Rib stress fractures in elite rowers

Abstract: The aim was to investigate potential risk factors and suggested injury mechanisms involved in the development of exercise-induced rib stress fractures (RSF) in elite rowers as well as investigate biomechanical and neuromuscular differences of ergometer rowing in stationary and slide-based ergometers.
BMD and muscle strength was assessed as well as EMG of thoracic muscles and rowing technique during ergometer rowing in rowers with previous RSF and controls. The RSF subjects displayed reduced lumbar spine BMD, increased co-contraction of thoracic muscles and increased elbow-flexion strength relative to knee-extension strength.
Testosterone levels and BMD were measured in male lightweight rowers. Correlations between BMD and testosterone levels as well as years of training were found.
The force production during ergometer rowing with and without slides was measured in male and female rowers. During slide-based ergometer rowing male rowers increased stroke rate and decreased peak force. Female rowers displayed a similar but less pronounced response.
The neuromuscular activity of muscles potentially involved in RSF development was measured during ergometer rowing with and without slides in male rowers. Slide-based ergometer rowing did not affect the neuromuscular activity significantly, except during the unloaded recovery phase of the rowing stroke. The timing of peak neuromuscular activity of the thoracic muscles coincided with the timing of peak force at the handle supporting rib cage compression as a potential injury mechanism.
The Thesis has added knowledge regarding risk factors and injury mechanisms involved in RSF development, which may be useful for future studies on RSF prevention in rowers.