Almost nine in 10 (89%) sports clubs saw no change in the number of people with disabilities joining their ranks in the months after the London Games.
A study of hundreds of clubs throughout the UK by the Sport and Recreation Alliance raises questions over the sporting legacy of the 2012 Paralympics, widely regarded as the most successful ever.
Andy Reed, Chairman of the Alliance, said the findings were "a massive wake-up call not just for government but all of us in the [sport] sector".
He added: "We all have to take some responsibility for not being as ready as we probably thought we should be.
"Clearly we've not demonstrated in the past that sport is welcoming to people with disability, and that's the difficult message from these figures, from our point of view."
The Alliance, which represents all governing bodies and 150,000 grassroots sports clubs, also discovered that:
- 86% of clubs said they had noticed no change in the number of enquiries they had received from people with disabilities wanting to take part.
- 96% reported no change in the number of people with disabilities volunteering at their clubs.
- Only one in four clubs (24%) said they had suitable facilities for people with disabilities to participate, suitably trained staff and the appropriate equipment to deliver this, indicating that three quarters of clubs need some form of additional support in order to facilitate disabled participation.
The report concluded: "If the interest around participating in sport and recreation is ever to translate into reality, clubs will undoubtedly need help and support to develop their offer, along with access to facilities that can cater for all, and it's worrying that these foundations weren't laid sooner."
With home medal success, record ticket sales and unprecedented media coverage, the 2012 Paralympics managed to achieve a shift in perceptions towards those with disabilities that extended well beyond merely sport.
The early signs that inspirational performances at London could trigger a growth in participation among an estimated 10 million disabled people in Britain were good; in October, the British Paralympic Association's Parasport website, which gives information about disability sports, reported a 2,000% increase in web traffic during the Paralympics compared with the same period a year before.
"We were quite confident many people would be looking to join sports clubs around the country, so these figures are very disappointing," said Reed.
"It probably demonstrates we haven't got that part of the planning right for legacy.
"We all have to take a collective responsibility for this... many of us didn't expect the type of lift-up that we saw. The Paralympics caught the nation off-guard.
"We need to understand why people who were inspired then didn't take those steps to join their local sports clubs."
When asked what could have been done better, Reed said: "There was a feeling that legacy planning was slightly behind the curve compared to the rest of the planning for a very successful Games, so it would have been having funding in the right place at the right time. Some things for disability sports are only just coming on stream now.
"Some research we've done shows sports clubs are scared of opening their doors which they don't need to be - perhaps there was a bit of complacency thinking we'd wait until afterwards and we should have got programmes in place earlier.
"I think we only have a short window in 2013 to get this sorted."
Of the £493m over the next four years that Sport England last month said it was investing into grassroots sport, £13.6m was specifically earmarked for disability sport programmes, with an additional £10.2m invested into an Inclusive Sport Fund to be shared among 44 projects.
Sport England has recently announced it will be investing £2m in the English Federation of Disability Sport over the next two years.
Sports are now encouraged to develop participation programmes in an inclusive way, making them accessible for disabled participants, with 40 out of 46 sports governing bodies signing up to that ambition. Sports that have not signed up to that commitment, such as boxing, wrestling and taekwondo, will soon be asked how they intend to help attract more disabled people.
Sport England says 362,000 more disabled people now play sport than in 2005, but it is estimated that only 18% of disabled adults undertake physical activity for more than 30 minutes a week, and those with impairments are still around half as likely to be active than their able-bodied counterparts.
Equestrian Sophie Christiansen, who was born with cerebral palsy, and won three gold medals for ParalympicsGB at London 2012, told BBC Sport: "The Paralympics was a really good chance to get more people involved in sport.
"I think maybe in the years to come you might see an increase when people have time to think about how great 2012 was and get round to researching about getting involved in sport.
"I think being disabled it is certainly harder to find clubs that can cater to your needs, however with the internet and Facebook and Twitter it's never been easier to find clubs that can help you or get advice from people. So I don't think there's an excuse to say there isn't any info out there. There is but it just takes a bit more effort.
"I think Locog and the government did a phenomenal job at the Games. We showed the world how it was done.
"But the word legacy has been bandied about ever since the bid. It's just a word, until it's put into action. And I think that should be done properly."
When asked what needs to change, Christiansen said: "I think advertising about getting fit and helping with disability, and maybe people are put off because they see elite sportspeople at the top of their game. Not everyone able-bodied or disabled is going to be an elite sportsperson.
"If we get the message across that being fit and healthy will help their lives in general, I think that is probably the key in getting more participants.
"Disabled sport is now in the public eye in a way that it wasn't before and now is the time to take action in getting more disabled people into sport recreational level as well."