Swing those arms : automatic movement controlled by the cerebral cortex

Charles Darwin (1871) wrote: ‘Man alone has become a biped: and we can, I think partly see how he has come to assume his erect attitude, which forms one of his most conspicuous characters. Man could not have attained his present dominant position in the world without his use of his hands.’ Freeing the hands from locomotor duty to allow carrying, feeding and tool use has remained prominent among the evolutionary theories of how homo sapiensbecame bipedal. Although not as precise as when we are stationary, our extraordinary dexterity and volitional control of the forelimbs during locomotion indicate the motor cortex candominate drive to these muscles.However, oftenwe don’t want to do anything with our arms. Then what do we do with them?