1. The parameters of presynaptic inhibition of the Ia spindle afferents from soleus muscle by vibration have been investigated. The inhibitory effects increase with the amplitude of vibration, but decrease when the vibration frequency is increased.2. The monosynaptic reflex threshold of twenty-one single soleus motor units activated in the H (Hoffmann) reflex by a single electrical stimulus to ...

Postcontraction depression of Hoffmann-reflex (H-reflex) amplitudes was examined to study the rationale underlying proprioceptive neuromuscular facilitation relaxation techniques. The time course of H-reflex amplitude depression was used to assess postcontraction changes in motoneuron reflex excitability. Sixteen healthy female subjects performed voluntary isometric plantar-flexion contractions...

Rhythmic arm movement reduces Hoffmann (H)-reflex amplitudes in leg muscles by modulation of presynaptic inhibition in group Ia transmission. To date only the acute effect occurring during arm movement has been studied. We hypothesized that the excitability of soleus H-reflexes would remain suppressed beyond a period of arm cycling conditioning. Subjects used a customized arm ergometer to perfo...

Spasticity is one of the common complications in upper motor neuron lesions and without appropriate treatment it causes disturbances in movement pattern. Assessments of patients are effective in patient's management. Modified Ashworth scale (MAS) is one of the criteria in qualitative assessment of spasticity, and there are lots of controversies about its validity. The purpose of this study is t...

Introduction It is well known that the integrated electromyographic (EMG) activity during lengthening (LEN) contractions is lower than that during shortening (SHO) contractions against the same load (Bigland and Lippold 1954). Even if the EMG activity is at a similar level in both contraction types, the excitability in spinal reflex pathway and/or corticospinal tract is lower during LEN contrac...

the purpose of this study was the comparison of neural and performance adaptations to plyometric training versus combined training. 22 young soccer players (age 14.28±0.82 years, weight 41.18±7.5 kg, height 154.5±9.36, body fat 7.43±2.68%) were randomly assigned to plyometric group (plyometric and soccer skills training, pl) (n=8), combined group (combined plyometric and sprint and soccer skill...

Experiments were carried out to test the effect of prolonged and repeated passive stretching (RPS) of the triceps surae muscle on reflex sensitivity. The results demonstrated a clear deterioration of muscle function immediately after RPS. Maximal voluntary contraction, average electromyographic activity of the gastrocnemius and soleus muscles, and zero crossing rate of the soleus muscle (record...