Non-oarside-arm pull to increase the propulsion in sweep-oar rowing

Sweep-rowing requires an asymmetric, two-handed-pull on the oar. The non-oarside-hand holds the end of the handle the oarside-hand is nearer the oar. Correspondingly, body-segments were described as non-oarside (not-the-same-side-as-the-oar) or oarside (same-side-as-the-oar). The study investigated the effect of oarside and non-oarside-arm-draw on pull-direction, handle-force (longitudinal and normal) and one-dimensional stretcher-force in the propulsive-plane from the oarside-and non-oarside-leg amongst 24 junior oarsmen in coxless-fours. Movement-variations of two-handed-rowing versus rowing with the non-oarside-or oarside-hand and two-handed-rowing with a dominant non-oarside-or oarside-arm-pull were compared in two field-tests with variance-analysis. Both tests reflected the dominance of the non-oarside-arm-draw in higher tangential (14%) and smaller longitudinal (11%) forces and advantageous draw-angle (2.7%) on the handle with lower stretcher-force in the propulsive-plane (25%). The dominance was expected as the non-oarside-hand has a longer lever and at the start of the drive draws tangentially more strongly than the oarside-hand. In on-water training at the start of the drive, tangential-force can be maximised, and longitudinal-force minimised, by a dominant non-oarside-arm-draw. The rotation in sweep-rowing increases the torsional and lateral-bending-load, and thus the injury-risk of the lowerspine. Overall, non-oarside-arm-draw enforces the trunk-asymmetry. But, oarside-leg stretcher-force in pull-direction is reduced and decreases lower extremities-asymmetry.