(medicine, anatomy, zoology) Of, pertaining to, or having the nature of a muscle, the parallel fibres of which attach to a tendon at an acute angle (as a feather that is barbed on one side).
1998, E. J. Brill, Netherlands Journal of Zoology, Volume 48, page 324,We applied this method to the proximal aponeurosis of the unipennate medial gastrocnemius muscle (MG) of the cat during active force production at fixed muscle length.
2006, Wistar Institute of Anatomy and Biology, Journal of Morphology, Volume 267, page 593,The most distal region of the muscle was again unipennate, with fibers oriented between the posterior aponeurosis and the anterior surface of the muscle (Fig. 1D,E).
2008, William Charles Whiting, Ronald F. Zernicke, Biomechanics of Musculoskeletal Injury, 2nd Edition, page 44,Although only one component of the muscle fiber force is used effectively to move the tendon, the advantage of the unipennate muscle system is that an increased number of sarcomeres can be placed in parallel to increase the effective force of the muscle (figure 2.19}.
