"It'll all end in tears," mutters Siobhan (Romola Garai) as she accepts a job caring for the disabled heroes of Irish comedy-drama Inside I'm Dancing. True enough, director Damien O'Donnell adds a healthy dose of saline sentiment to his engaging tale of disadvantaged Dubliners striking out on their own. Thanks to strong performances and some bracing one-liners, O'Donnell makes a convincing case for equality for disabled people in society, though casting able-bodied actors as his wheelchair-driving protagonists unavoidably weakens his argument.

Michael (Steven Robertson) has cerebral palsy and has spent all his life in residential care. Disowned by his successful lawyer father (Gerard McSorley), he knows nothing beyond the walls of the Carrigmore Home for the Disabled ("a special home for special people") and its kind but firm staff of nurses. Until, that is, he meets new resident Rory (James McAvoy), a wise-cracking rebel who will not allow his Duchenne muscular dystrophy to sap his spirit.

"COMPARISONS TO RAIN MAN AND MY LEFT FOOT ARE INEVITABLE"

Rory and Michael become firm friends and eventually persuade the authorities to give them a personal living allowance. After the soul-crushing regime at Carrigmore, their ground-floor flat on a rundown housing estate is, in Rory's words, "cripple heaven". But problems start when Michael falls hopelessly in love with Siobhan, the brassy young woman they've hired as their personal assistant.

Comparisons to Rain Man and My Left Foot are inevitable, especially with the latter's Brenda Fricker turning up in a supporting role. Yet O'Donnell’s film doesn't suffer from these parallels, making a virtue of its familiar theme of indomitable individuals rising above cruel circumstance. Bright Young Things star McAvoy capably conveys Rory's immobile frustration, while newcomer Robertson flawlessly essays Michael's mangled limbs and unintelligible speech. Both, however, are bested by Garai, who manages to be infinitely more moving and credible with only a fraction of her co-stars' technique.