Vibrationen im Radsport: Der Effekt eines Rennrad-Dämpfungssystems auf die neuromuskuläre Leistungsfähigkeit

Uneven road surfaces cause vibrations which potentially compromise neuromuscular performance in cycling. This is particularly relevant for the iconic Paris-Roubaix race, where approximately 20 percent of the track includes cobblestone sections. In order to support the athletes on these decisive parts of the race, racing bikes with damping systems are becoming more and more popular. However, in cycling the effect of vibration and damping on the musculoskeletal system is unclear. The purpose of the project was to understand if and how vibration and damping impact neuromuscular performance in cycling.
The initial project phase involved the development of an experimental set-up for realistic vibration interventions. Study I answered the first research question and identified, based on the vertical accelerations of the wheel hubs on cobblestones, criteria for standardised vibration interventions. Based on these recommendations, two vibration plates applied periodic oscillations directly to the front (44 Hz, 4 mm) and rear (38 Hz, 4 mm) dropouts of the bicycle frame during the subsequent laboratory interventions. Thirty trained male cyclists completed trials on an non-damped (Specialized Tarmac Pro Race 2015) and a damped bike (Specialized Roubaix Comp 2017) with and without vibration initiation at low-intensity, near-threshold and sub-maximal exercise intensities. The effects of vibration on neuromuscular performance were analysed on the basis of body segment accelerations, muscle activation, kinematics, oxygen demand, heart rate and cranking power. Studies II and III answered the second research question and illustrated that vibration applies a stimulus to the entire musculoskeletal system, but the effects on propulsion were limited since the main propulsive muscles on the thigh are not majorly affected. High vibration exposure of the arms and increased activation of the arm and shoulder muscles, as well as adapted kinematics of the upper body, suggest that secondary tasks such as stabilisation on the bike are more difficult with vibration. These also contribute to the 2.4% increase in oxygen uptake. In conclusion, vibration reduces short-term performance slightly. Study IV answered research question three and found that damping did not systematically modify vibration exposure or neuromuscular activation for the lower extremities, did not decrease oxygen uptake, and did not contribute to increased cranking power. In conclusion, road bike damping does not enhance short term performance. Reduced vibration exposure to the upper body minimises muscular activity of stabilising upper arm muscles and indicates increased riding comfort.
Practical implications: The results do not suggest that vibration or the use of a damped road bike have a substantial effect on neuromuscular performance when cycling on a single cobblestone section that lasts about four minutes. However, damping potentially contributes to increased riding comfort by reducing vibrations at the upper body systematically. The long duration of a cycling race also suggests physical and cognitive fatigue effects. The research gap between the vibration exposure of the body, the subjective perception of vibration and comfort and fatigue effects still needs to be closed.