Seen many hand launched planes go in after hand launch when the launcher threw the plane pointed "UP" at a high angle of attack. The stab and sometimes the wing are stalled out and the plane goes through several partial rolls, always getting worse as the pilot overcontrolled.

I've only found it necessary to run before throwing a plane once. The design was something called the 'Wasp'. 60 powered, fuselage was turned from a one piece balsa block. Also had less than 600 square inches of wing area. Weighed nearly 7 pounds. Couldn't take off from grass. This was back in the days of reed radios.
I've actually seen people trip while running to throw or during the throw. Usually ends up breaking the plane. Looks and sounds funny, till you think of somebody loosing control of one of today's high revving engines with razor sharp composite props.

My advise is, and sometimes I've demonstrated this, is to throw the plane firmly towards a spot maybe 100 or 150 in front of you, aiming it like you'd throw a dart.