A human motion assistance device has an upper torso harness for attaching to a user. The upper torso harness has a shoulder strap or backpack assembly. A belt is connected to the upper torso harness and extends around a waist and back area of the user. Leg straps are affixed to the upper torso harness proximate to a gluteal area of the user and configured to extend down a hamstring area to cross in front of a knee area and further extend down a calf area to a foot anchor. The leg straps are made of an elastic material with a pocket around the knee area of the user. The foot anchor may extend under the heel to an arch strap, or cross over the talus and under the arch of the foot. The upper torso harness and leg straps are passive without active members.