sd.setAsBox(50.0f, 0.4f);
BodyDef bd = new BodyDef();
bd.position.set(0.0f, 0.0f);
ground = getWorld().createBody(bd);
ground.createFixture(sd, 0f);
sd.setAsBox(0.4f, 50.0f, new Vec2(-10.0f, 0.0f), 0.0f);
ground.createFixture(sd, 0f);
sd.setAsBox(0.4f, 50.0f, new Vec2(10.0f, 0.0f), 0.0f);
ground.createFixture(sd, 0f);