If you learn to use the following Upper Body Protective Technique correctly, your forearm will act as a "bumper" to protect the upper part of your body from hanging plants, open cupboard doors, and room doors that are partially ajar.
It's important to remember that this technique will only partially protect your shoulder and chest area, and will not protect you below the waist or warn you about approaching drop-offs, such as steps and stairs. For maximum protection, you should use a combination of upper and lower body protective techniques [3]
See also the Lower Body Protective Technique [3], the Trailing Technique [4]
Links:
[1] http://www.visionaware.org/publications/visionaware-orientation-mobility.pdf
[2] http://www.visionaware.org/publications/visionaware-orientation-mobility-LP.pdf
[3] http://www.visionaware.org/lower_body_protective_technique
[4] http://www.visionaware.org/trailing_technique