The purpose of this study was to investigate the mechanism of the dynamic morphological change of the femoral extensor evoked by contraction.
In this study, the morphological changes during contraction and relaxation of the femoral extensor were analysed using MRI, and, the centers of gravity of the entire extensor group and of each extensor component were calculated using a pattern analyzer. The subjects were 10 female college basketball players, aged 18 to 22 years, with no history of knee injuries.
The results were as follows:
1. The shift of the center of gravity of each component was very characteristic.
2. The greatest dynamic morphological change was observed in the middle of the femoral extensors when the most muscle volume was involved, and the muscles were at their maximal volume.
3. During muscle contraction, obvious anterior protrusion of the muscle belly of each component of the quadriceps femoris was observed. The muscular force may be transferred effectively into the patellar tendon insertion.

Behçet’s disease (BD) is a multisystem inflammatory disease of unknown origin. Rarely, BD occurs together with myelodysplastic syndrome (MDS). Interestingly, it is speculated that these are not simple coexistence but that the etiology of intestinal BD is at least partly derived from MDS itself. Furthermore, there is a relationship between MDS in patients with intestinal BD and trisomy 8. Immunosuppressive agents alone are insufficient to control MDS-associated BD, and many of these patients die of infection or hemorrhage. Surgery is considered for intestinal BD patients who are unresponsive to medical treatment or those with bowel complications such as perforation or persistent bleeding. We report a case of intestinal BD associated with MDS and trisomy 8. The patient was unresponsive to oral steroids and immunosuppressive treatment; the patient improved by surgical repair of a bowel perforation. Five years after the surgery, the patient is free of recurrence and not on medication. Our experience suggests that surgery may provide an effective therapeutic option for the treatment of MDS-related BD.