<p>Technological skills associated with the Paleolithic culture have been explored extensively in recent years, with regard to the production of stone tools. Aspects of skill related to the use of these tools, however, have yet to be comprehensively explored. In this paper, we use a combined experimental-traceological approach to explore aspects of skill in the use of Lower Paleolithic (LP) shaped stone balls (SSBs) as percussion tools for marrow extraction. We examine the effect of skill, or lack thereof, on the accumulation of distinctive use wear traces upon these implements, while also considering handling, grip, and body posture of skilled versus unskilled participants in our experiment. In addition, we investigate possible indicative morphologies attesting to skill level on the processed bones. The results show that the observed differences in body posture, gestures, tool gripping and handling of skilled versus unskilled individuals influenced the intensity and dispersion of wear traces on the tools. Moreover, differences were also detected with regard to the processed bones. Thus, our study shows that while we tend to think that bone-breaking is intuitive, it in fact requires planning, knowledge of bone anatomy and tool use, as well as skill and experience. We hope that these experimental insights will offer a better grounding for understanding human skill and its visible expression on material culture.</p>