A surgical technique for individual control of the muscles of the rabbit lower hind-limb.

Little is known regarding the precise muscle, bone, and joint actions resulting from individual and simultaneous muscle activation(s) of the lower limb. An in situ experimental approach is described herein to control the muscles of the rabbit lower hind-limb, including the medial and lateral gastrocnemius, soleus, plantaris, and tibialis anterior. The muscles were stimulated using nerve-cuff electrodes placed around the innervating nerves of each muscle. Animals were fixed in a stereotactic frame with the ankle angle set at 90°. To demonstrate the efficacy of the experimental technique, isometric plantarflexion torque was measured at the 90° ankle joint angle at a stimulation frequency of 100, 60, and 30 Hz. Individual muscle torque and the torque produced during simultaneous activation of all plantarflexor muscles are presented for four animals. These results demonstrate that the experimental approach was reliable, with insignificant variation in torque between repeated contractions. The experimental approach described herein provides the potential for measuring a diverse array of muscle properties which is important to improve our understanding of musculoskeletal biomechanics. A reliable surgical technique was developed for isolated activation of the plantarflexor muscles and the tibialis anterior in the rabbit. Joint torque data are presented for four rabbits at a single joint angle and three stimulation frequencies.