The influence of backrest inclination on buttock pressure

Effects of the wheelchair sitting posture on gluteal pressure

[Purpose] To evaluate the efficacy of the "forward-tilting posture" (the trunk tilted forward against a table) in a wheelchair in relieving gluteal pressure. [Participants and Methods] Thirty-six healthy adults were instructed to sit in a wheelchair assuming the following three postures: (1) both feet placed on the foot support with the trunk upright ("basic sitting posture"), (2) both feet placed on the foot support with the trunk tilted forward against a table ("forward-tilting posture A"), and (3) both feet placed on the floor with the trunk tilted forward against a table ("forward-tilting posture B"). A seat-type sensor pad placed on a wheelchair cushion was used to measure the maximum gluteal pressure and gluteal contact area. [Results] The maximum gluteal pressures in "forward-tilting postures A" and "forward-tilting postures B" were significantly lower than those in the basic sitting posture. The maximum gluteal pressure in "forward-tilting posture B" was significantly lower than that in "forward-tilting posture A". The gluteal contact area in "forward-tilting posture B" was significantly larger than that in "forward-tilting posture A". [Conclusion] The study results indicate that the "forward-tilting posture" in a wheelchair effectively relieves gluteal pressure.

An investigation into the effectiveness of a novel wheelchair seat-cover assembly for the reduction of forces exerted onto the buttocks

Purpose: This purpose was to investigate developed seat-cover assemblies' effect on decreasing the fluctuation of the shear force exerted onto the buttocks as the factors causing decubitus ulcers when the back-support was inclined.Materials and Methods: The participants were 10 wheelchair users. The force plate was used to measure the horizontal force as the shear force. The back-support was inclined at increasing angles, starting from the upright position (IUP), then proceeding to a fully reclined position (FRP), and returning to the upright position (RUP). The experimental conditions were two conditions; the seat-cover assembly conditions and without the seat-cover assembly as the control conditions.Results: The average values in the seat-cover assembly condition were 14.4 ± 3.3, 13.9 ± 2.3, and 17.3 ± 3.3% body weight in the IUP, FRP, and RUP, respectively. The average values in the control condition were 14.8 ± 2.6, 11.4 ± 1.7, and 24.0 ± 6.7% body weight in the IUP, FRP, and RUP, respectively. In the FUP and the RUP, there were significant differences between two conditions (p < .01).Conclusion: These results suggested that the shear force exerted onto the buttocks may to be decreased by using novel seat-cover assembly.Implications for rehabilitationIt is possible to decrease the fluctuations in the shear force by moving the body up and down according the novel seat-cover assembly attached the back-support incline.Disabled, older individuals can be provided with a comfortable life on a reclining wheelchair while preventing decubitus ulcers.

Wheelchair Tilt-in-Space and Recline Functions: Influence on Sitting Interface Pressure and Ischial Blood Flow in an Elderly Population

Pressure ulcers (PUs) result from localised injury to the skin and underlying tissue and usually occur over a bony prominence as a result of pressure, often in combination with shear forces. Both pressure magnitude and duration are thought to be key risk factors in the occurrence of PUs, thus exposing wheelchair-bound subjects to high risk of PU development. As a result, wheelchairs that incorporate tilt-in-space and recline functions are routinely prescribed to redistribute pressure away from their ischial tuberosities. The goal of this study was to analyse the role of full-body tilt and recline angles in governing sitting interface pressure and blood circulation parameters in elderly subjects and thereby investigate the efficacy of tilt-in-space wheelchairs for aiding pressure relief activity. Sitting interface pressure and ischial blood flow parameters were examined in 20 healthy elderly subjects while seated in a tilt-in-space and recline wheelchair. Five different angles of seat tilt (5°, 15°, 25°, 35°, and 45°) were assessed in combination with three different angles of backrest recline (5°, 15°, and 30°). The results of the study show that when compared to the upright reference posture, every position (except 15°T/5°R) resulted in a significant decrease in sitting interface pressure. Ischial blood flow also showed significant increases at four different positions (45°T/15°R, 15°T/30°R, 35°T/30°R, and 45°T/30°R) but only at larger tilt-in-space and recline angles. The results therefore suggest that small tilt-in-space and recline angles are indeed able to reduce sitting interface pressures, whereas changes in ischial blood flow only occur at larger angles. In the literature, cell deformation is thought to be dominant over tissue ischemia in the development of tissue necrosis and PUs. Therefore, together with our findings it can be concluded that frequently undertaking small adjustments in tilt-in-space and recline angle might be important for preventing cell deformation and any associated cell necrosis. Larger angles of tilt-in-space and recline seem to support blood flow returning to the tissues, which is likely to play a positive role in healing damaged tissue.

Reconstruction of gluteal deformities: a systematic review and experience of four cases

BACKGROUND

The reconstruction of gluteal deformities remains a major challenge. The aim of this article is to provide a systematic review of the literature concerned, and to present a case series with representative defects from various zones.

METHODS

A review of the literature was performed using PubMed, EMBASE, and The Cochrane Library, in accordance with the PRISMA statement. Quality of evidence was rated according to GRADE. Patients with various buttock deformities were included and, depending on the defect, the reconstructive techniques applied consisted of lipoinjection, local fasciocutaneous flap, or pedicled gracilis muscle flap. Complications, patient's pain assessment, impairment in everyday-life activities, aesthetic outcome, objective assessment of sensitivity, and recurrence were considered.

RESULTS

A total of 498 records were identified in the literature search. Of those, 12 studies met the PICOS (participants, interventions, comparators, outcomes, and study design) criteria. Overall, 41 patients were analysed, the evidence of which was of low quality. In this study, four patients (three female and one male) with a mean age of 44 ± 15 years were operated on between 2010-2014. The mean operation time was 83 ± 30 minutes. One patient required revision due to persistent seroma and recurrence, and one patient required neurolysis and gracilis denervation due to neuroma and scarring. After a mean follow-up of 40 ± 21 months, the results were functionally and cosmetically satisfactory.

CONCLUSIONS

Reconstruction of buttock deformities using an integrated approach can lead to a long-lasting, functionally and aesthetically satisfactory result. However, evidence is limited due to the lack of good-quality studies.

Investigation of effect of leg support elevation timing on the horizontal force acting on the buttocks in a reclining wheelchair

[Purpose] The purpose of this study was to investigate the effect of the timing of leg support elevation on the horizontal force acting on the buttocks in a reclining wheelchair. [Subjects and Methods] The participants were 17 healthy men. Two experimental conditions were tested: the leg-down and leg-up conditions. The back support was reclined at increasing angles, from the initial upright position (IUP), proceeding to the fully reclined position (FRP), and returned to the upright position (RUP). The posterior inclination phase was from IUP to FRP, and the returning inclination phase was from FRP to RUP. [Results] The horizontal force under the leg-up condition was significantly higher than that under the leg-down condition in all positions of back support. [Conclusion] The leg supports should be positioned downward before reclining the back support of a wheelchair.

The effect of an acupressure backrest on pain and disability in office workers with chronic low back pain: A randomized, controlled study and patients' preferences

OBJECTIVE

This study investigated the effects of an acupoint-stimulating lumbar backrest on pain and disability in office workers who suffering from low back pain (LBP) as well as the preference influence on pain and disability.

METHODS

Sixty-four participants were randomly assigned to two groups: one with no intervention (n=32) and another with 1 month of backrest use (n=32). An additional group (n=37) who wished to try 1 month of acupressure backrest were recruited to indicate the preference effect. Pain and disability were two key outcomes.

RESULTS

Significant differences between control and randomized acupressure backrest groups were found at 2 week period for disability and at 4 weeks for pain after the backrest use. Also, significant differences were found in both groups for 3 month period with an increase of the treatment effect on pain and disability. Both control and randomized acupressure backrest groups showed greater improvement in pain and disability scores which were more than the minimal clinically important change (30% improvement for both outcomes). No significant difference was found for pain and disability between the randomized and preferred backrest groups.

CONCLUSION

These findings suggested 1-month of acupressure backrest use could improve LBP conditions. Preference was not a powerful moderator to the significant treatment effect.

Aspects of manual wheelchair configuration affecting mobility: a review

Many aspects relating to equipment configuration affect users' actions in a manual wheelchair, determining the overall mobility performance. Since the equipment components and configuration determine both stability and mobility efficiency, configuring the wheelchair with the most appropriate set-up for individual users' needs is a difficult task. Several studies have shown the importance of seat/backrest assembly and the relative position of the rear wheels to the user in terms of the kinetics and kinematics of manual propulsion. More recently, new studies have brought to light evidence on the inertial properties of different wheelchair configurations. Further new studies have highlighted the handrim as a key component of wheelchair assembly, since it is the interface through which the user drives the chair. In light of the new evidence on wheelchair mechanics and propulsion kinetics and kinematics, this article presents a review of the most important aspects of wheelchair configuration that affect the users' actions and mobility.