Efficacy of six months neuromuscular exercise on lumbar movement variability : a randomized controlled trial

Introduction: Lumbar movement variability during heavy, repetitive work may be a protective mechanism to diminish the progression of lumbar disorders and maintain neuromuscular functional integrity. The effect of neuromuscular exercise (NME) on the variability of lumbar movement is still to be determined. Methods: A randomised controlled trial was conducted on a population of nursing personnel with subacute LBP. Following randomization, the NME group participants completed an NME program of six months duration. The participants in the control group only attended the assessment sessions. The outcomes were assessed at: baseline; after six months intervention; 12 months. The primary outcome was lumbar movement variability based on angular displacement and velocity. Results: A positive treatment effect on lumbar movement variability was seen after six months of NME intervention. Angular displacement improved, and angular velocity remained constant. At the 12-month follow up, however, the effect faded in the NME group. Lumbar movement variability worsened in the control group over all time periods. Conclusion: NME may improve lumbar movement variability in the short term and may indicate improved neuromuscular functional integrity. The design of an optimal NME program to achieve long-term improvement in lumbar movement variability is a subject worthy of further research

The effect of muscle fatigue and low back pain on lumbar movement variability and complexity

Introduction: Changes in movement variability and complexity may reflect an adaptation strategy to fatigue. One unresolved question is whether this adaptation is hampered by the presence of low back pain (LBP). This study investigated if changes in movement variability and complexity after fatigue are influenced by the presence of LBP. It is hypothesised that pain free people and people suffering from LBP differ in their response to fatigue. Methods: The effect of an isometric endurance test on lumbar movement was tested in 27 pain free participants and 59 participants suffering from LBP. Movement variability and complexity were quantified with %determinism and sample entropy of lumbar angular displacement and velocity. Generalized linear models were fitted for each outcome. Bayesian estimation of the group-fatigue effect with 95% highest posterior density intervals (95%HPDI) was performed. Results: After fatiguing %determinism decreased and sample entropy increased in the pain free group, compared to the LBP group. The corresponding group-fatigue effects were 3.7 (95%HPDI: 2.3-7.1) and -1.4 (95%HPDI: -2.7 to -0.1). These effects manifested in angular velocity, but not in angular displacement. Discussion: The effects indicate that pain free participants showed more complex and less predictable lumbar movement with a lower degree of structure in its variability following fatigue while participants suffering from LBP did not. This may be physiological responses to avoid overload of fatigued tissue, increase endurance, or a consequence of reduced movement control caused by fatigue

The validity of the circumduction test in elderly men and women

This article focuses on the validity of the circumduction test for measuring shoulder flexibility in older adults. Participants included 137 community-dwelling older adults. Equipment consisted of a cord with a fixed handle on one end and a sliding handle on the other. The sliding handle was adjusted so that the cord length between the 2 handles equaled the participant's shoulder width. Holding the 2 handles, the participant must pass the cord from the front of the body over the head and as far back as possible with extended arms. The score is the fanning-out angle. Forward flexion, abduction, horizontal retroflexion, and outward rotation were also measured. The test and criterion measurements were administered within I wk. The criterion-related validity of the circumduction test as a measure of forward flexion and horizontal retroflexion received support from moderate correlations. Its use as a measure of abduction and outward rotation, however, received no support from the data