ABSTRACT
The stiffness can respond to the function of muscle and tendon. Resistance training leads to the change of muscle-tendon stiffness, and various with the patterns and strength of contraction. This paper reviewed the impacts of mechanical load on stiffness of muscle and tendon, to explore the adaptation of muscle and tendon to mechanical load.
ABSTRACT
Objective:To compare the difference in the onset time of the trunk muscles activity in individuals with and without nonspecific low back pain (NLBP) during upper limb flexion and abduction. Methods:From September to December, 2017, 21 patients with NLBP (NLBP group) and 21 volunteers (control group) participated in this study. Surface electromyography (sEMG) signals were recorded from the anterior deltoid, middle deltoid, multifidus and erector spinae muscles during upper limb flexion and abduction in standing position. Relative differences in the onset times between each muscle and the prime mover were calculated. Results:During upper limb flexion, the right multifidus muscle, bilateral erector spinae were activated in advance of the agonist muscle (anterior deltoid), while the left multifidus muscle was delayed relative to the agonist muscle in both groups. The onset time of the right erector spinae was significantly delayed in NLBP group than in the control group (t = -2.393, P = 0.019). During upper limb abduction, bilateral multifidus muscle and bilateral erector spinae were activated in advance of the agonist muscle (middle deltoid) in the control group. Additionally, in NLBP group, the left erector spinae was activated in advance of the agonist muscle, bilateral multifidus and right erector spinae were delayed relative to the agonist muscle. There was no significant difference in the relative onset time between both groups (t < 1.393, P > 0.05). Conclusion:During upper limb flexion and abduction, the trunk muscles of the lower back are activated in advance for healthy individuals, while individuals with NLBP have a possibly delayed activation of trunk muscles.
ABSTRACT
Postural control plays a crucial role in maintaining posture stability and improving performance efficiency. It involves involuntary and voluntary components. There is not a unified model for assessment of voluntary postural control. Based on the research framework of voluntary postural control, this paper reviewed three common voluntary postural control assessment tools (Timed "Up and Go" Test, Balance Evaluation System Test and Unified Balance Scale). The Timed “Up and Go” Test contains various capabilities which are recommended by the framework. There are few restrictions on the facilities and test circumstance, and it can be used in different populations. Balance Evaluation System Test consists of three different versions; each of them has high structure validity and shows different characteristics in the evaluation of voluntary postural control. The items of Unified Balance Scale also cover most of capabilities provided by the framework, and there are quality control methods in the scale. These tools would be selected according to purpose, occasion and time of study, or used in combination.
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Objective:To determine the test-retest reliability of lumbar passive reposition accuracy for older people. Methods:A total of 58 healthy older people stood on an isokinetic dynamometer, and passively moved their trunk forward and backward to the target positions as accurately as possible. The targeted positions were set as flexion forward 15°, 30° and 60°, and flexion backward 15°. The absolute error (AE) was recorded. They were tested again a week latter. The intraclass correlation coefficient (ICC) and standard errors of measurement (SEM and SEM%) were calculated. Results:The ICC of AE was 0.699 to 0.833 for all the subjects, SEM was 1.18 to 3.26, and SEM% was 26.84% to 37.13%. For the men, the ICC was 0.462 to 0.818, SEM was 1.60 to 3.68, and SEM% was 36.37% to 48.78%. For the women, the ICC was 0.782 to 0.891, SEM was 1.48 to 2.71, and SEM% was 28.48% to 33.34%. Conclusions:Lumbar passive reposition accuracy is some reliable to assess the position sense for older people. However, there are too large errors for clinical measurement, which need further improvment.
ABSTRACT
Neuropathic pain is a common health problem in clinic. The enriched environment can increase the threshold of pain in models of neuropathic pain, which may associate with the alleviation of inflammation and excitability of nerves.