Resumen de Importance of upper-limb inertia in calculating concentric bench press force
Olivier Rambaud, Abderrahmane Rahmani, Bernard Moyen, Muriel Bourdin
The purpose of this study was to investigate the influence of upper-limb inertia on the force¿velocity relationship and maximal power during concentric bench press exercise. Reference peak force values (Fpeakp) measured with a force plate positioned below the bench were compared to those measured simultaneously with a kinematic device fixed on the barbell by taking (Fpeakt) or not taking (Fpeakb) upper-limb inertia into account. Thirteen men (27.8 ± 4.1 years, 184.6 ± 5.5 cm, 99.5 ± 18.6 kg) performed all-out concentric bench press exercise against 8 loads ranging between 7 and 74 kg. The results showed that for each load, Faeakb was significantly less than Fpeakp (P < 0.0001), whereas no significant difference was found between FpeakP and Fpeakt. The values of maximal force (F0), maximal velocity (V0), optimal velocity (Vopt), and maximal power (Pmax), extrapolated from the force¿ and power¿velocity relationships determined with the kinematic device, were significantly underestimated when upper-limb inertia was ignored. The results underline the importance of taking account of the total inertia of the moving system to ensure precise evaluation of upper-limb muscular characteristics in all-out concentric bench press exercise with a kinematic device. A major application of this study would be to develop precise upper-limb muscular characteristic evaluation in laboratory and field conditions by using a simple and cheap kinematic device.
