It is not merely a boast when Tom Marshman tells us he has the sixth best legs in the country. In fact, it’s pretty much a proven fact. Last year, Marshman put himself and his legs to the public vote by entering and eventually became a finalist in the 2011 Pretty Polly competition that sought out Britain’s best pair of pins. A projected video shows Marshman, surrounded by leggy and vaguely perplexed-looking women, looking endearingly baffled, pleased and proud. The real-life incarnation, tall yet unimposing and amiably soft-spoken, stands before us in Summerhall’s Anatomy Lecture Theatre, dressed scantily in a gameshow host’s jacket and a pair of star-spangled stockings.

Marshman confides that he had various reasons for entering the competition. He was partially motivated by the memory of his mother’s supermarket job that, from childhood, had instilled the hosiery brand with an air of unbridled luxury. But more importantly, he had just undergone an operation on his hereditary case of varicose veins. An extension of his desire to showcase and celebrate the very legs that for some time had caused him anxiety and discomfort, this confessional piece, Legs 11, takes varying forms (sometimes a presentation, sometimes performance art) – an interesting structure somewhere between an eleven-step programme and a friendly, amusing chat. From running away at five years old to running a marathon almost two decades later, Marshman’s legs do have an interesting story to tell, and his ambition to glorify our over-worked and underappreciated lower limbs is a commendable one. Yet despite some novel use of a year’s supply of tights and nicely site-referential medical equipment, Legs 11 stumbles on its own overly-stretched material.

We follow Marshman’s somewhat unsteady narrative, supplemented by video and song, through his vaguely troubled adolescent years towards the eventual operation and titular competition. There are evidently Gok Wan-style good intentions beneath the sprawling story as Marshman calls for thigh-to-toe body confidence for everyone. At one point, he encourages us to elevate our legs and clambers with haphazard grace over the seats to film various audience members dancing limbs, replaying the footage to poignant effect at the show’s conclusion. But Legs 11’s strength lies in its honest and unpretentious writing, not its hit-and-miss mishmash of performance techniques. Marshman himself is a gracious and sincere host but his show is less of a coherent piece than a charming ramble that lacks surerfooting.

Legs 11 played at Summerhall until 26 August as part of the Edinburgh Festival Fringe.