Ankle-foot Orthosis In Patients Research Articles

Ankle dorsiflexion assistance of patients with foot drop using a powered ankle-foot orthosis to improve the gait asymmetry

BackgroundFoot drop is a neuromuscular disorder that causes abnormal gait patterns. This study developed a pneumatically powered ankle-foot orthosis (AFO) to improve the gait patterns of patients with foot drop. We hypothesized that providing unilateral ankle dorsiflexion assistance during the swing phase would improve the kinematics and spatiotemporal gait parameters of such patients. Accordingly, this study aims to examine the efficacy of the proposed assistance system using a strategy for joint kinematics and spatiotemporal gait parameters (stride length, swing velocity, and stance phase ratio). The analysis results are expected to provide knowledge for better design and control of AFOs in patients with foot drop.MethodTen foot drop patients with hemiparesis (54.8 y ± 14.1 y) were fitted with a custom AFO with an adjustable calf brace and portable air compressor for ankle dorsiflexion assistance in the gait cycle during the swing phase. All subjects walked under two different conditions without extensive practice: (1) barefoot and (2) wearing a powered AFO. Under each condition, the patients walked back and forth on a 9-m track with ten laps of level ground under the supervision of licensed physical therapists. The lower-limb joint and trunk kinematics were acquired using 12 motion-capture cameras.ResultsWe found that kinematic asymmetry decreased in the three lower-limb joints after ankle dorsiflexion assistance during the swing phase. The average ankle-joint angle increased after using the AFO during the entire gait cycle. Similarly, the knee-joint angle showed a slight increase while using the AFO, leading to a significantly decreased standard deviation within patients. Conversely, the hip-joint angle showed no significant improvements with assistance. While several patients exhibited noticeably lower levels of asymmetry, no significant changes were observed in the average asymmetry of the swing velocity difference between the affected and unaffected sides while using the AFO.ConclusionWe experimentally validated that ankle dorsiflexion assistance during the swing phase temporarily improves gait asymmetry in foot-drop patients. The experimental results also prove the efficacy of the developed AFO for gait assistance in foot-drop patients.

Ankle Foot Orthosis for Patients with Drop Foot Using Shape-Memory-Alloy Actuators

AbstractGait disorders can lower the quality of life of patients. Drop foot, a causative factor of deviated gait patterns, renders patients unable to lift their forefoot towards the body. Hence, a light and compact ankle–foot orthosis (AFO), which is the most common treatment for drop foot, must be designed, especially for patients with impaired lower limb muscles as oxygen consumption increases by 30% per 1.96 N load on their foot. Furthermore, the limited range of ankle angles in the first 10% of the gait cycle (GC) is a major drawback for patients with drop foot compared to healthy individuals. This limited range of ankle angles can be improved by gaining support from an AFO composed of shape memory alloy (SMA) actuators (SMA-AFO). Therefore, in this study, an SMA was used to fabricate a soft actuator to reduce the weight of the AFO. An adaptive frequency oscillator (AO) was implemented in real time for continuous gait phase detection. Walk tests were performed on a treadmill with the SMA-AFO attached to the participants (N = 3). The experimental results showed that the participants could lift their forefoot in the dorsiflexion direction with an ankle angle of 8.75° in the first 10% of the GC. Furthermore, the current required to operate the SMA actuator can be supplied to only 45.3% of the GC, reducing the power consumption. Therefore, the proposed SMA-AFO can be used in patients with drop foot.

The Determination of Assistance-as-Needed Support by an Ankle-Foot Orthosis for Patients with Foot Drop.

Patients who suffer from foot drop have impaired gait pattern functions and a higher risk of stumbling and falling. Therefore, they are usually treated with an assistive device, a so-called ankle-foot orthosis. The support of the orthosis should be in accordance with the motor requirements of the patient and should only be provided when needed, which is referred to as assistance-as-needed. Thus, in this publication, an approach is presented to determine the assistance-as-needed support using musculoskeletal human models. Based on motion capture recordings of multiple subjects performing gaits at different speeds, a parameter study varying the optimal force of a reserve actuator representing the ankle-foot orthosis added in the musculoskeletal simulation is conducted. The results show the dependency of the simulation results on the selected optimal force of the reserve actuator but with a possible identification of the assistance-as-needed support required from the ankle-foot orthosis. The required increase in support due to the increasing severity of foot drop is especially demonstrated with the approach. With this approach, information for the required support of individual subjects can be gathered, which can further be used to derive the design of an ankle-foot orthosis that optimally assists the subjects.

Assessing wear time and perceptions of wearing an ankle foot orthosis in patients with peripheral artery disease.

Peripheral artery disease (PAD) is a cardiovascular disease that affects walking ability. An ankle foot orthosis (AFO) may improve walking distances in those with PAD. Little research has explored if those with PADwear a prescribed AFO and their perceptions of wearing the device. To assess wear time of an AFO and explore perceptions of wearing the device in patients with PAD. Convergent mixed methods. The study was conducted through a tertiary care medical center, and the research participants used the device in the community. Thirty-six patients, all older adult males, were enrolled in this study. Fourteen patients completed the study and 11 supplied sufficient accelerometer data to include in the analysis. An AFO was worn for 3 months. An accelerometer was placed on the AFO for 7 days at the midpoint (1.5months) and endpoint of the intervention (3months) to assess wear time. Semi-structured interviews explored patients' perceptions of wearing the AFO. The primary outcome measure was wear time measured objectively via accelerometer and subjectively via interview. Patients (n=14) wore the AFO approximately 8hours/day. Patients reported barriers such as challenges wearing the AFO during daily household activities (using stairs, being on uneven terrain), discomfort, clothing or footwear issues, and driving challenges. Positive effects of wearing the AFO were also reported, primarily the ability to walk further. An AFO may be an acceptable therapeutic intervention to improve perceived walking performance in older adult males with PAD. Addressing participants' perceptions of the AFO and barriers to wear are essential to increasing the positive effect the device has on participants' ambulatory activity.

Effectiveness of an ankle\u2013foot orthosis on walking in patients with stroke: a systematic review and meta-analysis

We conducted a meta-analysis to investigate the effectiveness of ankle–foot orthosis (AFO) use in improving gait biomechanical parameters such as walking speed, mobility, and kinematics in patients with stroke with gait disturbance. We searched the MEDLINE (Medical Literature Analysis and Retrieval System Online), CINAHL (Cumulative Index to Nursing and Allied Health Literature), Cochrane, Embase, and Scopus databases and retrieved studies published until June 2021. Experimental and prospective studies were included that evaluated biomechanics or kinematic parameters with or without AFO in patients with stroke. We analyzed gait biomechanical parameters, including walking speed, mobility, balance, and kinematic variables, in studies involving patients with and without AFO use. The criteria of the Cochrane Handbook for Systematic Reviews of Interventions were used to evaluate the methodological quality of the studies, and the level of evidence was evaluated using the Research Pyramid model. Funnel plot analysis and Egger’s test were performed to confirm publication bias. A total of 19 studies including 434 participants that reported on the immediate or short-term effectiveness of AFO use were included in the analysis. Significant improvements in walking speed (standardized mean difference [SMD], 0.50; 95% CI 0.34–0.66; P < 0.00001; I2, 0%), cadence (SMD, 0.42; 95% CI 0.22–0.62; P < 0.0001; I2, 0%), step length (SMD, 0.41; 95% CI 0.18–0.63; P = 0.0003; I2, 2%), stride length (SMD, 0.43; 95% CI 0.15–0.71; P = 0.003; I2, 7%), Timed up-and-go test (SMD, − 0.30; 95% CI − 0.54 to − 0.07; P = 0.01; I2, 0%), functional ambulation category (FAC) score (SMD, 1.61; 95% CI 1.19–2.02; P < 0.00001; I2, 0%), ankle sagittal plane angle at initial contact (SMD, 0.66; 95% CI 0.34–0.98; P < 0.0001; I2, 0%), and knee sagittal plane angle at toe-off (SMD, 0.39; 95% CI 0.04–0.73; P = 0.03; I2, 46%) were observed when the patients wore AFOs. Stride time, body sway, and hip sagittal plane angle at toe-off were not significantly improved (p = 0.74, p = 0.07, p = 0.07, respectively). Among these results, the FAC score showed the most significant improvement, and stride time showed the lowest improvement. AFO improves walking speed, cadence, step length, and stride length, particularly in patients with stroke. AFO is considered beneficial in enhancing gait stability and ambulatory ability.

Machine learning analysis to predict the need for ankle foot orthosis in patients with stroke

We investigated the potential of machine learning techniques, at an early stage after stroke, to predict the need for ankle–foot orthosis (AFO) in stroke patients. We retrospectively recruited 474 consecutive stroke patients. The need for AFO during ambulation (output variable) was classified according to the Medical Research Council (MRC) score for the ankle dorsiflexor of the affected limb. Patients with an MRC score of < 3 for the ankle dorsiflexor of the affected side were considered to require AFO, while those with scores ≥ 3 were considered not to require AFO. The following demographic and clinical data collected when patients were transferred to the rehabilitation unit (16.20 ± 6.02 days) and 6 months after stroke onset were used as input data: age, sex, type of stroke (ischemic/hemorrhagic), motor evoked potential data on the tibialis anterior muscle of the affected side, modified Brunnstrom classification, functional ambulation category, MRC score for muscle strength for shoulder abduction, elbow flexion, finger flexion, finger extension, hip flexion, knee extension, and ankle dorsiflexion of the affected side. For the deep neural network model, the area under the curve (AUC) was 0.887. For the random forest and logistic regression models, the AUC was 0.855 and 0.845, respectively. Our findings demonstrate that machine learning algorithms, particularly the deep neural network, are useful for predicting the need for AFO in stroke patients during the recovery phase.

Problems caused by using knee ankle foot orthosis for patients with acute stroke : From data for our hospital

Problems caused by using knee ankle foot orthosis for patients with acute stroke : From data for our hospital

Effect of heel lift pad insert attached to the ankle-foot orthosis in patients with limited ankle dorsiflexion

Effect of heel lift pad insert attached to the ankle-foot orthosis in patients with limited ankle dorsiflexion

Six-month effects of early or delayed provision of an ankle-foot orthosis in patients with (sub)acute stroke: a randomized controlled trial

Objective: To study the six-month clinical effects of providing ankle-foot orthoses at different moments (early or delayed) in (sub)acute stroke; this is a follow-up to a published trial. Design: Randomized controlled trial. Setting: Rehabilitation centre. Subjects: Unilateral hemiparetic stroke subjects maximal six weeks post-stroke with indication for ankle-foot orthosis use. Interventions: Subjects were randomly assigned to early (at inclusion; week 1) or delayed provision (eight weeks later; week 9). Outcome measures: Functional tests assessing balance and mobility were performed bi-weekly for 17 weeks and at week 26. Results: In all, 33 subjects were randomized. No differences at week 26 were found between both groups for any of the outcome measures. However, results suggest that early provision leads to better outcomes in the first 11–13 weeks. Berg Balance Scale (P = 0.006), Functional Ambulation Categories (P = 0.033) and 6-minute walk test (P < 0.001) showed significantly different patterns over time. Clinically relevant but statistically non-significant differences of 4–10 weeks in reaching independent walking with higher balance levels were found, favouring early provision. Conclusion: No six-month differences in functional outcomes of providing ankle-foot orthoses at different moments in the early rehabilitation after stroke were found. Results suggest that there is a period of 11–13 weeks in which early provision may be beneficial, possibly resulting in early independent and safe walking. However, our study was underpowered. Further research including larger numbers of subjects is warranted.

Precision orthotics: optimising ankle foot orthoses to improve gait in patients with neuromuscular diseases; protocol of the PROOF-AFO study, a prospective intervention study

IntroductionIn patients with neuromuscular disorders and subsequent calf muscle weakness, metabolic walking energy cost (EC) is nearly always increased, which may restrict walking activity in daily life. To reduce walking...

Early or delayed provision of an ankle-foot orthosis in patients with acute and subacute stroke: a randomized controlled trial

Objective: (1) To study the effects of providing ankle-foot orthoses in subjects with (sub)acute stroke; and (2) to study whether the point in time at which an ankle-foot orthosis is provided post-stroke (early or delayed) influences these effects. Design: Randomized controlled trial. Setting: Rehabilitation centre. Subjects: Unilateral hemiparetic stroke subjects with indication for use of an ankle-foot orthosis and maximal six weeks post-stroke. Interventions: Subjects were randomly assigned to: early provision (at inclusion; Week 1) or delayed provision (eight weeks later; Week 9). Outcome measures: 10-metre walk test, 6-minute walk test, Timed Up and Go Test, stairs test, Functional Ambulation Categories, Berg Balance Scale, Rivermead Mobility Index and Barthel Index; assessed in Weeks 1, 3, 9 and 11. Results: A total of 33 subjects were randomized (16 early, 17 delayed). Positive effects of ankle-foot orthoses were found two weeks after provision, both when provided early (significant effects on all outcomes) or delayed (Berg Balance Scale p = 0.011, Functional Ambulation Categories p = 0.008, 6-minute walk test p = 0.005, Timed Up and Go Test p = 0.028). Comparing effects after early and delayed provision showed that early provision resulted in increased levels of improvement on Berg Balance Scale (+5.1 points, p = 0.002), Barthel Index (+1.9 points, p = 0.002) and non-significant improvements on 10-metre walk test (+0.14 m/s, p = 0.093) and Timed Up and Go Test (–5.4 seconds, p = 0.087), compared with delayed provision. Conclusions: We found positive effects of providing ankle-foot orthoses in (sub)acute stroke subjects that had not used these orthoses before.

Long-Term Follow-up to a Randomized Controlled Trial Comparing Peroneal Nerve Functional Electrical Stimulation to an Ankle Foot Orthosis for Patients With Chronic Stroke

Background. Evidence supports peroneal nerve functional electrical stimulation (FES) as an effective alternative to ankle foot orthoses (AFO) for treatment of foot drop poststroke, but few long-term, randomized controlled comparisons exist. Objective. Compare changes in gait quality and function between FES and AFOs in individuals with foot drop poststroke over a 12-month period. Methods. Follow-up analysis of an unblinded randomized controlled trial (ClinicalTrials.gov #NCT01087957) conducted at 30 rehabilitation centers comparing FES to AFOs over 6 months. Subjects continued to wear their randomized device for another 6 months to final 12-month assessments. Subjects used study devices for all home and community ambulation. Multiply imputed intention-to-treat analyses were utilized; primary endpoints were tested for noninferiority and secondary endpoints for superiority. Primary endpoints: 10 Meter Walk Test (10MWT) and device-related serious adverse event rate. Secondary endpoints: 6-Minute Walk Test (6MWT), GaitRite Functional Ambulation Profile, and Modified Emory Functional Ambulation Profile (mEFAP). Results. A total of 495 subjects were randomized, and 384 completed the 12-month follow-up. FES proved noninferior to AFOs for all primary endpoints. Both FES and AFO groups showed statistically and clinically significant improvement for 10MWT compared with initial measurement. No statistically significant between-group differences were found for primary or secondary endpoints. The FES group demonstrated statistically significant improvements for 6MWT and mEFAP Stair-time subscore. Conclusions. At 12 months, both FES and AFOs continue to demonstrate equivalent gains in gait speed. Results suggest that long-term FES use may lead to additional improvements in walking endurance and functional ambulation; further research is needed to confirm these findings.

Treatment Strategies for Genu Recurvatum in Adult Patients With Hemiparesis: A Case Series

ObjectiveTo report our clinical experience and propose a biomechanical factor–based treatment strategy for improvement of genu recurvatum (GR) to reduce the need for knee-ankle-foot orthosis (KAFO) or surgical treatment. DesignCase series. SettingOutpatient clinic of a Department of Physical Medicine and Rehabilitation in an academic medical center. Subjects and InterventionsAdult subjects (n = 22) with hemiparesis and GR who received botulinum injections alone or in combination with multiple types of orthotic interventions that included solid ankle-foot orthosis (AFO) ± heel lift, hinged AFO with an adjustable posterior stop ± heel lift, AFO with dual-channel ankle joint ± heel lift, or KAFO with offset knee joint. Biomechanical factors reviewed included muscle strength, modified Ashworth score for spasticity, presence of clonus, posterior capsule laxity, sensory deficits, and proprioception. Outcome MeasurementsOutcome factors were improvement or elimination of GR based on subjective assessment before and after the interventions by the same experienced clinician. ResultsMore than one biomechanical factor contributed to GR in all patients. Botulinum toxin A injection was used in patients who had significant plantar flexor spasticity and/or clonus. Four types of orthotic interventions were used based on the biomechanical factor: solid AFO in patients with severe ankle dorsiflexion and plantar flexion weakness or clonus; hinged ankle joint with adjustable posterior stop in patients with less severe ankle dorsiflexion weakness in the absence of clonus; AFO with a dual-channel ankle joint for quadriceps weakness or severe proprioceptive deficits; and KAFO with offset knee joints in patients with Achilles tendon contracture or severe proprioceptive deficits. Adjunctive options included the addition of heel lifts and toeplate modifications. Combinatorial interventions of botulinum injection, modified AFOs, and heel lifts improved or eliminated GR and avoided the need for cumbersome orthotics or surgical interventions. ConclusionsGR in hemiparesis is multifactorial and can be successfully controlled by using a conservative biomechanical factor–based approach and combined medical and orthotic interventions. An algorithmic approach and a prospective study design is proposed to determine a combination of effective interventions to correct GR.

The Effects of Peroneal Nerve Functional Electrical Stimulation Versus Ankle-Foot Orthosis in Patients With Chronic Stroke

Background. Evidence supports peroneal nerve functional electrical stimulation (FES) as an effective alternative to ankle-foot orthoses (AFO) for treatment of foot drop poststroke, but few randomized controlled comparisons exist. Objective. To compare changes in gait and quality of life (QoL) between FES and an AFO in individuals with foot drop poststroke. Methods. In a multicenter randomized controlled trial (ClinicalTrials.gov #NCT01087957) with unblinded outcome assessments, 495 Medicare-eligible individuals at least 6 months poststroke wore FES or an AFO for 6 months. Primary endpoints: 10-Meter Walk Test (10MWT), a composite of the Mobility, Activities of Daily Living/Instrumental Activities of Daily Living, and Social Participation subscores on the Stroke Impact Scale (SIS), and device-related serious adverse event rate. Secondary endpoints: 6-Minute Walk Test, GaitRite Functional Ambulation Profile (FAP), Modified Emory Functional Ambulation Profile (mEFAP), Berg Balance Scale (BBS), Timed Up and Go, individual SIS domains, and Stroke-Specific Quality of Life measures. Multiply imputed intention-to-treat analyses were used with primary endpoints tested for noninferiority and secondary endpoints tested for superiority. Results. A total of 399 subjects completed the study. FES proved noninferior to the AFO for all primary endpoints. Both the FES and AFO groups improved significantly on the 10MWT. Within the FES group, significant improvements were found for SIS composite score, total mFEAP score, individual Floor and Obstacle course time scores of the mEFAP, FAP, and BBS, but again, no between-group differences were found. Conclusions. Use of FES is equivalent to the AFO. Further studies should examine whether FES enables better performance in tasks involving functional mobility, activities of daily living, and balance.

Poster 299: Off-Loading Effect of Patella-Tendon-Bearing Ankle Foot Orthosis in Patients With Diabetic Charcot Neuroarthropathic Foot: A Pilot Study With 12 Months Follow-Up

Objective: To evaluate the off-loading effect of patella-tendon-bearing ankle foot orthosis (PTB/AFO) in patients with diabetic Charcot neuroarthropathic foot (DCNA) over 12 months. Design: Retrospective review of serial pedobarometric measurement in 6 patients with diabetic Charcot neuroarthropathic foot wearing PTB/AFO over 12 months. Setting: Diabetic foot and ankle clinic in tertiary hospital. Participants: 6 patients with DCNA treated with PTB/AFO (anterior and posterior shells encompassing the calf muscles with double uprights attached to custom made shoe). Interventions: Not applicable. Main Outcome Measures: Serial measurement of pedobarometric parameters, peak plantar pressure (PPPr) and force-time integral (FTI), at 2 weeks, 3, 6, and 12 months after application of PTB/AFO. Wilcoxon matched-pairs signed-rank test was used for analysis. Results: The median PPPr on the entire foot was reduced from 312.2kPa with Darco shoe to 140.7kPa with PTB/AFO at 2 weeks (54.9% reduction), 174.5kPa at 3 months, 175.8kPa at 6 months, and 175.5kPa at 12 months (43.7% reduction) after application. The difference in median PPPr at 2 weeks and 12 months approached statistical significance (P=0.0625). The median FTI of the entire foot was reduced from 636.2 newton seconds (Nsec) with Darco shoe to 469.9Nsec with PTB AFO at 2 weeks (26.1% reduction), 548.2Nsec at 3 months (13.8% reduction), 555.9Nsec at 6 months (12.6% reduction) and 570.1Nsec at 12 months (10.4% reduction). The median FTI at 12 months was significantly different from that at 2 weeks for hindfoot (P=0.031). The largest reduction in off-loading effect was seen between 2 weeks and 3 months. Conclusions: The initial off-loading ability of PTB/AFO in patients with DCNA foot is not maintained with substantial reduction over 12 months. Considering the largest reduction was observed during the first 3 months, adjustment of fitting is recommended during this period.