Article

Most posture problems encountered in persons who use wheelchairs in a
seated posture for extended periods are related to sacral sitting due to
posterior pelvic tilt. Posterior pelvic tilt places pressure and shearing force
on the sacrococcygeal area that can lead to pressure ulcers, but the relationship
between pelvic tilt and force applied to the sacrococcygeal and ischial
tuberosity areas has not yet been investigated. OBJECTIVE: To investigate the
relationships of posterior pelvic tilt in a seated posture with vertical force
and horizontal force on the sacrococcygeal and ischial tuberosity areas. STUDY
DESIGN: Repeated measures design. METHODS: Thirty male and female subjects aged
>/=60 years sat in a measurement chair at varying pelvic tilt angles, and force
on the sacrococcygeal and ischial tuberosity areas was measured. RESULTS: The
pressure on the sacrococcygeal area increased with pelvic tilt in all subjects,
with vertical force averaging 19% of the body weight at a pelvic tilt angle of 30
degrees . The horizontal force on the sacrococcygeal area increased in 93% of the
subjects, with an average increase equal to 3% of the body weight. CONCLUSIONS:
We confirmed changes in vertical and horizontal forces on the sacrococcygeal and
ischial tuberosity areas with a change in seated posture (pelvic tilt). CLINICAL
RELEVANCE: We propose guidelines for rehabilitation practitioners working with
wheelchair users to suggest improved ways of sitting in wheelchairs that avoid
pelvic tilt angles that might promote pressure ulcers on the buttocks.

Langue : ANGLAIS