What would the most likely cause of a scaphoid fracture,hitting a
person or putting your hand out to try to prevent yourself from
falling

Dear spankie,

The short answer to your question is "putting your hand out to try to
prevent yourself from falling", although it is not the only cause
(another being a severe blow to the wrist). A fracture is less likely
to be caused by hitting another person because it is a voluntary
movement and relies on strength - it is hard to fracture your bones
voluntarily. However, an involuntary movement such as a sudden fall
that has the weight of your body behind it, is much more likely to
cause a fracture.

"The usual cause of a fracture of the wrist is a fall where the wrist
is bent backward.  Most fractures will take place on the scaphoid, or
the radius of the wrist."
Berkeley.edu: HTML version
(no copyright found)
://www.google.ca/search?q=cache:OK4CFBo6dp8C:www.me.berkeley.edu/ME176/jointproj/tang_wrist.doc+caused+by+%22scaphoid+fracture%22&hl=en&ie=UTF-8

Additional links:

1. DynoMed.com: Hand & Wrist: Fracture of the Scaphoid:
http://www.dynomed.com/encyclopedia/encyclopedia/hand_and_wrist/Fracture_of_the_scaphoid.html

2. untitled:
http://www.cancoach.com/canmed/scaphoid.htm

3. CCHS digital library: Wrist Fracture Clinical Resources
http://cchs-dl.slis.ua.edu/clinical/orthopedics/upper/wrist-fracture.htm

4. Radiographers Reporting [includes x-ray images]:
http://members.fortunecity.com/radrep/id21.htm

5. Conditions of the Hand and Wrist: Fractures [click to view four
types]:
http://www.hhp.ufl.edu/ess/at/WristPage/conditions.htm

6. Sports Medicine Advisor 3.0: Navicular Navicular (Scaphoid)
Fracture:
http://www.preceptor.com/CrsSports/sma/navicfx.htm


Search Strategy:

://www.google.ca/search?as_q=caused+by&num=100&hl=en&ie=UTF-8&oe=UTF-8&btnG=Google+Search&as_epq=scaphoid+fracture&as_oq=&as_eq=&lr=&as_ft=i&as_filetype=&as_qdr=all&as_occt=any&as_dt=i&as_sitesearch=&safe=images

Terms Used:

"scaphoid fracture"
caused 
by

I hope this answers your question - if you need clarification, please
let me know before rating this answer. And I hope your wrist is ok!
Sincerely,
hummer

5 star top notch answer thanks alot,