Cláudia Silveira Lima

Influence of static stretching on hamstring flexibility in healthy young adults: Systematic review and meta-analysis

ABSTRACT The aim of the current study was to investigate the influence of static stretching on hamstring flexibility in healthy young adults by means of systematic review and meta-analysis. The search strategy included MEDLINE, PEDro, Cochrane CENTRAL, EMBASE, LILACS, and manual search from inception to June 2015. Randomized and controlled clinical trials studies that have compared static stretching to control group, and evaluated range of motion (ROM), were included. On the other hand, studies that have worked with special population such as children, elderly people, athletes, and people with any dysfunction/disease were excluded, as well as articles that have used contralateral leg as control group or have not performed static stretching. The meta-analysis was divided according to three types of tests. Nineteen studies were included out of the 813 articles identified. In all tests, the results favored static stretching compared to control group: passive straight leg raise (12.04; 95% CI: 9.61 to 14.47), passive knee extension test (8.58; 95% CI: 6.31 to 10.84), and active knee extension test (8.35; 95% CI: 5.15 to 11.55). In conclusion, static stretching was effective in increasing hamstring flexibility in healthy young adults.

Acute effect of different time periods of passive static stretching on the hamstring flexibility

BACKGROUND Several factors are associated with the presence of chronic low back pain; one of them is the flexibility of the hamstring muscles that influences the posture of the pelvic spine. OBJECTIVE Investigate the influence of two different time periods of passive static stretching on the flexibility of the hamstring. METHODS Forty-six physiotherapy students were divided into two groups performing stretching exercises: 30 s and 60 s duration. The collections consisted of: (1) pre-test: evaluation of the flexibility of the hip and knee, using a manual goniometer by means of the following tests: Straight Leg Raise Test (SLR), Passive Hip Flexion Test (PHFT) and Modified Knee Extension Test (MKET), (2) intervention: stretching with different runtimes, (3) post-test: reappraisal of flexibility, conducted immediately after the intervention. RESULTS Significant difference was observed intra groups, group that did stretching exercises lasting 30 seconds (G30) (SLR p = 0.000. PHFT p = 0.003 and MKET p = 0.000) and group that did stretching exercises lasting 60 seconds (G60) (SLR p = 0.000. PHFT p = 0.001 and MKET p = 0.002). Comparing the groups, no significant difference was found (SLR p = 0.307; PHFT p = 0.904; MKET p = 0.132). CONCLUSION Thus it can be inferred that 30 seconds are sufficient for increased flexibility of young women. Therefore the time-treatment sessions can be optimized. Only the acute effect of stretching was observed; further investigation of the long-term effect is required.

RELATIONSHIP BETWEEN WORKLOAD AND NEUROMUSCULAR ACTIVITY IN THE BENCH PRESS EXERCISE

Objective: To investigate the relationship between strength and electromyographic (EMG) signal in different intensities in the bench press exercise. Methods: Eleven healthy resistance trained men (22.8 ± 3.5) participated into the present study. Maximal isometric strength was determined in the bench press exercise using a load cell. Muscle activation was assessed using surface elec- tromyography (EMG) signals from the muscles pectoralis major, anterior deltoid and posterior deltoid at intensities ranging to 60-90% of maximal voluntary contraction (MVC), in the bench press exercise. This procedure allowed the analysis of the strength/EMG relationship. Results: In all muscles assessed, there were significant differences in the normalized muscle activation between the intensities of 60 and 70% of the MVC, as well as between 70 and 80% (P<0.05), while there were no differences between 80 and 90% of MVC. In addition, there were significant correlations between strength and EMG signals for the muscles pectoralis major (r=0.43, P=0.04), anterior deltoid (r=0.52, P=0.01), and posterior deltoid (r=0.32, P=0.046). Conclusions: These results suggest that levels of muscle activation near to maximal are obtained at the intensity of 80 of MVC and no additional motor unit recruitment are achieved at 90% of MVC.

Comparison between static stretching and proprioceptive neuromuscular facilitation on hamstring flexibility: systematic review and meta-analysis

Abstract Background: Both static stretching (SS) and proprioceptive neuromuscular facilitation (PNF) have been widely investigated, it is believed that PNF might have an advantage over SS because of its possible neural mechanisms. However, it remains uncertain which one is the most effective strategy. Objective: The aim of the present review was to compare the effects of SS and PNF stretching on hamstring flexibility. Methods: The search included the databases Cochrane CENTRAL, MEDLINE (via Pubmed), Lilacs, PEDro, and manual search. Studies that have compared SS and PNF on hamstring flexibility in sedentary and recreationally active young adults were included. In contrast, studies with samples composed by children, elderly, and people with any dysfunction/disease were excluded. Results: From the 757 studies identified, 19 were included in the systematic review, but only 12 had suitable data for the meta-analysis. The meta-analysis was divided into two types of tests: straight leg raise (SLR) and knee extension test (KET). Results from the SLR analysis showed no difference between SS and PNF either chronically (−2.56; 95%CI: −7.43 to 2.32) or acutely (−3.32; 95%CI: −11.58 to 4.93). Regarding the KET analysis, there was no difference between groups (0.93; 95%CI: −1.39 to 3.24). Conclusion: In conclusion, both SS and PNF stretching can be effective in increasing hamstring flexibility.

Comparison of neuromuscular and proprioceptive variables between legs during lunge in fencers

BackgroundThe fencer performs the lunge, an attack characterized by a forward push.AimsThe objective of the study was to compare the neuromuscular and proprioceptive variables between the front and back legs during the lunge.MethodsIt was a cross-sectional study of 19 fencers. Measurement of the concentric muscle torque peak of the ankle muscles, as well as muscle balance, through the conventional ratio and functional ratio, was performed through the isokinetic dynamometer. The reaction time (RT) of the peroneus longus (PL), anterior tibial (AT) and lateral gastrocnemius (LG) of both legs was collected from an electromyography during Lunge execution. Dynamic neuromuscular control of the ankles was evaluated by the Star Excursion Balance Test (SEBT) in eight different directions.ResultsIt was possible to identify a significant difference in the muscular torque of these muscle groups (p ≤ 0.05), as well as in the Conventional Ratio (p = 0.002) and Functional Ratio (p = 0.003) of dorsiflexors/plantiflexors of the back leg in relation to the front, that is, a decrease in the force of back leg. There was also no difference in the RT of the PL and AT (p ≥ 0.05), but have difference in RT of LG during the Lunge (p ≤ 0.05). Furthermore, there is difference in the eight directions of the SEBT (p ≤ 0.05) comparing the back with the front leg.ConclusionsThe training performed by fencing athletes is not able to produce similar stimuli for both legs with regard to dynamic neuromuscular control, reaction time and concentric torque of the ankle musculature.

Efeitos do número de séries de alongamento na flexibilidade do músculo isquiotibial em mulheres jovens

The aim of this study was to look at the influence of five different sets of passive stretching on hamstring muscle flexibility in young women. The sample consisted of 45 university students of physiotherapy. The range of motion of the hip and the knee was evaluated with a manual goniometer, using two tests: Straight Leg Raise test and Knee Extension modified test, before and after stretching. The stretching was performed once a week, with different numbers of series: one, two, three, four and five 30-second sets, the order established by lot. The data relating to pre and posttest were compared using the t test for paired samples. One-Way ANOVA was used for comparison between the number of runs; in the presence of post-hoc differences Bonferroni was used (α = 0.05). The results demonstrate that the post-test had a significant increase in range of motion compared to the pre all tests. Comparing the series showed a marked increase in range of motion of the hip when there were three, four and five series of stretching in the Straight Leg Raise test and in four and five series in the Knee Extension modified test. The data show that the stretching exercises, regardless of the number of series, increase joint range of motion. However, the application of the four for range of motion gains because the results are better.

Effects of proprioceptive training on the incidence of ankle sprain in athletes: systematic review and meta-analysis

Objective: To investigate how dynamic neuromuscular control, postural sway, joint position sense, and incidence of ankle sprain are influenced by balance training in athletes compared with the control group in randomized clinical trials. Data sources: The search strategy included MEDLINE, Physical Therapy Evidence Database, Cochrane Central Register of Controlled Trials, and Latin American and Caribbean Center on Health Sciences Information. Randomized controlled trials (RCTs) were published by June of 2018. Methods: RCTs that evaluate the effectiveness of proprioception in these outcomes: dynamic neuromuscular control, postural sway, joint position, and the incidence of ankle sprains in athletes aged between 18 and 35 years. Two reviewers independently screened the searched records, extracted the data, and assessed risk of bias. The treatment effect sizes were pooled in a meta-analysis using the RevMan 5.2 software. Internal validity was assessed through topics suggested by Cochrane Collaborations. Results: Of the 12 articles included (n = 1817), eight were in the meta-analysis (n = 1722). The balance training reduced the incidence of ankle sprains in 38% compared with the control group (RR: 0.62; 95% CI: 0.43–0.90). In relation to the dynamic neuromuscular control, the training showed increase in the distance of reach in the anterior (0.62 cm, 95% CI: 0.13–1.11), posterolateral (4.22 cm, 95% CI: 1.76–6.68), and posteromedial (3.65 cm, 95% CI: 1.03–6.26) through the Star Excursion Balance test. Furthermore, training seems to improve postural sway and joint position sense. Conclusion: Balance training reduces the incidence of ankle sprains and increases dynamic neuromuscular control, postural sway, and the joint position sense in athletes.

Nível de ativação muscular do vasto medial em diferentes exercícios fisioterapêuticos

A Sindrome da Dor Femoropatelar (SDFP) tem como uma das causas a lateralizacao excessiva da patela, que ocorre frequentemente pelo enfraquecimento do musculo Vasto Medial (VM). Dessa forma, na prevencao e reabilitacao da SDFP, o fortalecimento de VM e imprescindivel. Objetivo: Comparar o nivel de ativacao do VM em quatro diferentes exercicios utilizados na prevencao e na reabilitacao da SDFP compreendendo isometria de extensao de joelhos a 30° e 60° e isometria no agachamento a 60° associado ou nao a aducao de quadril. Metodos: A amostra foi de 14 sujeitos saudaveis sedentarios, com idade entre 20 e 40 anos. O sinal EMG do musculo VM foi coletado durante Contracao Isometrica Voluntaria Maxima (CIVM) com duracao de cinco segundos para cada exercicio. Do sinal EMG captado foi recortado um periodo de tres segundos e a partir disso foram obtidos os valores Root Mean Square (RMS) para cada exercicio. Resultados: Demonstram que houve ativacao do VM significativamente maior nos exercicios de extensao quando comparados com os exercicios de agachamento. Porem, nao houve diferenca significativa entre os dois exercicios de extensao, assim como entre os exercicios de agachamento. Conclusao: Os melhores exercicios para maximizar a ativacao do VM sao os exercicios isometricos de extensao do joelho, independente do ângulo avaliado, pois apresentam maior nivel de ativacao do VM, imprescindivel para a prevencao e reabilitacao da SDFPDOI: 10.5935/0104-7795.20160025 ABSTRACT Excessive lateralization, which often occurs by the weakening of Vastus Medialis (VM) muscle of the patella, is one of the causes of Patellofemoral Pain Syndrome (PFPS) For prevention and rehabilitation of PFPS, the VM strength is essential. Objective: The aim of the study was to compare the VM activation level in four different exercises used in the prevention and rehabilitation of PFPS that are isometric knee extension at 30° and 60° and isometric squat at 60° with or without hip adduction. Methods: A sample of 14 sedentary healthy subjects, aged between 20 and 40 years was included. The EMG signal of VM muscle was collected during Maximal Voluntary Isometric Contraction with duration of five seconds for each exercise. From the captured EMG signal, a period of three seconds was cut and thereafter the Root Mean Square value for each exercise was obtained. Results: The results showed that there was significantly greater activation in VM extension exercises compared to squat exercises. However, there was no significant difference between the two extension exercises, as well as between squat exercises. Conclusion: It can be concluded that the best exercises to maximize the activation of the VM are the isometric knee extension, regardless of the rated angle, since they have greater VM activation level, essential for the prevention and rehabilitation of PFPS.