Influence of back support shape in wheelchairs offering pelvic support on asymmetrical sitting posture and pressure points during reaching tasks in stroke patients.

Many poststroke hemiplegic patients have an asymmetrical wheelchair-sitting posture. This study aimed to investigate the impact of different back support shapes on asymmetrical sitting posture and pressure points among poststroke hemiplegic patients during an activities of daily living-related reaching task. This study included 23 poststroke hemiplegic patients who performed tasks that involved the movement of objects using the unaffected upper limb to the affected side while sitting in a conventional wheelchair (C-WC) with a flat back support or a wheelchair providing pelvic and thoracic support (P-WC). Body alignment angles from video images and pressure distribution on supporting surfaces were measured using a two-dimensional motion analysis software (Dartfish) and a pressure mapping system (FSA). Regarding movement performance, although postural asymmetry increased in both wheelchair types, the degree of postural variation was smaller with P-WC use than C-WC use (p < 0.05), with partly reduced postural asymmetry. With P-WC, one-sided ischial asymmetrical pressure was significantly less after the movement (p < 0.05). In conclusion, P-WC's back support shape contributed to a decrease in postural asymmetry for pelvic girdle support both at rest and during movement. This highlights the importance of a wheelchair back support shape and may help to increase the quality of activities of daily living movement in poststroke hemiplegic patients in wheelchairs.

Does a Novel-Developed Product of Wheelchair Incorporating Pelvic Support Prevent Forward Head Posture during Prolonged Sitting?

Disabled elderly individuals with kyphosis or loss of muscle strength often display forward head posture (FHP). This study aimed to determine the utility of a wheelchair incorporating pelvic support in preventing FHP in disabled elderly individuals. In this study, 14 disabled elderly individuals (87.1 ± 8.1 years) were selected. A wheelchair incorporating pelvic support (RX_ABS Lo) and a basic wheelchair (RX-1) were used. Each individual sat on both wheelchairs for 30 minutes. RX_ABS Lo has two belts to support the pelvic and thorax. Postures were recorded in the sagittal plane using a video camera. Cervical and trunk angles from horizontal were measured every 5 minutes. Simultaneously, contact areas and total pressures applied to the wheelchair seats and back supports were measured every 5 minutes. Comparisons of area under the curve values between the wheelchairs were performed using the paired t-test. Comparisons of time-dependent parameters for each wheelchair were performed using repeated one-way ANOVA. Cervical angles were greater when using RX_ABS Lo than RX-1. Although cervical angles were unchanged during 30 minutes when using RX_ABS Lo, the angles were significantly decreased after 30 minutes of using RX-1. Back support pressures and contact areas were greater for RX_ABS Lo than for RX-1. No significant difference in back support pressure distributions was observed during 30 minutes in the wheelchairs. The RX_ABS Lo may have utility in improving FHP by increasing cervical angles and improving stability with a back support to the upper thorax, lower thorax, and pelvis during prolonged sitting.

Backrest Shape Affects Head-Neck Alignment and Seated Pressure.

Unstable back support against gravity results in a forward head posture and contributes to buttocks pressure ulcers. However, the association between these health problems and a wheelchair backrest is unclear. Our newly developed wheelchair (N-WC) supports the back of the pelvis and thorax from obliquely underneath. The purpose of this study was to investigate the effect of different backrest shapes on head-neck alignment and seated pressure. Data from 28 healthy subjects were analyzed. Outcome measures were head-neck alignment angles, support angles of the backrest, and pressure distributions on the supporting surfaces. Compared with a typical wheelchair that has a flat backrest, the seat pressure decreased and the center of pressure was located in the middle of both the seat and backrest in the N-WC. Moreover, the head-neck alignment when seated in the N-WC was upright. These results highlight the importance of the shape of the wheelchair backrest.

Evaluating the relationships between the postural adaptation of patients with profound cerebral palsy and the configuration of the Seating Buggy's seating support surface.

We are currently investigating the physiological polymorphism of wheelchair users with profound cerebral palsy and the properties of the Seating Buggy (developed by S. Nishimura, 1998) to clarify important and general elements of wheelchairs for widespread use. Cerebral palsy is a diagnostic term used to describe a group of motor syndromes resulting from disorders in early brain development. Recently, it has been shown that the Seating Buggy produces functional head-neck alignments and active control of sitting balance for people with profound cerebral palsy. The Seating Buggy is a wheelchair for the profoundly disabled and features a wide adjustment range from heights of 120 cm to 175 cm. Its seating support surface is comprised of a sling-seat. To examine the relationships between the postural adaptation of patients with profound cerebral palsy and the configuration of the Seating Buggy's seating, we assessed the postural alignment of the Seating Buggy's user and then measured the configuration of its resulting seating support surface with a three dimensional scanning system. Twenty-one subjects were used for the purposes of this investigation in their everyday environment. Postural adaptation and wheelchair fitting in the Seating Buggy were assessed from the viewpoint of the Active Balanced Seating by a seating expert. The subjects fell into two categories, as follows: 11 for appropriate or nearly appropriate fitting, and 10 for ill-fitting. The depth of thoracic support and the forward distance of lumbar support for those who claimed that it was ill-fitting were significantly reduced compared with that of those who claimed that the Seating Buggy offered an appropriate or nearly appropriate fitting. It was suggested that the properly adjusted depth of thoracic support and distance of the lumbar support were related to the resulting satisfactory head-neck alignment and sitting balance of the patients with profound cerebral palsy.