The invention helps its wearer stand and provides extra strength to the legs. The 'trousers' were inspired by Aardman Animation's characters Wallace and Gromit.
Numerous technologies have gone into the £2m project funded by the Engineering and Physical Sciences Research Council (EPSRC), including smart electronics, graphene and artificial muscles.
Within 10 years, the scientists hope to produce a pair of lightweight "power trousers" that can boost the strength of weakening muscles and joints by 5 to 10 per cent.
"We have developed lightweight bubble artificial muscles, which could help people to stand up or to lift objects," said lead researcher Jonathan Rossiter, Professor of Robotics at the University of Bristol.
"The artificial muscles are not yet brain-controllable but rather work by measuring the muscle activity of the limbs."
"Our dream is to make our devices ubiquitous. In six or seven years' time you could go into Boots, select your trousers, try them on and take them home. They will be safe and will help you move around."
An estimated 10 million people in the UK have mobility problems and 1.2 million require mobility assistance following a stroke.
A range of 'trouser' technologies were demonstrated at the British Science Festival taking place at the University of Hull.
They included a pneumatic device based on air-filled bubbles designed to push a seated person up into a standing position.
One of the oddest inventions was a way to drop a pair of trousers at the touch of a button and prevent accidents when trying to get to the toilet.
"You go from size eight to size 10 and your trousers fall down," said Rossiter.
A more advanced concept was an electrically powered artificial 'origami' muscle that could be seen twitching spasmodically in a glass case. For commercial reasons, the team refused to say how it works.
Other innovations included graphene knee supports and electrical skin patches.
Rossiter said: "People are living longer and as the world faces an ageing population it is desirable that we are kept as active and independent for as long as possible.
"The 'right trousers' is a pioneering project which will eventually enable people with mobility impairments, disabilities and age-related weaknesses to live independently and with dignity."
The team is now bidding to work with a leading prosthetics company and has submitted a new funding request to the EPSRC.
Rossiter said: "So far, our trousers have cost about £2 million. That's quite an expensive pair of trousers, but the technologies have wide applications."
The global market for actuator technology alone was worth an estimated £40bn, he pointed out.
In 2015, Japanese researchers demonstrated an assistive suit designed for the elderly which included pneumatic muscles.
