摘要：This study aimed to reveal the ejfects of isometric strength training on the isometric strength and integrated EMG (IEMG) activities of vastus medialis (VM) and rectus feτnoris (FM) muscles at various knee angles (30-60-90-120°) and tibial positions (internal-external rotations and neutral).Ten healthy male subjects (Age:20A±1.5) were trained at 90o knee angle and neutral position for eight weeks.Maximal isometric contractions were performed by each sub ject using a fitn ess machine.Isometric training regime con sisted o f three sets/ da y for three days/w eek.Each set consisted of 6,9 and 12 second contractions with 90-120 second rest intervals.IEMG activities were measured in wall stance position using surface electrodes.Post-training IEMG activities were significantly lower than pre-training values at all angles and positions studied (p<0.05),Compared to 30 and 60of this increase was higher in 90 and 120° knee flexio n (p<0∙05)∙ IEMG activities in VM were higher than those of RF at 60t 90 and 120° knee flexio n in each tibial position.It can be concluded that 90.knee fle xio n at a neutral tibial position may be used to perform isometric quadriceps exercise to improve or maintain isometric strength.
