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 relevanceThis case study gave the authors confidence to extend the research to a more extensive study with a group of SCI patients.

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 relevanceThis orthosis has the potential to improve hip joint kinematics, the temporal-spatial parameters of gait in SCI patients walking.

Several limitations still exist for paraplegic patients when walking with orthoses. Such limitations include the reported high energy consumption during ambulation, high loads on the upper limb joints and the need for improvements in the kinetics and kinematics demonstrated while walking in current orthoses for this patient group. 1-9 The design of new orthoses such as the advanced reciprocating gait orthosis (ARGO) 3,10 the 'walk about' orthosis, 11 the 'prime walk' orthosis, 12 the hip and ankle linkage orthosis 13 and the isocentric reciprocating gait orthosis (IRGO), 14 have not solved these problems in the provision of paraplegic ambulation.Hybrid orthoses such as those using functional electrical stimulation (FES) in conjunction with RGOs, and powered orthoses using a combination of pneumatic, hydraulic or motorized actuators with RGOs have attempted to resolve these problems. 2,15 One limitation of using FES in combination with orthoses is the rapid reduction in muscle strength caused by fatigue [16][17][18][19] ; so another approach such as the use of powered orthoses has the potential to offer more effective walking by paraplegic patients. 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 relevanceThe 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.

The new powered SCKAFO facilitated controlled knee flexion and extension during ambulation for a volunteer poliomyelitis person.

Abstract:The goal of this study was to determine stress distribution in ankle joint by correlating with the strain distribution and its trend around tibia adjacent to the joint. Using an in-house device, an ankle from a cadaver was kept stable and loaded in various positions: neutral, dorsiflexion, plantar flexion, inversion and eversion. A total of six strain gauges were mounted around the shaft of the tibia, near the tibiotalar joint. This arrangement allowed us to measure deformations in the shaft of tibia. Patient-specific ankle joint geometry was generated from computed tomography data. The finite element model (FEM) of the ankle was validated using the experimental data logged by the strain gauges, and used for obtaining stress on the joint surface. A strong correlation was observed between the FEM and experimentally measured strains in magnitude (R = 0.94, P = 0.008), consequently stress distribution over the joint surface was obtained. 46A. Chitsazan et al.