Context: Hamstrings strains are common and debilitating injuries in many sports. Most hamstrings exercises performed at an inadequately low hip-flexion angle because this surpasses 70° the end of sprinting leg's swing phase, when most occur. Objective: To evaluate influence various angles on peak torques knee flexors isometric, concentric, eccentric contractions hamstrings-to-quadriceps ratio. Design: Descriptive laboratory study. Setting: Research laboratory. Patients Other Participants Ten...

Most common preventive eccentric-based exercises, such as Nordic hamstring do not include any hip flexion. So, the elongation stress reached is lower than during late swing phase of sprinting. The aim this study was to assess evolution architectural (fascicle length and pennation angle) functional (concentric eccentric optimum angles concentric peak torques) parameters following a 3-week resistance program performed at long (LML) vs. short muscle (SML). Both groups eight sessions 3-5 × 8...

The aim of this study was to investigate changes in running mechanics and spring-mass behaviour with fatigue induced by 5-hour hilly (5HHR). Running were measured pre- post-5HHR at 10, 12 14 km · h(-1) on an instrumented treadmill eight ultramarathon runners, sampled 1000 Hz for 10 consecutive steps. Contact (t(c) ) aerial (t(a) times determined from ground reaction force (GRF) signals used compute step frequency (f). Maximal GRF, loading rate, downward displacement the centre mass (Δz), leg...

The aim of study was to examine the effects world's most challenging mountain ultramarathon (Tor des Géants [TdG]) on running mechanics. Mechanical measurements were undertaken in male runners (n = 16) and a control group 8) before (PRE), during (MID), after (POST) TdG. Contact (tc) aerial (ta) times, step frequency (f), velocity (v) sampled. Spring-mass parameters peak vertical ground-reaction force (Fmax), downward displacement center mass (Δz), leg-length change (ΔL), (kvert) leg (kleg)...

To train hamstring muscle specifically to sprint, strengthening programs should target exercises associated with horizontal force production and high levels of activity. Therefore, the objectives this study were analyze correlation between capacities during sprinting exercises, compare activity these exercises. Fourteen track field regional level athletes performed two maximal 50-m sprints six exercises: Nordic without hip flexion, Upright-hip-extension in isometric concentric modalities,...

Clear decreases in horizontal force production capacity during sprint acceleration have been reported after hamstring injuries (HI) football players. We hypothesized that lower

We investigated postural control (PC) effects of a mountain ultra-marathon (MUM): 330-km trail run with 24000 m positive and negative change in elevation. PC was assessed prior to (PRE), during (MID) after (POST) the MUM experienced runners (n = 18; finish time 126±16 h) group 8) similar level sleep deprivation. Subjects were instructed stand upright on posturographic platform over period 51.2 seconds using double-leg stance under two test conditions: eyes open (EO) closed (EC). Traditional...

We aimed to describe hamstring muscle injury (HMI) history and specific training (HST) in elite athletes. A secondary aim was analyse the potential factors associated with in-championships HMI.

In the field of sport rehabilitation, an easy, valid, and reliable assessment maximal strength is crucial for efficient muscle rehabilitation. Classically, it performed on fitness equipment that not necessary available in field. Thera-Band has developed elastic bands with different resistances depending color band percentage its stretch. This may allow testing strength.To determine validity reliability maximal-strength knee flexors extensors using bands.Reliability study.22 healthy...

ObjectivesTo compare incidence rates of lower limb muscle injuries (LLMIs) and hamstring (HMIs) in 100 m, 200 m 400 sprints disciplines between finals, semi-finals heats international athletics championships.DesignProspective total population study.MethodsWe analysed in-competition LLMIs HMIs female male athletes during eight championships 2009 2022.ResultsLLMI HMI finals were significantly higher than for athletes. athletes.ConclusionsLLMI risk was compared to previous rounds championships.

Guex, KJ, Lugrin, V, Borloz, S, and Millet, GP. Influence on strength flexibility of a swing phase–specific hamstring eccentric program in sprinters' general preparation. J Strength Cond Res 30(2): 525–532, 2016—Hamstring injuries are common sprinters mainly occur during the terminal phase. Eccentric training has been shown to reduce injury rate by improving several risk factors. The aim this study was test hypothesis that an additional well-trained performed at commencement winter...

Context: A passive knee-extension test has been shown to be a reliable method of assessing hamstring tightness, but this does not take into account the potential effect gravity on tested leg. Objective: To compare an original with 2 adapted methods including gravity’s lower Design: Repeated measures. Setting: Laboratory. Participants: 20 young track and field athletes (16.6 ± 1.6 y, 177.6 9.2 cm, 75.9 24.8 kg). Intervention: Each subject was in randomized order 3 different methods: In one...

The Wim Hof breathing method (WHBM) combines periods of hyperventilation (HV) followed by voluntary breath-holds (BH) at low lung volume. It has been increasingly adopted coaches and their athletes to improve performance, but there was no published research on its effects. We determined the feasibility implementing a single WHBM session before repeated sprinting performance evaluated any acute ergogenic Fifteen amateur runners performed prior Repeated Ability Sprint Test (RAST) in comparison...

Context : The hamstrings are the most commonly injured muscle in sports and especially injury prone lengthened positions. Measuring knee strength such positions could be relevant to establish risk. Handheld dynamometry has been shown a valid, reliable, practical tool measure isometric clinically. aim of this study was assess validity reliability assessment with handheld dynamometer (HHD) at various lengths, by modifying hip angles during testing. Design Concurrent test–retest reliability....

Abstract The eccentric contraction mode was proposed to be the primary stimulus for optimum angle (angle at which peak torque occurs) shift. However, training range of motion (or muscle excursion range) could a as important. aim this study assess influence on hamstring length. It hypothesised that performing single set concentric contractions beyond optimal length (seated 80° hip flexion) would lead an immediate shift longer while it below (supine 0° not provide any Eleven male participants...

The final result in a 400 m hurdles race (400mH) is relative to the motor preparation, technique of clearing as well adopted strategy race, including temporal aspects (split times particular parts race) and spatial elements (the number strides taken between subsequent hurdles). objective study was identify an optimal for 400mH stride pattern split times. Data employed this were derived from results 273 races held during men’s finals international events (Olympic Games, World European...

It is well knows that postural control (PC) deteriorated with neuromuscular fatigue, altitude or sleep deprivation induced by a mountain ultra-marathon (MUM). Several regulatory mechanisms have also been reported during this type of event and the changes in PC at different points MUM remain unknown. The purpose study was to investigate time course an extreme MUM. We tested hypothesis alteration would not increase linearly. Methods: 16 participants (age 45.1 ± 9.6 years) were bipedaly on...

The Race Across AMerica (RAAM) is considered as one of the longest, and most difficult cycling races in world. It can be performed solo or relay two, four eight persons.The aim present study was to investigate several physiological, perceptual psychological responses before, during after RAAM a team amateur cyclists. Because logistics all demanding complex, crew members have followed same testing procedure.The main result that parameters were globally not altered greater extent cyclists than...