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Full-Text Articles in Biomechanics
A Motor And A Brake: Two Leg Extensor Muscles Acting At The Same Joint Manage Energy Differently In A Running Insect, Anna N. Ahn, Robert J. Full
A Motor And A Brake: Two Leg Extensor Muscles Acting At The Same Joint Manage Energy Differently In A Running Insect, Anna N. Ahn, Robert J. Full
All HMC Faculty Publications and Research
The individual muscles of a multiple muscle group at a given joint are often assumed to function synergistically to share the load during locomotion. We examined two leg extensors of a running cockroach to test the hypothesis that leg muscles within an anatomical muscle group necessarily manage (i.e. produce, store, transmit or absorb) energy similarly during running. Using electromyographic and video motion-analysis techniques, we determined that muscles 177c and 179 are both active during the first half of the stance period during muscle shortening. Using the in vivo strain and stimulation patterns determined during running, we measured muscle power output. …
Energy Absorption During Running By Leg Muscles In A Cockroach, Robert J. Full, Darrell R. Stokes, Anna N. Ahn, Robert K. Josephson
Energy Absorption During Running By Leg Muscles In A Cockroach, Robert J. Full, Darrell R. Stokes, Anna N. Ahn, Robert K. Josephson
All HMC Faculty Publications and Research
Biologists have traditionally focused on a muscle's ability to generate power. By determining muscle length, strain and activation pattern in the cockroach Blaberus discoidalis, we discovered leg extensor muscles that operate as active dampers that only absorb energy during running. Data from running animals were compared with measurements of force and power production of isolated muscles studied over a range of stimulus conditions and muscle length changes. We studied the trochanter-femoral extensor muscles 137 and 179, homologous leg muscles of the mesothoracic and metathoracic legs, respectively. Because each of these muscles is innervated by a single excitatory motor axon, …