While reciprocal inhibition causes increased net activity about a joint for an isolated movement (10), the gross activity may be reduced in the closed-chain as opposing, biarticular
muscles co-contract to allow for movement of all joints in the chain.
However, other authors demonstrated that big muscles, mainly the biarticular
muscles, do not have this relationship, because the linearity between muscular tension and EMG signal would occur only within smaller muscles such as the face and the hands.
1985) Activity of mono- and biarticular
leg muscles during sprint running.
1995) have reported 10-73 percent atrophy in the muscles of the residual limb of individuals with TFA, the atrophy being greater in cleaved muscles, biarticular
muscles, and weakly anchored muscles .
More specifically the VAM is monoarticular but the RF is biarticular
and so its activation is influenced by the position of the trunk.
Hamstrings are biarticular
muscles and are often subjected to longer excursions, higher velocities and smaller forces.
Normalization of these parameters has been associated with fewer adaptations aimed at minimizing the socket/foot interface pressure or compensating for atrophy and weakness of the biarticular
knee flexors and ankle plantar flexors .
Results from this study emphasize the role of knee and hip proprioceptors, especially the biarticular
sartorius muscle afferents, in initiating extensor spasms in SCI.
It is active concentrically during the 'push off phase of lower leg function and the nature of the gastrocnemius' biarticular
anatomy allows power and efficiency during explosive activities such as running and jumping.
The length changes of the biarticular
hip/knee muscles were obtained with the model described by Frigo and Pedotti .
2010) the magnitude of these changes were expected to be larger on the biarticular
Contribution of mono-and biarticular
muscles to extending knee joint moments in runners and cyclists.