A new walking orthosis for paraplegics: hip and ankle linkage system

Enhancing walking performance in patients with peripheral arterial disease: An intervention with ankle-foot orthosis

Lower extremity peripheral artery disease (PAD) is a cardiovascular condition manifesting from narrowed or blocked arteries supplying the legs. Gait is impaired in patients with PAD. Recent evidence suggests that walking with carbon fiber ankle foot orthoses (AFOs) can improve patient mobility and delay claudication time. This study aimed to employ advanced biomechanical gait analysis to evaluate the impact of AFO intervention on gait performance among patients with PAD. Patients with claudication had hip, knee, and ankle joint kinetics and kinematics assessed using a cross-over intervention design. Participants walked over the force platforms with and without AFOs while kinematic data was recorded with motion analysis cameras. Kinetics and kinematics were combined to quantify torques and powers during the stance period of the gait cycle. The AFOs effectively reduced the excessive ankle plantar flexion and knee extension angles, bringing the patients' joint motions closer to those observed in healthy individuals. After 3 months of the AFO intervention, the hip range of motion decreased, likely due to changes occurring within the ankle chain. With the assistance of the AFOs, the biological power generation required from the ankle and hip during the push-off phase of walking decreased. Wearing AFOs resulted in increased knee flexor torque during the loading response phase of the gait. Based on this study, AFOs may allow patients with PAD to maintain or improve gait performance. More investigation is needed to fully understand and improve the potential benefits of ankle assistive devices.

Wearable robotic exoskeleton for gait reconstruction in patients with spinal cord injury: A literature review

Objectives

Wearable robotic exoskeletons (WREs) have been globally developed to achieve gait reconstruction in patients with spinal cord injury (SCI). The present study aimed to enable evidence-based decision-making in selecting the optimal WRE according to residual motor function and to provide a new perspective on further development of appropriate WREs.

Methods

The current review was conducted by searching PubMed, Web of Science, and Google Scholar for relevant studies published from April 2015 to February 2020. Selected studies were analysed with a focus on the participants’ neurological level of SCI, amount of training (number of training sessions and duration of the total training period), gait speed and endurance achieved, and subgroup exploration of the number of persons for assistance and the walking aid used among patients with cervical level injury.

Results

A total of 28 articles (nine using Ekso, three using Indego, ten using ReWalk, one using REX, five using Wearable Power-Assist Locomotor) involving 228 patients were included in the analysis. Across all WREs, T6 was the most frequently reported level of SCI. The amount of training showed a wide distribution (number of training sessions: 2–230 sessions [30–120 min per session]; duration of the total training period: 1–24 weeks [1–5 times per week]). The mean gait speed was 0.31 m/s (standard deviation [SD] 0.14), and the mean distance on the 6-min walking test as a measure of endurance was 108.9 m (SD 46.7). The subgroup exploration aimed at patients with cervical level injury indicated that 59.2% of patients were able to ambulate with no physical assistance and several patients used a walker as a walking aid.

Conclusion

The number of cervical level injury increased, as compared to the number previously indicated by a prior similar review. Training procedure was largely different among studies. Further improvement based on gait performance is required for use and dissemination in daily life.

The translational potential of this article

The present review reveals the current state of the clinical effectiveness of WREs for gait reconstruction in patients with SCI, contributing to evidence-based device application and further development.

Effects of Ankle Joint Motion on Pelvis-Hip Biomechanics and Muscle Activity Patterns of Healthy Individuals in Knee Immobilization Gait

The purpose of the study was to investigate the pelvis-hip biomechanics and trunk and lower limb muscle activity patterns between healthy people walking in two gaits and evaluate the effects of ankle joint motion on these two gaits. The two gaits included walking with combined knee and ankle immobilization and with individual knee immobilization. Ten healthy participants were recruited and asked to walk along a 10 m walk away at their comfortable speeds in the two gaits. Kinematic data, ground reaction force, and electromyography waveforms of trunk and lower limb muscles on the right side were collected synchronously. Compared to individual knee immobilization gait, people walking in the combined knee and ankle immobilization gait increased the range and average angle of the anterior pelvic tilt during the first double support and the single support phase, respectively. The combined knee and ankle immobilization gait also increased the range of hip abduction during the second double support phase. These kinematic alternations caused changes in trunk and lower limb muscle activity patterns. The ankle immobilization increased the range of gluteus maximus activation in the first double support phase, the range of rectus abdominis activation, the average amplitude of rectus femoris activation in the single support phase, and the range of rectus femoris activation in swing phase and decreased the range of and tibialis anterior activation in the first double support phase. The ankle immobilization also increased the average values of proximodistal component in AKI gait during the single support phase. This study revealed significant differences in pelvis-hip biomechanics and trunk and lower limb muscle activity patterns between the two gaits.

Effects of Two Different Hip-Knee-Ankle-Foot Orthoses on Postural Stability in Subjects with Spinal Cord Injury: A Pilot Study

Study Design

Pilot study.

Purpose

Evaluation of two different hip-knee-ankle-foot orthoses (HKAFOs; medial linkage reciprocating gait orthosis [MLRGO] and isocentric reciprocating gait orthosis [IRGO]) using gait and postural stability analysis in four subjects with spinal cord injury (SCI).

Overview of Literature

To the best of our knowledge, no study has evaluated postural stability in subjects with SCI when using MLRGO and IRGO.

Methods

The relative efficacy of each orthosis was evaluated with relevant gait parameters, and an assessment of postural stability and sway during usage was made. Each analysis was conducted following an appropriate period of training and acclimatization. The gait parameters employed in the study were walking speed, cadence, and endurance; these were recorded and analyzed using current, validated methods. Postural stability was assessed using a verified force plate measurement system, and a modified Falls Efficacy Scale (mFES) was used for the measurement of postural sway and the perceived fear of falling.

Results

Walking speed, cadence, and endurance increased with the use of both HKAFOs. When the two types of HKAFOs were compared, all the parameters showed a slight (but not significant) increase with the use of MLRGO compared with the use of IRGO. In contrast, there were slight but insignificant improvements in postural sway with the use of IRGO. However, although there were no significant differences between the two sets of mFES scores, there was a slightly reduced fear of falling with the use of MLRGO compared with the use of IRGO in the static standing position.

Conclusions

It is noteworthy that meaningful interpretations of results can only be drawn if a larger sample is employed. This pilot study showed no significant data; however, the results indicate that the use of MLRGO is superior to that of IRGO in terms of potential improvement in the mobility and confidence levels of subjects with SCI.

Comparison of energy efficiency between Wearable Power-Assist Locomotor (WPAL) and two types of knee-ankle-foot orthoses with a medial single hip joint (MSH-KAFO)

OBJECTIVE

To compare the energy efficiency of Wearable Power-Assist Locomotor (WPAL) with conventional knee-ankle-foot orthoses (MSH-KAFO) such as Hip and Ankle Linked Orthosis (HALO) or Primewalk.

STUDY DESIGN

Cross over case-series.

SETTING

Chubu Rosai Hospital, Aichi, Japan, which is affiliated with the Japan Organization of Occupational Health and Safety.

METHODS

Six patients were trained with MSH-KAFO (either HALO or Primewalk) and WPAL. They underwent 6-minute walk tests with each orthosis. Energy efficiency was estimated using physiological cost index (PCI) as well as heart rate (HR) and modified Borg score. Trial energy efficiency with MSH-KAFO was compared with WPAL to assess if differences in PCI became greater between MSH-KAFO and WPAL as time goes on during the 6-minute walk. Spearman correlation coefficient of time (range: 0.5-6.0 minutes) with the difference was calculated. The same statistical procedures were repeated for HR and modified Borg score.

RESULTS

Greater energy efficiency, representing a lower gait demand, was observed in trials with WPAL compared with MSH-KAFO (Spearman correlation coefficients for PCI, HR and modified Borg were 0.93, 0.90 and 0.97, respectively, all P < 0.0001).

CONCLUSIONS

WPAL is a practical and energy efficient type of robotics that may be used by patients with paraplegia.

Active lower limb orthosis with one degree of freedom for people with paraplegia

The main challenges of designing devices for paraplegic walking can be summarized into three groups, stability and comfort, high efficiency or low energy consumption, dimensions and weight. A new economical device for people with paraplegia which tackles all problems of the three groups is introduced in this paper. The main idea of this device is based on HALO mechanism. HALO is compact passive medial hip joint orthosis with contralateral hip and ankle linkage, which keeps the feet always parallel to the ground and assists swinging the leg. The medial hip joint is equipped with one actuator in the new design and the new orthosis is called @halo. Due to this update, we can achieve more stable and smoother walking patterns with decreased energy consumption of the users, yet maintain its compact and lightweight features. It is proven by the results from preliminary experiments with able-bodied subjects during which the same device with and without actuator was evaluated. Waddling and excessive vertical elevation of the center of gravity were decreased by 40% with significantly smaller standard deviations in case of the active orthosis. There was 52% less energy spent by the user wearing @halo which was calculated from the vertical excursion difference. There was measured 38.5% bigger impulse in crutches while using passive orthosis. The new @halo device is the first active orthosis for lower limbs with just one actuated degree of freedom for users with paraplegia.

Influence of Reciprocating Link When Using an Isocentric Reciprocating Gait Orthosis (IRGO) on Walking in Patients with Spinal Cord Injury: A Pilot Study

Background: Studies collectively imply that the reciprocal link has no effect on walking when using reciprocating gait orthoses (RGOs). There may be differences between the 2 configurations of the RGO (eg, isocentric reciprocating gait orthosis [IRGO] and IRGO without reciprocating link), but the specific benefits and problems encountered in their use must be understood. Purpose: To highlight more evidence for the mechanical function of the reciprocal link in RGOs used for walking by individuals with spinal cord injury (SCI). Methods: Nine people with SCI participated in this study. Gait analysis was performed in 2 conditions (walking with IRGO and walking with IRGO without reciprocating link) in a random order. The Vicon digital capture system was used to obtain kinematic data. Results: There were significant differences between each orthotic configuration in terms of speed of walking (p = .029), step length (p = .048), hip joint range of motion (ROM) (p ≤ .001), and lateral and vertical compensatory motions (p ≤ .001). There was no significant difference between each orthotic configuration in cadence (p = .162). Conclusion: The reciprocating link in IRGO improved the walking parameters in SCI patients.

The influence of new medial linkage orthosis on walking and independence in spinal cord injury patients: a pilot study

In an effort to overcome the disadvantages of reciprocating gait orthoses (RGOs) and medial linkage orthoses (MLOs), a new design of MLO was developed. Therefore the aim of this study was comparison effect of a new reciprocating MLO and traditional isocentric RGO on gait parameters and functional independence (orthosis donning and doffing time) in spinal cord injury (SCI) subjects to provide more evidence of its efficacy. Four people with motor incomplete SCI participated in this study. Each participant was fitted with an MLO and isocentric reciprocating gait orthosis (IRGO) to enable a comparison of walking speed, cadence and endurance to be performed. There were no statistically significant differences demonstrated in temporal-spatial parameters between the orthotic walking conditions in this study, but walking with the MLO improved the stride length and speed of walking by 28.57 and 40.9% compared with walking with an IRGO as a control condition. Hip flexion occurred predominantly during single-support phases, with negligible motion during double-support phases. The first and second Subjects had hip kinematic pattern more near normal when they walked with medial linkage reciprocal gait orthosis (MLRGO) in comparison with IRGO. There was significant difference between donning and doffing in two conditions (P=0.046) but there was not significant difference between two conditions in standing and sitting although these two conditions improved by new MLO. The new MLO provided a quicker and more independent gait compared with IRGO, in addition the new MLO made it easier for subjects to get from sitting to standing and from standing to sitting.

The influence of orthosis options on walking parameters in spinal cord-injured patients: a literature review

OBJECTIVE

Orthoses for various joints sections are considered to greatly influence the gait function and energy expenditure in spinal cord-injured (SCI) patients. The aim of this review was to determine the influence of orthoses characteristics and options on the improvement of walking in patients with SCI.

METHODS

A search was performed using the Population Intervention Comparison Outcome (PICO) method, based on selected keywords; studies were identified electronically in the Science Direct, Google Scholar, Scopus, Web of Knowledge and PubMed databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method was used to report the results. Assessment of the quality of all articles was performed based on the Physiotherapy Evidence Database (PEDro scale).

RESULTS

Twelve studies evaluated the effects of different hip joint options on walking parameters and energy expenditure. Five studies investigated the role of knee joint options on gait parameters and compensatory trunk motion. Only five studies analyzed modified ankle joints on gait parameters in SCI patients. Nine studies analyzed gait parameters in SCI patients as powered orthoses and exoskeleton. These studies had a low level of evidence according to the PEDro score (2/10).

CONCLUSION

The various joint types of orthoses appear to be critical in the improvement of walking in patients with SCI. In particular, 'user friendly' orthoses that support the related structure such as the hip joint with a reciprocating mechanism, activated knee joint and movable ankle joint with dorsiflexion assist enable SCI patients to optimize their walking pattern when wearing an orthoses system.

Gait generation for powered Hip-Ankle-Linkage-Orthosis

A hip-knee-ankle-foot orthotic system called `HALO'(Hip and Ankle Linked Orthosis) for paraplegic walking has been developed in our previous study. Each ankle joint of the HALO system is linked with a medial single joint via a wire which allows both feet of the orthosis to stay always parallel to the floor during walking and assists swinging the leg. The tests of the HALO system demonstrated that it allows smoother walking and easy don/doff. In order to improve further the characteristics of the previous design, we started a new project called pHALO aiming at further reducing of the energy expenditure during walking. As a difference from the previous solution where ankle joints were restrained, the new solution will incorporate two actuators to control the ankle joints angles. As an intermediate step from the development of the pHALO system, in this study we added to the existing system a feedback PI controller to control the ankle joint angle of the right foot in the push-off phase and conducted an experiment to evaluate the effect of the new design on the walking patterns and energy efficiency. The results showed longer stride length, faster gait speed, smaller variation of the CoG, and less energy consumption.

The influence of new reciprocating link medial linkage orthosis on walking and independence in a spinal cord injury patient

OBJECTIVES

The purpose of this paper is to describe the development and evaluation of a new medial linkage reciprocating gait orthosis (MLRGO) that incorporates a reciprocal mechanism and is sensitive to pelvic motion to potentially assist paraplegic patients to walk and provide functional independence.

CASE DESCRIPTION AND METHODS

The new orthosis was constructed and tested by a 20-year-old female paraplegic subject with transverse myelitis at T10 level, who was 4 years post injury and had also been an isocentric reciprocating gait orthosis (IRGO) user for 2 years. She received gait training for 12 weeks before undertaking gait analysis, and also completed a questionnaire that was designed to assess the perceived functionality of the new MLRGO when compared with an IRGO.

RESULTS

The results demonstrated improvements in gait velocity, step length and cadence, and also improvement in functional independence with the new orthosis compared with an IRGO.

CONCLUSION

The results demonstrated that this new MLRGO could be used for paraplegic patients who would like an improvement in functional independence and ambulation.

Comparison of new medial linkage reciprocating gait orthosis and isocentric reciprocating gait orthosis on energy consumption in paraplegic patients: a case series

OBJECTIVES

As energy consumption during orthotics walking has main role in rehabilitation of walking in individuals with spinal cord injury (SCI), the aim of this study was comparison between new medial linkage orthosis (new MLO) and isocentric reciprocating gait orthosis (IRGO) on energy consumption in paraplegic patients.

METHODS

Four people with motor incomplete SCI (mean age 34.5 years, mass 73 kg and height 175 cm with injury levels ranging from T8-T12) participated in this study. Gait evaluation was performed using new MLO compared with using conventional IRGO. Walking speed and heart rate were measured to calculate the physiological cost index (PCI) to estimate metabolic energy consumption.

RESULTS

Reductions in energy consumption were observed using new MLO compared with using IRGO, but the difference was not statistically significant. However, walking distance and walking speed also improved, but not significantly.

CONCLUSION

All subjects had faster speeds of walking, walked longer distances and had lower PCI when using new MLO compared to walking with IRGO. Consequently, this orthosis should be examined and considered with larger sample size.

The effect of ankle joint mobility when using an isocentric reciprocating gait orthosis (IRGO) on energy consumption in people with spinal cord injury: preliminary results

OBJECTIVES

The aim of this study was to evaluate the effect of walking with isocentric reciprocating gait orthoses (IRGOs) utilizing two designs of ankle foot orthoses (AFOs) on specific outcome measures in people with spinal cord injury (SCI).

METHODS

Four volunteer SCI subjects participated in this study, and were fitted with an IRGO equipped with either solid or dorsiflexion-assisted AFOs in a randomized order. Subjects walked at their self-selected speed along a flat walkway to enable a comparison of walking speed, endurance and the resulting physiological cost index (PCI) to be performed.

RESULTS

Increased walking speed, increased distance walked and less PCI were demonstrated in walking with the IRGO incorporating dorsiflexion-assisted AFOs as compared to walking with an IRGO plus solid AFO as a control condition.

CONCLUSION

This study demonstrated that people with SCI could walk at relatively higher speeds and with greater endurance and a reduced PCI when utilizing an IRGO with dorsiflexion-assisted AFO components compared to solid ones. It is therefore concluded that the IRGO incorporating dorsiflexion-assisted AFOs may be an effective alternative in helping to reduce the energy consumption experienced by people with SCI.

Design and analysis of a new medial reciprocal linkage using a lower limb paralysis simulator

STUDY DESIGN

A feasibility study on the effect of a new reciprocating orthosis on specific gait parameters for use by people with spinal cord injury.

OBJECTIVES

The aim of this study was to design and develop a new medial linkage orthosis (MLO) mechanism incorporating a reciprocating motion and to determine its efficacy in improving specific spatiotemporal, kinematic and kinetic parameters while ambulating when worn by healthy subjects. This was achieved via the use of a lower limb paralysis simulator (LLPS).

METHODS

A reciprocating joint with a remote center of motion was designed for use as an MLO. A prototype was fabricated and incorporated into an orthosis and equipped with a saddle to make the reciprocating motion possible. The efficacy of the orthosis was evaluated on four able-bodied healthy subjects who were trained to walk with the MLO attached to the LLPS.

RESULTS

Mean walking speed, stride length, stride time and cadence was 0.09±0.007 m s(-1), 0.42±0.01 m, 4.89±0.45 s and 29.54±4.32 steps min(-1), respectively, when healthy subjects walked with the new orthosis. The mean hip joint torque produced was 0.36±0.13 Nm.

CONCLUSION

In this study a new MLO was designed and fabricated that provided a reciprocating mechanism using a four-bar mechanism to set the virtual axis of the mechanism in a more proximal position than hinge-type joints. Further investigation is currently underway to assess its effect on gait parameters and energy expenditure in paraplegic patients.

THE USE OF MOTION ANALYSIS SYSTEM AND ORTHOSIS IN PATIENTS WITH NEURO-MUSCULOSKELETAL DISORDERS

Background: Neuro-musculoskeletal disorders are a major source of physical disability involving more than one joint. Monitoring all joints during walking is achieved by using motion analysis system. There is limited evidence to show the suitability of motion analysis system to monitor neuro-musculoskeletal disorders. This research investigated the feasibility of this system to represent in patients with neuro-musculoskeletal disorders during walking. Method: Five groups of normal subjects with: knee osteoarthritis; avascular necrosis of hip joint; spinal cord injury and flat foot were recruited into this study. Kinetic and kinematic parameters were obtained by the use of motion analysis (Qualysis with seven cameras) and a Kistler force platform. The differences between gait parameters of normal and subjects with these disorders were examined using the independent t-tests. Paired t-test analysis was also used to determine the difference between walking with and without orthosis. Significant value was set at p ≤ 0.05. Results: There was a significant difference between the moment applied on the knee joint, the integral area between center of pressure (COP) and center of knee joint (COJ) graphs of normal and osteoarthritis (OA) subjects (p < 0.05). The area between COP and COJ of the ankle joint significantly differed between normal and flat foot subjects (p < 0.05). However, the force transmitted through the hip joint in subjects with Perthes did not differ significantly while walking with and without orthosis. In paraplegic subjects, the force applied on the limb and the mean values of gait parameters varied while walking with different orthoses which showed the feasibility of the system to monitor the performance of subjects with SCI disorder. Conclusion: The findings of the present study imply that the use of motion analysis is feasibility for assessing and monitoring neuro-musculoskeletal disorders. However, different parameters should be selected for various neuro-musculoskeletal disorders.

The efficiency of mechanical orthoses in affecting parameters associated with daily living in spinal cord injury patients: a literature review

OBJECTIVE

The most simple and common approach in providing standing and walking by subjects with spinal cord injury (SCI) is the use of mechanical orthoses. These include traditional orthoses, medial linkage orthoses (MLOs) and reciprocating gait orthoses (RGOs). Independence, energy expenditure, gait parameters, system reliability and cosmesis are important factors in orthotic design. The aim of this review was to compare the evidence of existing mechanical orthoses to that of other types regarding these factors.

METHODS

The preferred reporting items for systematic reviews and meta-analyses (PRISMA) method was used by an experience researcher based on selected keywords and their composition and an electronic search was performed in well-known databases.

RESULTS

Twenty articles were selected for final evaluation. Many were case studies, and also had limited and heterogeneous sample sizes with different instruments used for evaluation. The results of the analysis demonstrated that independence and cosmesis are improved when using MLOs, but gait parameters, energy expenditure and stability are all improved when using RGOs.

CONCLUSION

Those mechanical orthoses which have reciprocal motion and congruency between the anatomical and orthotic joints have been shown to provide positive effects on patient lifestyles. However, further improvement is needed to more effectively meet the needs of SCI patients.

IMPLICATIONS FOR REHABILITATION

The most simple and traditional approach to enable standing and walking by people with SCI is use of purely mechanical orthoses. The most important factors that increase rejection rates of orthoses in paraplegia patients are excessive energy expenditure and increased applied force on upper limb joints. Improvement of the structure of mechanical orthoses is needed to improve independence, energy expenditure, and gait parameters, and is an important approach to improve ambulatory function in subjects with paraplegia.

A new powered orthosis with hip and ankle linkage for paraplegics walking

Several types of hip-knee-ankle-foot orthotic systems have been proposed for paraplegic walking during these decades. Hip and ankle linked orthosis (HALO) is compact one in those orthoses, which seeks to achieve a smoother-movement and user-easiness on its don/doff in paraplegic walking. The idea of HALO is to link two ankle joints with medial single joint via wires so that the orthosis keeps both feet always parallel to the floor while walking and assist the swinging of the leg. So as to reduce the consumption energy of HALO walking, we have introduced two actuators to control the ankle-joints angles in this paper. The actuators placed at hip joint in HALO allow the orthosis to have more degree-of-freedom and are able to provide a propulsive force the coupled user-orthosis system. The results of preliminary experiments with normal subjects show that the users can walk smoother and the proposed orthotic system will be able to reduce the users' consumption energy while walking.

Effect of powered gait orthosis on walking in individuals with paraplegia

BACKGROUND

The important purpose of a powered gait orthosis is to provide active joint movement for patients with spinal cord injury.

OBJECTIVES

The aim of this study was to clarify the effect of a powered gait orthosis on the kinematics and temporal-spatial parameters in paraplegics with spinal cord injury.

STUDY DESIGN

Quasi-experimental.

METHODS

Four spinal cord injury individuals experienced gait training with a powered gait orthosis for a minimum of 6 weeks prior to participating in the following walking trials: walking with an isocentric reciprocating gait orthosis and walking with both separate and synchronized movements with actuated orthotic hip and knee joints in a powered gait orthosis. Specific parameters were calculated and compared for each of the test conditions.

RESULTS

Using separate and synchronized actuated movement of the hip and knee joints in the powered gait orthosis increased gait speed and step length and reduced lateral and vertical compensatory motions when compared to the isocentric reciprocating gait orthosis, but there were no significant differences in these parameters. Using the new powered gait orthosis improved knee and hip joint kinematics.

CONCLUSIONS

The powered gait orthosis increased speed and step length as well as hip and knee joint kinematics and reduced the vertical and lateral compensatory motions compared to an isocentric reciprocating gait orthosis in spinal cord injury patients.

CLINICAL RELEVANCE

This new powered gait orthosis has the potential to improve hip and knee joint kinematics, the temporal-spatial parameters of gait in spinal cord injury patients walking.

Gait evaluation of the advanced reciprocating gait orthosis with solid versus dorsi flexion assist ankle foot orthoses in paraplegic patients

BACKGROUND

Mechanical orthoses are used for standing and walking after neurological injury. Most orthoses such as the advanced reciprocating gait orthosis typically use solid ankle-foot orthoses.

OBJECTIVES

The goal of this study was to test the effects of ankle dorsiflexion assistance in patients with spinal cord injury when ambulating with an advanced reciprocating gait orthosis compared to walking with fixed ankles.

STUDY DESIGN

Quasi-experimental.

METHODS

Four patients with spinal cord injury were fitted with an advanced reciprocating gait orthosis equipped with solid and dorsiflexion assist-type ankle-foot orthoses and walked at their self-selected speed. Joint angles and spatial-temporal parameters were measured and analyzed.

RESULTS

The mean walking speed and stride length were both significantly increased along with cadence by the volunteer subjects when ambulating using the advanced reciprocating gait orthosis fitted with dorsiflexion assist ankle-foot orthoses compared to the advanced reciprocating gait orthosis with solid ankle-foot orthoses. The mean ankle joint ranges of motion were significantly increased when walking with the advanced reciprocating gait orthosis with dorsiflexion assist ankle-foot orthoses compared to when using the advanced reciprocating gait orthosis with the solid ankle-foot orthoses. Knee joint ranges of motion were reduced, and hip joint ranges of motion were increased but not significantly.

CONCLUSION

The advanced reciprocating gait orthosis fitted with the dorsiflexion assist ankle-foot orthoses had the effect of improving gait parameters when compared to the advanced reciprocating gait orthosis with solid ankle-foot orthoses. Clinical relevance The advanced reciprocating gait orthosis with dorsiflexion assist ankle-foot orthoses has the potential to improve hip and ankle joint kinematics and the temporal-spatial parameters of gait in spinal cord injury patients' walking.

Reciprocal gait orthoses and powered gait orthoses for walking by spinal cord injury patients

BACKGROUND

Using mechanical orthoses have some limitations for walking in paraplegic patients. The development of powered orthoses could potentially overcome some of the limitations of those currently available.

OBJECTIVES

The aim of this review was to compare the evidence of the effect of powered gait orthoses (PGOs) when compared to reciprocating gait orthoses (RGOs) and also hip guidance orthoses (HGOs) in improving gait parameters and the energy efficiency of walking by spinal cord injury (SCI) patients.

STUDY DESIGN

Literature review.

METHODS

Using the PRISMA method, and based on selected keywords and their composition, a search was performed in PubMed, Science Direct, and ISI Web of Knowledge databases. Eight articles were selected for final evaluation.

RESULTS

The results of the analysis demonstrated that there is lack of evidence to show that currently-developed powered orthoses improve the walking parameters of SCI patients when compared to RGOs and HGOs.

CONCLUSIONS

The changes offered by PGOs are not substantial enough for such orthoses to be currently considered preferable by SCI subjects for ambulatory purposes. Clinical relevance The development of powered orthoses is still in its infancy and progress needs to be made to improve their functionality and performance envelopes.

Studying the effect of kinematical pattern on the mechanical performance of paraplegic gait with reciprocating orthosis

Paraplegic users of mechanical walking orthoses, e.g. advanced reciprocating gait orthosis (ARGO), often face high energy expenditure and extreme upper body loading during locomotion. We studied the effect of kinematical pattern on the mechanical performance of paraplegic locomotion, in search for an improved gait pattern that leads to lower muscular efforts. A three-dimensional, four segment, six-degrees-of-freedom skeletal model of the advanced reciprocating gait orthosis-assisted paraplegic locomotion was developed based on the data acquired from an experimental study on a single subject. The effect of muscles was represented by ideal joint torque generators. A response surface analysis was performed on the model to determine the impact of the kinematical parameters on the resulting muscular efforts, characterized by net joint torques. Results indicated that a lateral bending manoeuvre at the trunk would facilitate the foot clearance by reducing the torque requirement of the whole body lateral tilting. For swing leg advancement, the trunk posterior bending manoeuvre was found to be more effective and efficient than the whole body axial rotation, owing to the coupled reciprocal action of the advanced reciprocating gait orthosis. It was hypothesized that a modified gait pattern, with larger trunk movements and no axial rotation, could improve the energy expenditure and upper body loading during advanced reciprocating gait orthosis-assisted locomotion. More detailed modelling and experimental studies are needed to verify this hypothesis and evaluate its potential effects on the soft tissue strains.

Evaluation of a novel powered gait orthosis for walking by a spinal cord injury patient

BACKGROUND

The aim of this case study was to analyze the effect on gait parameters of a new design of powered gait orthosis which applied synchronized motions to both the hip and knee joints when utilized for walking by a spinal cord injury (SCI) patient.

CASE DESCRIPTION AND METHODS

Two orthoses were evaluated while worn by an incomplete SCI subject. Gait evaluation was performed when walking with an isocentric reciprocating gait orthosis (IRGO) and compared to that demonstrated by a newly developed powered version. This new orthosis was based on the IRGO superstructure but incorporated powered hip and knee joints using electrically motorized actuators.

FINDINGS AND OUTCOMES

These gait parameters were improved when compared to standard IRGO and initial testing with the orthosis with only the hip or the knee joints activated in isolation. Maximum hip flexion and extension angles, as well as the maximum knee flexion and extension angles all increased when walking with the powered RGO compared to the IRGO.

CONCLUSIONS

Gait evaluation of this newly developed orthosis showed improvement in measured parameters when compared to walking with an IRGO. Clinical relevance This case study gave the authors confidence to extend the research to a more extensive study with a group of SCI patients.

Design and simulation of a new powered gait orthosis for paraplegic patients

BACKGROUND AND AIM

This article describes the development and testing of a new powered gait orthosis to potentially assist spinal cord injury patients to walk by producing synchronized hip and knee joint movements.

TECHNIQUE

The first evaluation of the orthosis was performed without users, and was followed by evaluation of the orthosis performance using three healthy subjects to test the structure under weight-bearing conditions. The orthosis was primarily evaluated to ascertain its ability to generate appropriate hip and knee motion during walking. The walking experiments replicated the flexion and extension of both the hip and knee produced by the actuators which had previously been demonstrated during the initial computer simulations.

DISCUSSION

The results suggest that this new orthosis could be used to assist paraplegic subjects who have adequate ranges of motion and also with weakness or reduced tone to ambulate, and may also be suitable for other subjects with impaired lower limb function (e.g. stroke, poliomyelitis, myelomeningocele and traumatic brain injury provided they do not have increased tone or movement disorders.

Motion Analysis by Independent Component Analysis with Phase Difference Information Among Joints

We configured a system that interpolates and extrapolates two different human movements at an arbitrary ratio for both periodic and discrete movement. This could, for example, extrapolate possible future movement from two data points from the past and present for a person with a certain disorder and enable quantitative assessment of the disorder by interpolating or extrapolating two typical movements of nondisabled and disabled persons at an arbitrary ratio and by comparing the result to the movement of subjects. We used independent component analysis involving phase difference information between joint movements. To demonstrate the system’s effectiveness, we generated three different gaits of periodic movement and conducted experiments with and without considering phase differences between joint movement. When results were implemented in a human model in computer graphics (CG) to picture movement, the system considering phase differences reconstructed the original movement naturally even with a number of independent variables as small as two. Movement analysis not considering phase differences, however, was unnatural, especially in ankle movement, due to the lack of appropriate phase differences between the knee and hip. We synthesized and evaluated discrete movement from two winning poses – one powerful and one weak – by interpolating movement I at 50% and movement II at 50%, and extrapolation of movement I at 150%. The former generated discrete movement with an in-between impression and the latter with a powerful impression. These results demonstrate that both periodic and discrete movement can be expressed by a small number of independent variables when phase difference information between joint movements is used appropriately.

[Gait orthosis in patients with complete thoracic paraplegia. Review of 43 patients]

OBJECTIVE

To evaluate of the effective use of gait orthosis in patients with spinal cord injuries.

PATIENTS AND METHODS

A total of 43 patients with complete paraplegia, level T3 to L1, who had a gait orthosis (hip-knee-ankle-foot orthosis, reciprocating gait orthosis, hybrid orthosis and functional electrical stimulation) answered a telephone questionnaire.

RESULTS

Orthotic gait use was discontinued in 65% of patients who used the orthosis twice a week for 15 to 60 minutes. Two-thirds of the patients were able to fit the orthosis independently, 60% for standing and 25% for walking. The main reasons for discontinuing use were psychological reasons in 30% of patients, the lack of functional use and the necessity for human help or supervision.

CONCLUSION

Presently available devices do not allow functional and independent use of gait orthoses. Their use is limited to physical training, and the only demonstrated physiological benefits are the effects of functional electrical stimulation on cardiovascular status. Prescription for gait orthosis appears justified only if requested by a motivated and well-informed patient or if it appears a useful step in the acceptation of the loss of the gait.