The Effects of Double Oscillation Exercise Combined with Elastic Band Exercise on Scapular Stabilizing Muscle Strength and Thickness in Healthy Young Individuals: A Randomized Controlled Pilot Trial

Abstract

This study aimed to investigate the effect of double oscillation exercise combined with elastic band exercise on the strength and thickness ratio of the scapular stabilizing muscles in healthy young individuals. A total of 30 subjects (17 male, 13 female) were randomly assigned to an elastic band exercise group (EBG) (n = 15) or an elastic band plus double oscillation exercise group (EB-DOG) (n = 15). A total of 28 subjects completed the experiment and evaluation. Patients in the EBG performed the elastic band exercise for shoulder flexion, extension, abduction, adduction, horizontal abduction/adduction, and internal/external rotation for 30 minutes/session, five times/week, for four weeks. Patients in the EB-DOG performed the elastic band exercise for 15 minutes and the double oscillation exercise in three planes of motion (frontal, sagittal, and transverse), using a Bodyblade® for 15 minutes/session, five times/week, for four weeks. Shoulder muscle strength was assessed using a manual muscle test device during maximal voluntary isometric contraction (MVIC), while the thicknesses of the scapular stabilizing muscles were assessed using rehabilitative ultrasound imaging both at rest and during MVIC. Both groups had significant effects on shoulder muscle strength, however, there was no significant difference between the two groups for change value of shoulder muscle strength (Bonferroni correction p < 0.005). Significant differences were observed in the group × time interactions for horizontal abduction, external rotation, and protraction. There was a statistically significant improvement in thickness ratio of LT and SA in the EB-DOG and no significant difference was founded in EBG (Bonferroni correction p < 0.006). In comparison between the two groups, EB-DOG showed a significant change in the thickness ratio of LT compared to EBG. In addition, significant differences were observed for the group × time interactions for the thickness ratio of the LT (F = 12.177, P = 0.002; Bonferroni correction p < 0.006). The double oscillation exercise combined with elastic band exercise more effectively increased the thickness of the shoulder stabilizing muscles compared with the resistance exercise alone.

Keywords: Shoulder stabilizer; muscle strength; oscillation exercises; rotator cuff; ultrasonography; upper extremity.

Figures

Figure 1.

Ultrasound images of the right upper trapezius muscle at the level of C6 at rest and during MVIC. MVIC: maximal voluntary isometric contraction.

Figure 2.

Ultrasound images of the lower trapezius muscle at the level of T8 at rest and during MVIC. MVIC: maximal voluntary isometric contraction.

Figure 3.

Ultrasound images of the serratus anterior muscle at rest and during MVIC. The rib was used as a reference for measurement of the serratus anterior. The vertical yellow lines, spaced out to incorporate the apex of the rib, were drawn from the rib to the superior fascial border of the serratus anterior. MVIC: maximal voluntary isometric contraction.

Figure 4.

Ultrasound images of the supraspinatus muscle at rest and during MVIC. The point of 2 cm from the angle formed by the superior muscular fascia of the supraspinatus was measured. Yellow lines represent the method for off-line supraspinatus muscle thickness measurement. MVIC: maximal voluntary isometric contraction.

Figure 5.

Ultrasound images of the infraspinatus muscle at rest and during MVIC. The ultrasound images were taken from the inferior-most aspect of the superficial fascia to the most superior aspect of the infraspinous fossa, which appeared as a bright, continuous hyperechoic line spanning the width of the screen.MVIC: maximal voluntary isometric contraction.

Figure 6.

Ultrasound images of the rhomboid major muscle at rest and during MVIC. Ultrasound images of the rhomboid major muscle located between the trapezius and posterior serratus muscles. The thickness can be examined as the vertical length between the inferior echogenic fascial line of the trapezius and the superior line of the posterior serratus. MVIC: maximal voluntary isometric contraction.

Figure 7.

Ultrasound images of the pectoralis major muscle at rest and during MVIC. Thickness was measured at each aspect of distance between superficial and deep aponeurosis. MVIC: maximal voluntary isometric contraction.

Figure 8.

Ultrasound images of the middle deltoid muscle at rest and during MVIC. Thickness was measured at a quarter of the distance from the acromion to the lateral epicondyle. MVIC: maximal voluntary isometric contraction.

Figure 9.

The double oscillation exercises included mediolateral oscillations in the frontal plane (A), dorsoventral oscillations in the sagittal plane (B), and superior and inferior oscillations in the transverse plane (C). Participants performed a double oscillation exercise by holding the middle portion of the flexible bar firmly with the flexion of the shoulder to 90 ° and elbows extended.