heyas; it depends on which way your thigh/shoulder/wing/neck/head are facing. but for a standard humanoid, the thigh is yzx, the shoulder/armparts are xyz, the neck and yead are yzx. you shouldn't need to use the spherical falloff zones on straight limbs with only one child each part. usually the only place you need it is where a part has multiple children that get in each other's way, or where an odd shape to the parent and/or child makes them neccessary.