Johansson C, Gerdle B
Department of Orthopaedic Surgery, Huddinge Hospital, Sweden.
Int J Sports Med. 1988 Oct;9(5):330-3. doi: 10.1055/s-2007-1025034.
Isokinetic plantar flexion peak torque (PT), contractional work (CW), and integrated electromyographic activity (iEMG) were analyzed in a group of untrained females and a group of female elite orienteers. Similar levels of PT, CW, and iEMG were observed in both groups during single maximum maneuvers (30-180 degrees s1). During repetitive (200) maximum plantar flexions, the untrained females showed a steeper and more pronounced decline in CW during the first 50 contractions than the orienteers. After this fatigue phase, all subjects could maintain a steady-state level of CW throughout the test. This level of CW was significantly (20%) higher in the orienteers than in the untrained females. The iEMGs of the gastrocnemii and soleus muscles decreased to significantly (10%) lower levels in the untrained women than in the orienteers. For both groups, the soleus muscle showed a significantly higher steady-state level of iEMG (10%) than mm. gastrocnemii. In the untrained group, CW/iEMG of m. triceps surae decreased to a plateau level significantly lower than in the orienteerers who could virtually maintain the initial CW/iEMG throughout the test. The differences observed could be explained by adaptations to performed endurance training in the orienteers.
对一组未经训练的女性和一组女性精英定向运动员的等速跖屈峰值扭矩（PT）、收缩功（CW）和肌电图积分活动（iEMG）进行了分析。在单次最大动作（30 - 180度/秒）期间，两组的PT、CW和iEMG水平相似。在进行200次最大跖屈重复动作时，未经训练的女性在前50次收缩期间CW的下降比定向运动员更陡峭、更明显。在这个疲劳阶段之后，所有受试者在整个测试过程中都能维持CW的稳态水平。定向运动员的这一CW水平比未经训练的女性显著高20%。与定向运动员相比，未经训练女性的腓肠肌和比目鱼肌的iEMG下降到显著低10%的水平。对于两组而言，比目鱼肌的iEMG稳态水平比腓肠肌显著高10%。在未经训练的组中，小腿三头肌的CW/iEMG下降到一个平台水平，显著低于定向运动员，后者在整个测试过程中实际上能维持初始的CW/iEMG。观察到的差异可以通过定向运动员对耐力训练的适应性来解释。
