Background The type of rowing ergometer may influence the injury risk in rowers. Overuse rowing injuries (ie, rib stress fractures and low back pain) may be related to the timing and magnitude of neuromuscular activity and handle force production, respectively.
Objective To investigate neuromuscular activity and force production profile during slide-based and stationary ergometer rowing.
Design Biomechanical cross-over study.
Setting Danish National Rowing Team.
Participants 14 male (M) and eight female (F) rowers.
Intervention Ergometer rowing with and without slides in a randomised order at matched exercise intensity.
Main outcome measurements Timing and magnitude of: (1) Normalised Electromyography (EMG) from selected thoracic and leg muscles. (2) Peak handle force (PF) including rate of force development (RFD).
Results Slide-based ergometer rowing decreased the magnitude of neuromuscular activity in m. vastus lateralis from 59/57% (M/F) to 51/52% EMGmax in the initial drive phase (p<0.01/0.05) and from 20/17% to 7/7% EMGmax in the late recovery phase (p<0.01) while Ankle dorsiflexors (M, F) and m. serratus anterior (M) showed increased neuromuscular activity (p<0.05) during the late recovery phase. EMG timing remained unchanged and no changes in magnitude were observed in other thoracic muscles. RFD (at 50–70% of PF) decreased (21%) in M (p<0.05) while PF decreased 8.4/3.1% (M/F) (p<0.001/0.05). PF and maximal shoulder retractor neuromuscular activity always occurred in the second quartile of the drive phase supporting previously suggested rib stress fracture injury mechanisms.
Conclusion Slide-based ergometer rowing affected neuromuscular activity in the leg muscles more than thoracic muscle activity. The reduced knee extensor neuromuscular activity in the catch phase may partly explain the observed reduction in peak force, which in addition to the decreased RFD (M), is likely to result in reduced loading of the ribs and spine. Prospective studies are needed to elucidate if long-term slide-based ergometer rowing leads to reduced injury incidence.