Knot, Barbican, London<br/>La Fille Mal Gardee, Royal Opera House, London

Tied up in technicalities

Four dancers of the Companhia de Dança Deborah Colker are mixed up in an elaborate sexual tangle, while the lush slow movement of a Ravel piano concerto plays on the soundtrack. As the piano hits a climax, the four heads go back, and a billowing silk curtain is unfurled behind them. The whole thing is cheesy.

The Brazilian choreographer Deborah Colker is known for acrobatic choreography and complicated set design. She's in characteristic form for Knot, which begins a British tour with performances at the Barbican. The first scene is dominated by ropes, knotted into a kind of tree that stands centre-stage.

A woman holds out her hands to a man, who binds her wrists and winds the rope around her, leaving her suspended mid-air. The woman is calmly submissive as she is pulled and tied. He goes on to truss up another woman. Men bind women in this show, but although there are several same-sex combinations, women never bind men.

The dancers go peacefully through their bondage motions. Colker has said that Knot is about desire, and about trust, and there's little sense of aggression in these domination games. There isn't much of anything else, either. The show proclaims its sexiness - in the grappled partnering, in Alexandre Herchcovitch's flesh-coloured costumes, which have dark patches marking the dancers' groins - but Colker's athletic choreography is oddly aimless.

Though her dancers are fearless and flexible, they don't do much in the way of theatrical projection. One man, with a shock of red curls, moves with real speed and attack, darting from pose to pose. That sense of phrase and contrast is rare in this company, and in Colker's choreography.

The soundtrack, by Berna Ceppas and Alexandre Kassin, uses a range of music: Ravel, Chet Baker, easy listening, linked by shuffling beats. It's all mood music, with little response to rhythm or melody.

The tree of ropes is broken into four, then into separate strands. Another strand, never part of the rope-tree, looks like long hair. Two women drape it about themselves, playing hide-and-seek in the tresses. Colker doesn't make this image powerful: the echoes of Rapunzel or Mélisande are more interesting than anything we see on stage.

All the ropes are cleared away for the second half, which is dominated by a Perspex box. Colker herself appears in this scene, skipping around the box in a ruffled skirt. The other dancers go on with their long-winded convolutions. This time, the multiple partnerings involve falls from the top of the box, precarious balances on its narrow rim. The acrobatics make more impression than anything else.

The Widow Simone's clog dance is perhaps the most famous number in La Fille mal gardée. Simone is danced by a man, in this case William Tuckett. He's an irresistible Widow, all the funnier for the seriousness of his dancing.

Frederick Ashton's 1960 ballet is a pastoral comedy, a tender-hearted masterpiece. Lise, Simone's daughter, is in love with the young farmer Colas, but her mother wants her to marry Alain, the dim son of a rich neighbour.

The current Royal Ballet revival opened with Miyako Yoshida and Viacheslav Samodurov. Yoshida is a very tidy dancer. Her movements are crisp, the brilliant steps cleanly executed but small in scale.

Samodurov is a powerful dancer who goes in for forceful effects - broad in dancing and comic playing. This isn't the warmest partnership, but the ballet's sheer sunniness carries them through. As the slow-witted Alain, José Martín's smiles can be a little too vacant, but he's lively and sharp-edged in these precisely clumsy dances.

Tuckett gives the evening's strongest performance. He's truly at home in the ballet, whether berating Lise, pondering a medicinal sip of wine or cautiously petting the real pony that appears for the harvest scene.

Ashton's sources were French, but this is a very English ballet, with British folk steps woven into the corps dances. These are one of the marvels of Fille, intricate and flowing, with vivid steps and rippling patterns. The Royal corps are sure and buoyant in the lilting rhythms.

'Knot' to tomorrow (0845 120 7550), then touring ( www.worldwidedanceuk.com). 'La Fille' in rep to 20 May (020-7304 4000)