Isokinetic peak torque and flexibility changes of the hamstring muscles after eccentric training: Trained versus untrained subjects

Abstract

ObjectiveThe aim of this study was to examine the effect of eccentric isotonic training on hamstring flexibility and eccentric and concentric isokinetic peak torque in trained and untrained subjects.MethodsSixty healthy subjects (mean age: 21.66 ± 2.64) were divided into three equal groups, each with 20 voluntary participants. Two experimental groups (untrained and trained groups) participated in a hamstring eccentric isotonic strengthening program (five days/week) for a six-week period and one control group that was not involved in the training program. The passive knee extension range of motion and hamstring eccentric and concentric isokinetic peak torque were measured at angular velocities 60° and 120°/s for all groups before and after the training period.ResultsTwo-way analysis of variance showed that there was a significant increase in the hamstring flexibility of the untrained and trained groups (25.65 ± 6.32°, 26.55 ± 5.99°, respectively), (p < 0.05) without a significant increase in the control group (31.55 ± 5.84°), (p > 0.05). Moreover, there was a significant increase in eccentric isokinetic peak torque of both the untrained and trained groups (127.25 ± 22.60Nm, 139.65 ± 19.15Nm, 125.40 ± 21.61Nm, 130.90 ± 18.71Nm, respectively), (p < 0.05) without a significant increase in the control group (109.15 ± 20.89Nm, 105.70 ± 21.31Nm, respectively), (p > 0.05) at both angular velocities. On the other hand, there was no significant increase in the concentric isokinetic peak torque of the three groups (92.50 ± 20.50Nm, 79.05 ± 18.95Nm, 92.20 ± 21.96Nm, 79.85 ± 18.97Nm, 100.45 ± 25.78Nm, 83.40 ± 23.73Nm, respectively), (p > 0.05) at both angular velocities. The change scores in the hamstring flexibility (06.25 ± 1.86°) and eccentric peak torque of the untrained group (16.60 ± 4.81Nm, 17.45 ± 5.40Nm, respectively) were significantly higher (p < 0.05) than those of the trained group (03.40 ± 1.14°, 9.90 ± 5.14Nm, 9.80 ± 7.57Nm, respectively), and the control group (00.90 ± 2.10°, 0.60 ± 2.93Nm, 1.40 ± 3.53Nm, respectively), at both angular velocities. Meanwhile, the change scores of the concentric peak torques of the three groups (1.15 ± 1.50Nm, −0.15 ± 2.16Nm, 1.35 ± 1.63Nm, 0.20 ± 2.95Nm, 0.60 ± 2.28Nm, −0.30 ± 2.25Nm) were statistically insignificant (p > 0.05).ConclusionAfter a six-week period of eccentric isotonic training, the hamstring eccentric peak torque and flexibility of trained and untrained groups improved without changes in the concentric peak torque. Moreover, the improvement of untrained subjects was higher than trained subjects. These findings may be helpful in designing the hamstring rehabilitation program.

Biceps Femoris Activation during Hamstring Strength Exercises: A Systematic Review

“…The isokinetic exercise category was the highest in BFlh activation of all the categories. Isokinetic exercises have been commonly used for testing, for predicting injury risk, and as criteria for return to play after both hamstring and anterior cruciate ligament injury [6,68,69]. However, results from this study also support its use as a potential form of hamstring strengthening due to its very high activation of the biceps femoris muscle.…”

The Effects of Eccentric Strength Training on Flexibility and Strength in Healthy Samples and Laboratory Settings: A Systematic Review

“…Additionally, the hand-search of references revealed 17 records, of which 6 were included in the systematic search of In the end a total of 18 studies met all inclusion criteria (Blazevich et al, 2007;Duclay et al, 2009;Potier et al, 2009;Guilhem et al, 2013;Franchi et al, 2014;Sharifnezhad et al, 2014;Coratella et al, 2015;Timmins et al, 2016b;Bourne et al, 2017;Seymore et al, 2017;Abdel-Aziem et al, 2018;Kay et al, 2018;Ribeiro-Alvares et al, 2018;Duhig et al, 2019;Delvaux et al, 2020;Marušič et al, 2020;Benford et al, 2021;Uysal et al, 2021) and were included in this systematic review.…”

“…Presented in Table 2, the number of participants ranged from n = 12 (Franchi et al, 2014) to n = 60 subjects (Abdel-Aziem et al, 2018). Samples' mean age ranged from 19 (Kay et al, 2018) to 28 years (Potier et al, 2009;Seymore et al, 2017).…”

Efectividad de los ejercicios nórdicos sobre la incidencia de lesiones de isquiotibiales en futbolistas profesionales y amateur masculinos entre los 15 y 41 años. Revisión sistemática

“…Estos se vuelven más susceptibles a las lesiones a causa de la edad, la presencia de lesiones previas y la arquitectura muscular, la fatiga, la flexibilidad, la fuerza estabilizadora lumbo-pélvica y principalmente por disminución de la fuerza excéntrica (8). Esta última juega un rol importante durante la carrera, siendo de gran importancia, no sólo para soportar y desacelerar la extensión de la rodilla durante la fase de oscilación tardía, sino también para equilibrar la fuerza isocinética del miembro inferior contralateral (9).…”

“…En este contexto, la evidencia actual sobre los efectos de los ejercicios nórdicos sobre la incidencia de lesiones de isquiotibiales se mantiene heterogénea. A pesar de la existencia de algunos estudios que sugieren la inclusión de ejercicios de fortalecimiento excéntrico en los programas de prevención de lesiones de isquiotibiales para disminuir su incidencia (3,9), los efectos de los ejercicios nórdicos por sí solos aún no han sido abordados de manera específica. Adicionalmente, se requiere clarificar la relevancia de este tipo de ejercicios en adultos y adolescentes, dado que las edades entre los 15 y los 40 años se caracterizan por ser de mayor exigencia competitiva, además de ser por sí mismas un factor de riesgo (8), demostrando que se requiere la verificación en cuanto a la efectividad y utilidad de estos ejercicios en específico para la disminución de la incidencia de lesión en los músculos isquiotibiales.…”