Monitoring the biomechanical and physiological effects of postural changes during leisure chair sitting.

BACKGROUND: Individuals with limited mobility can spend prolonged periods in leisure chairs, increasing their risk of developing a seated acquired pressure ulcer. The present study aims to use objective measures of posture and tissue viability to identify the associated risks of leisure chair related pressure ulcers.

METHODS: Healthy participants (n = 13) were recruited to sit on a leisure chair with either a viscoelastic foam or air cushion. Participants were asked to adopt four different postures for a period of 10 min followed by a 10 min refractory period. Measurements at the leisure chair-participant interface included interface pressure, transcutaneous tissue gas tensions at the ischial tuberosities, accelerometer data collected from the sternum and subjective comfort levels.

RESULTS: Results indicated that interface pressures remained consistent, with peak pressure index values of less than 60 mmHg across all conditions. A proportion of participants exhibited decreased oxygen tensions associated with increased carbon dioxide tensions during one or more test condition. This was particularly prevalent during the right lean posture on the air cushion (46%). In all cases, normal tissue viability was restored during standing. The accelerometer was able to detect significant changes (p < 0.05) in relative trunk angles during slump and right lean when compared to optimal sitting posture.

CONCLUSION: Commercially available leisure chairs have little evidence to support their pressure relieving properties. This study revealed that a proportion of healthy individuals demonstrated a compromised tissue viability in specific postures. Further research is required to assess the impact of these sitting conditions in vulnerable individuals.