A powered exoskeleton is no longer science fiction
Working models have been in existence since the mid 90's. The concept was first used in Comic book characters such as "Ironman". A super hero who gets super-human strength from his powered armor suit.
Many concepts and designs are on the drawing board or in development. The exoskeleton can take various forms and size. Another exciting idea is the "human motorcycle". A exoskeleton you wear and has wheels. Mind control computers are being developed to enable paralyzed people to one day walk, run and have every day motor skills that most take for granted. Experiments using monkeys has proved amazing results. Using thought process they can play computer games that reward them with a drink or treats. This technology can then be applied to humans with disabilities. In the very near future people who were previously bound to a bed or wheel chair will be able to live a near normal life with the exoskeleton.
Orthoses are a limited medical exoskeleton usually attached to a limb or torso. Designed to support / correct the limb or spine. An skeletal arm has been designed for assisting people sitting at desks also. Making the strain of typing all day long easier.
The powered exoskeleton has an exciting future. Various applications can be realized with the high tech hardware. Not only for military applications, but also assisting people to get out of their wheel chairs. Many jobs that require standing for long periods of time or lifting heavy objects can also benefit from the powered exoskeleton. As the technology advances, the units will be more affordable and adaptable.
Soldiers in the field usually have a lot of essential equipment to pack. The exoskeleton assist the soldiers in carrying out their mission. Rough mountain terrain can be tackled and still leave the soldier enough energy to complete their mission upon arrival. Fatigue can result in lack of awareness. Not something one wants in an active battlefield.
In nature an exoskeleton has a set of function roles. Protection, support, feeding, sensing and muscle support. Some organisms also use it as a defense or barrier against threats. For example a Hermit crab usually will have a empty gastropod shell attached to protect its soft abdomens. Fossils will usually only have the exoskeleton of the animal or organism as it is the hardest. Softer tissue or flesh will decomposs before fossilization can take place.