ABSTRACT
In this study two aspects of hybrid functional electrical stimulation (FES) orthoses were investigated: joint motion constraints and FES control strategies. First, the effects of joint motion constraints on the gait of normal subjects were investigated using modern motion analysis systems, including electromyogram (EMG) and heart rate measurements. An orthosis was developed to impose joint motion constraints; the knee and ankle could be fixed or free, and the hip joint could rotate independently or coupled, according to a preset flexion-extension coupling ratio (FECR). Compared with a 1:1 hip FECR, a 2:1 hip FECR was associated with a reduced energy cost and increased speed and step length. The knee flexion during swing significantly reduced energy cost and increased walking speed. Ankle plantar flexion reduced the knee flexing moment during the early stance phase. Second, trials on 3 paraplegic subjects were conducted to implement some of these findings. It appeared that the 2:1 FECR encouraged hip flexion and made leg swing easier. A simple FES strategy increased walking speed and step length and reduced crutch force impulse using fixed orthotic joints.
Subject(s)
Electric Stimulation Therapy , Muscle, Skeletal/physiology , Orthotic Devices/trends , Paraplegia/therapy , Ankle/physiology , Crutches , Electromyography , Heart Rate/physiology , Hip Joint/physiology , Humans , Knee Joint/physiology , Orthotic Devices/standards , Paraplegia/physiopathology , Walking/physiologyABSTRACT
It is recognised that, in paraplegic walking with reciprocating gait orthoses, inadequate hip flexion angles may contribute to the low walking speed and high energy cost. In this study a new orthotic hip joint was developed which had a 2:1 flexion extension coupling ratio. Experiments on paraplegic subjects were conducted to evaluate this orthotic hip joint. It was found that the new hip joint was associated with a reduced energy cost and increased step length. A simple application of FES assisted hip flexion further increased walking speed and step length and reduced energy cost and crutch force impulse.
Subject(s)
Electric Stimulation Therapy/methods , Orthotic Devices , Paraplegia/rehabilitation , Adult , Energy Metabolism , Hip Joint/physiology , Humans , Knee Joint/physiology , WalkingABSTRACT
In this study the effects of angular motion constraints of the lower limbs on the gait of normal subjects were investigated. An assessment orthosis was developed with a new hip coupling mechanism which allows its ratio of reciprocal flexion to extension to be altered. The knee and ankle joints of the orthosis could also be set to be free or locked in specific directions of angular motion in the sagittal plane. A total of 12 different orthosis configurations was tested on three normal subjects. The kinematic, kinetic and electromyographic (EMG) data were collected using the VICON system, two Kistler forceplates, foot switches and an eight channel EMG system. The physiological cost index of walking was assessed by measuring the heart rate and walking speed. It was found that (1) a higher hip flexion-extension ratio was associated with lower energy cost and faster walking; (2) allowing the knee to flex significantly reduced the energy cost and increased the walking speed; (3) allowing the ankle to plantarflex during early stance phase reduced the knee flexing moment. The implications of these effects on the further development of hybrid functional electrical stimulation orthotic systems are discussed.
Subject(s)
Ankle Joint/physiology , Electric Stimulation Therapy/instrumentation , Gait/physiology , Hip Joint/physiology , Knee Joint/physiology , Orthotic Devices , Paraplegia/rehabilitation , Adult , Biomechanical Phenomena , Electromyography/instrumentation , Energy Metabolism , Equipment Design , Heart Rate , Humans , Kinetics , Male , Movement , Muscle, Skeletal/physiology , Range of Motion, Articular , Walking/physiologyABSTRACT
A child with acute lymphocytic leukemia who was in clinical remission and developed coxsackie B4 meningoencephalitis is presented. Despite minimal evidence of immunodeficiency, the patient had progression of neurologic disease clinically, electroencephalographically and on laboratory evaluation of spinal fluid. A dramatic response to the use of intravenous immunoglobulins is reported and its rationale explained.
Subject(s)
Coxsackievirus Infections/therapy , Immunocompromised Host , Immunoglobulins, Intravenous/therapeutic use , Meningoencephalitis/therapy , Precursor Cell Lymphoblastic Leukemia-Lymphoma/immunology , Child, Preschool , Coxsackievirus Infections/immunology , Humans , Male , Meningoencephalitis/immunology , Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapyABSTRACT
There are few published surveys that are designed specifically to describe the total population of clients with communication disorders who might potentially benefit from the use of a communication aid. Such data, however, would be useful in planning the funding and staffing of rehabilitation services in a region. Figures are also needed to identify populations whose needs are currently not being met and thus to establish areas of future developments both for service and research purposes. The survey reported here was carried out as part of a project concerned with the provision of augmentative communication to the neurologically impaired child and young adult. It was intended to produce a broad description of the communication-impaired population in Tayside. The survey was then used to identify detailed information about clients who may benefit from using a communication aid, and it also highlighted some provision and research issues. Access to communication aids for the non-speaking population was found to have been restricted by lack of funding, resources and opportunities for training for therapists in the use of augmentative and alternative communication. Future research and development should particularly address the needs of the aphasic population whose needs were not found to be met by currently available communication aids.
