Changes in the Cross-sectional Diameter of Muscle Ultrasonography between Relaxation and Maximum Voluntary Isometric Contraction in Normal Young Subjects

Abstract

Ultrasonography is a non-invasive imaging technique that permits visualisation of muscle in real time. The purpose of this study was to investigate the changes in the cross-sectional-diameter (CSD) of the muscle ultrasonography of the rectus femoris and vastus intermedius muscles between maximum relaxation (MR) and maximum voluntary isometric contraction (MVIC). Thirty-eight normal young subjects (24 men and 14 women, mean age 21.87 years) participated in this study. A B-mode ultrasound scanner provided with a 7.5 MHz linear-array probe was used. The mean CSD of vastus intermedius and rectus femoris respectively during MR was 15.50 mm (SD 4.74) and 18.89 mm (SD 3.82) and during MVIC 21.74 mm (SD 4.55) and 25.54 mm (SD 5.89). Simultaneous with the MVIC a retroversion of the femoral bone, mean 9.85 mm (SD 4.38) was seen. A paired t-test (two-tailed) showed a significant increase of CSD from MR through MVIC in vastus intermedius and rectus femoris muscles (p = 0.0001). The mean MVIC:MR for vastus intermedius was 1.42 (SD 0.20) and for rectus femoris was 1.35 (SD 0.19). The results of this study suggest that the CSD parameter may be a valuable and quantitative measurement in muscle testing, showing the degree of muscle activity. However, further study of its relationship with force production is needed. Muscle ultrasonography is a potentially useful new technique for physiotherapists. Ultrasonography is a non-invasive imaging technique that permits visualisation of muscle in real time. The purpose of this study was to investigate the changes in the cross-sectional-diameter (CSD) of the muscle ultrasonography of the rectus femoris and vastus intermedius muscles between maximum relaxation (MR) and maximum voluntary isometric contraction (MVIC). Thirty-eight normal young subjects (24 men and 14 women, mean age 21.87 years) participated in this study. A B-mode ultrasound scanner provided with a 7.5 MHz linear-array probe was used. The mean CSD of vastus intermedius and rectus femoris respectively during MR was 15.50 mm (SD 4.74) and 18.89 mm (SD 3.82) and during MVIC 21.74 mm (SD 4.55) and 25.54 mm (SD 5.89). Simultaneous with the MVIC a retroversion of the femoral bone, mean 9.85 mm (SD 4.38) was seen. A paired t-test (two-tailed) showed a significant increase of CSD from MR through MVIC in vastus intermedius and rectus femoris muscles (p = 0.0001). The mean MVIC:MR for vastus intermedius was 1.42 (SD 0.20) and for rectus femoris was 1.35 (SD 0.19). The results of this study suggest that the CSD parameter may be a valuable and quantitative measurement in muscle testing, showing the degree of muscle activity. However, further study of its relationship with force production is needed. Muscle ultrasonography is a potentially useful new technique for physiotherapists.