Acute effects of static stretching on flexibility: A comparative study among students to identify the best timing to improve flexibility / 体力科学

Flexibility is an important factor of physical fitness to prevent sports injuries. However, the best timing to improve flexibility during the growth and development period in children has been unclear. To compare the acute effects of static stretching on flexibility between school-grade children in the growth and development period, we measured the hip joint flexion range of motion (RoM) by using straight leg raising (SLR) before and after static stretching (6 exercises, 15 seconds, 2 sets) in 50 young male children aged 7 to 13 years (the second grade of elementary school to the first grade of junior high school). The RoM in SLR significantly increased after stretching versus that before stretching in all subjects. This positive improvement of RoM was statistically significant among all grade levels. Notably, the change rate in RoM after stretching was significantly greater in the fourth grade of elementary school than in the other grades. The rate of height increase during the past year was lower in students from the fourth grade than in students from the second grade of elementary and the first grade of junior high school. These results suggest that flexibility training is more effective during the slow-down period of growth and development in young male children.

Efecto de los estiramientos estáticos durante el calentamiento sobre la potencia del salto en deportistas de fútbol sala

Objetivo: Determinar los efectos del estiramiento estático en la musculatura isquiosural durante el calentamiento sobre la potencia del salto. Materiales y métodos: Participaron 80 deportistas de fútbol sala universitario, distribuidos en 2 grupos; el primer grupo realizó calentamiento más estiramientos estáticos de la musculatura isquiosural, mientras que el segundo solo realizó los ejercicios precompetitivos. Para la evaluación de la potencia se utilizaron los test Squat Jump y Counter Movement Jump. Resultados: Se encontró posterior al estiramiento estático un descenso en la altura, velocidad y tiempo de vuelo al término y a los 5 minutos; se presentó una recuperación en los valores a los 10 minutos (p 0,05). Conclusión: Los estiramientos estáticos durante el calentamiento producen un descenso de la potencia del salto los primeros minutos posteriores a este tipo de ejercicios.

Objective: To determine the effects of static stretching in hamstring musculature during warm-up on jumping power. Materials and method: 80 indoor soccer players take part in this study, distributed in 2 groups. The first one warm-up and static stretching in hamstring musculature, and the second one did only precompetitive exercises. Squat Jump and Counter Movement Jump tests were used to evaluate power. Results: A descend in high, velocity, and fly time, at the end and after 5 minutes, were found after the static stretching. At 10 minutes (p = 0,05). Conclusion: Static stretching during warm-up produces a descend in jump power during the first minutes.

Effectiveness Of Muscle Energy Technique Versus Stretching In Subjects With Piriformis Syndrome

Objective: The present comparative study isto find out the effectiveness between the muscle energy techniques versus stretching in patient with piriformis syndrome along with short wave diathermy. Background: Piriformis syndrome is an uncommon neuromuscular condition misdiagnosed with sciatica because sciatic nerve may be compressed by the piriformis muscle. The signs and symptoms are similar to the sciatica. This study is helpful for the diagnosis of PS and to relieve pain, increase muscle length, decrease inflammation, increase range of motion using MET and stretching along with SWD. Methodology: This comparison study setting was done in Physiotherapy Department of ACS Medical College And Hospital by Pre-Post interventional type. Female subjects aged between 30-55 who hada gluteal pain and a positive test of pace abduction test and freiburg’s test were included. From the above criteria, subjects were divided into two groups by simple convenient sampling method. Treatment duration was 10-15 min/session for 14 sessions/week for two weeks. Visual Analog Scale (VAS), Lower Extremity Functional Scale (LEFS) were used as the outcome measures. Procedure: Based on the inclusion and exclusion criteria and outcome measures, 30 female subjects were separated into two groups and Group A (15 subjects) were received MET and Group B (15 subjects) were received static stretching. Along with these, both group were received Short Wave Diathermy. Result: On comparing the Mean values of Group A & Group B on VAS Scores& LEFSgroup A showed a highly significant difference in Mean values at P ≤ 0.001.

Alongamento estático de alta intensidade não afeta o volume absoluto de uma sessão de treinamento de força para o peitoral maior e deltoide anterior / High intensity static-stretching protocol does not affect the absolute volume in a resistance training session for pectoralis major and anterior deltoid

O alongamento estático (AE) reduz o desempenho de atividades máximas de força e potência tais como saltos, arremessos e levantamentos. Entretanto, seus efeitos em repetições submáximas levadas até a falha concêntrica em exercícios isolados para o peitoral maior e deltoide anterior são pouco conhecidos. Portanto, o objetivo do presente estudo foi verificar o efeito agudo do AE na máxima amplitude de movimento passiva (ADMP) e no volume absoluto por exercício (VAE) e por total de séries (VAS) em uma sessão de treinamento de força para o peitoral maior (PM) e deltoide anterior (DA). A amostra foi composta por 11 homens saudáveis (idade: 24,4 ± 3,6 anos; estatura: 174,8 ± 4,4 cm; massa: 83,4 ± 9,8 kg), todos treinados em força (6 ± 3 anos) e com experiência nos exercícios (pecdeck, crossover e crucifixo com halteres). Os sujeitos se apresentaram no laboratório em três sessões. Na primeira sessão foram coletados os dados pessoais, antropométricos e foi realizado o teste de 10RM para os três exercícios (pecdeck, crossover e crucifixo com halteres), separadamente. As condições experimentais foram realizadas na segunda e terceira sessão de forma aleatória. Os sujeitos realizaram a sessão de treinamento de forca para o PM e DA com 5 séries de 10RM e intervalo de 1-min para os exercícios pecdeck, crossover e crucifixo com halteres com alongamento (COM-A) e sem alongamento passivo (SEM-A). O protocolo de alongamento foi composto por 6 séries de 45" e 15" de intervalo a 70-90% da percepção subjetiva de desconforto visando os adutores horizontais do ombro. Os resultados indicam que para a ADMP, ambas as condições (COM-A e SEM-A) apresentaram redução entre os momentos pré-sessão vs. pós-sessão (P<0,01). O volume absoluto não apresentou diferenças entre exercícios ou condições (P=0,184). Conclui-se que a o alongamento estático não influencia o volume absoluto da sessão de treinamento para o peitoral maior e deltoide anterior, entretanto aumenta a máxima amplitude de movimento passivo....(AU)

Static stretching (SS) reduces the performance of maximum strength and power activities such as jumps, throws, and lifts. However, its effects on submaximal repetitions until concentric failure in isolated exercises (for the major pectoralis and anterior deltoid) are poorly understood. Therefore, the objective of the present study was to verify the acute effect of the SS in the maximum passive range of movement (PROM) and the absolute volume per exercise (VAE) and total number of sets (VAS) in a resistance training session targeting the pectoralis major (PM) and anterior deltoid (AD). The sample consisted of 11 healthy men (age: 24.4 ± 3.6 years, height: 174.8 ± 4.4 cm, mass: 83.4 ± 9.8 kg). The subjects presented in the laboratory in three different sessions. In the first session, the personal and anthropometrical data were collected, and the 10RM test was performed for all exercises (pecdeck, crossover and dumbbell flat fly), separately. The experimental conditions were performed in the second and third sessions at random fashion. The subjects performed the resistance training session with 5 sets of 10RM and 1-min of rest interval for all exercises with SS (W-SS) and without SS (WT-SS). The SS protocol was composed of 6 sets of 45-sec and 15-sec of rest intervals at 70-90% of the subjective perception of discomfort targeting the horizontal adductors of the shoulder. The absolute volume did not show significant differences between exercises or conditions (P=0.184). It is concluded that the SS does not influence the absolute volume of the resistance training session for the PM and AD, however, the SS increases the maximum passive range of movement....(AU)

Effect Of Pnf Stretching Versus Static Stretching On Calf Muscle Flexibility: A Comparative Experimental Study

Background: muscle tightness is the most common disorder in normal healthy Indiviuals.Calf muscle tightness is very common occurring condition. Stretching is form of physical exercise in which a specific muscle or tendon (muscle group) is deliberately flexed or stretched in order to improve the muscle’s felt elasticity and achieve comfortable muscle tone. Purpose of the study is to compare effectiveness of PNF stretching and static stretching in in improving the calf muscle flexibility. Materials and Methods: 30 subjects (n=30) between 5-22years (male and female) with calf tightness were randomly divided in to two groups equally. Each group consists of 15 subjects. Calf flexibility for each group was measured using the Silfverskiold test. Subjects of A group treated with PNF stretching technique, whereas the subjects of group B were treated with static stretching. Treatment was given for 15 days. Results: The PNF technique (group A) the value of the dorsiflexion is increased at the end of the 15 days (19.86) compared to baseline value (13.07). Conclusion: The both PNF and static stretching techniques are effective in improving the calf muscle flexibility but the PNF stretching is more effective compared to static stretching to improve calf muscle flexibility.

Comparison of Sit and Reach Test, Straight Leg Raise Test and Visual Analogue Scale When Applying Static Stretching and Mulligan's Two Leg Rotation in Young Adults with Hamstring Shortness

PURPOSE: This study compared the effects of Static stretching and Mulligan's Two-leg rotation about the Hamstring flexibility, Hip range of motion, and pain.METHODS: The subjects were allocated randomly into two groups: Static stretching group (n=13) and Mulligan's two leg rotation group (n=14). The study was designed with stretching protocols for four minutes and thirty seconds per day five times a week for three weeks in total. Measurements, including the Sit and reach test, Active/Passive Straight leg raise, and Visual analogue scale, were conducted before and after the intervention. The data were analyzed using a paired t-test and independent t-test.RESULTS: The flexibility of the two leg rotation group was higher than the static stretching group after the intervention. The post-sit and reach test value of the two leg rotation group was significantly higher than the pre-sit and reach test value of the static stretching group. In addition, the variance of the sit and reach test of the two leg rotation group was significantly higher than that of the static stretching group.CONCLUSION: These results showed that two leg rotation techniques have a positive effect on the changes in the sit and reach test and active straight leg raise test. Two leg rotation techniques can be recommended as a self-stretching and easier way to stabilize the lumbopelvic rhythm, reduce the stiffness of the muscle and relieve pain. This is effective in preventing muscle damage, enabling muscle relaxation and reducing the risk of injury to the spine during daily lives and in sports activities.

Does the combination of resistance training and stretching increase cardiac overload?

OBJECTIVES: To compare the effects of combinations of resistance training (RT) and static stretching (SS) on heart rate (HR), systolic pressure (SBP), diastolic pressure (DBP), rate pressure product (RPP), oxygen saturation (SpO2), rating of perceived effort (RPE), and heart rate variability (HRV) in men. METHODS: Twelve normotensive healthy men participated in four protocols: a) SS+RT, b) RT+SS, c) RT, and d) SS. Variables were measured before, immediately after, and 15, 30, and 45 min after the sessions. RESULTS: The combination of SS and RT increased (p<0.001) HR when compared to the effects of the noncombined protocols (from 2.38 to 11.02%), and this result indicated metabolic compensation. Regarding DBP, there were differences (p<0.001) between the RT and SS groups (53.93±8.59 vs. 67.00±7.01 mmHg). SS has been shown to be able to reduce (p<0.001) SpO2 (4.67%) due to the occlusion caused by a reduction in the caliber of the blood vessels during SS compared to during rest. The increase in RPP (6.88% between RT and SS+RT) along with the HR results indicated higher metabolic stress than that reflected by the RPE (combined protocols increased RPE from 21.63 to 43.25%). The HRV analysis confirmed these results, showing increases (p<0.01) in the LF index between the combined and noncombined protocols. Compared to the effect of RT, the combination of SS and RT promoted a vagal suppression root mean square of the successive differences (RMSSD) index (from 9.51 to 21.52%) between the RT and SS+RT groups (p<0.01) and between the RT and RT+SS groups (p<0.001). CONCLUSION: Static stretching increases cardiac overload and RPE, reducing oxygen supply, especially when performed in combination with RT.

Acute effect of static stretching on passive and active properties of the gastrocnemius muscle–tendon unit: an investigation based on different repetition durations and numbers / 体力科学

<p>Many previous studies have reported that static stretching (SS) may decrease muscle stiffness and compromise muscles’ ability to produce maximal strength. However, the effects of SS at different repetition durations and numbers within a constant total time remain unclear. Therefore, the purpose of this study was to examine whether SS for a constant total time (2 min) with different repetition durations and numbers (e.g., 60 s × 2 times, 30 s × 4 times, and 10 s × 12 times) produces different changes in muscle stiffness and strength. Fifteen healthy males (mean age: 23.3 ± 1.0 years) participated in this study. Muscle stiffness was measured during passive ankle dorsiflexion using dynamometer and ultrasonography. In addition, muscle strength of the plantar flexors was measured using a dynamometer at 0° of plantarflexion with the hip and knee joints fully extended. Muscle stiffness and strength were measured before and immediately after SS. Each experimental protocol was conducted in random order with at least a 1-week interval but no longer than a 2-week interval between testing sessions. The results showed that there were no significant interaction effects on muscle stiffness and strength. However, in all experimental protocols, muscle stiffness and strength immediately decreased after SS. In conclusion, SS for a constant total of 2 min decreases muscle stiffness and strength regardless of repetition durations and numbers of each individual SS.</p>

Low intensity static stretching does not modulate heart rate variability in trained men / Alongamento estático de baixa intensidade não modula a variabilidade da frequência cardíaca em homens treinados

OBJECTIVE: To investigate the acute effect of static stretching on heart rate variability in trained men. METHODS: Eight subjects were randomly submitted to two situations, as follows: a static stretch protocol and 20 minutes at rest. The stretch protocol consisted of two sets of 30 seconds of static stretch of the chest muscles with a 40 second of interval between them. After 48 hours, the procedures were reversed so that all the subjects should were submitted to the two situations. The values of heart rate variability were measured before and after the experimental and control situation (stretch vs. rest). We registered the following cardiac variables: root mean square of standard deviation (rMSSD), the number of pairs of successive beats that differ by more than 50 ms (pNN50), low frequency (LF) and high frequency (HF). The Shapiro-Wilk and the paired Student's test were used for statistical analysis; a critical level of significance of p < 0.05 was adopted. RESULTS: No significant differences (p > 0.05) were found (stretching vs. control) to the RMSSD, pNN50, LF and HF indices. However, although no statistical differences were observed, the figures show large changes on mean values, suggesting an unclear effect on the sympathetic-vagal modulation. CONCLUSION: The present results suggest that a low intensity (motion range until discomfort point) and volume (1 minute) of static stretching does not significantly affect the acute sympathetic-vagal control in trained men. Because the protocol did not show differences regarding the studied variables, we suggest that there is not a sufficient level of physiological basis to perform this type of exercise in a traditional pre-exercise setting, if the purpose is obtain gains in physical performance.

OBJETIVO: Nosso objetivo foi verificar o efeito agudo do alongamento estático sobre a variabilidade da frequência cardíaca (VFC) em homens treinados. MÉTODOS: Oito voluntários (n = 8) foram randomicamente submetidos a duas situações, a saber: alongamento estático (AE) ou 20 minutos em repouso (CTRL). O protocolo de alongamento consistiu em duas séries de 30 segundos para musculatura do peitoral (40 segundos de intervalo). Após 48 horas, os procedimentos foram realizados de maneira reversa, de forma que todos os participantes realizaram as duas situações (ALONGAMENTO e CRTL) ao final do estudo. Os valores de VFC foram medidos antes e imediatamente depois das situações experimental e controle (alongamento vs. repouso). Para registro das variáveis cardíacas coletadas (rMSSD, pNN50, LF e HF) no presente estudo, nós utilizamos um relógio Polar RS800CX (Polar Electro OY, Finland). As análises estatísticas realizadas foram feitas através da aplicação do teste de Shapiro-Wilk seguido pelo teste t de Student pareado, sendo adotado um nível crítico de significância de p < 0.05. RESULTADOS: Nenhuma diferença significativa (p > 0.05) foi observada (alongamento vs. controle) quando as variáveis foram analisadas. CONCLUSÃO: O presente estudo sugere que o alongamento estático com baixo volume de aplicação não altera significativamente o controle simpato-vagal em homens treinados. Na medida em que o protocolo utilizado não resultou em diferenças significativas nas variáveis estudadas, nós inferimos que não há fundamento fisiologicamente válido para a realização deste tipo de exercício em sua forma tradicional pré-exercício quando o objetivo for a obtenção de ganhos na performance física.

Comparative effect of ultrasound therapy versus static stretching on the extensibility of hamstring muscles.

Background: Many peoples suffer from tight hamstring muscles which predispose them to injury when they engage in vigorous physical activity. Ultrasound therapy have been used to enhance the effectiveness of muscle stretching, but evidence supporting their benefits is confusing. Aims & Objective: The Objective of the current study is to compare the immediate effect of ultrasound (US) and static stretching exercise on the extensibility of hamstring muscles. Materials and Methods: Forty normal Participants between the ages of 18 and 21 who demonstrated at least 15 degrees of unilateral hamstring tightness. They were randomly assigned to 1 of 4 groups: (1) ultrasound therapy; (2) 30 second static stretching; (3) ultrasound therapy and 30 second static stretching; and (4) control group which don't receive any treatment. The Main Outcome Measure was Hamstring extensibility measured by active knee extension test (AKE). Differences were compared within groups and between treatment groups using one way analysis of variance. Results: There was a significant difference between pre and post-treatment in all treatment groups (p<0.05), but there was no significant difference regarding the control group (p>0.05). 30 second Static stretching exercise followed by 1 MHZ ultrasound therapy showed a significant increase in AKE when compared by sole treatment or control group (p<0.05). Conclusion: The use of ultrasound therapy followed by 30 second static stretching enhance the flexibility of hamstring muscle. This results can aid in designing physical therapy protocols for similar conditions.

Influência de diferentes intervalos de recuperação entre o alongamento estático passivo e desempenho de força muscular / Influence of differents rest intervals between passive static stretching and strength performance

Estudos prévios indicam efeitos deletérios do alongamento muscular prévio sobre a força. Todavia, são escassas as evidências relacionadas aos efeitos de diferentes intervalos de recuperação entre o alongamento muscular e as séries de resistência de força. O objetivo do presente estudo foi verificar o efeito de diferentes intervalos de recuperação entre o alongamento estático passivo (AEP) e o desempenho de repetições máximas realizadas nos exercícios: voador peitoral (VP) e cadeira extensora (CE). Participaram do estudo 14 homens (22 ± 4 anos, 71 ± 7 kg, 1,75 ± 0,06 m e 23,1 ± 1,7 kg/m2) treinados em média há 2 ± 1 ano. Inicialmente, foi realizado teste e reteste de 10 RM nos exercícios VP e CE em dois dias distintos (intervalo de 48 h). Nas sessões seguintes aplicaram-se cinco protocolos: a) série de resistência de força (SF) sem AEP prévio no VP e CE (TSA); b) SF imediatamente após AEP (TSI); c) SF 5 min após AEP (T5); d) SF 10 min após AEP (T10); e) SF 15 min após AEP (T15), registrando-se o máximo de repetições realizadas com 90% da carga de 10RM sem falha na técnica. Aplicou-se o teste de Shapiro-Wilk e ANOVA one-way para medidas repetidas seguido pelo post hoc de Bonferroni adotando-se p < 0,05. Foram observadas diferenças significativas no número de repetições máximas realizadas no TSI comparado ao TSA, todavia, após intervalos de 5, 10 e 15 min não se verificou diferença significativa entre os protocolos. Os achados do presente estudo confirmam o efeito deletério do AEP sobre a força muscular quando realizados sem intervalo, todavia, intervalos de 5 a 15 min podem possivelmente evitar o comprometimento da resistência muscular durante exercícios monoarticulares em indivíduos treinados.

Previous researchers have suggested a deleterious effect of previous stretching exercises on muscle strength. However, there is not enough data indicating the effects of different rest intervals between stretching and muscle endurance. The purpose of this study was to investigate the effect of different rest intervals between passive static stretching (PSS) and the performance of repetitions maximum in the following exercises: pectoral fly (PF) and knee extension (KE). Fourteen men (22 ± 4 years, 71 ± 7 kg, 1.75 ± 0.06 m and 23.1 ± 1.7 kg/m2) with previous resistance training experience (2 ± 1 years) participated as subject in the current study. Initially, 10RM test and retest was performed in KE and PF exercises on two non-consecutive days (48 h apart). In the following sessions five protocols were applied: a) muscular endurance set (MES) without prior PSS in PF and KE (TWS); b) MES immediately after PSS (T1); c) MES 5 min after PSS (T5); d) MES 10 min after PSS (T10); e) MES 15 min after PSS (T15), and the, maximum number of repetitions completed at 90% of 10RM without technical failure were registered. Data was analyzed by Shapiro-Wilk test and one-way ANOVA for repeated measures followed by Bonferroni post hoc adopting p < 0.05. Significant differences were observed in the maximum number of repetitions completed in T1 compared to TWS. However, after intervals of 5, 10 and 15 min there was no significant difference between the protocols. The findings of the current study confirmed the deleterious effect of PSS on muscle strength when performed without interval. However, rest intervals between 5 and 15 min may avoid the deleterious effect on muscle endurance during single joint exercises performed by trained individuals.

Efeito agudo do alongamento estático em músculo agonista nos níveis de ativação e no desempenho da força de homens treinados / Acute effect of static stretching in agonist muscle on the levels of activation and on strength performance of trained men

Investigar os efeitos do alongamento muscular na resposta aguda neural tornou-se foco bastante atrativo de pesquisas atuais quando se considera que o desempenho da força está diretamente relacionado a alterações dos níveis de ativação muscular. Este estudo avaliou os efeitos de 10 a 40 segundos de alongamento estático na ativação muscular e no desempenho da força precedido ao teste de repetição máxima de sujeitos treinados. Foram avaliados 20 homens com idade média de 21,75 (± 3,49) randomizados em quatro grupos de acordo com os seguintes tempos de alongamento: TF10s, TF20s, TF30s, TF40s - TF corresponde a Treinamento de Força. Na etapa Controle (C) os sujeitos foram submetidos ao teste de repetição máxima no exercício de supino com halteres. Na etapa Experimental (E) foram submetidos ao alongamento estático com intensidade de 10 por cento de 1RM, seguidamente realizaram o teste de repetição máxima. Nas duas etapas foram realizadas as análises da ativação muscular com eletromiografia de superfície. Como procedimento estatístico utilizou-se ANOVA one way comparando características antropométricas e funcionais dos grupos, o teste t foi utilizado para amostras pareadas, comparando controle e experimental (p < 0,05). Resultados: Não foram encontradas diferenças estatisticamente significativas (p > 0,05); no desempenho da força e nos níveis de ativação agonista comparando os diferentes tempos de alongamento da etapa (E) ao experimento sem alongamento da etapa (C). Conclusão: O exercício de alongamento nos tempos e intensidades estudados parecem não exercer efeito agudo sobre os níveis de ativação a ponto de potencializar o desempenho da força em teste de repetições máxima. Desta forma, outras intensidades de alongamento podem ser investigadas buscando modular positivamente estes resultados.

The investigation of the effects of muscle stretching on the neural acute response has become a fairly attractive issue on current research when it is considered that strength performance is closely related to alterations on the levels of muscle activation. This study assessed the effects of 10 to 40 seconds of static stretching on the muscle activation as well as strength performance preceded by a repetition maximum test of trained subjects. 20 men, mean age of 21.75 (± 3.9), randomized in four groups according to the following stretching times: RT10s, RT20s, RT30s, RT40s - where RT corresponds to Resistance Training, were assessed. In the Control phase (C), the subjects were submitted to the repetition maximum test in the bench press with dumbbells exercise. In the Experimental Phase (E), they were submitted to static stretching with intensity of 10 percent of 1RM followed by the repetition maximum test. Muscle activation was assessed in the two phases with surface electromyography. One-way ANOVA was applied for statistical assessment, comparing anthropometric and functional characteristics of the groups, t test was used for paired samples, comparing control and experimental ones (p < 0.05). Results: Statistically significant differences have not been found (p > 0.05) in strength performance or levels of agonist activation when the different studied times and intensities in the (E) phase and the experiment with no stretching in the (C) phase were compared. Conclusion: Stretching exercise in the studied times and intensities does not seem to acutely affect the levels of activation in order to boost strength performance in a repetition maximum test. Therefore, different stretching intensities can be investigated with the aim to positively modulate these outcomes.