FREQUENCY LOCK—IN PHENOMENON OF FLAPPING MOTION WITH SURFACE WATER WAVE

To study the effect of a progressive surface wave on the flapping motion of a vertical turbulent plane jet in shallow water,the laser visualizations and measurements were carried out in a water tank.The images of visualization by laser-induced fluorescence(LIF)technique show that the jet flapping motion occurs in the wave environ-ment.Using the wave height gauge and laser Doppler velocimetry(LDV) ,experimental results show that the jet flapping motions indeed lock-in to the wave oscillations if the wave frequency is close to but lower than the nature frequency of jet flapping motion.The phenomenon does not occur when the wave frequency is above the nature frequency of jet flapping motion.

Slacklining as therapy to address non-specific low back pain in the presence of multifidus arthrogenic muscle inhibition

Low back pain(LBP)represents the most prevalent,problematic and painful of musculoskeletal conditions that affects both the individual and society with health and economic concerns.LBP is a heterogeneous condition with multiple diagnoses and causes.In the absence of consensus definitions,partly because of terminology inconsistency,it is further referred to as non-specific LBP(NSLBP).In NSLBP patients,the lumbar multifidus(MF),a key stabilizing muscle,has a depleted role due to recognized myocellular lipid infiltration and wasting,with the potential primary cause hypothesized as arthrogenic muscle inhibition(AMI).This link between AMI and NSLBP continues to gain increasing recognition.To date there is no‘gold standard’or consensus treatment to alleviate symptoms and disability due to NSLBP,though the advocated interventions are numerous,with marked variations in costs and levels of supportive evidence.However,there is consensus that NSLBP management be cost-effective,self-administered,educational,exercise-based,and use multi-modal and multi-disciplinary approaches.An adjuvant therapy fulfilling these consensus criteria is‘slacklining’,within an overall rehabilitation program.Slacklining,the neuromechanical action of balance retention on a tightened band,induces strategic indirect-involuntary therapeutic muscle activation exercise incorporating spinal motor control.Though several models have been proposed,understanding slacklining’s neuro-motor mechanism of action remains incomplete.Slacklining has demonstrated clinical effects to overcome AMI in peripheral joints,particularly the knee,and is reported in clinical case-studies as showing promising results in reducing NSLBP related to MF deficiency induced through AMI(MF-AMI).Therefore,this paper aims to:rationalize why and how adjuvant,slacklining therapeutic exercise may positively affect patients with NSLBP,due to MF-AMI induced depletion of spinal stabilization;considers current understandings and interventions for NSLBP,including the contributing role of MF-AMI;and details the reasons why slacklining could be considered as a potential adjuvant intervention for NSLBP through its indirect-involuntary action.This action is hypothesized to occur through an over-ride or inhibition of central down-regulatory induced muscle insufficiency,present due to AMI.This subsequently allows neuroplasticity,normal neuro-motor sequencing and muscle re-activation,which facilitates innate advantageous spinal stabilization.This in-turn addresses and reduces NSLBP,its concurrent symptoms and functional disability.This process is hypothesized to occur through four neuro-physiological processing pathways:finite neural delay;movement-control phenotypes;inhibition of action and the innate primordial imperative;and accentuated corticospinal drive.Further research is recommended to investigate these hypotheses and the effect of slacklining as an adjuvant therapy in cohort and control studies of NSLBP populations.

Urinary Extraction of Oxidative Damage in Carpet Weavers

Nearly 8.5 million people in Iran directly or indirectly make a living from hand-made carpet weaving industry. Ongoing work, poor postures, breathing problems and skin irritations are among factors affecting the health, safety and wellbeing of those involved in this industry. Hence, considering such factors seem to improve the quality of carpet as a valuable cultural commodity and expand its export. Accordingly, this study investigates the oxidative stress biomarkers among involved and non-involved people in the hand-made carpet industry. 25 carpet maker and 25 ordinary people (not involved in carpet industry) who had been matched for age and sex were selected as study groups. The level of oxidative stress biomarkers such as antioxidant capacity, total thiols and catalase were measured among subjects, and finally the biomarkers were compared between the two groups. To compare the oxidative stress biomarkers in two groups, Independent Sample T Test was used. The mean levels of total antioxidant capacity showed no significant difference between the two groups (0.05 p-value). In conclusion, carpet weaving industry induces oxidative stress and natural antioxidant may be considered beneficial for the protection of oxidative damage in such subjects.

The Influence of Socio-Demographic, Health and Work-Related Factors on Health-Related Quality of Life among Iranian Industrial Workers

Health-related quality of life (HRQOL) has not been investigated among Iranian industrial workers. The present paper aimed to study the influence of the socio-demographic, health and work-related factors on HRQOL among Iranian industrial workers. In this cross-sectional study, participants were 280 workers of two factories. The Persian version of World Health Organization Quality of Life-Brief (WHOQOL-BREF) was used to assess the HRQOL. A questionnaire was developed to assess the socio-demographic, health and work-related factors. Results showed that the means (SD) of physical health, psychological health, social relationships, and environment domains of HRQOL were 13.2 (2.7), 13.3 (2.6), 14.2 (3.5) and 12.6 (2.5), respectively. A multiple linear regression showed that types of job, exercise activity, working schedule, sleep quality, smoking, and conflict between work and social life were significantly associated with physical health domain;whereas, working schedule, marital status, working demand, sleep quality, BMI, and conflict between work and individual life were significantly associated with psychological health domain. Working schedule, working demand, sleep quality, conflict between work and individual life, and having children over two years were significantly associated with social relationship domain;however, working demand, working schedule, smoking, sleep quality, working hour, job satisfaction, marital status and exercise activity were significantly associated with environment domain. Collectively, work-related factors including unhealthy working conditions, unsafe working environments, long working hours, irregular working schedules, and the lack of occupational training may negatively influence the HRQOL of workers. To improve workers’ HRQOL, intervention programs should focus on improving work environment, working schedule, occupational training and restricting working hours.

Slacklining:An explanatory multi-dimensional model considering classical mechanics,biopsychosocial health and time

This paper aims to overcome slacklining’s limited formulated explanatory models.Slacklining is an activity with increasing recreational use,but also has progressive adoption into prehabilitation and rehabilitation.Slacklining is achieved through self-learned strategies that optimize energy expenditure without conceding dynamic stability,during the neuromechanical action of balance retention on a tightened band.Evolved from rope-walking or‘Funambulus’,slacklining has an extensive history,yet limited and only recent published research,particularly for clinical interventions and in-depth hypothesized multi-dimensional models describing the neuromechanical control strategies.These‘knowledge-gaps’can be overcome by providing an,explanatory model,that evolves and progresses existing standards,and explains the broader circumstances of slacklining’s use.This model details the individual’s capacity to employ control strategies that achieve stability,functional movement and progressive technical ability.The model considers contributing entities derived from:Self-learned control of movement patterns;subjected to classical mechanical forces governed by Newton’s physical laws;influenced by biopsychosocial health factors;and within time’s multi-faceted perspectives,including as a quantified unit and as a spatial and cortical experience.Consequently,specific patient and situational uses may be initiated within the framework of evidence based medicine that ensures a multi-tiered context of slacklining applications in movement,balance and stability.Further research is required to investigate and mathematically define this proposed model and potentially enable an improved understanding of human functional movement.This will include its application in other diverse constructed and mechanical applications in varied environments,automation levels,robotics,mechatronics and artificial-intelligence factors,including machine learning related to movement phenotypes and applications.

Slacklining:A narrative review on the origins,neuromechanical models and therapeutic use

Slacklining,the neuromechanical action of balance retention on a tightened band,is achieved through self-learned strategies combining dynamic stability with optimal energy expenditure.Published slacklining literature is recent and limited,including for neuromechanical control strategy models.This paper explores slacklining’s definitions and origins to provide background that facilitates understanding its evolution and progressive incorporation into both prehabilitation and rehabilitation.Existing explanatory slacklining models are considered,their application to balance and stability,and knowledge-gaps highlighted.Current slacklining models predominantly derive from human quiet-standing and frontal plane movement on stable surfaces.These provide a multi-tiered context of the unique and complex neuro-motoric requirements for slacklining’s multiple applications,but are not sufficiently comprehensive.This consequently leaves an incomplete understanding of how slacklining is achieved,in relation to multi-directional instability and complex multi-dimensional human movement and behavior.This paper highlights the knowledge-gaps and sets a foundation for the required explanatory control mechanisms that evolve and expand a more detailed model of multi-dimensional slacklining and human functional movement.Such a model facilitates a more complete understanding of existing performance and rehabilitation applications that opens the potential for future applications into broader areas of movement in diverse fields including prostheses,automation and machine-learning related to movement phenotypes.