Effects of Volume Training on Strength and Endurance of Back Muscles: A Randomized Controlled Trial.

CONTEXT: Strength/resistance training volume has historically been supported in the American College of Sports Medicine recommendations. However, for the back muscles, exercise prescription related to the number of sets, such as single versus multiple, is not well established in the literature. OBJECTIVE: The purpose of this study was to compare the effects of 2 training volumes on strength and endurance of back-extensor muscles in untrained young participants with regard to a repeated-measures design. DESIGN: Randomized controlled trial. SETTING: Laboratory of functional evaluation and human motor performance. PARTICIPANTS: Forty-four untrained young participants (mean age = 21 y) were randomized into single-set (n = 14), multiple-set (MSG, n = 15), and untrained control (n = 15) groups. INTERVENTION: The single-set group and MSG underwent a 10-week progressive resistance training program (2 d/wk) using a 45° Roman chair. MAIN OUTCOME MEASURES: Back maximal strength (dynamometer) and isometric and dynamic endurance (time limit, trunk extension-flexion cycles, and electromyography muscle fatigue estimates). RESULTS: The results showed differences between the MSG and control group for isometric endurance time (mean = 19.8 s; 95% confidence interval, -44.1 to 4.8), but without time intervention significance. Significant improvement after training (P < .05) was found predominantly during dynamic endurance (number of repetitions) for both the MSG (+61%) and single-set group (+26%) compared with preintervention, whereas the control group reported no benefit. There was no significant (P > .05) difference in either strength or electromyography estimates after training. CONCLUSIONS: Both multiple and single volume training were efficient in promoting better back endurance during dynamic performance based on mechanical variables (time and number of repetitions).

Effects of training volume on lower-body muscle strength in untrained young men: a contralateral control study

The purpose of this study was to examine the effects of training volume (1 vs. 3 sets) on lower-body muscle strength in untrained young men. Methodsː Eighteen untrained young men were recruited and their legs were trained with 1 or 3 sets (in a contralateral design) for 6 weeks, using a knee extension machine. Isokinetic peak torque and one repetition maximum (1RM) were assessed at pre- and post-training. Resultsː There was a similar improvement in the 1RM strength (1SET: +14.8% vs. 3SET: 16.3%, P > 0.05) and peak torque (1SET: +8.1% vs. 3SET: 9.3%, P > 0.05) for both conditions from pre- to post-training. The effect size (ES) for the change in 1RM was moderate for both conditions (1SET: 1.39 vs. 3SET: 1.41), and peak torque was trivial and small for 1SET (0.47) and 3SET (0.55), respectively. Additionally, there were no significant (P > 0.05) differences in the dietary intakes from pre- to post-training. Conclusionsː Our results indicate that 1 set is as effective as 3 sets for increasing lower-body muscle strength after a short-term RT period (6 weeks) in untrained young men.(AU)

Analysis of pain, functional capacity, muscular strength and balance in young women with Patellofemoral Pain Syndrome / Análise da dor, funcionalidade, comportamento muscular e equilíbrio em mulheres jovens com Síndrome da Dor Femoropatelar

Abstract Introduction: Patellofemoral Pain Syndrome (PFPS) is associated with anterior knee pain, changes in functional capacity, balance and muscle strength disorders. Objective: To quantify pain, functional capacity, strength in quadriceps (Q), gluteus medium (GM), hip external rotator (ER) muscles and balance in sedentary women with PFPS. Methods: Twenty sedentary women, aged 18 to 25 years, were divided into two groups: PFPS (N=10) and control group (N=10). All the volunteers answered the items of the Visual Analogue Scale (VAS), the Lysholm Knee Score Scale, the Anterior Knee Pain Scale (AKPS), and the Lower Extremity Functional Scale (LEFS). The participants performed the following tests: maximal voluntary isometric contraction measured by dynamometry; postural balance using the Star Excursion Balance Test (SEBT) and a force platform. Statistical analyses were performed using the Shapiro Wilk test, the Mann Whitney U test and Spearman's correlation coefficient. Data were submitted to SPSS 20 software. Results: The PFPS group presented greater pain, balance impairment and higher average velocity of oscillation; however, no differences were observed in Q, GM and RE muscle strength and in balance analyzed by SEBT. Conclusion: Women with PFPS exhibited greater pain, worse functional capacity and body balance. Moderate correlation between both balance tests suggests the use of SEBT when the force platform is not available, which could facilitate and highlight the importance of clinical diagnosis with regard to postural balance.

Resumo Introdução: A Síndrome da Dor Femoropatelar (SDFP) está relacionada à dor anterior do joelho, alteração de funcionalidade, déficits de equilíbrio e força muscular. Objetivo: Quantificar a dor, funcionalidade, força muscular do quadríceps (Q), glúteo médio (GM), rotadores externos de quadril (RE) e o equilíbrio em mulheres com SDFP. Métodos: Avaliou-se 20 voluntárias, sedentárias, entre 18 e 25 anos; divididas em grupo SDFP (N=10) e controle (N=10). Todas responderam a Escala Visual Analógica de Dor, Lysholm Knee Score Scale, Anterior Knee Pain Scale e Lower Extremity Functional Scale, realizaram a contração isométrica voluntária máxima dos músculos Q, GM e RE por meio de dinamometria e análise do equilíbrio postural pelo Star Excursion Balance Test (SEBT) e plataforma de força. Para análise estatística utilizou-se os testes Shapiro Wilk, Mann Whitney e Correlação de Spearmann, pelo SPSS® 20. Resultados: O grupo SDFP apresentou maior dor, incapacidade e velocidade média de oscilação do centro de pressão, entretanto não foram observadas diferenças para a força muscular de Q, GM e RE e equilíbrio analisado pelo SEBT. Estabeleceu-se correlação moderada entre SEBT e Centro de Oscilação de Pressão (COP) unipodal. Conclusão: Mulheres com SDFP apresentam maior dor, pior funcionalidade e alterações no equilíbrio corporal. A correlação moderada entre SEBT e o COP-unipodal aponta a possibilidade de uso deste teste funcional quando a plataforma de força não é acessível, o que facilita e destaca a importância do diagnóstico clínico do equilíbrio postural.

Effects of Holding an External Load on the Standing Balance of Older and Younger Adults With and Without Chronic Low Back Pain.

OBJECTIVE: The purpose of this study was to assess the effect of holding an external load on the standing balance of younger and older adults with and without chronic low back pain (CLBP). METHODS: Twenty participants with and 20 without CLBP participated in the study. Each group contained 10 younger (50% men) and 10 older adults (50% men). Participants were instructed to look straight ahead while standing on a force platform during two 120-second trials with and without holding an external load (10% of body mass). The center of pressure area, mean velocity, and mean frequency in the anteroposterior and mediolateral directions were measured. RESULTS: Older adults had worse standing balance than younger adults did (P < .001, d = 0.20). There were no significant balance differences between participants with and without CLBP within age groups during standing balance condition. However, holding the external load significantly increased postural instability for both age groups and CLBP status, with mean effect size across center of pressure variables of d = 0.82 for older participants without CLBP and d = 2.65 for younger participants without CLBP. These effects for people with CLBP were d = 1.65 for subgroup of older and d = 1.60 for subgroup of younger participants. CONCLUSION: Holding an external load of 10% of body mass increased postural instability of both younger and older adults with and without CLBP.

Mcconnell's patellar taping does not alter knee and hip muscle activation differences during proprioceptive exercises: A randomized placebo-controlled trial in women with patellofemoral pain syndrome.

The purpose of this study was to assess the effect of patellar taping on muscle activation of the knee and hip muscles in women with Patellofemoral Pain Syndrome during five proprioceptive exercises. Forty sedentary women with syndrome were randomly allocated in two groups: Patellar Taping (based in McConnell) and Placebo (vertical taping on patella without any stretching of lateral structures of the knee). Volunteers performed five proprioceptive exercises randomly: Swing apparatus, Mini-trampoline, Bosu balance ball, Anteroposterior sway on a rectangular board and Mediolateral sway on a rectangular board. All exercises were performed in one-leg stance position with injured knee at flexion of 30° during 15s. Muscle activation was measured by surface electromyography across Vastus Medialis, Vastus Lateralis and Gluteus medius muscles. Maximal voluntary contraction was performed for both hip and knee muscles in order to normalize electromyography signal relative to maximum effort during the exercises. ANOVA results reported no significant interaction (P>0.05) and no significant differences (P>0.05) between groups and intervention effects in all exercise conditions. Significant differences (P<0.01) were only reported between muscles, where hip presented higher activity than knee muscles. Patellar taping is not better than placebo for changes in the muscular activity of both hip and knee muscles during proprioceptive exercises. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT02322515.

Five-week sensory motor training program improves functional performance and postural control in young male soccer players - A blind randomized clinical trial.

Sensory motor training programs are used in the rehabilitation and prevention of injuries among soccer players. Inconsistencies are found in the literature regarding the duration of the protocols and the exercises and equipment used. OBJECTIVE: To evaluate the benefits of a five-week sensory motor training program on the functional performance and postural control of young soccer players. METHODS: The study sample comprised 22 young male soccer players who were evaluated using: the Figure-of-Eight Test (F8), Side Hop Test (SHT), Star Excursion Balance Test (SEBT), and a force platform. The players were randomly divided into a control group (N = 10), who continued their soccer practice sessions and an intervention group (N = 12), who continued their soccer practice sessions and were also enrolled in a supervised five-week sensory motor training program. RESULTS: After the five-week training program, the intervention group obtained significant results in the F8, SHT and SEBT, as well as in the following parameters: area of pressure of sway center (COP), mean velocity and mean frequency of COP. CONCLUSION: The five-week sensory motor training program, carried out with easily available and low cost equipment, was effective at improving functional performance and postural control in young soccer players.

Effects of weekly LED therapy at 625 nm on the treatment of chronic lower ulcers.

The aim of this study was to evaluate the effects of LED therapy associated with compression therapy on chronic venous leg ulcers (CVUs). The study included CVU patients (n = 17, eight men) who were eligible for Unna's boot treatment. Ulcers were treated on a weekly basis with either LED therapy (625 nm, 4 J/cm(2)) and an Unna's boot (LED ulcers, n = 14) or a placebo treatment and an Unna's boot (control ulcers, n = 14). The total surface area of the ulcers, the relative ulcer area, and the healing rate were recorded over a period of 30 weeks. Ulcer exudates were collected for determination of local tumor necrosis factor alpha (TNF-α) levels. The total area was not significantly different between the LED and control ulcers (P > 0.05, Mann-Whitney U test) throughout the study. However, the relative area indicated that non-healing treatment resistant ulcers (n = 6) persisted in the control group after 19 weeks (P < 0.05, Mann-Whitney U Test). No differences in median healing rate were observed (hazard ratio 0.89, CI 95%: 0.40-1.98) between LED (15 weeks) and control ulcers (19.5 weeks). No differences in TNF-α levels were detected (P > 0.05, Mann-Whitney U test). The results suggest that LED therapy improved the effectiveness of the Unna's boot since no refractory ulcer was observed in the LED group after 19 weeks. However, LED therapy did not alter the local secretion of TNF-α nor accelerate wound healing.

Relação entre testes funcionais e plataforma de força nas medidas de equilíbrio em atletas / Relationship between functional tests and force platform measurements in athletes' balance / Relación entre pruebas funcionales y plataforma de fuerzas en las medidas de balance de los atletas

INTRODUÇÃO: Poucos estudos correlacionaram as medidas de equilíbrio entre os principais testes funcionais e a plataforma de força em atletas. OBJETIVO: Determinar a relação entre três testes funcionais de equilíbrio com as principais medidas da plataforma de força em atletas. MÉTODO: Quinze atletas do sexo feminino praticantes de futebol de salão (futsal) e handebol, com idades entre 13 a 17 anos participaram do estudo. As atletas realizaram três testes funcionais: 1) Star excursion balance test, 2) Salto lateral e 3) Figura em oito; além de um teste em apoio unipodal sobre uma plataforma de força com os olhos abertos durante 30 segundos. Os parâmetros do centro de pressão dos pés (COP) foram calculados por análise estabilográfica. Para todos os testes (funcionais e plataforma), três tentativas foram realizadas e a média foi retida para as análises. RESULTADOS: As correlações entre os testes funcionais e a plataforma de força foram de r = 0,01 a -0,69 (fraca a moderada), dependendo da variável do COP. As melhores correlações (r = -0,69) foram encontradas entre o Star Excursion Balance Test de alcance e a área do COP, indicando que quanto maior a distância alcançada, melhor o equilíbrio. Segundo, uma correlação de fraca a moderada foi encontrada entre o teste da figura em oito e a área do COP (p. ex: r = 0.43). O teste de salto lateral não apresentou boa correlação com os obtidos na plataforma de força. CONCLUSÃO: Este estudo demonstrou que para a avaliação do equilíbrio em atletas de futsal e handebol feminino o teste Star Excursion Balance Test pode ser usados na ausência da plataforma de força para identificação de possíveis déficits de equilíbrio. .

INTRODUCTION: Few studies have correlated the balance measurements based in functional tests and force platform in athletes. OBJECTIVE: to determine the relationship between three functional balance tests with the main measurements of the force platform in athletes. METHODOLOGY: Fifteen female athletes, indoor soccer and handball players, aged between 13 and 17 years, participated of this study. The athletes performed tree functional tests: 1) the star excursion balance test, 2) the lateral jump, and 3) the figure eight test; as well as the one leg-stance test on a force platform with the eyes open for 30 seconds. The parameters of center of pressure (COP) of the foot were calculated by stabilographic analysis. For all the tests (functional and platform), tree trials attempts were made, and the mean value retained for the analyses. RESULTS: The correlations between the functional tests and the force platform were from r = 0.01 to -0.69 (weak to moderate), depending on the COP variable. The best correlations (r = -0.69) were found between the star excursion balance test and the COP area, indicating that when a greater distance was reached, the better the postural balance. Secondly, a weak to moderate correlation was found between the figure eight test and COP area (e.g. r = 0.43). The side hop test did not present good correlation with the values obtained on the force platform. CONCLUSION: This study shows that to evaluate balance in athletes practicing indoor soccer and handball, the Star excursion balance test may be used in the absence of a force platform, to identify possible balance deficits. .

INTRODUCCIÓN: Pocos estudios han correlacionado las medidas de equilibrio entre las principales pruebas funcionales y la plataforma de fuerza en los atletas. OBJETIVO: Determinar la relación entre tres pruebas de equilibrio funcionales con las principales medidas de la fuerza en la plataforma de los atletas. MÉTODO: Quince atletas del sexo femenino que practican el fútbol de salón y balonmano, entre 13 y 17 años participaron en el estudio. Los atletas realizaron tres pruebas funcionales: 1) Star excursion balance test, 2) salto lateral y 3) salto figura ocho, además de una prueba unipodal sobre una plataforma de fuerza con los ojos abiertos durante 30 segundos. Los parámetros del centro de la presión de los pies (COP) se calcularon por análisis estabilográfica. Para todas las pruebas (funcionales y plataforma), se llevaron a cabo tres ensayos y el promedio fue utilizado para su análisis. RESULTADOS: Las correlaciones entre las pruebas funcionales y la plataforma de fuerza fueron r = 0,01 a -0,69 (leve a moderada), en función de la variable COP. La mejor correlación (r = -0,69) se encontró entre el rango de la prueba Star Excursion Balance y el área del COP, lo que indica que cuanto mayor es la distancia que se logra, mejor es el equilibrio. En segundo lugar, se encontró correlación débil a moderada entre la prueba en figura de ocho y el área del COP (por ejemplo, r = 0,43). La prueba de salto lateral mostró una buena correlación con las pruebas en la plataforma de fuerza. CONCLUSIÓN: Este estudio demostró que para la evaluación del equilibrio de los atletas del sexo femenino de fútbol de salón y balonmano, el Star excursion balance test se puede utilizar en la ausencia de una plataforma de fuerza para identificar posibles deficiencias en el equilibrio. .

Análise comparativa do equilíbrio unipodal de atletas de ginástica rítmica / Comparative analysis of one-foot balance in rhythmic gymnastics athletes

INTRODUÇÃO: A ginástica rítmica (GR) requer alto nível de qualidade física; assim, o bom desempenho é dependente da força e resistência muscular, coordenação motora e equilíbrio postural. OBJETIVO: Desenvolver uma análise comparativa do equilíbrio unipodal de atletas de GR. MÉTODOS: Foram avaliadas dez atletas de GR, do sexo feminino, por meio de uma plataforma de força em apoio unipodal e testes funcionais de equilíbrio (Side Hop Test e Figure of Eight Hop Teste). Para a plataforma, os parâmetros do Centro de Pressão (COP) nas direções anteroposterior e mediolateral foram utilizados para análise, enquanto para os testes funcionais, o tempo-segundos de performance. RESULTADOS: Diferença significativa (p = 0,01) foi encontrada entre os membros inferiores no parâmetro de frequência média na direção mediolateral, no qual o membro inferior não dominante apresentou maior estabilidade postural do que o dominante. Para os testes funcionais não houve diferença significativa entre os membros. CONCLUSÃO: A diferença encontrada no controle do equilíbrio na direção mediolateral pode estar relacionada às diferenças nas ações musculares da região do quadril, na qual durante a prática do esporte para estabilização, manutenção do tronco e execução de manobras com os membros inferiores estão presentes. Estes resultados indicam a necessidade de um programa de reequilíbrio e estabilização pélvica para as atletas analisadas no intuito de preservar a simetria muscular dos membros para o bom desempenho esportivo.

INTRODUCTION: Rhythmic gymnastics requires a high level of physical quality; therefore, good performance depends on muscular strength and endurance, motor coordination and postural balance. OBJECTIVE: To develop a comparative analysis of postural balance in rhythmic gymnasts. METHODS: 10 female rhythmic gymnasts were evaluated by a force platform on one foot and balance functional tests (Side Hop Test and Figure of Eight Hop Test). The following data of the force platform were analyzed: anteroposterior and mediolateral of the center of pressure parameters, while for the functional tests, the time in seconds was analyzed. RESULTS: Significant difference (p = 0.01) was found between lower limbs in the median frequency parameter in the mediolateral direction, in which non dominant lower limb showed higher postural stability than the dominant one. For functional tests, there was no significant difference between limbs. CONCLUSION: The difference found in the balance control of mediolateral direction may be related to different muscular actions of the hip region, which is present during the sport practice for stabilization, trunk maintenance, and movement performance with lower limbs. These results indicate the need of a balance program and pelvic stabilization for the analyzed athletes in order to maintain muscular symmetry of the limbs for high sports performance.