Importance of upper-limb inertia in calculating concentric bench press force.
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, Fpeakb 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.
Biomechanics and Impact Mechanics Laboratory, Claude Bernard University Lyon 1, Lyon-South Teaching Hospital, Oullins, France. orambaud@univ-lyon1.fr
Olivier
O
Rambaud
Abderrahmane
A
Rahmani
Bernard
B
Moyen
Muriel
M
Bourdin
D000328:Adult; D001696:Biomechanical Phenomena; D055592:Biophysical Phenomena; D001703:Biophysics; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology*; D034941:Upper Extremity / Q000502:physiology*; D014891:Weight Lifting / Q000502:physiology*