european college of sport science

Saturday, June 27th, 2009
Methods: Five subjects (four males and one female) participated in this study. The subject’s foot was fixed to the foot plate of an electrical
myometer (VMP-004, VINE, JPN). The passive torque was measured in two conditions; the long condition (LC) and the short condition (SC).
In both conditions, initial ankle joint angle was set at anatomical position (AP). First, the ankle joint angle was slowly changed from AP to
15 deg dorsiflextioned (15DF) by the tester in the LC, then the subject exerted maximum voluntary contraction (MVC). After MVC, joint angle
was changed to AP again and kept 1min. Finally, joint angle was changed to 15DF and kept 1min. In SC, the MVC was exerted in AP. After
the ankle joint angle was kept AP in 1 min, the joint angle was changed 15DF. Subjects maintained the relaxation except the exerted the
maximum voluntary contraction (MVC). All sessions were repeated 5 times. Each of the trials was separated by 2min rest at 15DF of ankle
joint angle. Surface electromyogram (EMG) was recorded from medial and lateral gastrocnemius, soleus and tibialis anterior using
bipolar electrode (SX-230, DKH, Japan). The data of plantarflexion torque and EMG were stored on a personal computer by using an
analog-to-digital converter (PowerLab/16sp, ADInstruments). Passive torque was measured at the end of 5sec in AP following MVC and
in 15DF.
Results and Discussion: During measurement of passive torque, we confirmed that there was no significant EMG activity. The passive
torque was different according to the ankle joint angle in which the MVC was exerted. Although the passive torque at AP was significantly
smaller in LC than in the SC (P