Purpose. This study assessed the isometric torque, hamstring-to-quadriceps ratio, and jump performance among three age groups of soccer players. Methods. 67 male players were divided by chronological age into the under-17 (U17: n = 29), under-20 (U20: n = 22), and above-20-year (PRO: n = 16) groups. They performed countermovement (CMJ) and squat (SJ) jumps. Also, maximal isometric contractions during knee flexion and extension for right (R-TOR) and left limb (L-TOR) torque were assessed. Hamstrings-quadriceps (H:Q) and CMJ:SJ ratios were determined. Results. Compared with U17 and U20, PRO showed higher CMJ ( = 20% and 14%; both p < 0.01) and SJ ( = 19% and 13%; p < 0.01 and p = 0.02, respectively), and higher absolute R-TOR and L-TOR during knee extension ( = 40% and 58%; both p < 0.01). PRO exhibited higher absolute L-TOR and R-TOR during knee flexion than U17 ( = 22% and 26%; p = 0.04 and p < 0.01, respectively). Between-group differences were not detected in normalized torque, except for knee extension R-TOR (PRO > U17; p = 0.04). Greater differences for quadriceps absolute torque (effect size: 1.37-1.46) were observed in the hamstrings (effect size: 0.30-0.92) between PRO and U17. No differences were found for any H:Q torque ratio, but moderate effect sizes (0.71-0.75) were verified between PRO and the other groups. No differences were found for CMJ:SJ ratio. Conclusions. PRO players are more powerful than U17 and U20. Differences in strength level between PRO and U17/U20 are muscle-dependent. The larger strength development of quadriceps over hamstrings can result in lower isometric H:Q torque ratio for PRO.

Exercises for lower trapezius (LT) often use overhead positions, causing compressive forces to the subacromial space. Scapular retraction would be an alternative to activate LT muscle. The present study aimed to assess the excitation levels of infraspinatus, upper trapezius, and lower trapezius muscles during a scapular retraction exercise under progressive adduction loads in subjects with and without painful shoulder. Electromyography of infraspinatus (IS), upper trapezius (UT), and LT was recorded during scapular retraction under progressive adduction loads of 42 participants, divided into two groups: with (SP, n = 26) and without shoulder pain (nSP, n = 16). The adduction loads of 20%, 30%, 40%, and 50% of the maximal voluntary contraction (MVC) were applied using a load cell. Normalized electromyography and the ratio between UT and LT (UT:LT) were used for statistical analysis. No differences were observed between groups, but a condition effect occurred for all muscles: UT showed higher values at 50% vs. 20% of MVC (p = 0.004); LT showed higher values on 40% and 50% of MVC (p = 0.001; 0.006). Higher values for IS were noted at 40% of MVC (vs. 20% of MVC; p = 0.04) and at 50% of MVC (vs. 20% of MVC; p = 0.001, vs. 30% of MVC, p = 0.001; vs. 40% of MVC; p = 0.001). UT:LT showed lower values at 50% of MVC (vs. 20% of MVC; p = 0.001 and vs. 30% of MVC; p = 0.016). Scapular retraction with adduction loads at 40–50% is an alternative to overhead exercises aiming to activate the LT and the IS muscles. The exercise ensures higher levels of LT and IS excitation without increasing UT excitation.

INTRODUÇÃO: As dores musculoesqueléticas, em especial a dor ombro, ocupam grande porcentagem dos atendimentos médico-hospitalares e sendo o ombro o complexo articular com a maior amplitude de movimento, isso o torna o mais instável. Seu conjunto estrutural promove sua estabilidade e os seus movimentos, mas alterações musculares podem desalinhar a escápula, alterando o seu ritmo, comprimindo o espaço subacromial, dificultando a elevação do braço, proporcionando dor ao indivíduo. Teoricamente um aumento da atividade muscular do trapézio superior associado a diminuição da atividade de suas outras porções e alterações nos movimentos escapulares estão relacionados à Síndrome do Impacto Subacromial. Não há na literatura exercício combinando a ativação dos músculos Trapézio Inferior e do Infraespinal sem aumentar a excitação do Trapézio Superior, sendo assim, um exercício que ative os músculos hipoativados, sem estimular os já hiperativados, é a proposta ideal. OBJETIVOS: Avaliar os níveis de excitação dos músculos Infraespinho, Trapézio Superior e Trapézio Inferior em exercício de retração escapular com cargas progressivas de adução controladas via feedabck, avaliar qual o melhor nível de carga adutora geraria melhor relação entre o Trapézio Superior e Trapézio Inferior e verificar as diferenças eletromiográficas em indivíduos com e sem dor no ombro. MÉTODOS: 42 indivíduos, divididos em dois grupos, com e sem dor no ombro realizaram exercícios de retração escapular controladas por biofeedback. Os participantes realizaram um estudo de familiarização de 5 segundos seguidos de 3 minutos de descanso verificando o entendimento do procedimento. Em seguida, foram realizadas coletas de três contrações isométricas voluntárias máximas de 5 segundos de cada músculo com 5 minutos de descanso. Por fim, realizaram contrações resistidas a 60° por 10 segundos a 20%, 30%, 40 e 50% da Contração Isométrica Voluntária Máxima, com intervalos de 10 segundos entre as tarefas, enquanto realizava-se retração escapular máxima do ombro avaliado. Pela média e desvio padrão foram apresentados os dados e a classificação das diferenças entre os grupos se deu pelo ANOVA de medidas repetidas. Com o teste de post hoc de Holm os dados foram retrabalhados comparando diferenças entre os ensaios, evitando comparações múltiplas em pares, com significância de p <0,05. RESULTADOS: Não foram observadas diferenças entre os grupos, mas os resultados mostraram que nos dois grupos os objetivos foram atingidos com os exercícios. Houve efeito no tempo para todos os músculos na análise de grupo (Trapézio Superior: F = 4,19; p = 0,008/Trapézio Inferior: F = 32,7; p = 0,001/Infra Espinhoso: F = 19,09; p = 0,001). Houve diferenças entre pares com valores mais altos a 50% comparados com 20% da Contração Isométrica Voluntária Máxima. Diferenças no Trapézio Inferior foram observadas comparando 20% vs. 40%, 20% vs. 50%, 30% vs. 40%, 30% vs. 50% e 40% vs. 50% e valores mais altos de 40% e 50% de Contração Isométrica Voluntária Máxima. Houve efeito no tempo na Razão Trapézio Superior-Trapézio Inferior (TS:TI) em 20% vs. 50% e 30% vs. 50% (F = 5,83; p= 0,001) e em 50%, a relação TS:TI foi menor que 20% e 30%. CONCLUSÃO: O movimento de retração escapular apresentou-se significativamente benéfico, conseguindo ativação dos músculos Trapézio Inferior e Infraespinhoso em hiperestimulação do Trapézio Superior, gerando diferenças significativas entre os músculos.

This study aimed to compare electromyographic response of the lower trapezius muscle during maximal voluntary isometric contractions under two conditions: overhead shoulder position versus scapular position, rating the pain after each condition. Twenty-six participants with shoulder pain (SP; n = 15; Shoulder Pain and Disability Index-Pain = 34 [range 6–66]) and without shoulder pain (nSP; n = 11; Shoulder Pain and Disability Index-Pain = 0 [range 0–14]) performed maximal voluntary isometric contractions in those 2 conditions while the lower trapezius was monitored using surface electromyography. Pain was rated using the visual analog scale. The nSP group experienced no pain, whereas the SP group reported pain in both conditions with higher pain during the overhead movement. No differences were observed for muscle excitation between conditions, but higher levels were observed for the nSP group compared with the SP group. The overhead condition was more painful for the SP group (visual analog scale: SP = 4 vs nSP = 1.09, P = .036). Scapular position showed the same levels of LT excitation than overhead position. The scapular position is preferable, compared with overhead positioning, to normalize the lower trapezius instead of overhead positioning.

Exercises for lower trapezius (LT) often use overhead positions, causing compressive forces to the subacromial space. Scapular retraction would be an alternative to activate LT muscle. Electromyography of infraspinatus (IS), upper (UT) and LT was recorded during scapular retraction under progressive adduction loads of 42 participants, divided in 2 groups: with (SP, n=26) and without shoulder pain (nSP, n=16). The adduction loads of 20, 30, 40 and 50% of the maximal voluntary contraction were applied using a load cell. Normalized electromyography and the ratio between UT and LT (UT:LT) were used for statistical analysis. No differences were observed between groups, but a condition effect occurred for all muscles: UT showed higher values at 50% vs. 20% (p=0.004); LT showed higher values on 40% and 50% (p=0.001; 0.006). Higher values for IS were noted at 40% (vs 20%; p=0.04), and at 50% (vs. 20%; p=0.001, vs. 30%, p=0.001; vs. 40%; p=0.001). UT:LT showed lower values at 50% (vs. 20%; p=0.001, and vs. 30%; p=0.016). Scapular retraction with adduction loads at 40-50% is an alternative to overhead exercises aiming to activate the LT and the IS muscles. The exercise ensures higher levels of LT and IS excitation, without increasing UT excitation.