Past research has indicated that the dominant arm produces more efficient interactive torque control during multi-joint movements. In addition, a bimanual arm movement study found that the dominant arm produced more circular trajectories during circular drawing movements, particularly during fast speed conditions. The current study serves to determine whether statistical trajectory analysis of circular drawing patterns can be used as an objective indicator of handedness. The experiment involved subjects performing unimanual circle drawing movements in both arms at two different speeds. The subjects were given handedness questionnaires to separate them into Right-Handed, Left-Handed, and Mixed-Handed categories for data analysis. The movements were tracked by optoelectronic cameras, and a paired T-test comparing the trajectories in each arm established statistical differences in performance. Right-Handed subjects had significant differences in the trajectories of each arm in which the right arm movements produced more circular trajectories. This was more pronounced in fast movements. Left-Handed subjects had no significant differences among arms in movements of either speed, likely due to a low sample size, although the trend in the fast conditions was that the left arm movements were more circular. Mixed-Handed subjects tended to produce more circular trajectories in right arm movements, which reached statistical significance in both conditions. These results indicate that this test could potentially be used as an objective measure of handedness, but more research with stronger statistical significance according to the hypotheses would need to be conducted to confirm the trends observed.

The research being proposed would develop an objective test for handedness analyzing circle-drawing movements performed with the dominant arm versus non-dominant arm. Handedness is a unique and exceptional characteristic of human beings which impacts society on an individual basis that has far-reaching influence. Its correlation and possible causation has been studied and implied in everything from mental disorders (Deep-Soboslay et al. 2010) to advanced biological processes (Driscoll, Kei, & McPherson, 2002). Despite the importance of handedness, there are many faults surrounding the widely used methods for determining and classifying handedness. The most common of these, the Edinburgh Handedness Inventory, especially suffers from reporter bias, possibly confusing categories and instructions, and underestimating ambidextrous or mixed handedness. Research done by R.L. Sainburg of Penn State and N. Dounskaia of Arizona State University points to a possible method of measuring handedness. The findings of these studies show show that the dominant arm to perform better in drawing movements than the non-dominant arm. It is proposed that an objective test could be developed for handedness using circle-drawing tasks. A participant would draw circles with both arms, these movements would be analyzed to show which arm was dominant by showing which arm made the more perfect circle. By developing an objective test, handedness could be more properly classified and assessed, helping aid research and understanding in how handedness affects humans.