Exoskeleton legs to reduce fatigue during repetitive and prolonged squatting

An apparatus configured to be coupled to a wearer, the apparatus comprising:

• a first exoskeleton leg comprising:
• a thigh link;
• a shank link;
• a knee joint coupled to the thigh link and the shank link, and configured to allow flexion and extension motion between the thigh link and the shank link;
• a force generator comprising a first end and a second end, wherein the first end is coupled to the shank link, and wherein the second end is coupled to the thigh link;
• a constraining mechanism coupled to the thigh link, wherein the constraining mechanism is configured to have at least two operation modes, a constrained mode and an unconstrained mode;
• and
• a first signal processor configured to move the constraining mechanism between its at least two operation modes,
• wherein, when in the constrained mode, the constraining mechanism is configured to limit the second end of the force generator to a rotational motion relative to the thigh link, and is configured to provide support to the wearer when the knee of the wearer is flexing, and
• wherein, when in the unconstrained mode, the constraining mechanism is configured to allow additional motion of the second end of the force generator relative to the thigh link in addition to the rotational motion, and is configured to provide no support to the wearer when the knee of the wearer is flexing.