Search results for "hamstring"

Isokinetic strength and anaerobic power of elite, subelite and amateur French soccer players.

2001

Information about the influence of different practice levels on physical characteristics of a large number of soccer players is lacking. Therefore we assessed muscular strength and anaerobic power of elite, subelite and amateur soccer players to clarify what parameters distinguish the top players from the less successful. We tested 95 soccer players from the French first division (elite), second division (subelite), and amateurs and determined the isokinetic strength of the knee extensor and flexor muscles at angular velocities from -120 degrees x s(-1) to 300 degrees x s(-1). Vertical jump, 10 m sprint, 30 m sprint and maximum ball speed during shooting were also measured. The elite player…

REGIONAL DIFFERENCES IN BICEPS FEMORIS FASCICLE LENGTH AND PENNATION ANGLE AFTER A SIMULATED SOCCER MATCH

2017

Background Hamstring Strain Injuries (HSIs) represent 12% of all injuries in soccer players, and their incidence has increased in recent years. Between 53%-84% of HSIs involve the Biceps femoris muscle (BF). Recent studies have shown that soccer players with shorter BF fascicle length (FL) suffer more HSIs and exhibit regional differences in FL and pennation angle (PA) along BF. It is unclear whether there is any regional difference in the degree of change of these parameters after a soccer match. Objective Describe changes in BF muscle architecture after a simulated soccer match. Design Controlled laboratory study. Pre and Post single session. Setting Laboratory. Amateur Level. Participant…

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…

EMG amplitude of the biceps femoris during jumping compared to landing movements.

2013

Abstract Hamstrings injury is a common occurrence in athletic performance. These injuries tend to occur during a deceleration or landing task suggesting the negative work may be a key component in hamstrings injury. The purpose of this study was to investigate the muscular activity (EMG) of the biceps femoris (BF) in different phases (concentric vs. eccentric) of a Counter Movement Jump (CMJ), Squat Jump (SJ) and the Braking Phase (BP) of a landing task. Twelve female volleyball players performed 5 CMJs, SJs and BPs while surface EMG was recorded using a MuscleLab (BoscoSystemTM, Norway). EMG values were normalized to an maximal voluntary contraction. A repeated measures analysis of varianc…

RECRUITMENT OF BICEPS FEMORIS MUSCLE REGIONS AT DIFFERENT RUNNING SPEEDS

2017

Background The majority of hamstring strain injuries (HSIs) occur in the late swing phase of high-speed running when hamstrings work eccentrically. The proximal region of the biceps femoris (BF) seems to be the most common site of injury. Elongation of the fascicles in eccentric contractions is higher in the proximal region compared to the distal region of BF, but the neural background to this phenomenon is not clear. Objective To examine the region-specificity of BF muscle activity at different running speeds. Design Observational study. Running speeds were randomized. Setting Laboratory, amateur level. Participants Football players without acute injury/illness, and without HSI history wer…

Focusing on Increasing Velocity during Heavy Resistance Knee Flexion Exercise Boosts Hamstring Muscle Activity in Chronic Stroke Patients

2016

Background. Muscle strength is markedly reduced in stroke patients, which has negative implications for functional capacity and work ability. Different types of feedback during strength training exercises may alter neuromuscular activity and functional gains.Objective. To compare levels of muscle activity during conditions of blindfolding and intended high contraction speed with a normal condition of high-intensity knee flexions.Methods. Eighteen patients performed unilateral machine knee flexions with a 10-repetition maximum load. Surface electromyography (EMG) was recorded from the quadrics and hamstring muscles and normalized to maximal EMG (nEMG) of the nonparetic limb.Results. For the …

2020

Limited data are available regarding strength and endurance training adaptations to occupational physical performance during deployment. This study assessed acute training-induced changes in neuromuscular (electromyography; EMG) and metabolic (blood lactate, BLa) responses during a high-intensity military simulation test (MST), performed in the beginning (PRE) and at the end (POST) of a six-month crisis-management operation. MST time shortened (145 ± 21 vs. 129 ± 16 s, −10 ± 7%, p < 0.001) during the operation. Normalized muscle activity increased from PRE to POST in the hamstring muscles by 87 ± 146% (116 ± 52 vs. 195 ± 139%EMGMVC, p < 0.001) and in the quadriceps by 54 ± 81% (26 ± 8…

MRI evaluation to predict tendon size for knee ligament reconstruction.

2017

Background The aim of this study is to evaluate a possible correlation between specific anthropometric parameters and sizes of knee tendons commonly used for ACL reconstruction. We hypothesized that specific clinical and radiological knee measurements could be better tendon sizes predictors than age, gender, height and weight. Materials and methods 100 consecutive patients were enrolled and 77 patients met the inclusion criteria of the study. All patients underwent a MRI of the knee with a 1.5 T super conducting MR System. For each patient, anthropometric data such as gender, height, weight, body mass index (BMI) and knee circumference were recorded. Specific MRI knee measurements were perf…

Responsiveness of Electromyographically Assessed Skeletal Muscle Inactivity – methodological exploration and implications for health benefits

2022

Abstract Prolonged sedentary behaviour is detrimental to health due to low contractile activity in large lower extremity muscle groups. This muscle inactivity can be measured with electromyography (EMG), but it is unknown how methodological factors affect responsiveness longitudinally. This study aimed to rank 16 different EMG inactivity thresholds based on their responsiveness (absolute and standardized effect size, responsiveness) using data from a randomized controlled trial targeted at reducing and breaking up sedentary time (InPact, ISRCTN28668090). EMG inactivity duration and usual EMG inactivity bout duration (weighted median of bout lengths) were measured from large lower extremity …

Multifactorial individualised programme for hamstring muscle injury risk reduction in professional football: protocol for a prospective cohort study

2020

IntroductionHamstring muscle injuries (HMI) continue to plague professional football. Several scientific publications have encouraged a multifactorial approach; however, no multifactorial HMI risk reduction studies have been conducted in professional football. Furthermore, individualisation of HMI management programmes has only been researched in a rehabilitation setting. Therefore, this study aims to determine if aspecificmultifactorial and individualised programme can reduce HMI occurrence in professional football.Methods and analysisWe conducted a prospective cohort study over two seasons within the Finnish Premier League and compare the amount of HMI sustained during a control season to…