Effect of using the Flexi-Bar tool on erector spinae muscle activation under different standing weight-bearing conditions

Comparing the effectiveness of flexi-bar and stability exercises on postural control in chronic nonspecific low back pain: A randomized controlled study

Objectives

This study aimed to compare the effect of flexi-bar and stabilization exercises on static and dynamic postural control in patients with chronic nonspecific low back pain.

Patients and methods

In this randomized controlled study conducted between November 2019 and March 2020, 38 patients (19 males, 19 females; mean age: 33.8±6.2 years; range, 20 to 45 years) were randomly assigned into flexi-bar (n=19) and stabilization (n=19) groups. Both groups received general physiotherapy for three sessions per week, a total of 10 sessions. Besides, the flexi-bar group received flexi-bar exercises, and the stabilization group received stabilization exercises. Postural sway was assessed with a force platform in three difficult conditions, including open eye, close eye, and one-leg standing and dynamic posture with the modified Star Excursion Balance Test.

Results

After the intervention, both groups showed a significant improvement in static and dynamic postural control (p<0.05). However, no significant differences were found between groups after treatment, while only the phase-plane portrait of opened eyes condition was significantly improved (p=0.03), in the flexi-bar group compared to the stabilization group.

Conclusion

Both flexi-bar and stabilization exercises effectively improved static and dynamic postural control, but none of the exercises was superior to the other. Flexi-bar is recommended as an effective tool in low back pain rehabilitation.

Shoulder vibratory exercises improves shoulder external rotation muscle strength and shoulder function: Randomized comparison trial

BACKGROUND

Based on electromyography measurements, shoulder vibratory exercises efficiently stimulate shoulder muscles activity. Yet very few studies have supported that shoulder vibratory exercises increased shoulder muscles strength and function, and the noninferiority compared with conventional elastic resistance exercises remains unknown.

OBJECTIVE

This study investigated the effect of vibratory exercises versus conventional elastic resistance exercises with elastic bands on shoulder external rotation muscles strength and functional performance in young adults.

METHODS

26 young adults (7 males and 19 females, with age 23.89 ± 3.02) were recruited and randomly allocated to shoulder vibratory exercises with FLEXI-BAR (FLEXI-BAR group) or conventional resistance exercises with elastic band (TheraBand group) for 3 times/week, 4 weeks totally. Shoulder external rotator muscles strength test and Underkofler softball distance throw test (USDTT) were performed before and after the training period.

RESULTS

After 4 weeks training, shoulder external rotator muscles strength increased 22.25 ± 15.06 N (P= 0.004, effect size = 1.48) within FLEXI-BAR group and 22.81 ± 14.94 N (P= 0.007, effect size = 1.53) within TheraBand group. There were no statistically significant differences between groups in the three muscle strength tests (P> 0.65). Regarding shoulder function, FLEXI-BAR exercises increased the throw distance 0.81 ± 0.92 meters in USDTT (P= 0.041, effect size = 0.88) while TheraBand exercise did not (P= 0.284), yet there was no statistically significant between group effects (P= 0.608).

CONCLUSIONS

These findings suggest that shoulder vibratory exercises can improve shoulder muscles strength in young adults and can be a useful alternative to the conventional elastic resistance exercises to improve the shoulder muscles strength and function. This provides therapists with more options in terms of choosing training equipment for rehabilitation programs.

Trunk Movement and Sequential Trunk Muscle Activation During Oscillation Exercises Using Flexible Poles

OBJECTIVES

Oscillatory exercises using flexible poles, such as the Flexi-bar, were recommended as rehabilitation programs to increase trunk muscles strength; however, the strategy to enhance the training effects is under investigations. The aim of this study was to characterize the trunk movements and muscle activation patterns when performing an oscillation exercise with flexible poles in different weights.

METHODS

Twelve healthy male participants performed oscillation exercises with flexible poles of different weights. The center of mass, as well as surface electromyography for 10 trunk muscles were assessed while participants performed oscillation exercises.

RESULTS

The participants' trunks showed rhythmic anterior-posterior movement during oscillation exercises using flexible poles. The center-of-mass movement distances were 20.32 (6.73) mm, 25.33 (5.31) mm, 32.40 (9.94) mm, and 37.28 (21.59) mm for the Flexi-bar, light pole, medium pole, and heavy pole, respectively. Erector spinae, internal obliques, multifidus, and external obliques revealed significant activation levels during oscillation exercises. The participants who could perform steady and smooth oscillation with heavy pole for 30 seconds revealed phasic sequential muscle activation.

CONCLUSION

The present study suggested that oscillation exercises with flexible poles were associated with a concomitant trunk movement in anterior-posterior direction and an effective activation of trunk muscles.

Acute cardiovascular stress induced by shoulder vibratory exercise of different amplitudes

BACKGROUND

Vibration exercise has been investigated to enhance muscle activation, however, the effect of different amplitude vibratory exercises on cardiovascular stress is less understood.

OBJECTIVE

Our study aims to explore the acute effect of shoulder vibratory exercises with different postures and amplitudes on the cardiovascular response in healthy adults.

METHODS

Using a repeated measures randomized design, 36 subjects performed three different sessions with FLEXI-BAR exercise (FBE): (1) zero-amplitude, (2) small-amplitude, (3) large-amplitude. Each session included three different shoulder positions: 45-, 90- and 180-degree flexion. Heart rate variability (HRV), heart rate (HR) and rating of perceived exertion (RPE) were monitored continuously, while systolic blood pressure (SBP), diastolic blood pressure (DBP) and rate-pressure product (RPP) were measured before and after each exercise session.

RESULTS

Compared with zero-amplitude, both small- and large-amplitude FBE protocols induced higher SBP. By contrast, DBP decreased with small- and large-amplitude. The RPP immediately after the exercise session were higher than at baseline. For high frequency, low frequency of HRV and HR there was a main effect of amplitude.

CONCLUSION

Small- and large-amplitude FBE increased significantly SBP, RPE, HRV, HR and induced lower DBP, but the changes were modest, suggesting that FBE impose no extra threats to cardiovascular stress.