• Title/Summary/Keyword: physical theory

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A Comparative Study of Oswestry Back Pain Disability Questionnaire Versus Computer Adaptive Testing for Measuring Back Pain

  • Choi, Bong-Sam
    • Physical Therapy Korea
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    • v.20 no.4
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    • pp.22-31
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    • 2013
  • The aim of the present study was to compare measurement precisions of the Oswestry Back Pain Disability Questionnaire (ODQ) and a computer adaptive testing (CAT) method. The ODQ has been regarded as one of the most reliable condition-specific measure for back pain for decades. Cross-sectional study was carried out with two independent convenient samples from two out-patient rehabilitation clinics for back pain ($n_1=42$) and non-back pain group ($n_2=42$). Participants were asked to fill out the ODQ and CAT of International Classification of Functioning, Disability and Health-Activity Measure (ICF-AM). A series of Rasch analyses were performed to calculate person ability measures. The CAT measures had greater relative precision in discriminating the groups than did the ODQ measure in comparisons of the relative precision. The CAT measure appears to be more effective than did the ODQ measure in terms of measurement precision. By administering test items calibrated in a way, CAT measures using item response theory may promise a means with measurement precision as well as efficiency.

Vibration analysis of double-bonded micro sandwich cylindrical shells under multi-physical loadings

  • Yazdani, Raziye;Mohammadimehr, Mehdi;Zenkour, Ashraf M.
    • Steel and Composite Structures
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    • v.33 no.1
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    • pp.93-109
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    • 2019
  • In the present study, vibration analysis of double bonded micro sandwich cylindrical shells with saturated porous core and carbon/boron nitride nanotubes (CNT/BNNT) reinforced composite face sheets under multi-physical loadings based on Cooper-Naghdi theory is investigated. The material properties of the micro structure are assumed to be temperature dependent, and each of the micro-tubes is placed on the Pasternak elastic foundations, and mechanical, moisture, thermal, electrical, and magnetic forces are effective on the structural behavior. The distributions of porous materials in three distributions such as non-linear non-symmetric, nonlinear-symmetric, and uniform are considered. The relationship including electro-magneto-hydro-thermo-mechanical loadings based on modified couple stress theory is obtained and moreover the governing equations of motion using the energy method and the Hamilton's principle are derived. Also, Navier's type solution is also used to solve the governing equations of motion. The effects of various parameters such as material length scale parameter, temperature change, various distributions of nanotube, volume fraction of nanotubes, porosity and Skempton coefficients, and geometric parameters on the natural frequency of double bonded micro sandwich cylindrical shells are investigated. Increasing the porosity and the Skempton coefficients of the core in micro sandwich cylindrical shell lead to increase the natural frequency of the structure. Cylindrical shells and porous materials in the industry of filters and separators, heat exchangers and coolers are widely used and are generally accepted today.

Can Myofascial Release Techniques Reduce Stress Hormones in the Subject of Short Hamstring Syndrome? A Pilot Study

  • Cho, Sunghak
    • Journal of International Academy of Physical Therapy Research
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    • v.11 no.4
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    • pp.2237-2243
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    • 2020
  • Background: The myofascial release technique is known to be an effective technique for increasing posterior fascia flexibility in short hamstring syndrome (SHS) subjects. But therapeutic mechanism of myofascial relaxation remains unclear. Recently, the theory of autonomic nervous system domination has been raised, however, a proper study to test the theory has not been conducted. Objectives: To investigate whether the application of the myofascial release technique can induce changes in the autonomic nervous system and affect the secretion of stress hormones and myofascial relaxation. Design: Quasi-experimental study. Methods: Twenty-four subjects with SHS were randomly divided into two groups. In the experimental group, the suboccipital muscle inhibition (SMI) technique was applied to the subjects for 4 min in supine position, and in the control group, the subjects were lying in the supine position only. A forward flexion distance (FFD) was conducted, blood pressure, heart rate, and cortisol levels were measured before and after the intervention and 30 min after intervention to determine myofascial relaxation and stress hormone levels. The evaluation was conducted separately in blind by an evaluator. Results: A FFD decreased in the experimental group, no change in cortisol was observed. On the contrary, a decrease in cortisol appeared in the control group after 30 minutes. Conclusion: The myofascial release technique is an effective treatment to increase the range of motion through posterior superior myofascial chain, but there is no evidence that myofascial release technique can control the autonomic nervous system.

Nanocomposite reinforced structures to deal with injury in physical sports

  • Guojiao Wang;Kun Peng;Hui Zhou;Guangyao Liu;Zhiguo Lou;Feng Pan
    • Advances in nano research
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    • v.14 no.6
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    • pp.541-555
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    • 2023
  • The extensive use of polymeric matrix composites in the athletic sector may be attributed to its high strength-to-weight ratio, production economy, and a longer lifespan than conventional materials. This study explored the impact of carbon nanotubes on the properties of different composite field sports equipment components. The test specimens were fabricated using the compression molding technique. The insertion of carbon nanotubes increases mechanical properties related to the process parameters to account for an improvement in the stick sections' overall performance. The dynamic response of functionally graded reinforced nanocomposite wire structure is examined in this paper on the bases of high-order hyperbolic beam theory lined to the size-dependent nonclassical nonlocal theory under the external mechanical load due to the physical activities. Finally, the impact of different parameters on the stability of nanocomposite structures is discussed in detail.

Wave propagation at free surface in thermoelastic medium under modified Green-Lindsay model with non-local and two temperature

  • Sachin Kaushal;Rajneesh Kumar;Indu Bala;Gulshan Sharma
    • Structural Engineering and Mechanics
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    • v.90 no.2
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    • pp.209-218
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    • 2024
  • The present paper is focused on the study of the propagation of plane waves in thermoelastic media under a modified Green-Lindsay (MG-L) model having the influence of non-local and two temperature. The problem is formulated for the considered model in dimensionless form and is explained by using the reflection phenomenon. The plane wave solution of these equations indicates the existence of three waves namely Longitudinal waves (LD-Wave), Thermal waves (T-wave), and Shear waves (SV-wave) from a stress-free surface. The variation of amplitude ratios is computed analytically and depicted graphically against the angle of incidence to elaborate the impact of non-local, two temperature, and different theories of thermoelasticity. Some particular cases of interest are also deduced from the present investigation. The present study finds applications in a wide range of problems in engineering and sciences, control theory, vibration mechanics, and continuum mechanics.

Improve the stability of high resistance badminton net via reinforced light material: Development of industry and sport economy

  • Qiong Wu;Yi Sun;Wanxing Yin
    • Advances in nano research
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    • v.17 no.2
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    • pp.167-179
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    • 2024
  • This study investigates the stability and performance of high-resistance badminton nets through the integration of reinforced lightweight materials. By focusing on the structural and economic impacts, the research aims to enhance both the durability and practicality of badminton nets in professional and recreational settings. Using a combination of advanced material engineering techniques and economic analysis, we explore the development of nets constructed from innovative composites. These composites offer improved resistance to environmental factors, such as weather conditions, while maintaining lightweight properties for ease of installation and use. The study employs high-order shear deformation theory and high-order nonlocal theory to assess the mechanical behavior and stability of the nets. Partial differential equations derived from energy-based methodologies are solved using the Generalized Differential Quadrature Method (GDQM), providing detailed insights into the thermal buckling characteristics and overall performance. The findings demonstrate significant improvements in net stability and longevity, highlighting the potential for broader applications in both the sports equipment industry and related economic sectors. By bridging the gap between material science and practical implementation, this research contributes to the advancement of high-performance sports equipment and supports the growth of the sport economy.

On the Study of Physical Therapy for Part of Retarded Cerebral Palsied Child (지체 뇌성마비아동에 대한 물리치료사 역할에 관한 연구)

  • Sung, Chi-Doo
    • Journal of Korean Physical Therapy Science
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    • v.3 no.2
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    • pp.1055-1064
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    • 1996
  • To this is the concept and changes of physical treatment that intervenes the understanding and restoring cerebral infantile paralysis in the medical welfare of the social well-being areas: Cerebral palsy, originated by Littel in 1862 and reported as "The cerebral palsies" by William and Osler, come to have its name and meaning. The early stage of intervention generally accepted by the circle of physical treatment in the medical profession was introduced by Sax in 1964. In Sax' theory, cerebral palsy is defined as "the stumbling block in the bodily exercises and postures, causing by the intercurrent disease or physical, mental defect." As we have seen it is desirable that the abovementioned limited steps be removed and allow physical therapists to examine and to treat cerebral palsies. For this, first educational system should make its way to a substantial improvement and congenital abnormal Test should be rapidly expanding to great proportions the whole nation, not part of the low-income group. Physical therapists, cerebral palsies and their parents must combine to make cerebral palsies' welfare the crowning well being state. Physical therapists, cerebral palsies and their parents, forming of trinity, should combine to make cerebral palsies' welfare the Super-Welfare State existence.

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Physical insight into Timoshenko beam theory and its modification with extension

  • Senjanovic, Ivo;Vladimir, Nikola
    • Structural Engineering and Mechanics
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    • v.48 no.4
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    • pp.519-545
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    • 2013
  • An outline of the Timoshenko beam theory is presented. Two differential equations of motion in terms of deflection and rotation are comprised into single equation with deflection and analytical solutions of natural vibrations for different boundary conditions are given. Double frequency phenomenon for simply supported beam is investigated. The Timoshenko beam theory is modified by decomposition of total deflection into pure bending deflection and shear deflection, and total rotation into bending rotation and axial shear angle. The governing equations are condensed into two independent equations of motion, one for flexural and another for axial shear vibrations. Flexural vibrations of a simply supported, clamped and free beam are analysed by both theories and the same natural frequencies are obtained. That fact is proved in an analytical way. Axial shear vibrations are analogous to stretching vibrations on an axial elastic support, resulting in an additional response spectrum, as a novelty. Relationship between parameters in beam response functions of all type of vibrations is analysed.