A change from Disability Living Allowance to Personal Independence Payments means many could lose as much as £35 a week.
Anyone who can walk more than 20 metres (65ft) will no longer be entitled to the £56.75 enhanced weekly mobility allowance and could be offered the standard rate of just £21.55.
Before UK Government welfare reforms, a distance of 50 metres was used as a measure of significant mobility impairment.
A group of 50 charities known as the Disability Benefits Consortium launched a High Court challenge based on claims that a UK Government consultation was unfair.
Lawyers for disabled Steven Sumpter argued the consultation did not mention the new limit would be reduced to 20 metres.
However, Mr Justice Hickinbottom ruled the process had been lawful.
Karen Ashton, Mr Sumpter's solicitor, described the judgement as "very disappointing". She added: "We will be looking carefully at the possibility of an appeal."
It has been estimated as many as 80,000 working age disabled people in Scotland will lose some or all of the mobility allowance as a result of the changes.
Iain Workman, from Greenock, a 52-year-old father-of-three who was diagnosed with multiple sclerosis two years ago, said: "They are talking about phasing this in, but I do not know how long it will take. It will be something I will be up against in the coming months.
"It has the potential to affect every single person on Disability Living Allowance. We are going to have to jump through hoops for them and be performing monkeys. It's terrifying."
Claire Nurden, co-chairwoman of the Disability Benefits Consortium, said: "Personal Independence Payments are intended to help those most in need, but it is exactly these people that are set to lose.
"The benefit is alifeline for people - many use it to pay for their mobility scooter or adapted car so they can remain independent and travel to work, education or medical appointments.
"We would strongly support an appeal of this decision."
A spokeswoman for the Department for Work and Pensions said: "We are pleased with the judgment and welcome the clear statement that how public money is distributed is a matter for the Secretary of State and Parliament and not for the courts."