Dependency of knee extension torque on different types of stabilisation

Can isolated single-joint torque measurements be used for every practical use case concerning strength prediction or does the possibility of support and stabilisation influence the results? Some studies show that, for example, using or not using handgrips influences maximum knee extension joint torques. This suggests that a muscle can transmit a higher force than it can generate. This would have incisive consequences on digital human modelling. In this case, a strength prediction model would need the information about possible contact points that could increase the resulting joint torque by recruiting further muscle groups. In this study, three stabilisation methods (waist belt, upper body restraint, handgrips and waist belt) were used for maximum isometric knee joint torque measurements using 21 young, male subjects. The results show that in contrast to some earlier studies no significant differences could be obtained. Based on the results recommendations for appropriate stabilisation are given.