Gordon NM, Rudroff T, Enoka JA, Enoka RM. Handedness but not dominance influences variability in endurance time for sustained, submaximal contractions. J Neurophysiol 108: 1501-1510. First published June 13, 2012 doi:10.1152/jn.01144.2011The purpose of this study was to compare endurance time and accompanying neuromuscular adjustments when left-and right-handed subjects used the dominant and nondominant arms to sustain submaximal contractions that required either force or position control. Ten left-handed and 10 right-handed healthy adults (21 Ϯ 5 yr) participated in the study. Each subject exerted a similar net torque about the elbow joint during the force and position tasks to achieve a target force of 20% maximal voluntary contraction (MVC) force (56 Ϯ 18 N). MVC force declined to a similar level immediately after task failure for left-and righthanded subjects (27 Ϯ 13 vs. 25 Ϯ 15%, P ϭ 0.9). Endurance time for the position task was similar for the dominant and nondominant arms (task ϫ dominance interaction, P ϭ 0.17). Although the difference in endurance time between the two tasks was similar for left-handed (136 Ϯ 165 s) and right-handed individuals (92 Ϯ 73 s, task ϫ handedness interaction, P ϭ 0.38), there was greater variance in the ratio of the endurance times for the force and position tasks for left-handed (0.77) than right-handed subjects (0.13, P Ͻ 0.001; see Fig. 2). Furthermore, endurance time for the force and position tasks was significantly correlated for right-handed subjects (r 2 ϭ 0.62, P Ͻ 0.001), but not for left-handed subjects (r 2 ϭ 0.004, P ϭ 0.79). Multiple regression analyses identified sets of predictor variables for each endurance time, and these differed with handedness and task. Hand dominance, however, did not influence endurance time for either group of subjects. These findings indicate that endurance times for the elbow flexors when performing submaximal isometric contractions that required either force or position control were not influenced by hand dominance but did depend on handedness. electromyography; muscle fatigue; task failure THE PREFERENTIAL USE OF ONE ARM during motor tasks is known as hand dominance and defines the handedness of an individual. A right-handed individual, for example, tends to use the right hand to perform most activities of daily living, such as writing, throwing, using scissors, brushing teeth, cutting with a knife, eating with a spoon, striking a match, and opening a box. However, some actions are more commonly performed with the nondominant limb, which results in each arm developing a unique set of motor skills (Adamo and Martin 2009; Bernard et al.
