Related Experiment Video
Updated: Jun 6, 2026

Tilt Testing with Combined Lower Body Negative Pressure: a "Gold Standard" for Measuring Orthostatic Tolerance
Published on: March 21, 2013
The impact of tilting on blood flow and localized tissue loading
Sharon E Sonenblum1, Stephen H Sprigle
1School of Applied Physiology, Georgia Institute of Technology, Atlanta GA 30318, USA. sharon.sonenblum@coa.gatech.edu
Aim Of The Study:
The overall goal of this research was to improve the use of seated tilt to increase function, health and quality of life for people using power wheelchairs. Specifically, the objective of this study was to evaluate the biomechanical responses to seated full body tilt in persons with spinal cord injury (SCI).
Materials And Methods:
Laser Doppler Flowmetry and interface pressure measurement were employed to measure changes in blood flow and loading at the ischial tuberosities across different amounts of tilt. Eleven participants with SCI were studied in a laboratory setting.
Results:
Results showed that biomechanical responses to tilt were highly variable. Pressure reduction at the ischial tuberosity was not present at 15°, but did occur with tilts to 30° and greater, and could be explained by the tilt position and upright pressure. Unlike pressure, blood flow increased with all tilts from an upright position, but did not increase when tilting from 15° to 30°. Only 4 of 11 participants had increases in blood flow of ≥10% at 30° tilt, whereas 9 participants did during maximum tilt (i.e., 45°-60°).
Conclusions:
Based on the results of this study, tilting for pressure reliefs as far as the seating system permits is suggested to maximize the potential for significant blood flow increases and pressure relief. The use of interim small tilts is also supported, as they also provide some benefit.
Related Concept Videos
Applications of Integration to Find Blood Flow
Autoregulation of Blood Flow
Chemical Signaling in Autoregulation
Chemical signaling operates at the precapillary sphincter level, inciting either contraction or relaxation.
Blood Flow
Blood Pressure Imbalances and Circulatory Shock
Blood Pressure: Hypertension and Hypotension
Normal blood pressure is 120/80 mm Hg. Elevated blood pressure is 120-129/under 80 mm Hg. Hypertension, warranting treatment at 130/80 mm Hg, is often asymptomatic and can lead to severe cardiovascular events, aneurysms, peripheral arterial disease, chronic renal disease, or cardiac...
Impact Loading on a Cantilever Beam
When an object is dropped onto the free end of a cantilever, its potential energy due to gravity is...
Impact Loading
In cases of elastic deformation,...

