What is an exoskeleton? All about assisted skeletons

Although the idea for the first exoskeleton appeared more than 120 years ago, it is a technology that entered the consciousness of ordinary people relatively recently. So let’s look at the topic of assisted skeletons – what is their use and what are they for?

History of the exoskeleton – how did it start?

Exoskeleton – what exactly is it? Bionic, exo – that is, external, skeleton – also known as power armor, is a special structure that corresponds to human anatomy and imitates his movements. To create the system, highly advanced technology is used and knowledge from various fields of science is combined. Newer and newer versions of exoskeletons are created in order to increase the physical capabilities of a person and even restore the mobility of paralyzed people.

The first reports on the exoskeleton date back to the 19th century, when in 1890 Mikolaj Jagin created a pioneering apparatus “supporting walking, jumping and running”. The wooden armor is designed to increase the speed of marching soldiers for miles. It was the demand of the armed forces that initiated further work on the creation of the exoskeleton.

The twentieth century brought further attempts to build a reliable combat armor that would support human strength and endurance. Unfortunately, the poorly developed technology was not able to meet the ideas of the designers. In fact, it was only the 21st century that allowed for the intensification of work: the military exoskeleton was not only designed and built, but also tested by American soldiers during the armed conflict in Afghanistan, it was the Human Universal Load Carrier – HULC. 

HULC made it possible to carry heavy loads (even up to 90 kg), although it weighed relatively little (23 kg). It was the negative effects of overloading soldiers with the necessary equipment (which on average reaches about 30 kg) that gave impetus to the search for structures supporting physical abilities and preventing injuries. 

Advanced research on the combat exoskeleton allowed to distinguish structures also for another purpose – medical exoskeletons. Thanks to this technology, previously known rather from Science Fiction movies, has become widely available and provides invaluable help to patients. 

Application of the exoskeleton in medicine

Rehabilitation in neurological diseases, limb paralysis and spinal cord injuries is a field in which the exoskeleton turned out to be a real revolution. The construction of the mobile structure is based on the use of a system consisting of actuators of various types, including electric, hydraulic and pneumatic, which are mounted on the hip and knee joints. They are powered by a motor or battery, they initiate steps or other movements (e.g. standing up and sitting down). The control can be carried out in several ways:

• mechanically, e.g. with a joystick,
• voice,
• computer,
• using skin and subcutaneous sensors as well as force and movement,
• using brain waves.

The assisted exoskeleton for medical purposes is distinguished by great usefulness, which includes:

• replacing disabled muscles,
• rehabilitation of patients with neurological diseases (e.g. after stroke), with damaged spinal cord, partial or total paralysis and others,
• replacing a wheelchair,
• supporting natural motor skills,
• relieving of the osteoarticular system,
• strengthening of muscle strength,
• standing upright and gait re-education,
• support of medical staff and caregivers of people with disabilities.

The use of an exoskeleton also reduces the number of personnel necessary to conduct individual rehabilitation, e.g. gait re-education. Although faster achievement of visible rehabilitation results is one of the most important advantages of medical exoskeletons, the most important is the invaluable support of the patient’s psyche, who is able to take a step or perform a given activity on their own.

The use of the exoskeleton in the military

The search for solutions that would increase the physical capabilities of soldiers led to the creation of numerous prototypes, and as a result of technologically advanced structures, among them – the exoskeleton. The military has become a place where more and more innovative solutions are sought to support combat efficiency. 

The modern military exoskeleton takes the form of a mechatronic (robotic) system in the form of an armor put on a soldier, which may cover only the legs or all four limbs. First of all, it makes it easier to carry heavy equipment – it increases strength and endurance. In addition, it facilitates and accelerates long walks in difficult terrain, and supports rescue and evacuation operations.

Hopes placed in the dynamically developing technology translate into high requirements for combat exoskeletons. The US Department of the Army even defined them strictly, taking into account, inter alia:

• increasing combat capabilities by reducing the weight of equipment and facilitating transportation over long distances in difficult terrain,
• supporting the enemy observation processes,
• providing protection against the effects of the use of various types of weapons,
• supporting the senses of sight and hearing,
• ensuring hard-to-detect connectivity; and the possibility of rapid digital data transfer. 

The price of a military exoskeleton depends primarily on the type and advancement of the technology used to build it. For example, the armor introduced to the army by the Russians does not have an electric power supply, which translates into a relatively low price, estimated at around $ 3.5 thousand. For comparison, more technologically advanced American skeletons cost about $ 20,000 apiece.

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Other uses for the assisted skeleton

Exoskeletons are used wherever it is desired to enhance human endurance, strength or stability. So it turns out that their usefulness is not limited only to medical and combat applications, but they are successfully used in construction, agriculture, heavy industry and rescue. The industrial exoskeleton is used, among other things, for assembling and carrying heavy loads, the need to stay in an uncomfortable position for a long time, or to cover long distances on foot.

The first exoskeleton for physical work was presented by the American company Sarcos Robotics. The structure called Guardian XO allows you to carry a weight of up to 90 kg. As the manufacturer himself points out, the industrial exoskeleton was created from the need to enable employees to increase their productivity in a completely safe way and to reduce the risk of injuries. The company emphasizes that the equipment makes it possible to replace several employees with one equipped with support armor.

Exoskeleton as an element of SF pop culture

Probably your first association with exoskeletons were the robotic suits of superhero movies. This is not surprising, because the designs and prototypes of such support armor have been inspiring the creators for years. 

One of the most famous exoskeleton models in the movies is the Power Loader P-5000 from the movie Aliens. The main character used it in “hand-to-hand” combat with the Alien Queen aboard the USS Sulaco. Thanks to him, Ripley was able to engage in an equal fight with the extremely strong Queen. This should come as no surprise – according to the information, the P-5000 is capable of lifting a weight of 4 tons.

Another character deeply rooted in SF pop culture is the Marvel Comics superhero, Iron Man, who is associated with his red and gold cybernetic armor. It is not the only support armor in the series. The hero constructed technologically advanced armor that gave him superhuman strength, endurance, and even the ability to fly.

Another example is the film by Neill Blomkamp Elysium, where the exoskeleton plays an invaluable support role for the main character and Edge of Tomorrow – in which humanity uses the so-called Combat Jacket – an exoskeleton supporting soldiers in the fight against extremely dangerous aliens.

Presentation of selected models of assisted skeletons – their prices and purpose

1. Bionics Free Walk exoskeleton

It is characterized by a simple structure that is easy and quick to install. It allows you to control it through an application on a phone or tablet and with the use of the included elbow crutches, and when folded, it fits in a suitcase. It allows you to adjust the system to the patient in just 10 minutes. It is characterized by high comfort of use and is intended for rehabilitation: it allows you to get up, sit down and walk.

Device weight: 20 kg.

Designed for patients with a height of 150 cm to 190 cm and a body weight of up to 100 kg. 

Price: approx. $100.000

2. ReWalk Exoskeleton by ReWalk Robotics

This is the first exoskeleton model to be approved by the US Food and Drug Administration (FDA) for sale in the US. It is intended for paralyzed people and is designed to significantly improve the quality of life of patients, enabling independent walking. Operation is described as “trivial” through the controller worn on the hand. The user can use three modes: walking, sitting and standing.

Device weight: 23 kg.

Price: approx. $70.000

3. Fortis exoskeleton by Lockheed Martin

This lightweight 12 kg exoskeleton is designed for use in heavy industry. It allows you to carry loads up to 16 kg effortlessly. The advanced ergonomic design moves naturally with your body and adapts to different body types. The manufacturer also offers the tool arm itself. Interestingly, it does not need power for its work. 

Price: approx. $24.000 for the entire skeleton and about $7.000 for the arm.

4. Sarcos’ Guardian XO

The aforementioned four-limb industrial exoskeleton is used to increase employee productivity, allowing them to perform smooth movements and freely lift loads up to 90 kg. It takes less than 30 seconds to put it on.

Rental price per year: $100.000

As you can see, exoskeletons are the future not only of the military, but also of medicine and industry. It is a technology that, although designed mainly for warfare, becomes more and more available and makes life easier for those who need this type of specialist support.