on functional data analysis that may be worthy of exploration. We apply this to gait data analysis using repeated-measurements data from children with cerebral palsy who had been prescribed fixed ankle-foot orthoses as an example. We analyze entire gait curves by means of a new functional F test with comparison to multiple pointwise F tests and also to the traditional method - univariate repeated-measurements analysis of variance of joint angle minima and maxima. The new test maintains the nominal significance level and can be adapted to test hypotheses for specific phases of the gait cycle. The main findings indicate that ankle-foot orthoses exert significant effects on coronal and sagittal plane ankle rotation; and both sagittal and horizontal plane foot rotation. The functional F test provided further information for the stance and swing phases. Differences between the results of the different statistical approaches are discussed, concluding that the novel method has potential utility and is worthy of validation through larger scale patient and clinician engagement to determine whether it is preferable to the traditional approach.

Do research papers provide enough information on design and material used in ankle foot orthoses for children with cerebral palsy? A systematic review

OBJECTIVES

The purpose of this article is to determine how many of the current peer-reviewed studies of ankle foot or-thoses (AFOs) on children with cerebral palsy (CP) have included adequate details of the design and material of the AFO, to enable the study to be reproduced and outcomes clearly understood.

METHODS

A thorough search of studies published in English was conducted in March 2015, with no restriction on dates, within all major databases using relevant phrases. These searches were then supplemented by tracking all key references from the appropriate articles identified.

STUDY SELECTION

The inclusion criteria were as follows: (1) population - children with CP; (2) intervention - AFOs; and (3) outcome measure. One reviewer extracted data regarding the characteristics of the included studies, with the extracted data checked for accuracy and completeness by a second reviewer. None of the studies reviewed gave adequate details of the AFOs. Only 3.6% (n = 2) of papers tested the stiffness. Many studies (54.5%) did not describe the material used nor the material thickness (72.7 %). None of them gave any clinical justification for the chosen design of AFO.

CONCLUSIONS

There is a clear paucity of detail regarding the design and material used in AFOs on studies involving children with CP. Such a lack of detail has the potential to affect the validity of the reported outcomes, the ability to reproduce the studies and may misinform clinical practice.

Carbon Modular Orthosis (Ca.M.O.): An innovative hybrid modular ankle-foot orthosis to tune the variable rehabilitation needs in hemiplegic cerebral palsy

BACKGROUND

Hemiplegic Celebral Palsy (CP) children commonly use AFO orthoses as walking aids. It is known that AFOs may have a detrimental effect on gait. To enhance mechanical properties of AFOs we developed an innovative, custom-made, carbon, ankle-foot orthosis (Ca.M.O) which offers the opportunity to tune its response to the patient's gait characteristics and/or functional maturity.

OBJECTIVE

To assess the efficacy of Ca.M.O. in improving gait in a group of hemiplegic CP children and to compare its performances with those of commonly prescribed AFO.

METHODS

A clinical and instrumental gait analysis was performed on a group of 15 spastic hemiplegic children (WINTERS-GAGE type I-II) walking barefoot, with commonly prescribed AFOs and with Ca.M.O.Temporal, kinematic and kinetic data were collected with an 8 cameras optoelectronic system and 2 force plates.

RESULTS

Studied variables were comparable walking with Ca.M.O. and with the commonly prescribed AFO and are significantly different (p < 0.01) with respect to barefoot condition.

CONCLUSIONS

Both types of orthoses normalize the kinematics of the first and second ankle rocker. The main advantage of Ca.M.O. is its modularity that allows to tune its effect on gait in relationship with the progress or involution of the child's functional development.

Changes of Plantar Pressure and Gait Parameters in Children with Mild Cerebral Palsy Who Used a Customized External Strap Orthosis: A Crossover Study

Toe-in gait and crouch gait can make children with mild cerebral palsy fall and suffer improper balance during walking or ambulation training. A customized external strap orthosis for correcting leg alignment was used to resolve this problem. The purpose of this study was to research the immediate effects while wearing the customized external strap orthosis. Pressure platform was used to assess the plantar pressure through static and dynamic assessments and to record the changes in path of pressure trajectory. Motion image analysis system was used to record the gait parameters, which included gait speed, stride length, and cadence. The influence of both wearing and removing the orthosis on the dominant leg of children with mild cerebral palsy was analyzed. Nine children with mild cerebral palsy, who all had a dominant right leg, were recruited. After wearing the orthosis, all gait parameters improved, and foot motion changed in the stance phase of the gait cycle. The path of pressure trajectory closing to the midline was also observed during dynamic assessment. Changes in plantar pressure and path of pressure trajectory were observed and the orthosis device could provide immediate assistance to correct the leg alignment and improve the gait performance in children with mild cerebral palsy.

The Shank-to-Vertical-Angle as a parameter to evaluate tuning of Ankle-Foot Orthoses

The effectiveness of an Ankle-Foot Orthosis footwear combination (AFO-FC) may be partly dependent on the alignment of the ground reaction force with respect to lower limb joint rotation centers, reflected by joint angles and moments. Adjusting (i.e. tuning) the AFO-FC's properties could affect this alignment, which may be guided by monitoring the Shank-to-Vertical-Angle. This study aimed to investigate whether the Shank-to-Vertical-Angle during walking responds to variations in heel height and footplate stiffness, and if this would reflect changes in joint angles and net moments in healthy adults. Ten subjects walked on an instrumented treadmill and performed six trials while walking with bilateral rigid Ankle-Foot Orthoses. The AFO-FC heel height was increased, aiming to impose a Shank-to-Vertical-Angle of 5°, 11° and 20°, and combined with a flexible or stiff footplate. For each trial, the Shank-to-Vertical-Angle, joint flexion-extension angles and net joint moments of the right leg at midstance were averaged over 25 gait cycles. The Shank-to-Vertical-Angle significantly increased with increasing heel height (p<0.001), resulting in an increase in knee flexion angle and internal knee extensor moment (p<0.001). The stiff footplate reduced the effect of heel height on the internal knee extensor moment (p=0.030), while the internal ankle plantar flexion moment increased (p=0.035). Effects of heel height and footplate stiffness on the hip joint were limited. Our results support the potential to use the Shank-to-Vertical-Angle as a parameter to evaluate AFO-FC tuning, as it is responsive to changes in heel height and reflects concomitant changes in the lower limb angles and moments.

Acclimatization of the gait pattern to wearing an ankle-foot orthosis in children with spastic cerebral palsy

BACKGROUND

Ankle-foot orthoses can be prescribed to improve gait in children with cerebral palsy. Before evaluating the effects of ankle-foot orthoses on gait, a period to adapt or acclimatize is usually applied. It is however unknown whether an acclimatization period is actually needed to reliably evaluate the effect of a new orthosis on gait. This study aimed to investigate whether specific gait parameters in children with cerebral palsy would change within an acclimatization period after being provided with new ankle-foot orthoses.

METHODS

Ten children with cerebral palsy, walking with excessive knee flexion in midstance (8 boys; mean (SD) 10.2 (1.9) years; Gross Motor Function Classification System levels I-II) were provided with ventral shell ankle-foot orthoses. The orthoses were worn in combination with the child's own shoes and tuned, based on ground reaction force alignment with respect to the lower limb joints. Directly after tuning (T0) and four weeks later (T1), 3D-gait analysis was performed using an optoelectronic motion capture system and a force plate. From this assessment, ten spatiotemporal, kinematic and kinetic gait parameters were derived for the most affected leg. Differences in parameters between T0 and T1 were analyzed using paired t-tests or Wilcoxon signed rank tests (P<0.05).

FINDINGS

Over the course of four weeks, no significant differences (P ≥ 0.080) were observed for any investigated parameter.

INTERPRETATION

These results imply that the biomechanical effect of ventral shell ankle-foot orthoses on gait in independent walking children with cerebral palsy is immediately apparent, i.e., there is no further change after acclimatization.

Effect of Dynamic Elastomeric Fabric Orthoses on Postural Control in Children With Cerebral Palsy

PURPOSE

The aim of this study was to evaluate the effect of dynamic elastomeric fabric orthoses (DEFOs) on postural control in children with cerebral palsy (CP).

METHODS

Ten children with spastic diplegic CP and 10 children with typical development participated. Knee extension was measured using electrogoniometry. The standard deviation of excursion and phase plane portraits of velocity in the anteroposterior and mediolateral directions were calculated from force platform signals as center of pressure parameters with or without a DEFO.

RESULTS

Maximum standing knee extension for children with CP improved after 6 weeks of wearing DEFOs (P < .05). Center of pressure parameters did not improve when comparing pre- to 6 weeks post-DEFO use (P < .05).

CONCLUSION

The DEFO can reduce the crouch position without any negative effect on postural stability in children with CP. However, postural control does not improve in a 6-week timeframe.

Ankle-foot orthoses in children with cerebral palsy: a cross sectional population based study of 2200 children

Background

Ankle-foot orthosis (AFO) is the most frequently used type of orthosis in children with cerebral palsy (CP). AFOs are designed either to improve function or to prevent or treat muscle contractures. The purpose of the present study was to analyse the use of, the indications for, and the outcome of using AFO, relative to age and gross motor function in a total population of children with cerebral palsy.

Methods

A cross-sectional study was performed of 2200 children (58% boys, 42% girls), 0–19 years old (median age 7 years), based on data from the national Swedish follow-up programme and registry for CP. To analyse the outcome of passive ankle dorsiflexion, data was compared between 2011 and 2012. The Gross motor classification system (GMFCS) levels of included children was as follows: I (n = 879), II (n = 357), III (n = 230), IV (n = 374) and V (n = 355).

Results

AFOs were used by 1127 (51%) of the children. In 215 children (10%), the indication was to improve function, in 251 (11%) to maintain or increase range of motion, and 661 of the children (30%) used AFOs for both purposes. The use of AFOs was highest in 5-year-olds (67%) and was more frequent at lower levels of motor function with 70% at GMFCS IV-V. Physiotherapists reported achievement of functional goals in 73% of the children using AFOs and maintenance or improvement in range of ankle dorsiflexion in 70%.

Conclusions

AFOs were used by half of the children with CP in Sweden. The treatment goals were attained in almost three quarters of the children, equally at all GMFCS levels. AFOs to improve range of motion were more effective in children with a more significant decrease in dorsiflexion at baseline.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-327) contains supplementary material, which is available to authorized users.

Defining the mechanical properties of a spring-hinged ankle foot orthosis to assess its potential use in children with spastic cerebral palsy

A rigid ventral shelf ankle foot orthosis (AFO) may improve gait in children with spastic cerebral palsy (SCP) whose gait is characterized by excessive knee flexion in stance. However, these AFOs can also impede ankle range of motion (ROM) and thereby inhibit push-off power. A more spring-like AFO can enhance push-off and may potentially reduce walking energy cost. The recent development of an adjustable spring-hinged AFO now allows adjustment of AFO stiffness, enabling tuning toward optimal gait performance. This study aims to quantify the mechanical properties of this spring-hinged AFO for each of its springs and settings. Using an AFO stiffness tester, two AFO hinges and their accompanying springs were measured. The springs showed a stiffness range of 0.01-1.82 N · m · deg(-1). The moment-threshold increased with increasing stiffness (1.13-12.1 N · m), while ROM decreased (4.91-16.5°). Energy was returned by all springs (11.5-116.3 J). These results suggest that the two stiffest available springs should improve joint kinematics and enhance push-off in children with SCP walking with excessive knee flexion.

Translating research into prosthetic and orthotic practice

BACKGROUND

Evidence-based practice is commonly accepted as a means of improving patient outcomes; however, there is little understanding of the processes required to successfully implement it into prosthetic and orthotic practice.

OBJECTIVES

To discuss factors affecting adoption of evidence-based practice and present a theoretical framework for its implementation into prosthetic and orthotic practice.

DISCUSSION

Numerous factors that affect adoption of evidence-based practice are discussed, ranging from individual factors to those that can be attributed to administrative and environmental issues. Specific factors are likely to be context specific and are influenced by the manner in which evidence-based practice is introduced into the working environment. It is argued that successful implementation of evidence-based practice requires consideration of numerous interrelated factors. A formal translating research into practice model is presented as a means of developing a strategic plan that considers all relevant factors and maximizes acceptance of evidence-based practice into prosthetics and orthotics clinical practice.

CONCLUSIONS

The use of a theoretical model for implementation of evidence-based practice is likely to improve its adoption by prosthetic and orthotic clinicians. Clinical relevance The demand for prosthetists/orthotists to utilize evidence-based practice is increasing. Lack of strategic planning throughout the implementation phase is likely to compromise adoption of evidence-based practices by clinicians.

The effect of floor reaction ankle foot orthosis on postural control in children with spastic cerebral palsy

BACKGROUND

Children with cerebral palsy (CP) often demonstrate postural control difficulties. Orthotic management may assist in improving postural control in these children.

OBJECTIVE

The purpose of this investigation was to examine the influence of floor reaction ankle foot orthosis (FRAFO) on postural flexion called the crouch position in children with CP.

STUDY DESIGN

Quasi-experimental.

METHODS

Eight children with spastic diplegic CP and eight matched typically developing children participated in this study. Postural control of children with CP was assessed in a static standing position on a force platform with/without a FRAFO. The parameters used were centre of pressure (CoP) measures, calculated from force platform signals including the standard deviation (SD) of excursion; phase plate portrait and SD of velocity in anteroposterior (AP) and mediolateral (ML) directions.

RESULTS

The maximum knee extension was statistically significant in children with CP when barefoot compared to wearing braced footwear (p < 0.05, t = 10.01). AP and ML displacement, AP velocity and AP phase plate portrait of CoP were not statistically significant between children with CP with/without a FRAFO (p < 0.05).

CONCLUSION

FRAFO can improve the alignment of the knee, but may not be helpful in improving postural control in children with CP in a short time period.

A candidate core set of outcome measures based on the International Classification of Functioning, Disability and Health for clinical studies on lower limb orthoses

BACKGROUND

Although many core sets of measurement concepts have been published in the literature, this has not been done for the field of lower limb orthoses.

OBJECTIVES

This paper provides an overview of the measurement concepts that are relevant in lower limb orthotic evaluations, and it proposes a candidate Core Set of outcome measures to be used in clinical studies on ankle-foot orthoses (AFOs) and knee-ankle-foot orthoses (KAFOs).

STUDY DESIGN

Literature review.

METHODS

The International Classification of Functioning, Disability and Health (ICF) was used as framework to select relevant concepts.

RESULTS AND CONCLUSION

Measurement concepts covering all ICF levels of functioning were identified as relevant for the Core Set, including functions of the joints and bones (b710-b729), muscle functions (b730-b749), gait pattern functions (b770), walking (b450), moving around in different locations (d460), and daily-life functioning (d5-d9). Further validation of this candidate Core Set through a formal decision-making process is needed to obtain consensus among experts in the field. Based on such a consensus, the next step will be to systematically review the literature and identify those measurement instruments that are best suited to assess the proposed concepts, based on their psychometric properties in a given sample and context. Thereafter, we suggest that this ICF Core Set of measurement instruments should be applied in orthotic studies on AFOs and KAFOs in ambulatory patients with gait problems.

CLINICAL RELEVANCE

Although many ICF Core Sets have been published, this has not been done for the field of lower limb orthoses. We feel that such a Core Set is urgently needed, to enable comparison of results, and establish evidence on the efficacy of orthotic treatment, which will improve patient care.

Studies examining the efficacy of ankle foot orthoses should report activity level and mechanical evidence

Ankle Foot Orthoses (AFOs) to promote walking ability are a common treatment in patients with neurological or muscular diseases. However, guidelines on the prescription of AFOs are currently based on a low level of evidence regarding their efficacy. Recent studies aiming to demonstrate the efficacy of wearing an AFO in respect to walking ability are not always conclusive. In this paper it is argued to recognize two levels of evidence related to the ICF levels. Activity level evidence expresses the gain in walking ability for the patient, while mechanical evidence expresses the correct functioning of the AFO. Used in combination for the purpose of evaluating the efficacy of orthotic treatment, a conjunct improvement at both levels reinforces the treatment algorithm that is used. Conversely, conflicting outcomes will challenge current treatment algorithms and the supposed working mechanism of the AFO. A treatment algorithm must use relevant information as an input, derived from measurements with a high precision. Its result will be a specific AFO that matches the patient's needs, specified by the mechanical characterization of the AFO footwear combination. It is concluded that research on the efficacy of AFOs should use parameters from two levels of evidence, to prove the efficacy of a treatment algorithm, i.e., how to prescribe a well-matched AFO.