Seating System Research Articles

Effect of Wheelchair Design on Posture and Comfort of Users

The canvas sling seat and backrest incorporated into a conventional wheelchair provide a seating system which fails short of many basic ergonomic requirements, which may compromise the comfort, health and level of dependency of the user. The high incidence of back pain among able-bodied people gives rise to much concern. Yet although there are indications that a similar proportion suffer, back pain in the disabled population receives less specific attention. Two prospective studies were undertaken involving a total of 58 subjects. The first evaluated the effects of wheelchair design on posture and the second looked at the effects that this had on the comfort of the user. Posture was recorded using a technique for measuring spinal curves, and data on the comfort of each seat were collected by questionnaire. The studies evaluated three different seating systems. The first was that of a conventional model 8BL wheelchair; the second and third were experimental rigs incorporated into an 8BL frame. One rig had cushions chamfered to fit the concavities of the canvas seat and backrest and the second had a rigid base on which was mounted cushioning material. The unmodified 8BL was shown to encourage a kyphotic posture and caused discomfort in both able-bodied and disabled subjects especially in the neck and back. The two experimental rigs promoted an acceptable degree of lordosis and, although both proved more comfortable than the canvas seat, of the two the hard-based seat was preferred. The canvas sling seat and backrest incorporated into a conventional wheelchair provide a seating system which fails short of many basic ergonomic requirements, which may compromise the comfort, health and level of dependency of the user. The high incidence of back pain among able-bodied people gives rise to much concern. Yet although there are indications that a similar proportion suffer, back pain in the disabled population receives less specific attention. Two prospective studies were undertaken involving a total of 58 subjects. The first evaluated the effects of wheelchair design on posture and the second looked at the effects that this had on the comfort of the user. Posture was recorded using a technique for measuring spinal curves, and data on the comfort of each seat were collected by questionnaire. The studies evaluated three different seating systems. The first was that of a conventional model 8BL wheelchair; the second and third were experimental rigs incorporated into an 8BL frame. One rig had cushions chamfered to fit the concavities of the canvas seat and backrest and the second had a rigid base on which was mounted cushioning material. The unmodified 8BL was shown to encourage a kyphotic posture and caused discomfort in both able-bodied and disabled subjects especially in the neck and back. The two experimental rigs promoted an acceptable degree of lordosis and, although both proved more comfortable than the canvas seat, of the two the hard-based seat was preferred. Biography: Michele Harms qualified as a physiotherapist in 1982 and worked for four years at The Royal Free Hospital. During this time she spent six months in Cape Town at Groote Schuur Hospital on a working exchange. This study was initiated as a result of her interest in improving posutre and lessening the back pain felt by wheelchair users. Since completing this project she has been working as a superintendent research physiotherapist in the Bloomsbury Health District.

New wheelchair seating system

New wheelchair seating system

A Seat Belt Is a Seat Belt Is a…

Pelvic-positioning straps are usually used to maintain the client/seating system interface. This article discusses the proper use of these straps. Proper selection and use of a pelvic-positioning strap will affect the success of the entire seating system, so careful attention must be paid to the size of the strap(s) and components and the placement of the strap as it crosses over the client's thigh/lower pelvic area. The direction of pull as the fastening system is closed and tightened may affect pelvic position as well. The author suggests the use of belts mounted to cross the upper thigh at a 90° angle to the seating surface. Placing the pelvic positioning strap at this angle leaves the pelvis free for active anterior movement during weight shift and functional reaching. Adjustable mounting hardware is recommended as a method of providing a pelvic-positioning system that is flexible enough to achieve proper alignment.

Adaptive Seating for the Motor Handicapped — Problems, a solution, assessment and prescription

Summary An analysis of the problems of available adaptive seating has led to the development of a modular seating system capable of assembly and adjustment without workshop facilities. Seven levels of sitting ability are defined and a methodical assessment procedure and prescription criteria for the provision of adaptive seating are described.

Adaptive Seating for Motor Handicap: Problems, a Solution, Assessment and Prescription

An analysis of the problems of available adaptive seating has led to the development of a modular seating system capable of assembly and adjustment without workshop facilities. Seven levels of sitting ability are defined and a methodical assessment procedure and prescription criteria for the provision of adaptive seating are described.

Car Seat System of the Future as Seen in “ARC-X”

Car seats of the future will have to give even greater consideration to the human aspects of comfort and style. Moreover, driver and passenger seats need to be designed separately, to optimize each seat according to its function and location the car interior. The seat system of the “ARC-X” experimental car is based on the results of body pressure distribution measurement, subjective evaluation, and other human engineering techniques. These were used to analyze driver and passenger postures from the standpoints of performance and comfort. This paper introduces features of the driver's seat and front and rear passenger seats adopted in the “ARC-X”, and reports some of the analytical results on which their design was based.

Therapeutic seating system

Therapeutic seating system

Therapeutic seating system

Therapeutic seating system

Sitting comfortably?

Bay Jacobsen Ltd have introduced a new Therapeutic Seating System, designed for the wheelchair (illegible word) or for people who spend long hours in the car or sitting in the office. It consists of a cushion and back rest which, the manufacturers claim, protect and support the back while providing enhanced comfort.

Improvement of seating comfort due to a new wheelchair seating system

Improvement of seating comfort due to a new wheelchair seating system

Improvement of seating comfort due to a new wheelchair seating system

Improvement of seating comfort due to a new wheelchair seating system

Adaptive seating and pulmonary function in adults with muscular disease

Pulmonary infections, possibly due to poor pulmonary functions, are common in individuals with muscular dystrophy. In order to evaluate the relative effects of seating devices on pulmonary function the forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and forced expiratory time (FET) in eight adults aged between 12 and 21 years with Duchenne Muscular Dystrophy was measured while seated in an adaptive and a nonadaptive seating device. The results showed a 28.0% increase in FVC, a 14.5% increase in FEV1, and a 17.3% increase in FET in the adaptive seating system compared to the nonadaptive system. This result emphasizes the need for proper seating as an important way of maximising pulmonary function and minimizing pulmonary complications in this population.

Straddle Seating for the Cerebral Palsied Child

This paper describes an alternative approach to seating the cerebral palsied child, and presents the development and use of a seating system primarily designed to seat the cerebral palsied child during functional therapy.

The Design and Development of the XJ40 Seating System

This paper describes the research, design and development processes involved in the creation of the Jagurn XJ40 seating system.

Electric goniometer for positioning children with cerebral palsy. Suggestion from the field.

The spatial relationship between the angle of inclination of a seating system's backrest from the seat and the hip flexion angle has not been established for children with cerebral palsy. Therefore, the child's hip flexion angle should not be described as the angle between the seat and the backrest unless the relationship between the hip flexion angle and the backrest's angle of inclination is established. The purpose of this article is to describe the components, operation, and uses of an electric goniometer designed to monitor and measure changes in hip flexion angle while positioning children with cerebral palsy. The position of the hip joint during sitting is crucial to the overall effectiveness of the seating system for children with cerebral palsy. Clinical observations1,2 and research results3 suggest that the position of the hip joint contributes to controlling hyperactive muscle activity.…

Effect of adaptive seating on pulmonary function of children with cerebral palsy.

The vital capacity (VC), forced expiratory volume in one second (FEV1) and expiratory time (ET) of eight cerebral-palsied children aged between five and 12 years was measured, when seated in a regular sling-type wheelchair and in an adaptive seating system. The results showed a 57.7 per cent increase in VC, a 51.6 per cent increase in FEV1 as a percentage of VC, and a 55 per cent increase in ET in the adaptive seating system compared with the standard wheelchair. These results have important implications for speech, sitting for prolonged periods and prevention of hypoxia and pulmonary hypertension.

Experience of a seating clinic.

Patients who cannot walk, particularly those with orthopaedic deformities, need more than a simple wheelchair; they require a special seating system. Since the early 1970's many different systems have been introduced to the field of orthotics and prescribed through "Seating Clinics" in many centres in North America and around the world. Our experience in the Seating Clinic at the University of Kansas Medical centre is presented. Most patients were children (70%) with 69% male and 31% female. Various seating systems were prescribed, including the Safety Travel Chair, the Moulded Plastic Insert, the Orthopaedic Body Support (foam on plywood), the Spinal Support System, the Moulded Seat Total Contact Shell (sitting support orthosis) and the DESEMO support system. The majority of patients had cerebral palsy (58%) and muscular dystrophy (33%). Other conditions included spinal cord injury, spina bifida and multiple orthopaedic deformities. Sixty five percent of the custom made seating systems prescribed were the Orthopaedic Body Support. Unilateral dislocation of the hip presents a major problem in seating because of pelvic obliquity.

Technology in the education of multiply-handicapped children.

The number of technical aids now available has allowed severely multiply-handicapped children to better participate in their education. Project TEACH (Technical-Educational Aids for Children with Handicaps), a 3-year early childhood demonstration project of the Federal Office of Education, provided ten children with seating systems, mobility aids, feeding devices, and augmentative communication aids. The children's performance of academic, motor, daily living, and communication skills as they relate to their educational program is reported as well as the model used to deliver technical services in an educational environment.

Emergency release from two child restraints : Freedman, K., and Humphreys, M. In: Ergonomics in Practice, Proceedings of the 17th Annual Conference of the Ergonomics Society of Australia and New Zealand, Sydney, 27–28 Nov 1980, pp 91–102

The development of child restraint seats has naturally emphasised crash protection. The need to make the release mechanism child proof has been tackled from two different directions which are demonstrated in the two seats studied. The study was concerned with the problem that a child restraint which is difficult for a child to release may be difficult for adults to release in an emergency. Although this is undoubtedly a perceived problem, it is emphasised that in practice it is rarely a safety problem. Measurements were taken of the time it took adult rescuers to release occupants from two different child seat systems under controlled conditions. Video tape records allowed for detailed examination of the release procedure used by each subject and of any problems encountered with the systems used. Several variables were examined for their effects on release time: sex of rescuer; type of occupant (dummy/ child); age of occupant (6 months/ 3 years); familiarity with child restraint system; familiarity with child and lighting levels. Results are discussed with respect to release problems with particular systems and quick release testing procedures to be incorporated in Australian standard 1754-1975 (a).

Scoliosis in Friedreich's ataxia.

SUMMARY:The preliminary results based on a three year study on the evolution and management of scoliosis in Friedreich’s ataxia are presented. Thirty-two patients were followed in the Neuromuscular Disease Clinic at Sainte-Justine Hospital where standardized spinal radiographs were taken periodically with the Scoliosis Chariot and the Throne.Pathomechanics — Between the age groups I (5 – 10 years) and II (10 – 15 years), a substantial increase in the Cobb values occurs. Associated with it, an increase was observed in the thoracic and thoraco-lumbar projected surface area indices. The relative torsion between the thoracic and lumbar segments was associated with a sudden increase in the Cobb measurements.A computer program which generates a tri-dimensional display of the spine from the coordinates obtained from the standardized radiographs has been adapted to study the importance and influence of the thoracic torsion on the progress of the scoliosis and on the evolution of the total spinal deformity.Management — Prevention of the progression of established curves was our main objective. Careful examination of the spine, depending on the age of the child, in our preliminary study, stimulated early orthopaedic treatment in any curve of 20° or more. There was always concern for curves of 30° or more. In the growing child, bracing which was recommended is now under a more thorough investigation. The use of spinal pacemakers is being clinically evaluated.In the older child, the curve was usually stable after sixteen years of age. Surgery was usually attempted in curves over 40° in the growing child. The same curve was usually stable after the growth period.For the non-ambulatory patients, the present study suggested the prescription of a molded seat with the following characteristics: i) a posterior lumbar support, ii) low thoracic lateral supports and Hi) a slight inclination of the seating system. This was presumed to be beneficial in maintaining stability of the spine.