College of Physical Education, University of Brasilia - UnB, Distrito Federal - Brazil.
Departament of Physical Education, UDF University Center, Distrito Federal - Brazil.
Int J Sports Med. 2020 Oct;41(13):929-935. doi: 10.1055/a-1179-8374. Epub 2020 Jul 8.
This study investigated the acute effects of seated and supine knee extension exercise on muscle swelling, torque, and work output. Twelve resistance-trained men performed two isokinetic concentric-only knee-extension training protocols at different hip positions in a counter-balanced order. They completed the knee extension exercise in the seated (hip angle at 85°) and supine (hip angle at 180°) positions. The torque and work output were assessed during each set. Moreover, muscle thickness of the middle and proximal vastus lateralis and rectus femoris were evaluated before and after each protocol and used as an indicator of muscle swelling. Middle rectus femoris and proximal vastus lateralis thickness increased significantly (p=0.01) with no difference between exercise variations. However, the middle vastus lateralis thickness increased (p=0.01) only after the seated knee extension exercise (~7%). Knee extensors' peak torque and work output were approximately 8% higher (p=0.04) in the seated when compared to the supine hip position. There was a similar decrease in torque and work output throughout both protocols (p=0.98). In conclusion, seated knee extension exercises produced greater torque, work output, and muscle swelling in the vastus lateralis when compared to the supine knee extension exercise.
本研究旨在探讨坐姿和仰卧位膝关节伸展运动对肌肉肿胀、扭矩和功输出的急性影响。12 名经过抗阻训练的男性以平衡的顺序，在不同的髋关节位置下，以两种等速向心的膝关节伸展训练方案进行测试。他们在坐姿（髋关节角度为 85°）和仰卧位（髋关节角度为 180°）下完成膝关节伸展运动。在每组运动中评估扭矩和功输出。此外，在每个方案前后评估股中间肌和股外侧肌中部及近端的肌肉厚度，并将其作为肌肉肿胀的指标。股中间肌和股外侧肌中部厚度显著增加（p=0.01），但两种运动变化之间没有差异。然而，只有在坐姿膝关节伸展运动后，股外侧肌中部厚度才会增加（p=0.01，约 7%）。与仰卧位相比，坐姿时膝关节伸肌的峰值扭矩和功输出约高 8%（p=0.04）。在两个方案中，扭矩和功输出都呈现相似的下降趋势（p=0.98）。综上所述，与仰卧位膝关节伸展运动相比，坐姿膝关节伸展运动可产生更大的扭矩、功输出和股外侧肌肿胀。
