Comparing the effects of different dynamic sitting strategies in wheelchair seating on lumbar-pelvic angle

Abstract

BackgroundProlonged static sitting in a wheelchair is associated with an increased risk of lower back pain. The wheelchair seating system is a key factor of this risk because it affects spinal loading in the sitting position. In this study, 7 dynamic sitting strategies (DSSs) are examined: lumbar prominent dynamic sitting (LPDS), back reclined dynamic sitting (BRDS), femur upward dynamic sitting (FUDS), lumbar prominent with back reclined dynamic sitting (LBDS), lumbar prominent with femur upward dynamic sitting (LFDS), back reclined with femur upward dynamic sitting (BFDS), and lumbar prominent with back reclined with femur upward dynamic sitting (LBFDS). The objective of this study was to analyze the biomechanical effects of these sitting strategies on lumbar-pelvic angles.MethodsTwenty able-bodied participants were recruited for the study. All participants performed LPDS, BRDS, FUDS, LBDS, LFDS, BFDS, and LBFDS in a random order. All lumbar-pelvic angle parameters, including the static lumbar angle, static pelvic angle, lumbar range of motion, and pelvic range of motion were measured and compared.ResultsResults show that LBDS and LBFDS enabled the most beneficial lumbar movements, although the difference between the 2 strategies was nonsignificant. BRDS and BFDS enabled the most beneficial pelvic movements, although the difference between the 2 strategies was nonsignificant. Among all the upright DSSs, LPDS and LFDS enabled the most beneficial lumbar and pelvic movements, although no significant difference was observed between these 2 strategies.ConclusionsWe identified the effects and differences among 7 DSSs on lumbar-pelvic angles. Wheelchair users can choose the most suitable DSS that meets their needs. These findings may serve as a reference for practicing physicians or wheelchair users to choose an appropriate dynamic wheelchair seating system.Trial registration ISRCTN12389808, 18th November 2016, retrospectively registered.

Biomechanical analysis of different dynamic sitting techniques: an exploratory study

“…Before the experiment started, each subject was first asked to rest their upper body on the backrest and relax their arms on both sides. Moreover, they had to keep their thighs parallel to the ground, feet approximately shoulder-width apart and firm on the footrest, and eyes looking straight ahead [16, 17]. Afterward, the sequence of three DSTs was randomly drawn by each subject (illustrated in Fig.…”

Evaluation of the effect of different sitting assistive devices in reclining wheelchair on interface pressure

“…(2) LBM: the backrest of the wheelchair was pushed backward to reach a 150° recline, while a lumbar airbag, fully inflated to a thickness of 4 cm, was placed at the L3 spinal segment of the participant [ 20 – 23 ]. (3) FBM: the backrest of the wheelchair was pushed backward to reach a 150° recline, and a femur airbag, fully inflated to a thickness of 4 cm, was placed at the midpoint of the thighs of the participant [ 19 – 21 ]. (4) LFBM: the backrest of the wheelchair was pushed backward reach a 150° recline and both lumbar and femur airbags were used, the lumbar airbag, fully inflated to a thickness of 4 cm, was placed at the L3 segment of the participant, whereas the femur airbag, also fully inflated to a thickness of 4 cm, was placed at the midpoint of the thighs of the participant [ 19 – 23 ].…”

“…These devices can be used independently on different types of wheelchairs. Some studies have shown that lumbar supports can reduce stress on the intervertebral discs by creating lumbar lordosis at the waist and shifting part of the stress from the buttocks area to the lumbar support that the back area is leaning on [ 13 – 16 , 19 ]. Furthermore, cushions correct the problem of stress concentration at the ITs by redistributing stress on the buttocks and thighs [ 4 , 12 , 18 ].…”

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

“…On the other hand, stroke patients' less symmetrical posture during wheelchair-sitting may related not only to their imbalance characteristics but also the wheelchair's shape itself. One study suggested that different positioning of the wheelchair seat and back affected the lumbarpelvic angle and dynamic movement [21]. Additionally, variable thoracic or lumbar or pelvic (PL) support can generate different changes in muscle activation or pressure distribution or postural alignment, respectively [22][23][24].…”