The effect of combining vibratory platform and unstable footwear on static balance in active young people.

Vibratory platforms (VPs) and unstable footwear (UF) have both shown benefits on balance in some populations. However, there is no evidence about the combined effects of using UF while training on an VP in healthy and physically active young people. We aimed to evaluate the effects of wearing unstable footwear (UF) while training on a whole-body VP on balance in healthy, physically active young people. 23 participants were randomized into groups assigned UF (n = 11) or stable footwear (SF; n = 12). Both groups followed the same training program on an VP with the assigned footwear type twice a week for 12 weeks. The training consisted of performing 8 isometric exercises for progressively longer periods and higher oscillation amplitudes (15-60 s, 1-3 mm), at a fixed vibration frequency (20 Hz). The main outcomes were the antero-posterior and medio-lateral velocities of the center of pressure (COP) recorded using a plantar pressure corridor at baseline, post-treatment and 1-month follow-up. We found a statistically significant difference in the antero-posterior velocity during the monopodal test in the UF group between the different time-points (χ2(2) = 13.282, p = 0.001). Mediolateral COP velocity ranking during the bipodal test was lower for UF than for SF group (U = 19.50, z = - 2.86, p = 0.003) at follow-up. The traditional vibratory platform training does not seem to be effective to improve static balance in physically active young people, however, adding UF provided slightly greater effect.

Effects of myofascial release in erector spinae myoelectric activity and lumbar spine kinematics in non-specific chronic low back pain: Randomized controlled trial.

BACKGROUND: Flexion-relaxation response of the lumbar erector spinae has been previously studied after different interventions such as exercise programs or spinal manipulation, in subjects with chronic low back pain. The objective of the study was to investigate the effects of an isolated myofascial release protocol on erector spinae myoelectric activity and lumbar spine kinematics in chronic low back pain. METHODS: Thirty-six participants, with nonspecific chronic low back pain, were randomized to myofascial release group (n = 18) receiving four sessions of myofascial treatment, each lasting 40 min, and to control group (n = 18) receiving a sham myofascial release. Electromyographic and kinematic variables as well as pain and disability questionnaires were analyzed. FINDINGS: There was a bilateral reduction of the flexion relaxation ratio in individuals receiving myofascial release and who did not show myoelectric silence at baseline (right difference M = 0.34, 95% CI [0.16, 0.33], p ≤ .05 and left difference M = 0.45, 95% CI [0.16, 0.73], p ≤ .05). There was also a significant reduction in pain in the myofascial release group (difference M = -9.1, 95% CI [-16.3, -1.8], p ≤ .05) and disability (difference M = -5.6, 95% CI [-9.1, -2.1], p ≤ .05), compared with control group. No significant differences between groups were found for the kinematic variables. INTERPRETATION: The myofascial release protocol contributed to the normalization of the flexion- relaxation response in individuals who did not show myoelectric silence before the intervention, and also showed a significant reduction in pain and disability compared with the sham group.

Effects of unstable shoes on trunk muscle activity in patients with chronic low back pain.

INTRODUCTION: Unstable shoes were developed as a walking device to strengthen the lower extremity muscles and reduce joint loading. Many studies have reported increased muscle activity throughout the gait cycle in most of the lower limb muscles in healthy adults using these shoes. However, no previous studies have explored the effects of wearing unstable shoes on trunk muscle activity in patients with chronic low back pain (CLBP). Therefore, the aim of the present study was to compare the activity of selected trunk muscles in patients with CLBP during a gait test while walking wearing unstable shoes or conventional flat shoes (control). METHODS: Thirty-five CLBP patients (51.1 ±â€¯12.4 y; 26 ±â€¯3.8 kg/m2; 9.3 ±â€¯5.2 Roland Morris Disability Questionnaire score) were recruited from the Orthopedic Surgery Service at the Hospital to participate in this cross-sectional study. All the participants underwent gait analysis by simultaneously collecting surface electromyography (EMG) data from erector spinae (ES), rectus abdominis (RA), obliquus internus (OI), and obliquus externus (OE) muscles, while walking on a treadmill with flat control shoes or experimental unstable shoes. RESULTS: The results showed significantly higher %EMG activity in the ES (mean difference: 1.8%; 95% CI: 1.3-2.2), RA (mean difference: 1.5%; 95% CI: 0.3-2.7), and OI (mean difference: 1.5%; 95% CI: 0.2-2.8) in the unstable versus the flat-shoe condition, with a large effect size for the ES (Cohen's d = 1.27). CONCLUSIONS: Based on these findings, the use of unstable shoes may be implicated in promoting spine stability, particularly in improving neuromuscular control of the trunk muscles in CLBP treatment.