Soroka V. Nonlinear characteristics of soleus rat muscle contractions

Dissertation expounds results of experimental research of nonlinear characteristics of soleus rat muscle contractions un-der the treatment with different types of modulated elec-trostimulation. The experiments were conducted by means of tensometric method, were registered contraction force, muscle length changes, arterial pressure, temperature and parameters of stimulating signal. Principal inconsistency between level of incoming to muscle efferent activity and changes of length were revealed. It was shown that time of obtaining of equilib-rium stationary state under the use of modulated stimulatory signal depends both on external load and efferent stimulus fre-quency accretion. Complexity of active muscle response on pre-tetanus contraction area was determined. It testifies absence of simple linear correlations between efferent control signals and muscle response. It was showed that hysteresis of muscle contraction is characterized by enduring afteraction. It was established that stationary level of efferent command is only one of the factors that is responsible for obtaining and retention of stationary state of contraction.