1. Temporal patterns of electromyographic (EMG) activity were related to the direction of fast reaching movements. Reaches were to 20 targets in the sagittal plane of the human arm. 2. The subtraction of EMG levels recorded during very slow movements to each target allowed this study to focus on the phasic aspects of complex EMGs. 3. General features of the phasic spatial/temporal patterns differed across muscles, even across muscles at the same joint. This indicates that future models of cortical to motoneuronal processing must include nonuniform space-time transformations.