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1.
J Clin Med ; 12(17)2023 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-37685676

RESUMO

BACKGROUND: In the primary and secondary medical health sector, patient reported outcome measures (PROMs) are widely used to assess a patient's disease-related functional health state. However, the World Health Organization (WHO), in its recently adopted resolution on "strengthening rehabilitation in all health systems", encourages that all health sectors, not only the rehabilitation sector, classify a patient's functioning and health state according to the International Classification of Functioning, Disability and Health (ICF). AIM: This research sought to optimize machine learning (ML) methods that fully and automatically link information collected from PROMs in persons with unspecific chronic low back pain (cLBP) to limitations in activities and restrictions in participation that are listed in the WHO core set categories for LBP. The study also aimed to identify the minimal set of PROMs necessary for linking without compromising performance. METHODS: A total of 806 patients with cLBP completed a comprehensive set of validated PROMs and were interviewed by clinical psychologists who assessed patients' performance in activity limitations and restrictions in participation according to the ICF brief core set for low back pain (LBP). The information collected was then utilized to further develop random forest (RF) methods that classified the presence or absence of a problem within each of the activity participation ICF categories of the ICF core set for LBP. Further analyses identified those PROM items relevant to the linking process and validated the respective linking performance that utilized a minimal subset of items. RESULTS: Compared to a recently developed ML linking method, receiver operating characteristic curve (ROC-AUC) values for the novel RF methods showed overall improved performance, with AUC values ranging from 0.73 for the ICF category d850 to 0.81 for the ICF category d540. Variable importance measurements revealed that minimal subsets of either 24 or 15 important PROM variables (out of 80 items included in full set of PROMs) would show similar linking performance. CONCLUSIONS: Findings suggest that our optimized ML based methods more accurately predict the presence or absence of limitations and restrictions listed in ICF core categories for cLBP. In addition, this accurate performance would not suffer if the list of PROM items was reduced to a minimum of 15 out of 80 items assessed.

2.
Bioengineering (Basel) ; 10(3)2023 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-36978691

RESUMO

As part of our quest for digital biomarkers of neuromuscular aging, and encouraged by recent findings in healthy volunteers, this study investigated if the instantaneous median frequency (IMDF) derived from back muscle surface electromyographic (SEMG) data monitored during cyclic back extensions could reliably differentiate between younger and older individuals with cLBP. A total of 243 persons with cLBP participated in three experimental sessions: at baseline, one to two days after the first session, and then again approximately six weeks later. During each session, the study participants performed a series of three isometric maximal voluntary contractions (MVC) of back extensors using a dynamometer. These were followed by an isometric back extension at 80% MVC, and-after a break-25 slow cyclic back extensions at 50% MVC. SEMG data were recorded bilaterally at L5 (multifidus), L2 (longissimus dorsi), and L1 (iliocostalis lumborum). Linear mixed-effects models found the IMDF-SEMG time-course changes more rapidly in younger than in older individuals, and more prominently in male participants. The absolute and relative reliabilities of the SEMG time-frequency representations were well compared between older and younger participants. The results indicated an overall good relative reliability, but variable absolute reliability levels. IMDF-SEMG estimates derived from cyclic back extensions proved to be successful in reliably detecting differences in back muscle function in younger vs. older persons with cLBP. These findings encourage further research, with a focus on assessing whether an IMDF-SEMG-based index could be utilized as a tool to achieve the preclinical detection of back muscle aging, and possibly predict the development of back muscle sarcopenia.

3.
Geroscience ; 42(2): 817, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31981006

RESUMO

Unfortunately, the author names in the author group section were incorrectly captured in the published online paper.

4.
Geroscience ; 42(1): 251-269, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31773454

RESUMO

The impact of aging on the back muscles is not well understood, yet may hold clues to both normal aging and chronic low back pain (cLBP). This study sought to investigate whether the median frequency (MF) surface electromyographic (SEMG) back muscle fatigue method-a proxy for glycolytic muscle metabolism-would be able to detect age- and sex-specific differences in neuromuscular and muscle metabolic functions in individuals with cLBP in a reliable way, and whether it would be as sensitive as when used on healthy individuals. With participants seated on a dynamometer (20° trunk anteflexion), paraspinal SEMG activity was recorded bilaterally from the multifidus (L5), longissimus (L2), and iliolumbalis (L1) muscles during isometric, sustained back extensions loaded at 80% of maximum from 117 younger (58 females) and 112 older (56 female) cLBP individuals. Tests were repeated after 1-2 days and 6 weeks. Median frequency, the SEMG variable indicating neuromuscular fatigue, was analyzed. Maximum back extensor strength was comparable between younger and older participants. Significantly less MF-SEMG back muscle fatigue was observed in older as compared to younger, and in older female as compared to older male cLBP individuals. Relative reliability was excellent, but absolute reliability appeared large for this SEMG-fatigue measure. Findings suggest that cLBP likely does not mask the age-specific diagnostic potential of the MF-SEMG back extensor fatigue method. Thus, this method possesses a great potential to be further developed into a valuable biomarker capable of detecting back muscle function at risk of sarcopenia at very early stages.


Assuntos
Músculos do Dorso , Dor Lombar , Idoso , Eletromiografia , Feminino , Humanos , Dor Lombar/diagnóstico , Masculino , Fadiga Muscular , Reprodutibilidade dos Testes
5.
Front Physiol ; 8: 299, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28559851

RESUMO

Purpose: To investigate the differences in neural control of back muscles activated during the eccentric vs. the concentric portions of a cyclic, submaximal, fatiguing trunk extension exercise via the analysis of amplitude and time-frequency parameters derived from surface electromyographic (SEMG) data. Methods: Using back dynamometers, 87 healthy volunteers performed three maximum voluntary isometric trunk extensions (MVC's), an isometric trunk extension at 80% MVC, and 25 cyclic, dynamic trunk extensions at 50% MVC. Dynamic testing was performed with the trunk angular displacement ranging from 0° to 40° and the trunk angular velocity set at 20°/s. SEMG data was recorded bilaterally from the iliocostalis lumborum at L1, the longissimus dorsi at L2, and the multifidus muscles at L5. The initial value and slope of the root mean square (RMS-SEMG) and the instantaneous median frequency (IMDF-SEMG) estimates derived from the SEMG recorded during each exercise cycle were used to investigate the differences in MU control marking the eccentric vs. the concentric portions of the exercise. Results: During the concentric portions of the exercise, the initial RMS-SEMG values were almost twice those observed during the eccentric portions of the exercise. The RMS-SEMG values generally increased during the concentric portions of the exercise while they mostly remained unchanged during the eccentric portions of the exercise with significant differences between contraction types. Neither the initial IMDF-SEMG values nor the time-course of the IMDF-SEMG values significantly differed between the eccentric and the concentric portions of the exercise. Conclusions: The comparison of the investigated SEMG parameters revealed distinct neural control strategies during the eccentric vs. the concentric portions of the cyclic exercise. We explain these differences by relying upon the principles of orderly recruitment and common drive governing motor unit behavior.

6.
Clin J Pain ; 33(10): 912-920, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28118259

RESUMO

OBJECTIVES: Evidence suggests that chronic low back pain patients with fear-avoidance (FAR) or endurance behavior are at risk of treatment failure and pain maintenance, with bodily overuse or underuse being assumed as mediating mechanisms for pain chronification. This study sought to examine whether or not the avoidance-endurance model subgroups, FAR, distress-endurers (DER), eustress-endurers (EER), and adaptive responders (AR), differed in physical measures and outcomes after training therapy. MATERIALS AND METHODS: A total of 137 chronic low back pain patients were assessed before, at the end of, and 6 months after a 6-month rehabilitation training. Patients performed maximum back extension strength and trunk range-of-motion measures, flexion-relaxation tests, and completed the following questionnaires: Avoidance-Endurance Questionnaire, Roland-Morris Disability Questionnaire, Pain Disability Index, 36-Item Short-Form Health Survey, International Physical Activity Questionnaire, and visual analog scale. Statistical analysis included cluster analysis, analysis of covariances, and mixed-effects models. RESULTS: At baseline, avoidance-endurance model subgroups did not differ in physical measures and activity levels. At the end of training, patients' back-related health was significantly improved in all subgroups. However, the DER and the FAR were found to be more impaired before and after the intervention compared with EER and AR, as indicated by a higher pain intensity, higher disability levels, lower quality of life, and inferior working capacity. DISCUSSION: Although FAR and DER did not differ in physical measures or activity levels from EER and AR, they demonstrated poor lower back-related health at baseline and after intervention. Thus, future research should elucidate as to which additional interventions could optimize their health.


Assuntos
Adaptação Psicológica , Dor Crônica/psicologia , Dor Crônica/reabilitação , Dor Lombar/psicologia , Dor Lombar/reabilitação , Aprendizagem da Esquiva , Catastrofização , Dor Crônica/fisiopatologia , Estudos Transversais , Avaliação da Deficiência , Medo , Feminino , Seguimentos , Humanos , Estudos Longitudinais , Dor Lombar/fisiopatologia , Masculino , Pessoa de Meia-Idade , Modelos Psicológicos , Medição da Dor , Qualidade de Vida , Resiliência Psicológica , Tronco/fisiopatologia , Resultado do Tratamento
7.
Eur Spine J ; 26(2): 510-517, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27600250

RESUMO

PURPOSE: Dynamic trunk flexion-extension testing has been proven to objectively diagnose low back pain in persons under the age of 60 years but older persons have difficulty complying with standardized movement velocity. METHODS: 190 patients and 71 matched healthy volunteers (18-90 years of age) performed modified testing by holding static positions at standing, half, and full trunk flexion. RESULTS: Lumbar extensor muscle activity in isometric positions was significantly higher in patients with higher activity in the oldest (60-90 years) and the middle-aged (40-59 years) but not in the youngest (18-39 years) subgroups compared to normal. There were no differences in gross trunk range of motion, half flexion relaxation ratio, proprioception, muscle activity differences between positions, and fear-avoidance behavior. The diagnostic accuracy as expressed by the area under the curve was fair (0.74). CONCLUSIONS: Lumbar extensor muscle activity demonstrated moderate to good diagnostic value in old patients.


Assuntos
Músculos do Dorso/fisiologia , Dor Crônica/fisiopatologia , Dor Lombar/fisiopatologia , Movimento/fisiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Eletromiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Força Muscular/fisiologia , Adulto Jovem
8.
J Rehabil Med ; 48(10): 893-902, 2016 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-27735987

RESUMO

OBJECTIVE: To investigate the short- and long-term reliability of isometric trunk strength measurements in patients with chronic low back pain in different age groups. DESIGN: Test-retest reliability study. PATIENTS: A total of 210 patients (age groups 18-39, 40-59 and 60-90 years). METHODS: Patients performed testing at baseline, 1-2 days (day 2) and 6 weeks. RESULTS: Only the oldest age group showed similar extension strength on all three test days All age groups showed significant changes in rotation and flexion scores from baseline to 6 weeks. Younger age groups (18-39 and 40-59 years) showed significant increases in extension, flexion, and rotation strength at both short-term (baseline to day 2) and long-term (baseline to 6 weeks) retests, but not from day 2 to 6 weeks. In patients over 60 years of age the smallest real differences normalized to baseline (%) were smaller from day 2 to 6 weeks than from baseline to 6 weeks. Long-term intraclass correlation coefficients were lowest between baseline and 6 weeks. No relevant impacts of feelings, motivation, or pain on reliability were detected. CONCLUSION: Reliability of isometric trunk strength measurements in patients with chronic low back pain is similar in older and younger patients. Short-term test repetition a few days after baseline is recommended, if clinically feasible, and especially in research evaluating the effects of exercise on strength.


Assuntos
Envelhecimento/fisiologia , Contração Isométrica/fisiologia , Dor Lombar/fisiopatologia , Torque , Tronco/fisiopatologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Exercício Físico/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Força Muscular , Músculo Esquelético/fisiopatologia , Amplitude de Movimento Articular , Reprodutibilidade dos Testes , Adulto Jovem
10.
J Neuroeng Rehabil ; 13: 16, 2016 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-26896325

RESUMO

BACKGROUND: The root mean square surface electromyographic activity of lumbar extensor muscles during dynamic trunk flexion and extension from standing has repeatedly been recommended to objectively assess muscle function in chronic low back pain patients. However, literature addressing older patients is sparse. This cross sectional study sought to examine differences in neuromuscular activation between age groups (>60 versus 40-60 versus <40 years) and sexes during a standardized trunk flexion-extension task. METHODS: A total of 216 patients (62 older, 84 middle-aged, 70 younger) performed maximum trunk extensions followed by trunk flexion extension testing thereby holding static positions at standing, half, and full trunk flexion. The lumbar extensor muscle activity and 3d-accelerometric signals intended to monitor hip and trunk position angles were recorded from the L5 (multifidus) and T4 (semispinalis thoracis) levels. Permutation ANOVA with bootstrapped confidence intervals were performed to examine for age and gender related differences. Ridge-regressions investigated the impact of physical-functional and psychological variables to the half flexion relaxation ratio (i.e. muscle activity at the half divided by that in maximum flexion position). RESULTS: Maximum back extension torque was slightly but significantly higher in youngest compared to oldest patients if male and females were pooled. Normalized RMS-SEMG revealed highest lumbar extensor muscle activity at standing in the oldest and the female groups. Patients over 60 years showed lowest activity changes from standing to half (increments) and from half to the maximum flexion position (decrements) leading to a significantly lower half flexion relaxation ratio compared to the youngest patients. These oldest patients demonstrated the highest hip and lowest lumbothoracic changes of position angles. Females had higher regional hip and gross trunk ranges of movement compared to males. Lumbothoracic flexion and the muscle activity at standing had a significant impact on the half flexion relaxation ratio. CONCLUSIONS: The neuromuscular activation pattern and the kinematics in this trunk flexion-extension task involving static half flexion position changed according to age and sex. The test has a good potential to discriminate between impaired and unimpaired neuromuscular regulation of back extensors in cLBP patients, thereby allowing the design of more individualized exercise programs.


Assuntos
Dor Lombar/fisiopatologia , Movimento , Músculo Esquelético/fisiopatologia , Tronco/fisiopatologia , Acelerometria , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento , Estudos Transversais , Eletromiografia , Feminino , Quadril/fisiopatologia , Humanos , Região Lombossacral/fisiopatologia , Masculino , Pessoa de Meia-Idade , Contração Muscular , Relaxamento Muscular , Dinamômetro de Força Muscular , Músculo Esquelético/inervação , Caracteres Sexuais , Adulto Jovem
11.
Acta Biomater ; 24: 251-65, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26141153

RESUMO

The generation of functional biomimetic skeletal muscle constructs is still one of the fundamental challenges in skeletal muscle tissue engineering. With the notion that structure strongly dictates functional capabilities, a myriad of cell types, scaffold materials and stimulation strategies have been combined. To further optimize muscle engineered constructs, we have developed a novel bioreactor system (MagneTissue) for rapid engineering of skeletal muscle-like constructs with the aim to resemble native muscle in terms of structure, gene expression profile and maturity. Myoblasts embedded in fibrin, a natural hydrogel that serves as extracellular matrix, are subjected to mechanical stimulation via magnetic force transmission. We identify static mechanical strain as a trigger for cellular alignment concomitant with the orientation of the scaffold into highly organized fibrin fibrils. This ultimately yields myotubes with a more mature phenotype in terms of sarcomeric patterning, diameter and length. On the molecular level, a faster progression of the myogenic gene expression program is evident as myogenic determination markers MyoD and Myogenin as well as the Ca(2+) dependent contractile structural marker TnnT1 are significantly upregulated when strain is applied. The major advantage of the MagneTissue bioreactor system is that the generated tension is not exclusively relying on the strain generated by the cells themselves in response to scaffold anchoring but its ability to subject the constructs to individually adjustable strain protocols. In future work, this will allow applying mechanical stimulation with different strain regimes in the maturation process of tissue engineered constructs and elucidating the role of mechanotransduction in myogenesis. STATEMENT OF SIGNIFICANCE: Mechanical stimulation of tissue engineered skeletal muscle constructs is a promising approach to increase tissue functionality. We have developed a novel bioreactor-based 3D culture system, giving the user the possibility to apply different strain regimes like static, cyclic or ramp strain to myogenic precursor cells embedded in a fibrin scaffold. Application of static mechanical strain leads to alignment of fibrin fibrils along the axis of strain and concomitantly to highly aligned myotube formation. Additionally, the pattern of myogenic gene expression follows the temporal progression observed in vivo with a more thorough induction of the myogenic program when static strain is applied. Ultimately, the strain protocol used in this study results in a higher degree of muscle maturity demonstrated by enhanced sarcomeric patterning and increased myotube diameter and length. The introduced bioreactor system enables new possibilities in muscle tissue engineering as longer cultivation periods and different strain applications will yield tissue engineered muscle-like constructs with improved characteristics in regard to functionality and biomimicry.


Assuntos
Reatores Biológicos , Matriz Extracelular/química , Fibrina/química , Hidrogéis/química , Músculo Esquelético/metabolismo , Estresse Mecânico , Animais , Antígenos de Diferenciação/biossíntese , Linhagem Celular , Camundongos , Proteínas Musculares/biossíntese , Músculo Esquelético/citologia
12.
J Neuroeng Rehabil ; 12: 3, 2015 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-25566847

RESUMO

BACKGROUND: The root mean square surface electromyographic activity of lumbar extensor muscles during dynamic trunk flexion and extension from a standing position and task specific spine ranges of motion objectively assess muscle function in healthy young and middle age individuals. However, literature on neuromuscular activation and associated spine and hip kinematics in older individuals is sparse. This cross sectional study sought to examine the sex and age (<40 versus >60 years) related differences in the neuromuscular activation profiles of the lumbar extensors and the related spine and hip kinematics from healthy individuals during a standardized trunk flexion-extension task. METHODS: Twenty five older (13 females, 60-90 years) and 24 younger (12 females, 18-40 years) healthy individuals performed trunk flexion-extension testing by holding static positions at half-flexion way and full range of motion between standing and maximum trunk flexion. The associated lumbar extensor muscle activity was derived from measurements at standing, half, and maximum flexion positions. The range of motion at the hip and lumbar spine was recorded using 3d accelerometers attached to the skin overlying the multifidus and semispinalis thoracis muscles lateral to the L5 and T4 spinous processes, respectively. Statistical calculations were performed using a permutation ANOVA with bootstrap confidence intervals. RESULTS: The muscle activity in the half related to the maximum flexion position (half flexion relaxation ratio) was significantly smaller in older males when compared with younger males. Moreover, measurements revealed smaller activity changes from standing to the half and from half to the maximum flexion position in older compared to younger individuals. Older males displayed smaller gross trunk range of motion from standing to maximum flexion than any other group. CONCLUSIONS: Gender and normal aging significantly affect both the activation patterns of the lumbar extensor muscles and the kinematics of the trunk during a standardized trunk flexion-extension task. Measurement results from healthy young and middle age individuals should not be used for the assessment of individuals older than 60 years of age.


Assuntos
Fenômenos Biomecânicos/fisiologia , Movimento/fisiologia , Músculo Esquelético/inervação , Músculo Esquelético/fisiologia , Acelerometria , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Estudos Transversais , Eletromiografia , Feminino , Quadril/anatomia & histologia , Quadril/diagnóstico por imagem , Quadril/fisiologia , Humanos , Região Lombossacral/inervação , Região Lombossacral/fisiologia , Masculino , Pessoa de Meia-Idade , Dinamômetro de Força Muscular , Músculo Esquelético/crescimento & desenvolvimento , Cintilografia , Caracteres Sexuais , Coluna Vertebral/anatomia & histologia , Coluna Vertebral/inervação , Coluna Vertebral/fisiologia , Tórax/inervação , Tórax/fisiologia , Adulto Jovem
13.
J Neuroeng Rehabil ; 11: 106, 2014 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-24985941

RESUMO

BACKGROUND: To examine whether or not median frequency surface electromyographic (MF-EMG) back muscle fatigue monitoring would be able to identify alterations in back muscle function in elderly muscles, if a protocol was used that allowed optimum standardization of the processes underlying electromyographic fatigue, and whether these tests were reliable from day to day. METHODS: A total of 42 older (21 females; 67 (±10.5) years old) and 44 younger persons (19 females; 33 (±10) years) performed maximum isometric back extensions which were followed by one 30 s lasting 80% submaximum extension. Participants were seated on a dynamometer with their trunks 30° anteflexed, and they repeated all tests after 1-2 days and 6 weeks. SEMG was recorded bilaterally from the L1 (iliocostalis lumborum), L2 (longissimus), and L5 (multifidus) recording sites. Outcome variables included maximum back extension torque, initial MF-EMG (IMF-EMG), MF-EMG slope declines, and individual MF-EMG muscular imbalance scores. Two-factorial ANOVAs served to examine the age and gender-specific effects, and models from Generalizability Theory (G-Theory) were used for assessing retest-reliability. RESULTS: Maximum back extension moment was non-significantly smaller in elders. IMF-EMG was overall higher in elders, with significant differences at the L5 recordings sites. In the elderly, MF-EMG fatigue declines were significantly smaller in L5, in the recording with the most negative slope, or if the slope of all electrodes was considered. Retest reliability was unanimous in young and older persons. ICC-type measurements from G-Theory of both the IMF and the fatigue slopes ranged from 0.7 to 0.85. Absolute SEM values were found clinically acceptable for the IMF-EMG, but relatively high for the fatigue slope declines. CONCLUSIONS: The MF-EMG fatigue method is able to elucidate alterations of aging back muscles. This method, thus, might be suggested as a potential biomarker to objectively identify persons at risk for sarcopenia. Considering the clinical relevance of the IMF-EMG relative to the MF-EMG slope declines, spectral EMG may also be used as an outcome monitoring tool in elderly populations.


Assuntos
Envelhecimento/patologia , Músculos do Dorso/fisiopatologia , Eletromiografia/métodos , Fadiga Muscular/fisiologia , Sarcopenia/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Feminino , Humanos , Masculino , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Contração Muscular/fisiologia , Processamento de Sinais Assistido por Computador , Adulto Jovem
14.
J Rehabil Med ; 46(3): 241-9, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24473577

RESUMO

OBJECTIVE: To determine the short- and long-term test-retest reliability of maximum isometric trunk moment measurements in healthy volunteers over 50 years of age, to compare these results with those from volunteers younger than 50 years, and to test whether volunteers' anticipatory emotional state affects the precision of these measurements. METHODS: Forty-two older persons (21 females; age range 50-90 years) and 44 younger persons (19 females; age range 18-49 years) performed maximum isometric trunk extensions, flexions, and rotations using dynamometers (DAVID, Fi, David Health Solutions Ltd, Helsinki, Finland). They repeated the tests after 1-2 days (short-term) and at 6 weeks (long-term). Retest-reliability was evaluated for age- and gender-specific subgroups, with assessment of intraclass correlation coefficient (ICC2,1) , standard error of measurement, smallest real difference, and smallest real difference, in percent. RESULTS: For the elderly group, smallest real difference, in percent values varied up to 33% and were similar to those obtained from young volunteers. Precision of the trunk rotation tests was lower than that of trunk flexion or extension. Retest agreement exceeded 0.75 (ICC2,1) for all tests, with no relevant differences observed between gender- and age-specific subgroups. Neither participants' motivation nor their anticipatory emotions correlated with the individual coefficients of variation of the trunk muscle moment measurements. CONCLUSION: Isometric maximum trunk extension and flexion moment measurements taken from healthy persons > 50 years old are as reliable as those from persons < 50 years old, and can be expected to enable an acceptable level of detection of expected changes in muscle strength parameters as a result of planned exercise interventions.


Assuntos
Envelhecimento/fisiologia , Contração Isométrica/fisiologia , Músculo Esquelético/fisiologia , Tronco/fisiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Finlândia , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Movimento/fisiologia , Força Muscular/fisiologia , Amplitude de Movimento Articular/fisiologia , Valores de Referência , Reprodutibilidade dos Testes , Torque , Adulto Jovem
15.
Eur J Appl Physiol ; 89(3-4): 384-6, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12682839

RESUMO

This study identified those harmonics from the frequency spectrum of electrical impedance rheographic signals that discriminate between patients with and without peripheral arterial occlusive disease (PAOD). Ninety-four patients with suspected PAOD were evaluated by impedance rheography and ankle-arm blood pressure index. The leg with the lower ankle-arm index was used in the analysis and a haemodynamically relevant PAOD was assumed at an ankle-arm index lower than 0.85. The frequency spectrum of the impedance signals of the shank was calculated by means of a fast Fourier transformation algorithm. The first ten harmonics were used as independent variables in a stepwise logistic regression analysis to evaluate the dependent variable PAOD. In the regression analysis only the third harmonic was accepted ( P<0.0001). The correct classification of the patients was 90%. In conclusion, by means of Fourier analysis of impedance rheographic signals, a high accuracy in the diagnosis of PAOD can be achieved.


Assuntos
Algoritmos , Arteriopatias Oclusivas/diagnóstico , Diagnóstico por Computador/métodos , Impedância Elétrica , Doenças Vasculares Periféricas/diagnóstico , Pletismografia de Impedância/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Arteriopatias Oclusivas/diagnóstico por imagem , Feminino , Análise de Fourier , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Vasculares Periféricas/diagnóstico por imagem , Pletismografia de Impedância/instrumentação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Ultrassonografia
16.
Med Sci Sports Exerc ; 34(8): 1316-23, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12165687

RESUMO

PURPOSE: To test the short-term and long-term reliability of time-frequency electromyographic (EMG) measures of fatigue during repetitive dynamic lifting and compare it with the reliability of median frequency (MF) EMG measures of fatigue during static lifting. METHODS: Fourteen' healthy male subjects (26 +/- 5 years) repetitively (12 lifts/min) lifted and lowered a box (29 x 25 x 23 cm, 13 kg) for 4.5 min during 3 different tests on 2 different days. EMG data and the biomechanics of motion were recorded. Before and after dynamic lifting, static maximum lifting tests were performed. At the end of each of the two sessions, subjects performed a static lift at 80% of their maximum lifting force for 30 s. RESULTS: Significant fatigue-related changes were observed during the lifting exercise via EMG time-frequency analysis at the paravertebral L5, L2, T10, and vastus lateralis (VL) electrode sites. Two parameters for assessing fatigue during dynamic contractions [i.e., the Instantaneous Median Frequency (IMDF) and its time dependent change] were shown to be reproducible both in the short-term (2 h) and long-term (2 wk). The corresponding ICCs reflecting the reproducibility of values between sessions were 96.9% (L5), 98.1% (L2), 90.1% (T10), 96.4% (UT), 98.0% (GM), 89.5% (VL), and 99.0% (BF), respectively. For most EMG recording sites, the reliability of the IMDF measures was not dependent upon the postural strategy that the subject used to accomplish the lifting task or on the subject's strength as measured via the static maximum lifting test. A comparison between the ICC values of the IMDF measures and those of the parameters utilized to assess fatigue during static sustained lifts [i.e., the Median Frequency (MDF) and its change during the test] revealed equally good reproducibility for most EMG recording sites. The respective ICC values that took into account time dependent trends for the IMDF parameter were 87.1% (L5), 62.4% (L2), 90.1% (T10), 0% (UT), 72.7% (GM), 45.4% (VL), and 100% (BF), and for the MDF parameter 94.9% (L5), 73.0% (L2), 80.9% (T10), 100% (UT), 89% (GM), 91.7% (VL), and 90.9% (BF), respectively. CONCLUSIONS: The time-frequency approach allows one to derive EMG spectral parameters that can be used to monitor muscle fatigue during dynamic real-world tasks such as lifting.


Assuntos
Eletromiografia/métodos , Contração Muscular/fisiologia , Fadiga Muscular/fisiologia , Esforço Físico , Levantamento de Peso/fisiologia , Adulto , Fenômenos Biomecânicos , Índice de Massa Corporal , Humanos , Dor Lombar/fisiopatologia , Masculino , Medição da Dor , Probabilidade , Estudos Prospectivos , Valores de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
17.
J Biomech ; 35(5): 585-94, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-11955498

RESUMO

Any voluntary motion of the body causes an internal perturbation of balance. Load transfer during manual material handling may increase these perturbations. This study investigates effects of stance condition on postural control during lifting. Nineteen healthy subjects repeatedly lifted and lowered a load between a desk and a shelf. The base of support was varied between parallel and step stance. Ground reaction force and segmental kinematics were measured. Load transfer during lifting perturbed balance. In parallel stance postural response consisted of axial movements in the sagittal plane. Such strategy was accompanied by increased posterior shear forces after lift-off. Lifting in step stance provided extended support in anterior/posterior direction. The postural control mechanisms in the sagittal plane are less complex as compared to parallel stance. However, lifting in step stance was asymmetrical and thus accompanied by distinct lateral transfer of the body. Lateral shear forces were larger as compared to parallel stance. Both lifting techniques exhibit positive and negative aspects. We cannot recommend either one as being better in terms of postural control.


Assuntos
Remoção , Postura/fisiologia , Adulto , Fenômenos Biomecânicos , Humanos , Perna (Membro)/fisiologia , Masculino , Pessoa de Meia-Idade , Equilíbrio Postural/fisiologia , Suporte de Carga/fisiologia
18.
Cranio ; 20(1): 23-7, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11831340

RESUMO

In a previous study, exercise and manual therapy demonstrated a 90% success rate in patients with osteoarthrosis of the temporomandibular joints in the short-term. The aim of this follow-up study was to assess the long-term effect of these treatment modalities. Seventeen patients were evaluated. All patients suffered from osteoarthrosis of the temporomandibular joints with pain in the temporomandibular joint at baseline and were treated successfully in a prior short-term study. The parameters were pain at rest and at chewing, impairment in daily life, and mouth opening. At follow-up, 11 patients (65%) experienced no pain and 13 patients (76%) had no pain at rest (Fisher's Exact Test: p<0.02). Thirteen patients (76%) had a normal incisal edge clearance, and ten patients (59%) felt no impairment due to the disease (Fisher's Exact Test: p=0.01). Thirteen patients (76%), who had been treated once successfully, have not needed treatment within the three years after cessation of their therapy. Exercise therapy is an effective tool to treat osteoarthrosis of the temporomandibular joints.


Assuntos
Terapia por Exercício , Osteoartrite/terapia , Modalidades de Fisioterapia , Transtornos da Articulação Temporomandibular/terapia , Atividades Cotidianas , Adulto , Idoso , Oclusão Dentária , Dor Facial/terapia , Feminino , Seguimentos , Humanos , Estudos Longitudinais , Masculino , Mandíbula/fisiopatologia , Pessoa de Meia-Idade , Movimento , Medição da Dor , Recidiva , Estatística como Assunto , Estatísticas não Paramétricas , Resultado do Tratamento
19.
Wien Klin Wochenschr ; 114(15-16): 678-84, 2002 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-12602111

RESUMO

BACKGROUND AND METHODS: Pulsed magnetic field therapy is frequently used to treat the symptoms of osteoarthritis, although its efficacy has not been proven. We conducted a randomized, double-blind comparison of pulsed magnetic field and sham therapy in patients with symptomatic osteoarthritis of the knee. Patients were assigned to receive 84 sessions, each with a duration of 30 minutes, of either pulsed magnetic field or sham treatment. Patients administered the treatment on their own at home, twice a day for six weeks. RESULTS: According to a sample size estimation, 36 consecutive patients were enrolled. 34 patients completed the study, two of whom had to be excluded from the statistical analysis, as they had not applied the PMF sufficiently. Thus, 15 verum and 17 sham-treated patients were enrolled in the statistical analysis. After six weeks of treatment the WOMAC Osteoarthritis Index was reduced in the pulsed magnetic field-group from 84.1 (+/- 45.1) to 49.7 (+/- 31.6), and from 73.7 (+/- 43.3) to 66.9 (+/- 52.9) in the sham-treated group (p = 0.03). The following secondary parameters improved in the pulsed magnetic field group more than they did in the sham group: gait speed at fast walking [+6.0 meters per minute (1.6 to 10.4) vs. -3.2 (-8.5 to 2.2)], stride length at fast walking [+6.9 cm (0.2 to 13.7) vs. -2.9 (-8.8 to 2.9)], and acceleration time in the isokinetic dynamometry strength tests [-7.0% (-15.2 to 1.3) vs. 10.1% (-0.3 to 20.6)]. CONCLUSION: In patients with symptomatic osteoarthritis of the knee, PMF treatment can reduce impairment in activities of daily life and improve knee function.


Assuntos
Campos Eletromagnéticos , Osteoartrite do Joelho/terapia , Idoso , Método Duplo-Cego , Feminino , Marcha , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Resultado do Tratamento
20.
Wien Klin Wochenschr ; 114(23-24): 992-8, 2002 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-12635467

RESUMO

The purpose of the study was to evaluate the impact of step aerobic (StA) and cycle ergometer training (CET) on physical performance, coordination, and pleasure, during workout. Forty untrained persons (40-70 years) were randomly assigned to either of the two regimens. Prior to and after three months of training, we investigated the participants' physical performance with a cycle ergometer test and by testing coordinative tasks (upper extremities: tapping test; lower extremities: one-leg stance). After the training period, visual analog scales were used to evaluate personal assessment (pleasure, wellbeing, team spirit, interest in prolongation of training). StA increased the relative oxygen uptake at the anaerobic threshold (RVO2AT) while CET increased the relative maximal oxygen uptake (RVO2max) to a statistically significant extent. However, intergroup comparison failed to show group-specific differences. Concerning coordinative tasks, the members of the StA group achieved a significant time reduction for both hands' tapping test. However, only the improvement in left-handed tapping was significantly higher than that achieved by members of the CET group. Despite the absence of group-specific differences, CET members showed a statistically significant change when comparing the duration of pre- with post-training time for one-leg stance under proprioceptive conditions. Team spirit was significantly higher in the StA group than in the CET group. Except for the time reduction in left-handed tapping, the present study found no group-specific differences in physical performance and coordination. Participating in a StA class has a more cohesive effect on the individual members than attending a CET group.


Assuntos
Teste de Esforço , Exercício Físico , Educação Física e Treinamento/métodos , Aptidão Física , Adulto , Idoso , Interpretação Estatística de Dados , Frequência Cardíaca , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos
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