Do athletes with hamstring strain injury have shorter muscle fascicles in the injured limb?

INTRODUCTION: Previous studies have suggested that a reduced length of the biceps femoris long head (BFlh) fascicles may increase the risk of hamstring strain injury (HSI). However, it remains unclear whether the BFlh fascicles of the injured limb are shorter than those of the contralateral limb in athletes with an acute HSI. OBJECTIVE: To investigate the between-limb asymmetry of BFlh fascicle length in amateur athletes with an acute HSI. METHODS: Male amateur athletes were evaluated using ultrasound scans within five days following an HSI. The BFlh fascicle length was estimated using a validated equation. RESULTS: Eighteen injured athletes participated in this study. There was no significant difference (p = 0.27) in the length of BFlh fascicles between the injured limb (9.53 ± 2.55 cm; 95%CI 8.26 to 10.80 cm) and the uninjured limb (10.54 ± 2.87 cm; 95%CI 9.11 to 11.97 cm). Individual analysis revealed high heterogeneity, with between-limb asymmetries (percentage difference of the injured limb compared to the uninjured limb) ranging from -42% to 25%. Nine out of the 18 athletes had a fascicle length that was more than 10% shorter in the injured limb compared to the uninjured limb, five athletes had a difference of less than 10%, and four athletes had a fascicle length that was more than 10% longer in the injured limb compared to the uninjured limb. CONCLUSION: The architecture characteristics of injured and uninjured muscles is not consistent among athletes with HSI. Therefore, rehabilitation programs focused on fascicle lengthening should be evaluated on a case-by-case basis.

Construct validity and reliability of tests for sacroiliac dysfunction: standing flexion test (STFT) and sitting flexion test (SIFT).

CONTEXT: Sacroiliac dysfunction is characterized by a hypomobility of the range of motion of the joint, followed by a positional change regarding the relationship between the sacrum and the iliac. In general, the clinical tests that evaluate the sacroiliac joint (SIJ) and its dysfunctions lack validity and reliability values. OBJECTIVES: This article aims to evaluate the construct validity and intra- and inter-rater reliability of the standing flexion test (STFT) and sitting flexion test (SIFT). METHODS: In this prospective study, the sample consisted of 30 individuals of both sexes, and the evaluation team was composed of five researchers. The evaluations took place on two different days: first day, inter-rater reliability and construct validity; and second day, intra-rater reliability. The reference standard for the construct validity was 3-dimensional measurements obtained utilizing the BTS SMART-DX system. For statistical analysis, the percentage (%) agreement and the kappa statistic (K) were utilized. RESULTS: The construct validity was determined for STFT (70% agreement; K=0.49; p<0.01) and SIFT (56.7% agreement; K=0.29; p<0.05). The intra-rater reliability was determined for STFT (66.3% agreement; K=0.43; p<0.01) and SIFT (56.7% agreement; K=0.38; p<0.01). The inter-rater reliability was determined for STFT (10% agreement; K=-0.02; p=0.825) and SIFT (13.3% agreement; K=0.01; p=0.836). CONCLUSIONS: The STFT confirmed the construct validity and was reliable when applied by the same rater to healthy people, even if the rater had no experience. It was not possible to achieve minimum scores using the SIFT either for construct validity or reliability. We suggest that further studies be conducted to investigate the measurement properties of palpatory clinical tests for SIJ mobility, especially in symptomatic patients.

Effects of low-level laser therapy on hamstring strain injury rehabilitation: A randomized controlled trial.

OBJECTIVES: To evaluate the effects of low-level laser therapy (LLLT) on functional rehabilitation following hamstring strain injury (HSI) in amateur athletes treated with an exercise-based rehabilitation program. DESIGN: Randomized controlled trial. METHODS: Male athletes (18-40 years old) who sustained HSI were randomized in LLLT or placebo groups. All patients were engaged in the same exercise-based rehabilitation program until they met specific criteria to return to sport. Hamstring muscles were treated with LLLT or placebo immediately after each rehabilitation session. The primary outcome was time-to-return to sport. Secondary outcomes were the number of rehabilitation sessions, hamstring flexibility, hamstring strength, and re-injury rate. RESULTS: Twenty-four athletes began rehabilitation, and 22 (11 per group) completed the study schedule. Participants of LLLT and placebo groups had similar age, body size, injury characteristics, and baseline levels of hamstring flexibility and strength. The two groups increased flexibility and strength similarly throughout the rehabilitation program. Time-to-return to sport was the same for athletes treated with LLLT (23 ± 9 days) and placebo (24 ± 13 days). There were no re-injuries within 6 months after return to sport. CONCLUSION: LLLT, as used in this study, did not optimize functional rehabilitation following HSI in amateur athletes treated with an exercise-based rehabilitation program.

Correlation between cervical morphology, pain, functionality, and rom in individuals with cervicalgia / Correlação entre morfologia cervical, dor, funcionalidade e adm em indivíduos com cervicalgia / Correlación entre morfología cervical, dolor, funcionalidad y adm en individuos con cervicalgia

ABSTRACT Objective: To verify if there is a correlation between the morphology of the cervical spine curvature, pain intensity, functional disability, and range of motion in individuals with cervicalgia. Methods: Thirty-nine individuals were evaluated using x-rays in the right sagittal plane (Cobb C1-C7 two-line method), visual analogue scale, Neck Disability Index questionnaire, and fleximeter. Descriptive statistical analysis (percentage, mean and standard deviation) and inferential (independent t-test and Pearson product-moment correlation coefficient, α=0.05) were performed. Results: There were significant correlations, ranging from moderate to high, between functional capacity and pain intensity (r=0.637, p<0.001), and total range of motion (r=-0.568, p<0.001), and extension (r=-0.610, p<0.001), and between pain intensity and range of motion (r=-0.422, p=0.007). Regarding the morphology of the cervical spine curvature, none of the variables showed a significant correlation. Conclusions: Cervical morphology, more specifically related to the curvature in the sagittal plane, does not seem to interfere alone with pain, functionality, and range of motion. In contrast, it is possible to affirm that higher levels of pain generate a smaller range of cervical movement, especially of extension, which, in turn, results in greater functional losses in individuals with neck pain. Level of Evidence II; Prognostic Studies - Investigating the Effect of a Patient Characteristic on the Outcome of Disease.

RESUMO Objetivo: Verificar se existe correlação entre a morfologia da curvatura da coluna cervical, a intensidade da dor, a incapacidade funcional e a amplitude de movimento em indivíduos com cervicalgia. Métodos: Foram avaliados 39 indivíduos, por meio de Raios x no plano sagital direito (método Cobb C1-C7 duas linhas), da escala visual analógica, do questionário Neck Disability Index e de um flexímetro. Foi realizada análise estatística descritiva (porcentagem, média e desvio padrão) e inferencial (teste t independente e coeficiente de correlação produto-momento de Pearson, α = 0,05). Resultados: Foram encontradas correlações significativas, que variaram de moderada a alta, entre a incapacidade funcional e a intensidade da dor (r=0,637; p<0,001) e a amplitude de movimento total (r=-0,568; p<0,001) e de extensão (r=-0,610; p<0,001); e, entre a intensidade da dor e a amplitude de movimento de extensão (r=-0,422; p=0,007). Quanto a morfologia da curvatura da coluna cervical, nenhuma das variáveis apresentou correlação significativa. Conclusões: A morfologia cervical, relacionada mais especificamente à curvatura no plano sagital, parece não interferir por si só no acometimento álgico, na funcionalidade e na amplitude de movimento. Em contrapartida, é possível afirmar que níveis mais elevados de dor geram uma menor amplitude de movimento cervical, especialmente de extensão, os quais, por sua vez resultam em maiores perdas funcionais, em indivíduos com cervicalgia. Nível de Evidência II; Estudos prognósticos - Investigação do efeito de característica de um paciente sobre o desfecho da doença.

RESUMEN Objetivo: Verificar si existe correlación entre la morfología de la curvatura de la columna cervical, la intensidad del dolor, la incapacidad funcional y la amplitud de movimiento en individuos con cervicalgia. Métodos: Se evaluaron 39 individuos, por medio de rayos X en el plano sagital derecho (método Cobb C1-C7 dos líneas), de la escala visual analógica, del cuestionario Neck Disability Index y de un flexímetro. Se realizó un análisis estadístico descriptivo (porcentaje, promedio y desviación estándar) e inferencial (prueba t independiente y coeficiente de correlación producto-momento de Pearson, α = 0,05). Resultados: Se encontraron correlaciones significativas, que variaron de moderada a alta, entre la incapacidad funcional y la intensidad del dolor (r = 0,637, p < 0,001) y la amplitud de movimiento total (r = −0,568, p < 0,001) y de extensión (r = −0,610; p < 0,001) y entre la intensidad del dolor y la amplitud de movimiento de extensión (r = −0,422, p = 0,007). En cuanto a la morfología de la curvatura de la columna cervical, ninguna de las variables presentó correlación significativa. Conclusiones: La morfología cervical, relacionada más específicamente a la curvatura en el plano sagital, parece no interferir por sí solo en la manifestación álgica, en la funcionalidad y en la amplitud de movimiento. En cambio, es posible afirmar que niveles más elevados de dolor generan una menor amplitud de movimiento cervical, especialmente de extensión, el cual a su vez resulta en mayores pérdidas funcionales en individuos con cervicalgia. Nivel de Evidencia II; Estudios pronósticos - Investigación del efecto de características de un paciente sobre el desenlace de la enfermedad.

Posture, muscle endurance and ROM in individuals with and without neck pain / Postura, resistência muscular e ADM em indivíduos com e sem dor cervical / Postura, resistencia muscular y ROM en individuos con y sin dolor de cuello

Abstract Introduction: Factors such as postural changes, reduced neck muscle endurance and reduced range of motion (ROM) are common characteristics attributed to people with neck pain. Objective: (a) Identify differences in postural, muscular endurance and ROM characteristics between individuals with and without neck pain and (b) relate the presence and intensity of neck pain with the characteristics of static posture, muscular endurance and cervical ROM. Method: A cross-sectional study with 60 subjects equally divided into two groups with respect to the presence of neck pain carrying out the following evaluations: (1) static postural evaluation by digital photogrammetry; (2) the neck flexor endurance test; and (3) evaluation of cervical ROM using a fleximeter. The data were analyzed with independent t-tests, the Mann-Whitney U test, and the Spearman and Tau of Kendall correlation tests (α < 0.05). Results: There were no statistical differences between individuals with and without neck pain regarding the postural, muscle endurance and cervical ROM characteristics. No statistically significant correlations were found between pain and posture, muscle endurance and cervical ROM. Conclusion: Individuals with neck pain do not appear to present differences in their postural, neck flexor muscle endurance or cervical ROM characteristics when compared to individuals without neck pain, and neck pain appears to be unrelated to these variables.

Resumo Introdução: Fatores como alterações posturais, redução da resistência muscular do pescoço e redução da amplitude de movimento (ADM) da cervical são características comuns atribuídas a pessoas com dor cervical. Objetivo: (a) Identificar diferenças existentes em relação às características posturais, de resistência muscular e de ADM entre indivíduos com e sem dor na região cervical e (b) relacionar a presença e intensidade da dor cervical com as características da postura estática, da resistência muscular e da ADM cervical. Método: Estudo transversal em que 60 indivíduos foram divididos igualmente em dois grupos quanto à presença de dor cervical. Foram realizados: (1) avaliação postural estática pela fotogrametria digital; (2) teste de resistência dos flexores do pescoço; e (3) avaliação da ADM cervical, por meio do flexímetro. Os dados foram analisados com: testes t independentes, U de Mann-Whitney, correlação de Spearman e Tau de Kendall (α < 0,05). Resultados: Não houve diferença estatística quanto às características posturais, de resistência muscular e de ADM da cervical entre os indivíduos com e sem dor cervical. Não foram encontradas correlações estatisticamente significativas entre a dor e a postura, a resistência muscular e a ADM da cervical. Conclusão: Indivíduos com dor cervical parecem não apresentar diferenças relacionadas às características posturais, de resistência muscular do flexores do pescoço e de ADM da cervical quando comparados a indivíduos sem dor cervical, bem como a dor cervical parece não ter relação com essas variáveis.

Resumen Introducción: Factores como los cambios posturales, la reducción de la resistencia del músculo del cuello y la reducción del rango de movimiento (RDM) son características comunes atribuidas a las personas con dolor de cuello. Objetivo: Verificar si existen: (a) diferencias en las características posturales, resistencia muscular y RDM entre individuos con y sin dolor en la región cervical y (b) relación entre la presencia e intensidad del dolor de cuello con las características de la postura estática, resistencia muscular y ROM cervical. Método: Estudio Transversal cuyos 60 sujetos se dividieron por igual en dos grupos con respecto a la presencia de dolor en el cuello. Se realizó: (1) evaluación postural estática, mediante fotogrametría digital; (2) la prueba de resistencia de los flexores del cuello; y (3) evaluación de la RDM cervical usando el flexímetro. Los datos se analizaron con: pruebas t independientes, U de Mann-Whitney, correlación de Spearman y Tau de Kendall (α < 0,05). Resultados: No hubo diferencias estadísticas con respecto a la postural, la resistencia muscular y las características de la RDM cervical entre las personas con y sin dolor de cuello. No se encontraron correlaciones estadísticamente significativas entre el dolor y la postura, la resistencia muscular y la RDM del cuello. Conclusión: Las personas con dolor de cuello no parecen presentar diferencias en las características posturales, la resistencia muscular de los flexores del cuello y la RDM cervical en comparación con las personas sin dolor de cuello, y el dolor de cuello parece no estar relacionado con estas variables.