Our results suggest that reduced blood velocity is a hallmark of SSc. Furthermore, measurement of red blood cell velocity may be useful in evaluating therapeutic effects on microcirculation.

The purpose of this study was to test the endurance of the soleus muscle, and to examine the joint position at which it is most active, while simultaneously suppressing the activity of the gastrocnemius. Ten young males performed maximum isometric contraction of the triceps surae for 100 s, and the endurance and plantar flexion torque of this muscle were measured at various angles of the knee and ankle joints. The electromyogram was measured simultaneously and subsequently converted into integrated electromyogram (IEMG) values. With the knee flexed at 130 degrees, the rate of change in IEMG values for the soleus (0.454% x s(-1)) with the ankle in a neutral position was significantly higher than that for the medial and lateral gastrocnemius. Both with the ankle dorsiflexed at 10 degrees and in the neutral position, the rate of change in IEMG for the soleus was significantly higher with the knee flexed at 90 degrees and 130 degrees than with the knee fully extended. With the knee flexed at 90 degrees and 130 degrees, the IEMG activity of the soleus during the initial (5-10 s) and final 5 s tended to be higher than those for the medial and lateral gastrocnemius, regardless of the ankle joint position. We conclude that the position in which the soleus acts most selectively during a sustained maximum isometric contraction of the triceps surae is with the ankle in a neutral position and the knee flexed at 130 degrees.

Although functional recovery in skeletal muscle after partial denervation has been an object of study for a long time, little agreement has been reached regarding the effect of exercise training on skeletal muscle after partial denervation. The present study examined the effects of exercise training after partial denervation. We developed a rat model for partial denervation of the soleus muscle by resecting the fifth lumbar vertebral nerve on one side. The central side of the fifth lumbar vertebral nerve was ligated to inhibit regeneration of the resected nerve. Animals were exercised on a treadmill for 2 or 6 weeks. We measured muscle mass, muscle fiber-type ratio and cross-sectional area of muscle fibers in the soleus muscle after transection of the tibial nerve. Muscle mass and muscle fiber-type ratios were unchanged. Partially denervated tibial nerves displayed local degeneration up to 6 weeks. Muscle fiber area was significantly higher for exercised soleus muscle after partial denervation than for spontaneous recovery at 2 weeks. At 6 weeks, spontaneously recovered muscles had returned to control levels, while exercised muscle displayed increased growth compared with control muscle. Mechanical stimulation appears to prevent muscle atrophy in the soleus muscle after partial denervation. These results suggest that exercise therapy after partial denervation is effective.