We present a 50-year-old woman who sustained spastic left hemiplegia secondary to the right thalamic hemorrhage 6 years ago. She complained of persistent severe left calf pain after serial casting for the treatment of shortened plantar flexors of the left ankle. Two months later, magnetic resonance T1-weighted images showed diffuse high signal intensity involving the whole muscle bulk of the soleus and normal signal intensity of thin atrophied gastrocnemius. Needle electromyography of the soleus revealed myopathic patterns. Histologic findings of the soleus showed necrotic muscle fibers with phagocytosis, endomyseal collagen and fat deposition. We concluded that prolonged passive stretch of spastic plantar flexors of the ankle under serial casting induced soleus myopathy with segmental myonecrosis, and which developed left calf pain. Selective induction of soleus myopathy could be explained by the higher stretch tension produced by ankle dorsiflexion in the soleus compared to the gastrocnemius because of different proximal ends.

Objective: To identify the relationship between the location of motor points of gastrocnemius and soleus and the skin surface landmarks.

Method: Compound muscle action potentials (CMAPs) of each lattice of gastrocnemius and soleus in 11 healthy subjects were recorded. Standardized reference lines were made as follows: 1) a horizontal reference line (popliteal crease) and 2) a vertical reference line drawn between mid-points of the horizontal reference line and inter-malleolus connection line. The CMAPs were mapped horizontally and vertically 1cm width to the standardized reference lines. Location of motor points was mapped to the skin surface in the ratio of length of the vertical and horizontal reference lines.

Results: The motor point of medial head of gastrocnemius was located at 41.0⁑6.1% distal and 54.6⁑19.2% medial to the mid-point of horizontal reference line. The location of the motor point of the lateral head of gastrocnemius was 35.7⁑5.2% distal and 48.5⁑15.1% lateral, respectively. In the soleus, the motor point was at 68.6⁑8.0% distal and 10.5⁑9.0% lateral, respectively.

Conclusion: The motor point of the lateral head of gastrocnemius was located more proximally relative to medial head, and the motor point of soleus was located at slightly lateral side of the vertical reference line. The author concluded that mapping of motor points of the gastro-soleus muscles would increase accessibility in performing phenol motor point block or botulinum toxin injection for management of spasticity or abnormal tonicity of the ankle.

Objective: To investigate the effects of Jendrassik maneuver on latency and amplitude of the T-reflex and H-reflex of the soleus muscle in normal adults.

Method: The T-reflex and H-reflex tests were performed on sixty normal adults with standardized technique using the soleus muscle. The shortest latency and the largest peak-to-peak amplitude were chosen for representative values.

Results: The results were as follows: 1) There was a significant difference in latency of the T-reflex between with and without Jendrassik maneuver. 2) The increment ratio of the amplitude with Jendrassik maneuver was 88% in the T-reflex and 18% in the H-reflex. There were a significant difference in the amplitude of both reflexes between with and without Jendrassik maneuver. 3) A high correlation was present between the latency of H- & T-reflex and the length.

Conclusion: According to these results, we suggest that Jendrassik maneuver primarily increases the sensitivity of muscle spindles and decreases the presynaptic inhibition of the Ia terminals at cortical, subcortical and spinal levels. Jendrassik maneuver can be a useful tool in cases of clinically decreased or absent deep tendon reflex.