A walking assistance device having a leg link connected to a load transmit
portion via a first joint and to a foot attachment portion via a second
joint, and having an intermediate third joint moving such that a distance
between the first joint and the second joint is variable; a drive source
for the third joint; and a battery for the drive source. When in an
upstanding position, force in the forward-backward direction is prevented
from acting on the load transmit portion to enhance stability. Also, a
moment of inertia of the leg link is decreased to curtail a load applied
to the leg of the user. The drive source and the battery are located at
positions higher than the third joint, and when the user is in an
upstanding position, a plane passing through the second joint lies
between the drive source and the battery.