Over the past decade or so, one of the most popular constructions in dance has been that in which the strain and pain of physical effort and risk isn't so much left deliberately undisguised as seized upon for its own sake. That this kind of gratuitously dangerous movement, devoid of any emotional dimension, is now such a familiar sight, suggests that all too many choreographers treat it as nothing more than another aesthetic option. And while there may be plenty of dancers willing to court potentially crippling injury, their masochism, although disturbing, is usually less sinister than what registers as the choreographer's psychological sadism.

If none of this bothers you - or if you can't be bothered with dance unless it deals in physical feats that go beyond the range of most ordinary human beings - Streb / Ringside, an eight-strong troupe of kamikaze acrobats from New York, might be your kind of show. Led by Elizabeth Streb, Ringside has adopted the term "popaction" for its particular brand of circus gymnastics. The performers throw themselves against walls, somersault and backflip, collapse on top of one another and, hoisting the mass of their combined weight, form precarious group sculptures. Contact microphones dress every surface so the impact of bodies is heard and felt by the audience. And the feeling that a fractured skull or dislocated joint is never far away induces levels of anxiety which mingle awkwardly with any sense of enjoyment.

The safety and success of Ringside's work depends on split-second timing and fully co-operative action. But this is often at the expense of a satisfying precision in movement itself. And this is what makes popaction more akin to an army assault course than an artistic endeavour. Scrums, repetitive manoeuvres, barked instructions ("go, go, up..."): the entire point of the exercise is to get from A to B in numbingly disciplined fashion. Occasionally, a choreographic impulse takes over from plain drill. In Up the performers circumnavigate the stage set of platforms, trampoline and overhead parallel bars in a dance of rebounding swallow dives; in the solo number, Little Ease, Streb writhes and jerks within the confined space of a rectangular box, only to exit with amusing suddenness.

Mercurial movement stemming from a more dance-concerned imagination than Streb's is at the forefront of Siobhan Davies's new work The Art of Touch. Davies has shown a taste for rapid, intricate steps in previous works, but in The Art of Touch, to Domenico Scarlatti's keyboard sonatas and Matteo Fargion's commissioned score for clavichord, she responds with dances of irascibly fast footwork which send the whole body into expansive arcs of movement and busy flurries of gesture. Sometimes the music's elaborate energy is visually gathered up and held in a clenched fist, only to be released again. Sometimes its question-and-answer phrases are highlighted by dividing the group so that one half's zig-zagging shuffles are met with a beguiling sequence of hand signals. The choreography jogs or races where appropriate, but its strangest, most hypnotic effect is how it and Scarlatti's music seem to keep fast-forwarding, then pausing, then replaying over and over again.

n Streb / Ringside tours to Manchester, Oxford and Nottingham as part of the Dance Umbrella festival (0181-741 5881)

n The Siobhan Davies Dance Company performs at Edinburgh Festival Theatre, 17 Oct (0131-529 6000); Marlowe Theatre, Canterbury, 20 and 21 Oct (01227 787787); and Sadler's Wells Theatre, London EC1, 25 and 26 Oct (0171-278 8916)