Influence of ergometer design and stroke rate on lower-limb coordination variability in elite rowers

This study aimed to examine lower-limb coordination and coordination variability between fixed and dynamic rowing ergometers across different stroke rates. Twelve international- and national-level rowers participated in this study. Kinematic data were collected by the Xsens inertial measurement system on a fixed Concept2 ergometer (C2F) and a C2F on slides (C2S) at stroke rates of 20, 26 and 34. A modified vector coding analysis was used to calculate the coordination and its variability throughout the rowing cycle. The C2F showed a higher frequency of in-phase sagittal hip-ankle coordination during the drive phase (p = 0.002, ƞ²_p = 0.595). In two of the three couplings, stroke rate increased the frequency of the in-phase pattern during the recovery phase (hip-ankle: p = 0.011, ƞ²_p = 0.438; hip-knee: p < 0.001, ƞ²_p = 0.893). Coordination variability was greater on the C2S than on the C2F, particularly at the first half of the drive phase. Stroke rate significantly decreased the variability during the recovery phase. In conclusion, elite rowers displayed similar movement patterns between ergometer types. Stroke rate-related changes in joint coordination during the recovery may influence lower-limb biomechanics.