Exoskeleton (human)

An exoskeleton is a wearable device that augments, enables, assists, or enhances motion, posture, or physical activity through mechanical interaction with and force applied to the user’s body.^[2]

Other common names for a wearable exoskeleton include exo, exo technology, assistive exoskeleton, and human augmentation exoskeleton. The term exosuit is sometimes used, but typically this refers specifically to a subset of exoskeletons composed largely of soft materials.^[3] The term wearable robot is also sometimes used to refer to an exoskeleton, and this does encompass a subset of exoskeletons; however, not all exoskeletons are robotic in nature. Similarly, some but not all exoskeletons can be categorized as bionic devices.

Exoskeletons are also related to orthoses (also called orthotics). Orthoses are devices such as braces and splints that provide physical support to an injured body part, such as a hand, arm, leg, or foot. The definition of exoskeleton and definition of orthosis are partially overlapping, but there is no formal consensus and there is a bit of a gray area in terms of classifying different devices. Some orthoses, such as motorized orthoses, are generally considered to also be exoskeletons. However, simple orthoses such as back braces or splints are generally not considered to be exoskeletons. For some orthoses, experts in the field have differing opinions on whether they are exoskeletons or not.

Exoskeletons are related to, but distinct from, prostheses (also called prosthetics). Prostheses are devices that replace missing biological body parts, such as an arm or a leg. In contrast, exoskeletons assist or enhance existing biological body parts.

Wearable devices or apparel that provide small or negligible amounts of force to the user’s body are not considered to be exoskeletons. For instance, clothing and compression garments would not qualify as exoskeletons, nor would wristwatches or wearable devices that vibrate. Well-established, pre-existing categories of such as shoes or footwear are generally not considered to be exoskeletons; however, gray areas exist, and new devices may be developed that span multiple categories or are difficult to classify.