Age-Related Differences in Hamstring Flexibility in Prepubertal Soccer Players: An Exploratory Cross-Sectional Study

This study aimed to investigate the hamstring flexibility rate among prepubertal soccer players from U8 to U12 and the role of age and soccer years of practice on the course of hamstring flexibility. Six hundred eleven young Italian soccer players from a local soccer school in Turin were recruited for this research and assigned to each group according to their chronological age (U8 = 124 players; U9 = 130 players; U10 = 151 players; U11 = 89 players; and U12 = 120 players). Hamstring flexibility was measured using the Sit and Reach Test (SAR), while data analysis was run using a one-way analysis of variance (one-way ANOVA). Furthermore, Tuckey’s post hoc was used to determine differences among the classes of age. Finally, a bivariate ordinal regression analysis was used to evaluate a potential association between age categories and hamstrings flexibility. In addition, multivariable ordinal regression was used to analyze this relationship adjusted for the Body Mass Index (BMI). The one-way ANOVA showed significant differences in flexibility among groups (F = 32.76, P < 0.0001). Tuckey’s post hoc identified significant differences between U8 and U10 (p < 0.01; −2,39 cm of hamstring stretching), U8 and U11 (p < 0.05; −2.19 cm), U8 and U12 (p < 0.0001; −5.90), U9 and U12 (p < 0.0001; −4.98 cm), U10 and U12 (p < 0.0001; −3.5 cm), U11 and U12 (p < 0,001; −3.70 cm). In the bivariate ordinal regression analysis, there was a negative association between the age categories and hamstrings flexibility (R² = 0.137; p < 0.0001). The association persisted in multivariable ordinal regression analysis adjusted for BMI (R² = 0.138; p < 0.0001). This study underlines changes in hamstring flexibility across different age groups of prepubertal soccer players. The older and more experienced in soccer are less flexible than the younger, considering the hamstring muscles. Thus, appropriate stretching protocols should be included in prepubertal soccer training to avoid the risk of lead players to excess hamstring tightness.

The Effect of Static and Dynamic Stretching Exercises on Sprint Ability of Recreational Male Volleyball Players

The aim of the present trial was to investigate the effect of two stretching programs, a dynamic and a static one, on the sprint ability of recreational volleyball players. The sample consisted of 27 male recreational volleyball players (age 21.6 ± 2.1 years, mean ± standard deviation, body mass 80.3 ± 8.9 kg, height 1.82 ± 0.06 m, body mass index 24.3 ± 2.5 kg.m⁻², volleyball experience 7.7 ± 2.9 years). Participants were randomly divided into three groups: (a) the first performing dynamic stretching exercises three times per week, (b) the second following a static stretching protocol on the same frequency, and (c) the third being the control group, abstaining from any stretching protocol. The duration of the stretching exercise intervention period was 6 weeks, with all groups performing baseline and final field sprinting tests at 4.5 and 9 m. The post-test sprint times were faster in both the 4.5 (p = 0.027, η² = 0.188) and 9 m tests (p < 0.001, η² = 0.605) compared to the pre-test values. A large time × group interaction was shown in both the 4.5 (p = 0.007, η² = 0.341) and 9 m tests (p = 0.004, η² = 0.363) with the static and dynamic stretching groups being faster in the post-test than in the pre-test, whereas no change was found in the control group. The percentage change in the 4.5 m sprint time correlated with volleyball experience (r = −0.38, p = 0.050), i.e., the longer the volleyball experience, the larger the improvement in the 4.5 m sprint. Thus, it is concluded that both stretching techniques have a positive effect on the velocity of recreational male volleyball players, when performed at a frequency of three times per week for 6 weeks under the same conditions as defined in the study protocol.

Efeito agudo do alongamento na marcha de idosas em terreno inclinado

Introdução O envelhecimento causa modificações musculares que influenciam negativamente a capacidade funcional dos idosos na locomoção, em especial durante a transposição de superfícies inclinadas. Essas mudanças geram redução da performance, diminuindo a mobilidade e aumentando o risco de queda na execução de tal tarefa. Os exercícios de alongamento podem reduzir a influência de dessas degenerações, preservando a capacidade muscular e a mobilidade. Objetivo O objetivo deste estudo foi avaliar a atuação do efeito agudo de uma sessão de exercícios de alongamento sobre a marcha de idosas durante a locomoção em uma rampa. Materiais e métodos Doze mulheres idosas, saudáveis e independentes, caminharam subindo e descendo uma rampa com inclinação de 10%. A análise cinemática (2D) e eletromiográfica foi realizada durante uma única sessão experimental, imediatamente antes (PRÉ) e após (PÓS) a realização de um exercício de alongamento estático dos flexores do quadril. Resultados O exercício de alongamento gerou aumento da amplitude (PRÉ 52,3 ± 18,30; PÓS 63,6 ± 16,90) e velocidade (PRÉ 195,8 ± 31,20/s; PÓS 241,8 ± 29,80/s) do quadril, assim como redução do tempo de ativação do tibial anterior (PRÉ TAFIN1 29,7 ± 6,7%; TAFIN2 100,0 ± 0,0%; PÓS TAFIN1 23,3 ± 7,4%; TAFIN2 87,7 ± 3,4%) e do bíceps femoral (PRÉ 45,0 ± 5,4%; PÓS 36,1 ± 10,4%) na subida na rampa. Na descida ocorreu aumento na velocidade da marcha (PRÉ 0,95 ± 0,18 m.s-1; PÓS 1,01 ± 0,22 m.s-1) e tamanho do passo (PRÉ 1,02 ± 0,15 m; PÓS 1,08 ± 0,18 m). Conclusão Os exercícios utilizados foram capazes de alterar de forma significativa os parâmetros avaliados, permitindo uma marcha mais veloz e reduzindo a ativação muscular. Estudos longitudinais são necessários para que os resultados aqui encontrados de forma temporária possam ser confirmados de forma permanente.

The comparison of the effects of three physiotherapy techniques on hamstring flexibility in children: a prospective, randomized, single-blind study

The aim of the study was to evaluate changes in hamstring flexibility in 120 asymptomatic children who participated in a 6-week program consisting of one physiotherapy session per week and daily home exercises. The recruitment criteria included age (10-13 years), no pain, injury or musculoskeletal disorder throughout the previous year, physical activity limited to school sport. Subjects were randomly assigned to one of the three groups: (1) post-isometric relaxation - PIR (n = 40), (2) static stretch combined with stabilizing exercises - SS (n = 40) and (3) stabilizing exercises - SE (n = 40). Hamstring flexibility was assessed with straight leg raise (SLR), popliteal angle (PA) and finger-to-floor (FTF) tests. The examinations were conducted by blinded observers twice, prior to the program and a week after the last session with the physiotherapist. Twenty-six children who did not participate in all six exercise sessions with physiotherapists were excluded from the analysis. The results obtained by 94 children were analyzed (PIR, n = 32; SS, n = 31; SE, n = 31). In the PIR and SS groups, a significant (P<0.01) increase in SLR, PA, FTF results was observed. In the SE group, a significant (P<0.001) increase was observed in the SLR but not in the PA and FTF (P>0.05). SLR result in the PIR and SS groups was significantly (P<0.001) higher than in the SE group. As far as PA results are concerned, a significant difference was observed only between the SS and SE groups (P = 0.014). There were no significant (P = 0.15) differences regarding FTF results between the three groups. Post-isometric muscle relaxation and static stretch with stabilizing exercises led to a similar increase in hamstring flexibility and trunk forward bend in healthy 10-13-year-old children. The exercises limited to straightening gluteus maximus improved the SLR result, but did not change the PA and FTF results.