Biomechanical parameters assessed during running among running-related athletes with recurrent hamstring strain injury: A scoping review

Background@#Hamstring strain injury (HSI) is the most common cause of missing practices and sporting events among running-related athletes. The incidence rate of recurrence in individuals with HSI ranges from 12% to 63%. While various risk factors for HSI have been identified, the alterations and role of biomechanical factors as potential causes of injury have been largely overlooked. @*Objectives@#To report the critical biomechanical parameters assessed among running-related athletes with a recurrent HSI and to present common testing protocols in assessing the biomechanical parameters among running-related athletes with a recurrent HSI. @*Methods@#Eligibility Criteria: Included studies investigated biomechanical parameters assessed among collegiate or elite running-related athletes with recurrent HSI. Sources of Evidence: This scoping review was registered in OSF and was conducted based on PRISMA-ScR. Six electronic databases were systematically searched from 1993 to May 2022. Charting Methods: The reviewers created a data charting tool for the scoping review.@*Results@#Out of 874 articles, a total of 10 articles were included in the scoping review. The critical biomechanical parameters assessed include trunk flexion, hip flexion, and knee extension angles (kinematic variables), flight and stance times and velocity (spatiotemporal variables), and EMG activity of biceps femoris, semitendinosus, semimembranosus, vastus lateralis, and rectus femoris, knee flexion and extension angle peak joint torque (kinetic variables). The most common running test protocols used were the 30-meter overground repeated sprint test, a percentage of maximum running velocity (treadmill), and repeated sprints on a non-motorized treadmill. The most common protocols for isokinetic muscle testing were 60 degrees (concentric), 300 degrees (concentric), and 180 degrees (eccentric) per second angular velocities.@*Conclusion@#The review demonstrated a need for more research on this topic, leading to only limited biomechanical parameters being discussed in the literature. This underscores the need for more rigorous research that could have practical applications for athletes and coaches.

Lateral and functional asymmetries in the lower limbs of college-level female handball players

Abstract Aim: The present study aimed to screen for differences in isokinetic peak torque, hamstrings-to-quadriceps ratio, and proprioception within the lower limbs of female handball athletes. Methods: Twelve college-level female handball athletes with no previous experience with resistance training performed five maximal isokinetic contractions of the knee extensors and knee flexors to determine isokinetic peak torque and hamstring-to-quadriceps ratios. Proprioception was determined by assessing passive position sense on an isokinetic dynamometer. Results: The athletes presented significantly greater (p < 0.01) knee extensors isometric peak torque for the jumping limb (144.9 ± 23.1) when compared to the non-jumping limb (132.9 ± 21.5). The Hamstrings-to-quadriceps ratio was below 0.6 for both limbs, being significantly greater (p < 0.01) for the non-jumping limb (0.56 ± 0.08) when compared to the jumping limb (0.50 ± 0.08). Conclusion: Female handball athletes that do not engage in resistance training can experience functional bilateral asymmetries in the knee extensors and knee-joint instability, as assessed by the hamstrings-to-quadriceps ratio due to the asymmetric characteristics of handball. Regular strength training might correct such asymmetries and instabilities.

Efeito de duas técnicas de alongamento no ganho de flexibilidade de cadeia posterior em mulheres sedentáriasS / Effect of two stretching techniques on the flexibility gain of back chain in sedentary women

Introdução: A perda da flexibilidade da cadeia posterior resulta em diversas disfunções biomecânicas, o alongamento apresenta-se como recurso para restauração desse déficit. Objetivo: Verificar o efeito e comparar a eficácia do alongamento estático e da técnica de energia muscular para ganho de flexibilidade de cadeia posterior. Métodos: Estudo de intervenção com grupo controle, que avaliou 27 mulheres, que apresentavam encurtamento de cadeia posterior, divididas em 3 grupos: alongamento estático, técnica de energia muscular e grupo controle. Ao final do período de intervenção as mulheres foram reavaliadas através do banco de Wells. A comparação das médias, antes e após a realização das técnicas foi avaliada através do Teste T de Student. Já para verificação da classificação das mulheres de acordo com o banco de Wells, foi utilizado o teste de Wilcoxon. Resultados: Houve aumento significativo em relação as médias após o alongamento estático (aumento de 35%, p = 0,001) e da técnica de energia muscular (aumento de 72%, p = 0,001), enquanto o grupo controle se manteve inalterado. Também foi verificado que após a intervenção, as mulheres tiveram melhores classificações de acordo com o banco de Wells. Conclusão: Ambas as técnicas foram positivas, entretanto a técnica de energia muscular mostrou ser mais eficaz. (AU)

Introduction: The loss of flexibility of the posterior chain results in several biomechanical dysfunctions, the use of stretching presents itself as a resource to restore this deficit. Objective: To verify the effect and compare the effectiveness of static stretching and muscle energy technique for gain of posterior chain flexibility. Methods: Intervention study with a control group, which evaluated 27 sedentary women, who presented posterior chain shortening, divided into 3 groups: static stretching, muscular energy technique, and the control group. At the end of the intervention period women were revaluated through the Banco de Wells. The comparison of means, before and after the performance of the techniques was evaluated through Student's TTest. The Wilcoxon test was used to verify the classification of women according to the Banco de Wells. Results: There was a significant increase in the means after static stretching (35% increase, p = 0.001) and muscle energy technique (72% increase, p = 0.001), while the control group remained unchanged. It was also verified that after the intervention, the women had better ratings according to the Banco de Wells. Conclusion: Both techniques were positive in obtaining hamstring flexibility. However, the muscle energy technique was more effective when compared to static stretching. (AU)

MRI Observations of Patellar Tendon Length Change after ACL Reconstruction with Hamstring Autografts / 华中科技大学学报（医学）（英德文版）

The post-operative patellar tendon length was studied to evaluate the possible tendon length change after anterior cruciate ligament (ACL) reconstruction with hamstring autografts.The Insall-Salvati index,modified Insall-Salvati index,curved modified Insall-Salvati index and Caton-Deschamps index were observed by MRI during a follow-up period of 12 weeks on 20 ACL reconstructed knees.The results showed no patellar baja or alta pre-existed on those ACL injured patients.After a follow-up period of 12 weeks,no patellar tendon length change was observed.It is suggested that the change of patella was not the primary reason that may contribute to the premature patellofemoral joint osteoarthritis after ACL reconstruction.

Síndrome de fricción de la cintilla iliotibial posterior a reconstrucción del ligamento cruzado anterior con pines transversos bioabsorbibles / Iliotibial band friction syndrome due to bioabsorbable pins in ACL reconstruction

Resumen: Las lesiones del ligamento cruzado anterior (LCA) hoy en día son tratadas principalmente con injerto de isquiotibiales y una amplia gama de técnicas y sistemas de fijación del LCA en busca de una menor morbilidad del paciente. Se reporta un caso de una paciente de 42 años que sufrió ruptura de LCA, tratada con reconstrucción de LCA con injerto autólogo de isquiotibiales, fijación femoral con pines transversos bioabsorbibles y fijación tibial con tornillo bioabsorbible. La paciente evolucionó con presencia de dolor en región lateral de rodilla, diagnosticado como síndrome de fricción de la banda iliotibial un año posterior a la cirugía. Se realizaron estudios de imagen que incluyeron rayos X y resonancia magnética (RM) donde se observó adecuada fijación del LCA con presencia de migración y ruptura del pin proximal bioabsorbible. Se decidió extraer el fragmento del pin bioabsrobile en un segundo tiempo quirúrgico y la paciente regresó a sus actividades cotidianas y deportivas sin dolor y con una adecuada estabilidad.

Abstract: Injuries of the anterior cruciate ligament are currently treated primarily with the use of hamstring graft with a wide range of different techniques and fixation systems for anterior cruciate ligament in reducing patient morbidity. We report the case of a female patient aged 42 that suffered an anterior cruciate ligament rupture and was treated with anterior cruciate ligament reconstruction with hamstring autograft with femoral fixation with bio-absorbable cross-pin and tibial fixation with bio-absorbable screw. The patient presented lateral knee pain that was diagnosed one year after the operation as an iliotibial band friction syndrome. Imaging studies were performed. X-rays and magnetic resonance imaging demonstrated adequate fixation of the anterior cruciate ligament with the presence of migration and rupture of the proximal bio-absorbable cross-pin. It was decided to remove the bio-absorbable cross-pin fragment in a second surgical procedure after which the patient went back to her daily activities and sports without pain and with stability stable knee.

Male and female runners demonstrate different sagittal plane mechanics as a function of static hamstring flexibility

ABSTRACTBackground:Injuries to runners are common. However, there are many potential contributing factors to injury. While lack of flexibility alone is commonly related to injury, there are clear differences in hamstring flexibility between males and females.Objective: To compare the effect of static hamstring length on sagittal plane mechanics between male and female runners.Method: Forty subjects (30.0±6.4 years) participated and were placed in one of 4 groups: flexible males (n=10), inflexible males (n=10), flexible females (n=10), and inflexible females (n=10). All subjects were free of injury at the time of data collection. Three-dimensional kinematics and kinetics were collected while subjects ran over ground across 2 force platforms. Sagittal plane joint angles and moments were calculated at the knee and hip and compared with a 2-way (sex X flexibility) ANOVA (α=0.05).Results: Males exhibited greater peak knee extension moment than females (M=2.80±0.47, F=2.48±0.52 Nm/kg*m, p=0.05) and inflexible runners exhibited greater peak knee extension moment than flexible runners (In=2.83±0.56, Fl=2.44±0.51 Nm/kg*m, p=0.01). For hip flexion at initial contact, a significant interaction existed (p<0.05). Flexible females (36.7±7.4º) exhibited more hip flexion than inflexible females (27.9±4.6º, p<0.01) and flexible males (30.1±9.5º, p<0.05). No differences existed for knee angle at initial contact, peak knee angle, peak hip angle, or peak hip moment.Conclusion: Hamstring flexibility results in different mechanical profiles in males and females. Flexibility in the hamstrings may result in decreased moments via active or passive tension. These differences may have implications for performance and injury in flexible female runners.

Comparison Of The Effect Of Active Release Technique Versus Proprioceptive Neuromuscular Facilitation Stretching (Modified Hold-Relax) On Hamstring Flexibility In Patients Having Chronic Low Back Pain.

Abstracts: Background and Objectives: Low back pain(LBP) is the leading cause of occupational injury and disability.The hamstring tightness was found to be one of the leading causes for development of LBP. Active Release Technique(ART)&PNF(Proprioceptive neuromuscular facilitation) stretchingboth the methods work on different physiological principles to increase the hamstrings flexibility. Hence objective of the study was to compare the effect of ART and PNF on hamstrings flexibility, Pain and functional disability in patients having LBP. Methodology: 30 subjects were taken in the study and divided in to 2 groups, 15 in each group.Measurement of the severity of pain by using VAS, degree of hamstrings tightness by active knee extension test and functional disability by modifies oswestry disability index was done. Group A was given modified hold relax PNF stretch and Group B was given ART for 10 sessions. Results: There was significant difference forMean of AKE (t=2.31, p=0.028), pain at activity (t=52.00, p=0.012) and functional disability (U=-2.224, p=0.026) between both groups. Conclusion: Both the techniques Modified hold-relax PNF stretch and ART improve hamstrings flexibility and reduce pain and disability over time but PNF (modified hold relax) was more effective than ART.

Effect of knee flexion angles during maximum isometric hip extension / 体力科学

The purpose of this study was to examine the effects of knee flexion angles during maximum isometric hip extension. Ten healthy men performed maximum isometric hip extension in prone position at 15° and 90° knee flexion. Then, the hip extension torque was measured, and electromyographic (EMG) data were obtained from the biceps femoris long head, semitendinosus, semimembranosus, adductor magnus, and gluteus maximus muscles. The EMG data were full-wave rectified and integrated (IEMG). The IEMG values obtained during the measurement of isometric hip extension were normalized with the values collected at 90° knee flexion (normalized IEMG [NIEMG]). The hip extension torque at 15° knee flexion was significantly greater than that at 90° knee flexion. The NIEMG values from the hamstrings at 15° knee flexion significantly increased compared with those at 90° knee flexion. Meanwhile, the NIEMG values from the gluteus maximus at 90° knee flexion were significantly greater than those at 15° knee flexion. However, the NIEMG values from the adductor magnus did not significantly differ between 15° and 90° knee flexion. These results indicate that the hamstrings effectively generate contracting force during isometric hip extension and at knee extended position because its fiber length was close to the optimal length.

Assessment and comparison of the effects of two techniques on hamstring flexibility / Avaliação e comparação dos efeitos de duas técnicas de alongamento na flexibilidade dos músculos isquiotibiais

Introduction There are several stretching techniques that help increase flexibility, however, there are still questions regarding which method leads to the most effective gains. Objectives To assess and compare the effects of two stretching techniques, namely proprioceptive neuromuscular facilitation (PNF) and static stretching on the flexibility of hamstring muscles of young women. Methods The study sample consisted of 45 young women, mean age 20.45 (± 1.66),assigned to one of three groups: static stretching group (SSG, n = 15), proprioceptive neuromuscular facilitation group (PNFG, n = 15) and control group (CG, n = 15). Both SSG and PNFG carried out three weekly stretching sessions over a four-week period. The sit and reach and popliteal angle tests were used at the beginning and end of the intervention. Normally distributed data were analyzed using Student’s t-test, whereas data with non-normal distribution were analyzed using the Wilcoxon test, to compare initial and end measurements for each technique. Finally, we used the Mann-Whitney U test to compare both techniques with each other. A significance level of 5% (p < 0.05) was adopted. Results There was a significant increase in hamstring flexibility when analyzing the assessments and reassessments of both stretching protocols. Conclusions Both techniques were effective in increasing hamstring flexibility and there were no significant differences to indicate which one is better in increasing the flexibility of this muscle group. .

Introdução Existem diversas técnicas de alongamento que auxiliam o aumento de flexibilidade, entretanto ainda prevalecem dúvidas sobre qual método aponte ganhos majoritariamente eficazes. Objetivos Avaliar e comparar os efeitos das técnicas de alongamento Facilitação Neuromuscular Proprioceptiva (FNP) e o Alongamento Estático na flexibilidade dos músculos isquiotibiais de jovens mulheres. Métodos Participaram do estudo 45 jovens, mulheres, com média de idade entre 20,45 (± 1,66), que foram divididas em três grupos: grupo alongamento estático (GAE, n = 15), grupo alongamento facilitação neuromuscular proprioceptiva (GFNP, n = 15) e grupo controle (GC, n = 15). Os grupos GAE e GNFP realizaram três sessões semanais de alongamento durante quatro semanas. As voluntárias foram avaliadas por meio do Teste Sentar e alcançar e pelo Teste do Ângulo poplíteo no início e ao fim das intervenções. Os dados com distribuição normal foram analisados pelo Teste t de student, para os dados com distribuição não normal, foi utilizado o Teste de Wilcoxon para comparar cada técnica e o Teste de Mann-whitney para comprar as duas técnicas. Foi adotado o nível de significância de 5% (p < 0,05). Resultados Houve aumento significativo da flexibilidade dos músculos isquiotibiais quando analisadas as avaliações e reavaliações em ambos os protocolos de alongamento. Conclusões Ambas as técnicas são eficazes para o ganho de flexibilidade dos músculos isquiotibiais, não apresentando diferenças significativas que evidenciasse qual delas é a melhor para o ganho de flexibilidade desse grupo muscular. .

Compression with active movements in osteoarthritis of knee: a case study.

The objective of this case study was to find out the immediate effectiveness of an innovative approach in form of CAM (Compression with Active movements) in a woman with chronic osteoarthritis of knee. Participant was an individual with chronic osteoarthritis of knee participated in this study. The intervention was hands on manual therapy approach called compression with active movements where hamstrings muscle were compressed with therapist hands as if they were splinted or supporting by hand and simultaneously patient was asked to perform the active knee flexion and extension for three bouts of 10 repetitions. Main outcome measured in this case was pain relief in terms of visual analogue scale and active knee flexion. Pain was reduced by 3.1 cm on VAS scale and active knee flexion improved by 16 degree. Compression with active movements may be used for immediate relief of pain in chronic osteoarthritis of knee when it is associated with hamstrings spasm so as to get confidence of patient in performing active movements.

Relationship between physical function and hamstrings strain in junior high school soccer players / 体力科学

In this study, we examined the relationship between physical function and muscle strain of hamstrings in junior high school soccer players. The subjects were 29 junior high school soccer players. The muscle strength of knee flexors and extensors relative to body weight and the hamstrings/quadriceps muscle strength ratio (H/Q ratio) were measured, and a tightness test, general joint looseness test and the New Physical Fitness Test of Japanese Ministry of Education and science were performed. We contacted the trainer to confirm occurrence of hamstrings strain, and we compared the above measurement and test results in subjects with and those without hamstring strain. Differences were analyzed by the unpaired t-test. There were significant differences between the two groups in muscle strength of knee extensors, H/Q ratio and tightness of hamstrings (p<0.05). The results suggest that increasing the H/Q ratio and stretching hamstrings are important for preventing hamstrings strain in junior high school soccer players.

Utilização do teste de 1-RM na mensuração da razão entre flexores e extensores de joelho em adultos jovens / Use of 1-RM test in the measurement of knee flexors and extensors ratio in young adults

A razão de força entre agonista/antagonista fornece informação significativa sobre o equilíbrio muscular sendo importante na detecção de alterações musculoesqueléticas, na orientação de medidas preventivas e na implementação de programas de treinamento específicos. A dinamometria isocinética fornece valores fidedignos sobre o torque gerado e, subsequentemente, sobre a razão de força entre flexores e extensores. Porém, trata-se de um método pouco acessível. Uma possível alternativa para avaliação de força é o teste de uma repetição máxima (1-RM), que é o mais utilizado para avaliação da força dinâmica. Contudo, não existem na literatura trabalhos que tenham utilizado o teste de 1-RM para quantificação da razão entre flexores e extensores de joelho. O objetivo deste estudo foi utilizar o teste de 1-RM na mensuração da razão entre flexores e extensores de joelho em adultos jovens, a fim de encontrar dados normativos. A amostra foi composta por 80 adultos jovens (com média de idade de 22,7 ± 3,40 anos), sendo 40 homens e 40 mulheres, sem lesões osteomioarticulares, que foram submetidos à aplicação do IPAQ-curto, pesagem e predição de 1-RM, aquecimento, teste de 1-RM unilateralmente nos bancos flexor e extensor e posterior análise de dados. Foram encontrados valores de razão agonista/antagonista de 52,34 por cento (±9,72) para homens e 43,19 por cento (±5,82) para mulheres (havendo uma diferença significativa entre os grupos). Valores de referência quanto à razão dos flexores e extensores de joelho utilizando o teste de 1-RM em adultos jovens foram encontrados, podendo servir como referência para indivíduos assintomáticos nessa faixa etária.

Force ratio between agonist and antagonist muscles provides significant information about muscular equilibrium, which helps to detect musculoskeletal changes and to guide preventive and rehabilitation programs. Isokinetic dynamometry provides reliable values for muscle torque and subsequently on the force ratio between knee flexors and extensors. However, this method is not clinically accessible. A possible alternative to evaluate this force is the One-Repetition Maximum test (One-Rep Max or just 1-RM), which is the most commonly used test for dynamic force assessment. However, there is no report in the literature of the use of 1-RM test for the quantification of knee flexors and extensors ratio. For this reason, the objective of this study was to use the 1-RM test to measure the ratio between knee extensors and flexors in young adults in order to find reference values. The studied sample was composed of 80 young adults (40 men and 40 women), mean age of 22.21 (±3.58) years with no musculoskeletal injuries. They were submitted to the following procedure: IPAQ-short version, weighing and prognostic of 1-RM, warm-up, and unilateral 1-RM test (at the flexor and extensor machine). After the test application, the data were analyzed and the mean values for the ratio between agonist/antagonist found were 52.34 percent (±9.72) for men and 43.19 percent (±5.82) for women (which were significantly different between groups). The values found in the present study may be used as reference for asymptomatic individuals with similar age.

Efeitos agudos do alongamento: uma comparação entre as técnicas de facilitação neuromuscular proprioceptiva e energia muscular / Immediate effects of the stretching: a comparison between proprioceptive neuromuscular facility and muscular energy thecniques

As técnicas de alongamento são descritas pela literatura como uma das modalidades terapêuticas mais utilizadas devido a sua capacidade de aumentar a flexibilidade dos tecidos moles, favorecendo um bom desempenho osteomuscular. O alongamento associado à técnica Facilitação Neuromuscular Proprioceptiva (FNP) tem sido exaustivamente pesquisado, sendo apontado como o que apresenta os melhores resultados. Contudo, poucos estudos têm dado ênfase sobre a Técnica de Energia Muscular (TEM). O objetivo do presente estudo foi comparar os efeitos imediatos de duas técnicas de alongamento baseadas na inibição ativa, a FNP e a TEM. Participaram da pesquisa 98 voluntários (65 homens e 33 mulheres), distribuídos aleatoriamente em 3 grupos: FNP, TEM e controle. As medidas antes e depois foram comparadas pela ANOVA univariada. As análises estatísticas mostraram que ambas as técnicas foram significativamente mais efetivas do que o grupo controle (p<0,05), porém, a técnica FNP apresentou maiores ganhos na ADM de quadril (8,8º±5,0) comparado à TEM (7,0º±6,8). Nossos resultados indicaram que as duas técnicas induziram respostas semelhantes na flexibilidade dos músculos isquiotibiais, sugerindo que ambas podem ser efetivas num programa de alongamento. Mais estudos são necessários para confirmar a eficiência da TEM, sobretudo os efeitos adaptativos em longo prazo.

The stretching techniques are described by the literature as one of the therapeutic modalities more used due to your capacity to increase the flexibility of the soft tissues favoring a high osteomuscular performance. The Proprioceptive Neuromuscular Facility (PNF) stretching has been exhaustly researched, being pointed as that presents the best results. However, few studies have been giving emphasis on the Muscle Energy Technique (MET). The objective of the present study was to compare the immediate effects of two techniques of stretching based on the inhibition active, PNF and MET. 98 volunteers participated of the research (65 men and 33 women), randomized allocating in 3 groups: PNF, MET and control. The measures pre and pos-treatment were compared by the ANOVA oneway. The statistical analysis showed that both techniques were significantly more effective than the control group (p < 0.05), however, the participants receiving PNF technique showed a greater improvement in hip ROM (8.8º±5.02) compared with those receiving MET (7.0º±6.8). Our results showed that the two techniques induced similar improvements in the flexibility of the hamstrings, suggesting that both can be effective in a program of stretching. More studies are necessary to confirm the efficiency of the MET, especially the adaptative effects in long term.

Influência da freqüência de alongamento utilizando facilitação neuromuscular proprioceptiva na flexibilidade dos músculos isquiotibiais / Influence of the stretching frequency using proprioceptive neuromuscular facilitation in the flexibility of the hamstring muscles

A utilização de manobras de alongamento é um dos recursos mais utilizados na prática de reabilitação. Porém, alguns parâmetros, como a freqüência, não têm sido estudados quando se utilizam as técnicas de facilitação neuromuscular proprioceptiva (FNP). O objetivo deste estudo foi analisar a freqüência ótima visando aumentar a flexibilidade dos músculos isquiotibiais, medida pela amplitude ativa de extensão do joelho. Selecionaram-se 36 sujeitos do sexo feminino (média de idade (DP) de 21,7 (1,9) anos), com limitação da flexibilidade dos músculos isquiotibiais. Os sujeitos foram distribuídos aleatoriamente em quatro grupos (n = 9). Os três grupos de alongamento receberam a intervenção cinco dias por semana durante duas semanas consecutivas. O quarto grupo, que serviu como controle, não foi alongado. Os grupos de alongamento com FNP variaram quanto à freqüência em uma, três e seis manobras por sessão. Uma análise de variância (ANOVA) foi utilizada para as medidas iniciais e finais (p < 0,05). Em seguida, foi realizada uma análise post hoc por meio do teste de Tukey (p < 0,05). A análise estatística dos dados indicou que os grupos de alongamento tiveram ganho de amplitude significativo em relação ao grupo controle, mas não entre eles mesmos. Em relação à velocidade do ganho, os grupos que utilizaram três e seis manobras alongaram (p < 0,05) mais rapidamente que o grupo que utilizou apenas uma manobra. Conclui-se, portanto, não haver diferença em relação ao ganho tardio quando se utilizam uma, três ou seis manobras de alongamento com a técnica de sustentar-relaxar nos isquiotibiais.

Stretching techniques are one of the most used devices in rehabilitation practice. However, some parameters such as frequency have not been studied when proprioceptive neuromuscular facilitation (PNF) techniques are used. The purpose of this study was to analyze in the short and middle-terms the optimal frequency to increase hamstring muscle flexibility, measured by knee extension range of motion (ROM). Thirty-six female subjects were selected, (mean (SD) age 21.7 (1.9) years) with limited hamstring muscle flexibility. The subjects were randomly assigned to four groups (n = 9). The three stretching groups received the intervention five days a week for two consecutive weeks. The three PNF stretching groups alternated concerning frequency with one, three, and six maneuvers per session. Analysis of variance (ANOVA) was used for the first and final measures (< 0.05). A post hoc analysis using the Tukey test (< 0.05) was performed. Data indicated that the PNF stretching groups had a statistically significant ROM gain in relation to the control group, but not among themselves. Concerning gain velocity, the groups that used three and six maneuvers had faster stretching gains (p < 0.05) than the one that used only one maneuver. The results showed that there was no difference in relation to delayed gains when one, three or six stretching maneuvers were used with the hold-relax technique on hamstring muscles.

El uso de maniobras de alongamiento es uno de los recursos más utilizados en la práctica de rehabilitación. Sin embargo, algunos parámetros, como frecuencia, no se estudian cuando se utilizan las técnicas de facilitación neuromuscular propioceptiva (FNP). El objetivo de este estudio ha sido analizar la frecuencia óptima buscando aumentar la flexibilidad de los músculos isquio tibiales, medida por la amplitud activa de extensión de la rodilla. Se seleccionaron 36 individuos del sexo femenino (con edad media (DP) de 21,7 (1,9) años), con limitación de flexibilidad de los músculos isquio tibiales. Los individuos fueron distribuidos aleatoriamente en cuatro grupos (n = 9). Los tres grupos de alongamiento recibieron intervención cinco días por semana durante dos semanas consecutivas. El cuarto grupo que sirvió como control, no fue alongado. Los grupos de alongamiento con FNP variaron en relación a la frecuencia en una, tres y seis maniobras por sesión. Un análisis de varianza (ANOVA) se usó para las medidas iniciales y finales (p < 0,05). En seguida se utilizó un análisis post hoc por medio del test de Tukey (p < 0,05). El análisis estadístico de los datos indicó que los grupos de alongamiento tuvieron incremento de amplitud significativo en relación al grupo control, pero no entre ellos mismos. En relación a la velocidad de incremento, los grupos que utilizaron tres y seis maniobras alongaron (p < 0,05) más rápido que el grupo que utilizó apenas una maniobra. Se concluye, por tanto, que no hay diferencia en relación al incremento tardío cuando se utiliza una, tres, o seis maniobras de alongamiento con la técnica sustentar relajar en los isquios tibiales.

Results of ACL Reconstruction with Autologous Hamstrings Fixed by Two Bioabsorbable Cross Pins on the Femoral Side and a Bioabsorbable Interference Screw with Additional Fixation on the Tibial Side / 대한정형외과학회잡지

PURPOSE: To evaluate the clinical outcomes of an anterior cruciate ligament reconstruction using autologous hamstring tendons with stable fixation. MATERIALS AND METHODS: Seventy-six ACL reconstructions using autologous hamstring tendons were reviewed for an average of 16.5 months (Range, 12-35.6 months) postoperatively. All the patients were examined using standard clinical techniques and evaluated by stress radiography, Cybex(TM), Lysholm score, and International Knee Documentation Committee (IKDC) ratings. RESULTS: In all cases, there were no limitations in the range of motion. The mean Lysholm score was 72.9 preoperatively, which later improved to 91.1 postoperatively. According to the IKDC grade, 74 cases were categorized as 'normal' or 'nearly normal' postoperatively. In addition, the CybexTM study showed that at an angular velocity of 60degrees/sec, the strength deficit of the hamstrings decreased to 16% from 24% while the strength deficit of the quadriceps decreased to 27% from 31%. The mean side-to-side difference in stress radiography was 2.4 mm postoperatively. There was a single case of graft failure resulting from a deep infection. CONCLUSION: ACL reconstructions using autologous hamstrings using stable fixation techniques showed satisfactory results at the 16.5 months follow-up. However, further studies will be needed to confirm these findings over a longer follow-up period.

Arthroscopic ACL Reconstruction Using Quadrupled Hamstring Graft-Result of Stump Preserving Technique: Follow-up More Than 3 Years

PURPOSE: This article describes the technique for ACL reconstruction using hamstring grafts and looped sutures to preserve the tibial remnant of injured ACL effectively and reports the clinical results. MATERIALS AND METHODS: From Feb. 1995 to May 1996, fourteen injured ACL knees were treated with arthroscopic reconstruction using a quadrupled hamstring autograft. At the last follow-up(average 41 months), subjective and OBJECTIVE assessments were evaluated. Two proprioceptive function tests(motion and position sense) were performed and statistically analysed(paired t-test). Clinical results were recorded by HSS rating scale. RESULTS: Average HSS score was improved from 56.2(preoperative) to 92.1(last follow-up). At the last follow-up, the average anterior displacement(side to side difference) was measured 3.1mm on stress x-rays and 3.4mm on KT-1000 arthrometer(maximum manual force). No significant differences in mean proprio-ceptive values were found between both knees(p<0.05). CONCLUSTION: The clinical results were satisfactory and we suggest the possibility of preservation of the proprioception is increased if integrity of tibial stump of the ACL is preserved. Further supportive studies for the proprioception will be needed.

Emg-angle relationship during maximum voluntary movement / 体力科学

The purpose of this study is to investigate the relationship between joint angle and EMG activity concerning the human knee joint and hamstring muscles. Ten healthy males participated in this study. They performed maximum voluntary isokinetic knee flexion in the flexion angle range of 0° to 120° in a prone position on a table. The EMG activities of the semitendinosus, semimembranosus, long and short heads of the biceps femoris muscles were detected by bipolar fine wire electrode, and were integrated at knee flexion range intervals of 15° from 0° to 120°. After three months, the same examination was performed with the same subjects to confirm the reliability of this study. Results showed the mean peak isokinetic torque was attained from a 15° to 45° knee flexion angle. The EMG activities of the hamstring muscles varied with changes in the knee flexion angle. The integrated EMG of the semitendinosus, semimembranosus and short head of the biceps femoris muscles in-creased gradually as the knee flexion angle was increased from 0° to 105°. The peak integrated EMG of these three muscles was attained between 90° and 105° knee flexion in both trials. On the other hand, the peak integrated EMG of the long head of the biceps femoris muscle was largest at a knee angle ranging from 15° to 30°. Peak integrated EMG decreased when the knee flexion angle increased in both trials. These results show that the electromyographic activity of agonist muscles during maximum voluntary movement varied with the change of muscle length or joint angle. Therefore, it was considered that the relationship between joint torque and joint angle is influenced not only by the sarcomere length and the moment arm but also muscle activities of agonist muscles, even if the movement is performed with maximum effort.