This paper describes the application of the inverse dynamic method developed by Bosco and colleagues for measuring the mechanical properties of knee extensor muscles under ballistic conditions. Twenty elderly men performed a series of maximal ballistic leg extensions at different loads. Accurate measurements of friction and inertial effects during the movement were used to calculate the torque and power produced during extension. The error of the results was 6.2–45.3% when the friction and inertial effects were neglected. The torque-angular velocity relationships were linear (r = 0.92 to 0.99, p < .001). The peak measurements obtained were in agreement with published isokinetic values. This new ergometer allows assessment of movements similar to those performed in day-to-day activities and can be used. without training, by elderly or disabled subjects.
A. Rahmani and J.-R. Lacour are with the Laboratoire de Physiologie de l’Exercice, GIP Exercise, Faculté de Médecine, Lyon Sud, B.P. 12, F-69921 Oullins Cedex, France. A. Belli is with the Laboratoire des sciences du sport, UFR-STAPS Besançon, bâtiment d’anatomie, 2, place Saint-Jacques, 25000 Besançon, France. T. Kostka is with the Department of Preventive Medicine at the Medical University, Lodz, Poland. G. Dalleau is with the Centre Universitaire de Recherche en Activité Physique et Sportive, Département Sciences et Techniques des Activités Physiques et Sportives, Faculté des Sciences et Technologie, Université de la Réunion, 117 rue du Général Ailleret, 97430 Le Tampon, France. M. Bonnefoy is with the Service de Médecine Gériatrique, Centre Hospitalier Lyon-Sud, F-69495 Pierre Bénite Cedex, Lyon, France.