Abstract: The objective of this study was to characterize the variance of hammering movement and to determine movement dimensionality as related to hammer properties. Positions of markers attached to upper-extremity and hammers were recorded while 19 subjects hammered nails with four different hammers. Principal movements were calculated with principal components analysis. The principal movements differed between hammers and subjects used different principal movements indicating different movement strategies. Contributions of principal movements to variance and differences in movement dimensionality were determined between hammers and across subjects. Long handle hammers resulted in lower movement dimension as four principal movements were required to explain 95% of variance. For short handle hammers five principal movements were required to explain the same variance. Differences in explained variance and dimensionality provide insight into effects of hammers with different properties on strategies for movement and demands on motor control and musculoskeletal systems.