Search results for "Hamstring injury"

Region-dependent hamstrings activity in Nordic hamstring exercise and stiff-leg deadlift defined with high-density electromyography

2018

Recent studies suggest region-specific metabolic activity in hamstring muscles during injury prevention exercises, but the neural representation of this phenomenon is unknown. The aim of this study was to examine whether regional differences are evident in the activity of biceps femoris long head (BFlh) and semitendinosus (ST) muscles during two common injury prevention exercises. Twelve male participants without a history of hamstring injury performed the Nordic hamstring exercise (NHE) and stiff-leg deadlift (SDL) while BFlh and ST activities were recorded with high-density electromyography (HD-EMG). Normalized activity was calculated from the distal, middle, and proximal regions in the e…

Superimposing hip extension on knee flexion evokes higher activation in biceps femoris than knee flexion alone.

2021

Hamstring muscle function during knee flexion has been linked to hamstring injury and performance. However, it is unclear whether knee flexion alone (KF) requires similar hamstring electromyography (EMG) activity pattern to simultaneous hip extension and knee flexion (HE-KF), a combination that occurs in the late swing phase of sprinting. This study examined whether HE-KF maximal voluntary isometric contraction (MVIC) evokes higher (EMG) activity in biceps femoris long head (BFlh) and semitendinosus (ST) than KF alone. Effects of shank rotation angles were also tested. Twenty-one males performed the above-mentioned MVICs while EMG activity was measured along ST and BFlh. Conditions were com…

Individual Region- and Muscle-specific Hamstring Activity at Different Running Speeds

2019

Introduction \ud Hamstring strain injuries typically occur in the proximal biceps femoris long head (BFlh) at high running speeds. Strain magnitude seems to be the primary determinant of strain injury, and may be regulated by muscle activation. In running, BFlh strain is largest in the proximal region, especially at high speeds. However, region-specific activity has not been examined. This study examined the proximal–distal and intermuscular activity of BFlh and semitendinosus (ST) as a function of increasing running speed.\ud \ud Methods \ud Thirteen participants ran at steady speeds of 4.1 (slow), 5.4 (moderate), and 6.8 m·s−1 (fast) on a treadmill. Region- and muscle-specific EMG activit…

High-density electromyography activity in various hamstring exercises

2019

Proximal-distal differences in muscle activity are rarely considered when defining the activity level of hamstring muscles. The aim of this study was to determine the inter-muscular and proximal-distal electromyography (EMG) activity patterns of hamstring muscles during common hamstring exercises. Nineteen amateur athletes without a history of hamstring injury performed 9 exercises, while EMG activity was recorded along the biceps femoris long head (BFlh) and semitendinosus (ST) muscles using 15-channel high-density electromyography (HD-EMG) electrodes. EMG activity levels normalized to those of a maximal voluntary isometric contraction (%MVIC) were determined for the eccentric and concentr…

2020

This study aimed to explore the acute effects of static stretching on the musculotendinous properties of two hamstring muscles. Twelve male volunteers underwent two testing sessions. One session was dedicated to the evaluation of the semitendinosus muscle before (PRE) and after (POST) static stretching (five sets of 30-s stretching), and the other session similarly explored the long head of biceps femoris muscle. In addition to the displacement of the myotendinous junction (MTJ), passive torque and maximal voluntary isometric torque (MVIT) were evaluated. MVIT (−8.3 ± 10.2%, p = 0.0036, d = 0.497) and passive torque (−28.4 ± 16.9%, p = 0.0003, d = 1.017) were significantly decreased POST st…

Causas de la lesión de isquiosurales en fútbol: Una revisión bibliográfica desde las etapas formativas hasta la profesional

2021

espanolObjetivos: identificar las principales causas de lesion de isquiosurales en las diferentes etapas de formacion, desde la etapa sub-12 hasta la etapaprofesional, y establecer la influencia de la lesion previa de isquiosurales como causa principal de sufrir una nueva lesion.Metodo: la busqueda bibliografica se realizo en Dialnet, Pubmed, Web of Science, Scopus y SportDISCUS, entre las fechas de enero de 2010 hasta mayo de2020.Resultados: la busqueda concluyo que el patron de lesion isquiosural mas concurrido es el de jugador de edad avanzada, con mayores valores de fuerza ymenores valores de flexibilidad, y con un mayor grado de anteversion pelvica. El envejecimiento, los movimientos c…

Comparison of Electromyographic Activity During Hip Extension Exercises Under Gravitational or Inertial Loading Conditions.

2021

Background: Hamstring injury prevention programs include strengthening, especially eccentric exercises using both gravitational and inertial loading. Inertial exercises are characterized by eccentric contractions of high intensity and velocity. This study aimed to analyze the muscular activation of the biceps femoris (BF), semitendinosus (ST), gluteus maximus (GM), and gracilis (GC) muscles during hip extension (HE) exercises performed under both gravitational and inertial loading conditions. Hypothesis: Inertial training would generate a greater activation of HE muscles than gravitational training. Study Design: Cross-sectional study. Level of Evidence: Level 4. Methods: Fifteen resistance…

Effects of an eccentric training programme on hamstring strain injuries in women football players

2015

Summary Study aim: to test the hypothesis that an eccentric training programme applied on women football players would reduce the hamstring injury rate by improving thigh muscle balance and, particularly, hamstring strength. Material and methods: three football teams were recruited for this randomised controlled trial. They played in the first and second divisions in Spain. Players were randomised within clubs either to the intervention (eccentric exercises, n = 22) or control (control exercises, n = 21) groups, and randomisation was stratified according to previous history of thigh strains. The eccentric programme was divided into 3 phases, and each phase was composed of 7 weeks. Complianc…

Range of Motion and Injury Occurrence in Elite Spanish Soccer Academies. Not Only a Hamstring Shortening-Related Problem.

2020

Sanz, A, Pablos, C, Ballester, R, Sanchez-Alarcos, JV, and Huertas, F. Range of motion and injury occurrence in elite Spanish soccer academies. Not only a hamstring shortening-related problem. J Strength Cond Res 34(7): 1924-1932, 2020-Age-related development of range of motion (ROM) during an active hip flexion (active straight leg raise) and its relationship with hamstring injury occurrence were examined in 1657 young male soccer players (9-18 years of age). Age-related differences in ROM showed a significant decrease from U9 to U11 (p = 0.001), from U11 to U13 (p0.005), and from U9 to U13 (p0.001), whereas ROM increased from U13 to U15 and from U13 to U18 (both p's0.001). Interestingly, …