Stephen W Hutchins

The physiological cost index of walking with an isocentric reciprocating gait orthosis among patients with T12–L1 spinal cord injury

Objective: The objective of this study was to compare the Physiological Cost Index of walking with a reciprocating gait orthosis to that of walking with bilateral knee-ankle-foot orthoses (KAFOs) by subjects with paraplegia resulting from T12 – L1 spinal cord lesions. Methodology: Six chronic paraplegic subjects who had T12 – L1 spinal cord lesions and who previously wore bilateral KAFOs were recruited. Each subject was fitted with an isocentric reciprocating gait orthosis (IRGO) and received a standardized training program. Subjects were then asked to walk using the two orthotic devices along a 40 m rectangular pathway at a speed that was comfortable for them. The walking speed was measured using a stop watch, and a Polar Heart Rate Monitor was used to measure the heart rate of the subjects. The Physiological Cost Index (PCI) was calculated for comparison. Results: Ambulation using the IRGO (10.46 +/− 2.00 m/min) was significantly faster (p = 0.009) than ambulation using the bilateral KAFOs (5.51 +/− 4.30 m/min). The PCI demonstrated when walking with the IRGO (2.85 +/− 0.77 beats/m) was significantly lower (p = 0.0306) than that of the bilateral KAFOs (6.77 +/− 3.28 beats/m). Conclusion: Paraplegic patients with T12 – L1 spinal cord lesions walk faster and more efficiently using the isocentric reciprocating gait orthosis as compared to using the bilateral KAFOs.

The physiological cost index of walking with mechanical and powered gait orthosis in patients with spinal cord injury

Objectives:Mechanical orthoses, such as the hip knee ankle foot orthosis (HKAFO) and the isocentric reciprocating gait orthosis (IRGO), are both used for walking in spinal cord injury (SCI) patients. The aim of this study was to analyze the energy expenditure during walking with these orthoses compared with a powered gait orthosis (PGO) in patients with SCI.Methods:Five patients with SCI who were experienced users of HKAFOs participated in this study. Subjects were also fitted with an IRGO and PGO and underwent a specific gait training program. Patients walked along a flat walkway using the three types of orthosis at their self-selected walking speed. A stop watch and a polar heart rate monitor were used to measure the speed of walking and heart rate.Results:Walking speed, the distance walked and the physiological cost index (PCI) all improved with both the new PGO and the IRGO as compared with the HKAFO.Conclusions:A PGO can improve walking speed and the distance walked and reduce the PCI of walking as compared with mechanical orthoses, probably due to the activated movements of the lower limb joints.

Design of a stiffness-adjustable ankle-foot orthosis and its effect on ankle joint kinematics in patients with stroke

Ankle-foot orthoses (AFOs) are commonly prescribed to improve gait. The stiffness of an AFO is central for successful prescription; however, the recommended level of stiffness is currently based on the experience of clinicians. Therefore, the aim of this study was to design an experimental AFO (EAFO) whose stiffness was adjustable using commercially available oil-damper joints, and to demonstrate its potential capability in investigating the effects of altering AFO stiffness on gait. The influence of the EAFO stiffness on ankle joint kinematics in sagittal plane was evaluated in 10 patients with stroke by altering the stiffness of its oil-damper- type orthotic ankle joints using the four levels pre-set and defined by the manufacturer in dorsi- and plantarflexion directions independently. The mean peak plantarflexion angle was reduced by 105%, showing a change from 8.18 (3.14) degrees of plantarflexion to 0.38 (4.17) degrees of dorsiflexion, whilst the mean peak dorsiflexion angle was reduced by 44%, showing a change from 11.46 (5.57) degrees of dorsiflexion to 6.47 (5.23) degrees of dorsiflexion by altering the EAFO stiffness. The EAFO would therefore serve as a convenient tool when investigating the influence of AFO stiffness on gait in both clinical and research settings.

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.

The effect of a knee ankle foot orthosis incorporating an active knee mechanism on gait of a person with poliomyelitis

Background: The aim of this case study was to identify the effect of a powered stance control knee ankle foot orthosis on the kinematics and temporospatial parameters of walking by a person with poliomyelitis when compared to a knee ankle foot orthosis. Case description and methods: A knee ankle foot orthosis was initially manufactured by incorporating drop lock knee joints and custom molded ankle foot orthoses and fitted to a person with poliomyelitis. The orthosis was then adapted by adding electrically activated powered knee joints to provide knee extension torque during stance and also flexion torque in swing phase. Lower limb kinematic and kinetic data plus data for temporospatial parameters were acquired from three test walks using each orthosis. Findings and outcomes: Walking speed, step length, and vertical and horizontal displacement of the pelvis decreased when walking with the powered stance control knee ankle foot orthosis compared to the knee ankle foot orthosis. When using the powered stance control knee ankle foot orthosis, the knee flexion achieved during swing and also the overall pattern of walking more closely matched that of normal human walking. The reduced walking speed may have caused the smaller compensatory motions detected when the powered stance control knee ankle foot orthosis was used. Conclusion: The new powered SCKAFO facilitated controlled knee flexion and extension during ambulation for a volunteer poliomyelitis person. Clinical relevance The powered stance control knee ankle foot orthosis has the potential to improve knee joint kinematics in persons with poliomyelitis when ambulating.

Comparison of custom-made and prefabricated neoprene splinting In patients with the first carpometacarpal joint osteoarthritis

Aim: The objective of this study was to compare the effect of prefabricated and custom made thumb splints on pain, function, grip strength and key pinch In patients with basilar joint osteoarthritis. Method: Volunteer patients (n = 35) with first carpometacarpal joint osteoarthritis were assigned randomly to wear either a prefabricated or custom-made thumb splint or assigned to a control group. This was designed as a cross over study with two 4-week treatment periods, 2 weeks of wash out time for intervention groups between the test conditions and 10-weeks follow-up for the control group. All parameters were measured at the first visit and during the 4th, 6th and 10th weeks In the three groups. Results: In the control group, paIn increased and pinch strength decreased but no statistically significant differences were found In function and grip strength. Both splints changed grip strength with no significant differences between them. PaIn was reduced with the splints, and functions and pinch strength increased significantly as compared to the baseline and control groups. In comparing the two splints only significant differences were observed In pain. Conclusion: In comparing two splints, paIn was the only significantly different parameter between tested parameters; with the custom-made splints demonstrating better results In paIn reduction. Implications for Rehabilitation A high level of disability has been reported In those patients with thumb carpometacarpal joint osteoarthritis. Custom-made and prefabricated neoprene splinting is an effective method to improve pain, pinch strength and function by patients with the first carpometacarpal joint osteoarthritis. The custom made splint demonstrated better results In paIn reduction.

Evaluation of a novel powered hip orthosis for walking by a spinal cord injury patient: a single case study.

Background: The aim of this case study was to identify the effect of a powered hip orthosis on the kinematics and temporal-spatial parameters of walking by a patient with spinal cord injury (SCI). Case Description and Methods: Two orthoses were evaluated while worn by an incomplete SCI subject with a T-8level of injury. Gait evaluation was performed when walking with an Isocentric Reciprocating Gait Orthosis (IRGO) and compared to that demonstrated by a newly powered version of the orthosis; based on the IRGO superstructure but incorporating powered hip joints using an electrically motorized actuator that produced active hip joint extension and flexion. Findings and Outcomes: The powered hip orthosis, when compared to the IRGO, increased the speed of walking, the step length and also the cadence demonstrated by this subject. Vertical and horizontal compensatory motions with new orthosis decreased. Hip angles when walking with this orthosis were comparative to those demonstrated by normal walking patterns. Conclusions: The hip actuator produced positive effects on the kinematics and temporal-spatial parameters of gait during level-ground walking trials, resulting in an alternative approach to walking by SCI patients. Clinical relevance This orthosis has the potential to improve hip joint kinematics, the temporal-spatial parameters of gait in SCI patients walking.

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. Clinical relevance The new powered gait orthosis can provide walking assistance for patients with a spinal cord injury who have a good range of motion at the hip and knee and who also have weakness or reduced tone.

Quantitative measurement of spastic ankle joint stiffness using a manual device: a preliminary study.

Quantitative measurement of ankle joint stiffness following stroke could prove useful in monitoring the progress of a rehabilitation programme. The objective of this study was to design a manual device for use in the clinical setting. Manual measurement of spastic ankle joint stiffness has historically been conducted using hand-held dynamometers or alternative devices, but some difficulties have been reported in controlling the velocity applied to the ankle during the measurement. In this study, a manually operated device was constructed with a footplate, a torquemeter and a potentiometer. It was mechanically designed to rotate around an approximated axis of the ankle joint and to measure ankle joint angular position and its corresponding resistive torque. Two stroke hemiplegic subjects pariticapted in a pilot study. The results suggested that difficulty in controlling the applied velocity might be complemented by presenting torque data as a function of peak angular velocity in each stretching cycle. Moreover, the results demonstrated that the device could potentially apply a wide range of angular velocities and provide potentially useful clinical information. Quantitative data successfully acquired using this method included the approximate ankle angular position, where the velocity-dependent characteristics of stiffness was notably initiated and its corresponding torque and velocity.