Recumbent vs. upright bicycles: 3D trajectory of body centre of mass, limb mechanical work, and operative range of propulsive muscles.
Recumbent bicycles (RB) are high performance, human-powered vehicles. In comparison to normal/upright bicycles (NB) the RB may allow individuals to reach higher speeds due to aerodynamic advantages. The purpose of this investigation was to compare the non-aerodynamic factors that may potentially influence the performance of the two bicycles. 3D body centre of mass (BCoM) trajectory, its symmetries, and the components of the total mechanical work necessary to sustain cycling were assessed through 3D kinematics and computer simulations. Data collected at 50, 70, 90 110 rpm during stationary cycling were used to drive musculoskeletal modelling simulation and estimate muscle-tendon length. Results demonstrated that BCoM trajectory, confined in a 15-mm side cube, changed its orientation, maintaining a similar pattern across all cadences in both bicycles. RB displayed a reduced additional mechanical external power (16.1 ± 9.7 W on RB vs. 20.3 ± 8.8 W on NB), a greater symmetry on the progression axis, and no differences in the internal mechanical power compared to NB. Simulated muscle activity revealed small significant differences for only selected muscles. On the RB, quadriceps and gluteus demonstrated greater shortening, while biceps femoris, iliacus, and psoas exhibited greater stretch; however, aerodynamics still remains the principal benefit.
a Department of Pathophysiology and Transplantation, Division of Physiology , Università degli Studi di Milano , Milano , Italy.
Riccardo
R
Telli
a Department of Pathophysiology and Transplantation, Division of Physiology , Università degli Studi di Milano , Milano , Italy.|b Department for Health , University of Bath , North East Somerset , UK.
Elena
E
Seminati
a Department of Pathophysiology and Transplantation, Division of Physiology , Università degli Studi di Milano , Milano , Italy.
Gaspare
G
Pavei
a Department of Pathophysiology and Transplantation, Division of Physiology , Università degli Studi di Milano , Milano , Italy.
Alberto Enrico
AE
Minetti
D000328:Adult; D001642:Bicycling / Q000502:physiology*; D001696:Biomechanical Phenomena; D003198:Computer Simulation; D004734:Energy Metabolism; D004867:Equipment Design; D006801:Humans; D035002:Lower Extremity / Q000502:physiology*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D019876:Sports Equipment; D013996:Time and Motion Studies
Cycling; centre of mass; mechanical power; muscle length; recumbent