2.4. Maximal Voluntary Isometric Contraction (MVC)
hip joints
MVC in elbow joint flexion was measured by using a custom-made myometer, with tension/compression load cells (TR22S, SOHGOH KEISO CO., LTD., Japan). The elbow joint was held at a 90° flexed position (0° corresponds to full elbow extension). Participants were seated on an adjustable chair with the shoulder, and hip joints flexed at 90°. The force signals were amplified and attenuated with a low-pass filter (<100 Hz, DPM-912B, KYOWA, Japan). The force and angle signals were sampled at a frequency of 2 kHz, via a 16-bit analog/digital converter (PowerLab/16s: ADInstruments Sydney, Australia), and stored on a personal computer. The highest value among the two or three isometric forces was adapted as the elbow flexion MVC force. The value was divided by mCSA (MVC/mCSA) as an index of muscle quality.