In rowing, leg force is an important factor to optimize the power per stroke. However the transmission of high leg forces during trunk flexion is associated with an overload of the lower back. In sweep rowing an additional trunk rotation within the transverse plane around the longitudinal axis occurs and asymmetric stretcher forces (oarside vs. nonoarside) can be expected. A dominant nonoarside arm pull at the handle will affect leg asymmetry. Male elite rowers (N=29) participated in the study. Handgrip strength (hand dynamometer) and force at the oar handle (both hands as well as the nonoarside hand separately), the nonoarside and oarside stretcher force were measured (mobile measuring system) at four stroke rates in coxless fours. Baseline versus dominant nonoarside arm pull was compared. Statistical analysis was performed using ANOVA with repeated measures. With increasing stroke rate the nonoarside stretcher force and the leg asymmetry were reduced. Dominant nonoarside arm pull increased the nonoarside handle force, the nonoarside stretcher force and the stretcher force asymmetry independent of the handedness and boat side. Change of the boat side and a dominant nonoarside arm pull in sweep rowing should be prepared muscularly and technically controlled during rowing training to prevent an overload of the lower back. ABSTRACT FROM AUTHOR