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Can low gluteus maximus activation during sprinting predict hamstring strain injury risk?

The study: Schuermans, J., Danneels, L., Van Tiggelen, D., Palmans, T., & Witvrouw, E. (2017). Proximal Neuromuscular Control Protects Against Hamstring Injuries in Male Soccer Players: A Prospective Study With Electromyography Time-Series Analysis During Maximal Sprinting. The American Journal of Sports Medicine.

What did the researchers do?

The researchers measured the muscle activation of the hip and trunk muscles in the acceleration phase of sprint running, in order to assess whether it is related to the risk of incurring a hamstring strain injury, in amateur soccer players. Therefore, they measured the muscle activation of the external and internal obliques, thoracic erector spinae, lumbar erector spinae, gluteus maximus, medial hamstrings, and biceps femoris (bilaterally) in the front swing, stance, and backswing phases of gait during a 40m linear sprint on a running track, and then measured injuries over the subsequent 1.5 seasons.

What happened?

The researchers found that non-injured athletes displayed higher gluteus maximus EMG amplitudes in the front swing phase, and higher trunk muscle EMG amplitudes in the backswing phase of the sprinting test. Receiver operating characteristic (ROC) curve analysis was performed to identify the cut-off points that were the best predictors of HSI. ROC curve analysis showed that gluteus maximus EMG amplitude in the initial part of the front swing phase was able to predict HSI with a sensitivity of 82% and a specificity of 74%, with a cut-off value at 145% of normalized EMG amplitude. In comparison with many other previous injury prediction tests, this is a very high score. In addition, ROC curve analysis showed that trunk muscle EMG amplitude in the terminal part of the backswing phase was able to predict HSI with a sensitivity of 60% and a specificity of 68%, with a cut-off value at 90% of normalized EMG amplitude.

What did the researchers conclude?

The researchers concluded that higher levels of gluteus maximus and trunk muscle activation in the flight phases of sprinting were prospectively associated with a lower risk of hamstring injuries during subsequent follow-up.

Does “practice-based evidence” show that the Nordic curl reduces hamstring strain incidence in high-level track sprinters?

The study: Sugiura, Y., Sakuma, K., Sakuraba, K., & Sato, Y. (2017). Prevention of hamstring injuries in collegiate sprinters. Orthopaedic Journal of Sports Medicine, 5(1).

What did the researchers do?

The researchers performed a retrospective analysis to compare the incidence of hamstring strain injury in 613 collegiate male sprinters over 24 years over 3 consecutive periods of time, in which different injury prevention methods were used. An incident of hamstring strain injury was defined as one that occurred during supra-maximal running training, and which led to >1 week without training or competition. The injury prevention program changed over the 24 seasons. Between 1988 – 1991 (period 1), the program involved only strength training; between 1992 – 1999 (period 2), the program involved both strength training and agility training; between 2000 – 2011 (period 3), the program involved strength training, agility training, and also added eccentric strength training (using the Nordic curl) and dynamic stretching. However, the sprint running training program did not change very substantially over the same period of time.

What happened?

The incidence of hamstring strain injury during supramaximal running training per athlete-periods was 137.9 for period 1, 60.6 for period 2, and 6.7 for period 3, indicating a very substantial reduction in injury incidence over the 24 seasons.

What did the researchers conclude?

The researchers concluded that the incidence of hamstring strain injury in track sprinters decreased over the successive 3 periods of time, during which (1) agility, and then (2) eccentric hamstring strength training and dynamic stretching were added to the injury prevention program.

Does Nordic hamstring curl training cause increases in muscle size and stiffness?

The study: Seymore, K. D., Domire, Z. J., DeVita, P., Rider, P. M., & Kulas, A. S. (2017). The effect of Nordic hamstring strength training on muscle architecture, stiffness, and strength. European Journal of Applied Physiology, 1-11.

What did the researchers do?

The researchers assessed the effects of long-term eccentric strength training using the Nordic hamstring curl on changes in muscle architecture, stiffness, knee flexion strength, and knee flexion angle of peak torque (APT), in recreationally active subjects. Subjects in the training group trained for 6 weeks using only the Nordic hamstring curl exercise in each workout. In addition, at each workout, both of the training and control groups performed 3 sets of static hamstring stretches (standing, seated, and supine), 6 times on each leg, for 30s per stretch.

What happened?

Nordic hamstring curl strength training produced only non-significant increases in fascicle length and pennation angle (1.23% and 9.56%, respectively) but the increases in muscle volume and physiological cross-sectional area were significant (10.45% and 12.25%, respectively). Shear modulus (passive stiffness), passive knee flexion torque, and both eccentric knee flexion torque and APT measured by the dynamometer did not change.

What did the researchers conclude?

The researchers concluded that the primary adaptation occurring within the biceps femoris (long head) after strength training using the Nordic hamstring curl was an increase in muscle volume.

Does Nordic hamstring curl training change hamstrings muscle fascicle length?

The study: Alonso-Fernandez, D., Docampo-Blanco, P., & Martinez-Fernandez, J. (2017). Changes in muscle architecture of Biceps Femoris induced by eccentric strength training with Nordic Hamstring Exercise.

What did the researchers do?

The researchers assessed the effects of long-term eccentric strength training with the Nordic hamstring curl, and of a subsequent detraining period, on the changes in muscle architecture, in recreationally active males. All subjects performed 8 weeks of eccentric strength training with the Nordic hamstring curl, followed by 4 weeks of detraining.

What happened?

After training, muscle fascicle length increased by 23.9%, muscle thickness increased by 7.7%, and pennation angle decreased by 14.8%. After the detraining period, muscle fascicle length then decreased by 12.1%, muscle thickness decreased by 6.6%, and pennation angle increased by 9.2%. All changes were significant.

What did the researchers conclude?

The researchers concluded that an 8-week period of eccentric strength training with the Nordic hamstring curl increases muscle fascicle length, increases muscle thickness, and decreases pennation angle. However, a detraining period of only 4 weeks reverses a large proportion of these adaptations.

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The post April Research Preview – Hamstring Strain Edition appeared first on Bret Contreras.

PubMed link here: A Multifactorial, Criteria-based Progressive Algorithm for Hamstring Injury Treatment

ResearchGate link HERE

Here is a YouTube video detailing the algorithm:

Now, onto the interview:

1. Wow Jurdan, what a study! Please tell me how, when, and why you came up with the original rationale behind this protocol?

It is a long story with several events that end up leading to this algorithm concept… But the most important arises about 10 years ago with a professional first division player who came to visit me after having suffered more than 14 hamstring injuries (summing both legs) and not having been able to play more than 5 matches per season in 3 years. It was an extreme case because despite having a contract the player wanted to end his football career. The fact is that after examining him, I was surprised to see that the strength of his hamstrings was huge and that contradicted in part what the literature commented about hamstring injury relation /probability related to a lack of eccentric strength. This, coupled with the fact that the player had strenuously trained eccentrically his knee flexors, made me think that I had to do something else as a physiotherapist. So, I decided to re-examine the player in detail and started training him considering those factors that I thought were related with his injury (and that were altered in this player) and from the interaction of the different body segments that acted on sprint mechanics. With all this I designed a specific program for the player (only once every 2 weeks 2 specific eccentric exercises 2×3 reps). The player did not get injured again, renewed his contract and played almost every game during the following 4 seasons. The same thing I have seen afterwards in several complex cases I was consulted for. All this led me to start thinking about the idea of ​​INDIVIDUALIZATION and customization for the treatment of the hamstring injury and that perhaps while most of the players (as the general evidence pointed) needed to work on strength-related factors (mainly eccentrics) others did not and had to focus on other factors.

2. Why an algorithm and not a protocol. What is the difference?

Such a structure had the necessary flexibility that allowed me to express my concern at that time in relation to the multifactorial origin of the pathology and the need to customize it to each patient. While a fixed and rigid protocol did not allow me to assess the different factors and forced me to work without references, and assume that with that I would solve all the problems of the patient. I didn’t want to rehab machines I wanted to treat individual persons. An algorithm is nothing more than a systematic process consisting of a sequence of steps, each step depending on the outcome of the previous one in order to solve a complex problem such as a hamstring tear or make decisions related to RTP. The only thing we did was to configure the different steps according to the different risk factors, tissue repair biology and a detailed analysis of injury mechanism…. But be careful!! This is an open and flexible structure that must adapt and incorporate future research findings of course. We tried to create a process that is adaptable over time. I think this type of concept fits better and is exportable to the treatment of most sports injuries not only hamstrings.

3. So, this experiment essentially tested the theory proposed in your previously published article (HERE is a link to the full PDF: Hamstring Strain Injuries – Are We Headed in the Right Direction)?

As I said before, the structure and concept has been preserved since its first publication in 2010 but has already evolved. Science changes thanks to the great work of our peers and the algorithm therefore also changes. New criteria have been incorporated according to the new investigations of colleagues and to our work in the last years with special emphasis on the analysis of sprint mechanics, having the pleasure of working with JB Morin and collaborators, authentic trailblazers in this area of ​​knowledge. For us it is very important to correct the altered factors but also at the same time that the player develops their performance. That is very well reflected in our favourite sentence in relation to the rehabilitation of the hamstring: “Prepare and repair”. In summary, we could say that this work is a compendium of all the experiences and learning of my last years in relation to hamstrings and the complex task of understanding sprint in depth.

4. You have talked about criteria but what principles have you followed for the design of the content, its progression and periodization …?

Basically, what we have done is a detailed analysis of each factor and its specific role in the different injury mechanisms and also in each phase of each injury mechanism where they can have different functions. From there the progression and design for each factor has been designed based on own and individual principles. Ex: knowing that the abdominal oblique musculature works concentrically during normal gait but eccentrically during sprinting, we have designed tasks and progressions accordingly… For the glutei, different tasks have been designed according to the torque -angle relationship of each exercise in order to cover all their roles during sprinting (I had a good teacher called Contreras on this) and for example in the design of how hamstrings work we rely on our work about activation / damage of different exercise published a few years ago with MRI (2012) in order to stimulate different muscles and portions and we progress through increased muscle length.

Anyway, sure there are many more exercises, more beautiful ones, so this is just an example.

Another novelty lies in the periodization and design of the content. For example, based on our clinical experience and muscular physiology, we decided to incorporate both very early eccentric exercises (as tolerated by the patient, with mild discomfort allowed) and running (mild discomfort and more vertically oriented in case of PAIN). However, during the last phase (functional phase) we did not allow to match during the same workout strength training with sprints and that´s why we propose a periodization by blocks of 3 days consisting of Day 1: sprint oriented tasks Day 2: strength and plyometric oriented tasks Day 3: mobility, lumbopelvic control and manual therapy.

Also note that for the first time and I think it was necessary in the field of physiotherapy, we tried to take into account the design of volumes and intensities given the increasing importance and relationship that is being observed with regard to injuries. However, it is our approach and a first step opened to change because it is difficult to propose magic recipes.

5. Please summarize the findings of this study in layman’s terms so that coaches can understand it.

It could be summarized as saying that an individualized intervention that works (to the intensity and marked volumes) and accounts for both the different risk factors of hamstring injury and sprint performance may be more effective in terms of re-injuries and performance, although moderately slower (2 days on average) than a standardized protocol that does not account for the evolution of the player and only focuses on 1 or 2 risk factors.

6. What does this study add and why is so important for practitioners?

The main novelties are:

– Multifactorial and individualized approach

– Detailed program (intensity and volumes) and periodization on the last phase (functional phase) prior to return to sport (day 2: Strength, Day 3: manual therapy, mobility and lumbopelvic control)

– Early eccentrics (as tolerated with mild discomfort allowed) and running (more vertically oriented in case of PAIN but not mild discomfort)

– Sprint performance oriented (running drills, ankle stabilizer / stiffness training, resisted sled…)

– Assessment of sprint acceleration mechanical outputs like horizontal ground reaction force and power

Given the poor prognostic value of MRI shown in the latest research I think that practitioners can use our algorithm as a reference framework and a guide if the injury is a grade 1 or 2, because they will introduce it in the work system which will in turn mark the gravity (costing more or less depending on criteria and phases) and will evolve in a safe way according to the injury and athlete characteristics in a specific and individual way, having a customized program for their athlete.

7. Moving forward, do you think that this approach can apply to prevention?

I think so, that is its natural evolution since the origin of an injury can be explained by different causes and specific interactions to each person. In fact, this is what I do every day in consulting with soccer teams: Individualize prevention by analyzing each player’s particularities and those of the injury to prevent. The prevention feature will be difficult to test in research because of the tremendous work involved and the difficulty of its design but the door is open and it is clear that it is part of the future. In my opinion we have to move beyond the limitations inherent to the current reductionist model used to study hamstring injuries. We must understand better how for example the cause that one factor is altered, is provoked by another factor etc.

Jurdan’s Published Works:

1. Hamstring strain injuries: are we heading in the right direction?
2. Hamstring injury prevention: Contributions of biomechanics
3. Athletic injury prevention: Determinants of sprint performance
4. Rating of muscular and respiratory perceived exertion in professional soccer players
5. A return-to-sport algorithm for acute hamstring injuries
6. Negative Associations between Perceived Training Load, Volume and Changes in Physical Fitness in Professional Soccer Players
7. Muscle and intensity based hamstring exercise classification in elite female track and field athletes: implications for exercise selection during rehabilitation
8. Hamstring exercises for track and field athletes: injury and exercise biomechanics, and possible implications for exercise selection and primary prevention
9. Effects of hamstring-emphasized neuromuscular training on strength and sprinting mechanics in football players
10. Effects of different agility training programs among first-grade elementary school students
11. Sprint Acceleration Mechanics: The Major Role of Hamstrings in Horizontal Force Production
12. The use of MRI to evaluate posterior thigh muscle activity and damage during Nordic hamstring exercise
13. Nonuniform changes in MRI measurements of the thigh muscles after two hamstring strengthening exercises
14. Biomechanical and neuromuscular characteristics of male athletes: implications for the development of anterior cruciate ligament injury prevention programs
15. Prevention of anterior cruciate ligament injuries in sports. Part I: systematic review of risk factors in male athletes
16. Prevention of non-contact anterior cruciate ligament injuries in sports. Part II: systematic review of the effectiveness of prevention programmes in male athletes
17. Sex differences in proximal control of the knee joint
18. Short-term training effects of vertically and horizontally oriented exercises on neuromuscular performance in professional soccer players
19. Field monitoring of sprinting power-force-velocity profile before, during and after hamstring injury: two case reports
20. Effects of eccentric exercise on optimum length of the knee flexors and extensors during the preseason in professional soccer players
21. Contralateral leg deficits in kinetic and kinematic variables during running in Australian rules football players with previous hamstring injuries
22. Asymmetry after Hamstring Injury in English Premier League: Issue Resolved, Or Perhaps Not?
23. Progression of mechanical properties during on-field sprint running after returning to sports from a hamstring muscle injury in soccer players
24. Rectus femoris muscle injuries in football: a clinically relevant review of mechanisms of injury, risk factors and preventive strategies
25. Hamstring strain injuries: are we heading in the right direction?
26. In Response to Letter to the Editor
27. Relationships Between Sprinting, Agility, One- And Two-Leg Vertical And Horizontal Jump In Soccer Players
28. Muscle and ligament injuries in sports: future directions / Muscle and ligamentous injuries in sports. Further directions

The post Hamstring Strain Injury Rehabilitation (and Most Likely Prevention) Works Better When You Tailor the Approach to the Athlete Based on Multiple Criteria: an Interview with Jurdan Mendiguchia appeared first on Bret Contreras.

The post May Research Round-Up: Hamstring Strain Injury Prevention Edition appeared first on Bret Contreras.

The exercise has many names, including the Russian leg curl, Russian lean, Russian ham curl, kneeling Russian hamstring curl, Nordic ham curl, Nordic hamstrings, Nordic hamstrings lower, Nordic leg curl, Nordic reverse curl, glute-ham curl, bodyweight leg curl, natural hamstring curl, and bodyweight hamstring curl. The most common name used in the literature is the Nordic ham curl (NHC).

The Nordic Ham Curl (NHC)

These exercise variations typically involve kneeling on a pad and lowering under control while the ankles are held in place by a partner, a lat pulldown apparatus, a sit-up apparatus, a loaded barbell, a poor man’s glute-ham apparatus, or any other immovable object you can think of using. Here’s a video of my sister from several years ago busting out 3 reps.

NHC and Hamstring Strain Injury Prevention

I would guess that the NHC is one of the top ten most studied and referenced exercises in the literature, probably behind squats, Olympic lifts, bench press, push ups, lunges, and deadlifts. In fact, at the end of this article, you’ll see over 100 studies listed. The reason why it is so popular is due to the prevalence of hamstring strain injuries in sports and the belief that the NHC can help prevent them. The eccentric nature of the NHC is believed to increase hamstrings length and shift the maximum strength of the muscle toward longer muscle lengths, which is believed to be important in sports. For more information along these lines, please read:

Can eccentric training help prevent hamstring strains?

Questioning the NHC as a Hamstring Injury Prevention Method 

If you’re a strength coach or physical therapist, then you should definitely include the NHC in your arsenal. There’s a wealth of research behind it, and there’s no doubt that it can help prevent hamstring strains. Moreover, knee flexion torque is highly correlated with sprint speed, and the hamstrings contract to both extend the hips and flex the knees during sprint running (and this is vital during the window immediately before, during, and immediately after the foot strikes the ground). So knee flexion shouldn’t be omitted in sport training.

But before I delve further, I want to be very clear about something. Possessing high levels of eccentric hamstring strength does not guarantee that hamstring strains will not occur. In Hamstring strain injuries: are we heading in the right direction?, Mendiguchia et al. explain how hamstring strains are predicted by the interrelated nature between flexibility, strength, fatigue, core stability, architecture, and previous injury.

An athlete could possess sound levels of hamstring strength to absorb eccentric stress, sound levels of hamstring flexibility to lengthen sufficiently during high load activity, and sound levels of core stability to prevent aberrant pelvic motion, but still wind up with a hamstring strain due to excessive fatigue, a prior injury, or simply a skeletal anatomy or muscle architecture that lends itself to large strains on the hamstrings.

Furthermore, the NHC works primarily on knee flexion. In sports, the knee joints do not move independently from the hip joints; they work in concert with one another. Moreover, hip extension exercises stretch the hamstrings to a greater degree than knee flexion exercises. Therefore, it is very important to perform hip extension exercises as they will lead to a greater stretch in the hamstrings, and they are more specific to sport movement.

The NHC as a Hamstrings Builder

Can the NHC pack on serious hamstrings muscle mass? I believe it can. Take a look at a study conducted by Ebben et al. which showed that NHCs (in this study they were called Russian Curls or RCs) outperformed seated leg curls, stiff leg deadlifts, single leg stiff leg deadlifts, good mornings, and squats in hamstring EMG activity.

As you can see, the NHC is no joke. Now, there are several articles in the literature investigating hamstring EMG activity, and they show conflicting results, probably because hamstring activation is highly influenced by the precise placement of the electrodes along the length of the muscles. At any rate, the NHC undoubtedly leads to high levels of hamstring muscle activation and should be included in a comprehensive hamstring strengthening protocol, especially in conjunction with other exercises such as Romanian deadlifts (RDLs), glute ham raises (GHRs), and lying leg curls. RDLs, GHRs, and NHCs are well-suited for producing high levels of tension and damage, whereas lying leg curls are well-suited for producing high levels of metabolic stress.

The Band Assisted Nordic Ham Curl: A Better Alternative

In this article, I’d like to impress upon you what I believe is a more effective NHC variation compared to the standard exercise. The vast majority of lifters and athletes are not strong enough to adequately control the lowering portion of the exercise throughout the entire range of motion (ROM). Almost inevitably, athletes lower their bodies under control during the first half of the movement and then sink like a ship during the second half of the movement. This rapid descent is accompanied by a sharp decline in muscle activity.

To prevent this occurrence, the lifter can simply use a band to provide assistance, which kicks in more and more as the lifter descends into the latter portion of the movement. This is importance since the torque angle curve of the NHC is sharp such that the most torque out of the knee flexors is required at the end of the movement when the muscle is lengthened (but it’s important to realize that in a NHC, the hamstrings don’t even reach resting length at their maximum stretch).

Of course, not every athlete needs the band assisted version of the NHC. Take a look HERE at former NFL athlete Adam Archuleta – skip to the 2 minute and 32 second mark and watch Adam bust out NHCs with ease. But guys like Adam are the exception, not the norm.

In the video below, you can see that I’m able to control my body throughout the entire range of motion. In fact, I don’t even have to use my arms to “push up” and provide assistance.

I hope that you give this variation a try, I think you will find it to be more effective than the traditional version, at least until you build up enough strength to sufficiently control your bodyweight during the eccentric phase without the use of bands.

Research on Nordic Ham Curls

Below is a list of over 100 linked journal articles that investigate, program, discuss, or recommend the Nordic Ham Curl exercise.

A 10-week randomized trial comparing eccentric vs. concentric hamstring strength training in well-trained soccer players.

Effects of a low volume injury prevention program on the hamstring torque angle relationship.

Medial hamstring muscle activation patterns are affected 1-6 years after ACL reconstruction using hamstring autograft.

Incidence, risk, and prevention of hamstring muscle injuries in professional rugby union.

Human hamstring muscles adapt to eccentric exercise by changing optimum length.

Hamstring activation during lower body resistance training exercises.

Effect of timing of eccentric hamstring strengthening exercises during soccer training: implications for muscle fatigability.

Preventive effect of eccentric training on acute hamstring injuries in men’s soccer: a cluster-randomized controlled trial.

The use of MRI to evaluate posterior thigh muscle activity and damage during nordic hamstring exercise.

Kinematic and electromyographic analysis of the Nordic Hamstring Exercise.

A novel device using the Nordic hamstring exercise to assess eccentric knee flexor strength: a reliability and retrospective injury study.

The preventive effect of the Nordic hamstring exercise on hamstring injuries in amateur soccer players: study protocol for a randomised controlled trial.

Effectiveness of injury prevention programs on developing quadriceps and hamstrings strength of young male professional soccer players.

Risk factors, testing and preventative strategies for non-contact injuries in professional football: current perceptions and practices of 44 teams from various premier leagues.

Eccentric Hamstring Strength and Hamstring Injury Risk in Australian Footballers.

The Effect of Previous Hamstring Strain Injuries on the Change in Eccentric Hamstring Strength During Preseason Training in Elite Australian Footballers.

Prevention of hamstring strains in elite soccer: an intervention study.

The Validity of the Nordic Hamstring Lower as a Field-Based Assessment of Eccentric Hamstring Strength.

Evidence-based treatment of hamstring tears.

‘Nordic’ hamstrings exercise – engagement characteristics and training responses.

Effectiveness of injury prevention programs on developing quadriceps and hamstrings strength of young male professional soccer players.

Exercises to prevent lower limb injuries in youth sports: cluster randomised controlled trial.

The Assisted Nordic Hamstring Curl.

A return-to-sport algorithm for acute hamstring injuries.

Hamstring injury occurrence in elite soccer players after preseason strength training with eccentric overload.

The Nordic Eccentric Hamstring Exercise for Injury Prevention in Soccer Players.

Effectiveness of a neuromuscular and proprioceptive training program in preventing anterior cruciate ligament injuries in female athletes: 2-year follow-up.

Training Considerations after Hamstring Injury in Athletes.

The Effects of Injury Preventive Warm-Up Programs on Knee Strength Ratio in Young Male Professional Soccer Players

F-MARC – Football for Health 15 years of F-MARC Research and Education 1994 – 2009

Isokinetic strength effects of FIFA’s “The 11+” injury prevention training programme.

Performance Enhancement Effects of Fe´de´ration Internationale de Football Association’s “The 11+” Injury Prevention Training Program in Youth Futsal Players.

The Impact of the FIFA 11+ Training Program on Injury Prevention in Football Players: A Systematic Review.

Effects of the 11+ and Harmoknee Warm-up Programs on Physical Performance Measures in Professional Soccer Players.

The effectiveness of different exercises protocols to prevent the incidence of hamstring injury in athletes

The Effects of Comprehensive Warm-Up Programs on Proprioception, Static and Dynamic Balance on Male Soccer Players

How and When to Use an Injury Prevention Intervention in Soccer

The effectiveness of neuromuscular warm-up strategies, that require no additional equipment, for preventing lower limb injuries during sports participation: a systematic review

Strength and power characteristics in English elite rugby league players.

Altering the length-tension relationship with eccentric exercise : implications for performance and injury.

At return to play following hamstring injury the majority of professional football players have residual isokinetic deficits.

Kettlebell swing targets semitendinosus and supine leg curl targets biceps femoris: an EMG study with rehabilitation implications.

The role and implementation of eccentric training in athletic rehabilitation: tendinopathy, hamstring strains, and ACL reconstruction.

Preventing Hamstring Injuries in Sport.

Why hamstring eccentrics are hamstring essentials.

Recurrent hamstring muscle injury: applying the limited evidence in the professional football
setting with a seven-point programme

At return to play following hamstring injury the majority of professional football players have residual isokinetic deficits

Bridging the Gap Between Content and Context: Establishing Expert Consensus on the Content of an Exercise Training Program to Prevent Lower-Limb Injuries.

Biceps Femoris Long-Head Architecture: A Reliability and Retrospective Injury Study.

Clinical and morphological changes following 2 rehabilitation programs for acute hamstring strain injuries: a randomized clinical trial.

Comprehensive warm-up programme to prevent injuries in young female footballers: cluster randomised controlled trial

Conceptual Framework for Strengthening Exercises to Prevent Hamstring Strains.

Core stability training for injury prevention.

Development and validation of a questionnaire (FASH—Functional Assessment Scale for Acute Hamstring Injuries): to measure the severity and impact of symptoms on function and sports ability in patients with acute hamstring injuries.

Differences in activation patterns of knee flexor muscles during concentric and eccentric exercises.

Eccentric exercise: mechanisms and effects when used as training regime or training adjunct.

Eccentric exercise training: modalities, applications and perspectives.

Eccentric Muscle Actions and How the Strength and Conditioning Specialist Might Use Them for a Variety of Purposes.

Eccentric training for prevention of hamstring injuries may depend on intervention compliance: a systematic review and meta-analysis.

Effect of hip flexion angle on hamstring optimum length after a single set of concentric contractions.

Effects of a 10-week in-season eccentric overload training program on muscle injury prevention and performance in junior elite soccer players.

Evidence based prevention of hamstring injuries in sport.

Examination and treatment of hamstring related injuries.

Hamstring exercises for track and field athletes – injury and exercise biomechanics, and possible implications for exercise selection and primary prevention.

Hamstring injury rehabilitation and prevention of reinjury using lengthened state eccentric training: a new concept.

Hamstring Strains: Basic Science and Clinical Research Applications for Preventing the Recurrent Injury.

Hamstring strain injuries: are we heading in the right direction?

Hamstring strain injuries: factors that lead to injury and re-injury.

Interventions for preventing hamstring injuries.

Prevention of injuries among male soccer players: a prospective, randomized intervention study targeting players with previous injuries or reduced function.

A pilot randomised controlled trial of eccentric exercise to prevent hamstring injuries in community-level Australian Football.

Hamstring Strain Prevention in Elite Soccer Players.

Strength deficits identified with concentric action of the hip extensors and eccentric action of the hamstrings predispose to hamstring injury in elite sprinters.

Influence of Hip-Flexion Angle on Hamstrings Isokinetic Activity in Sprinters.

Intrinsic risk factors for hamstring injuries among male soccer players: a prospective cohort study.

Lower eccentric hamstring strength and single leg hop for distance predict hamstring injury in PETE students.

Methods of Developing Power to Improve Acceleration for the Non-Track Athlete.

Neuromuscular training improves knee kinematics, in particular in valgus aligned adolescent team handball players of both sexes.

Risk factors for hamstring injuries in male soccer players: a systematic review of prospective studies.

Specific exercise effects of preventive neuromuscular training intervention on anterior cruciate ligament injury risk reduction in young females: meta-analysis and subgroup analysis.

Strength and Conditioning for Soccer Players.

Female Soccer: Part 2—Training Considerations and Recommendations

The Nordic Eccentric Hamstring Exercise for Injury Prevention in Soccer Players

Anterior Cruciate Ligament Injury Prevention for Female High School Athletes

Training Considerations after Hamstring Injury in Athletes

Hamstring Strains: Basic Science and Clinical Research Applications for Preventing the Recurrent Injury

The effect of 40 m repeated sprint training on physical performance in young elite male soccer players

The effect of 40-m repeated sprint training on maximum sprinting speed, repeated sprint speed endurance, vertical jump, and aerobic capacity in young elite male soccer players

The effect of an eccentrically-biased hamstring strengthening home program on knee flexor strength and the length-tension relationship.

The effect of combined resisted agility and repeated sprint training vs. strength training on female elite soccer players.

The effectiveness of different exercises protocols to prevent the incidence of hamstring injury in athletes.

The effects of isometric and isotonic training on hamstring stiffness and anterior cruciate ligament loading mechanisms.

The effects of resistance training prioritization in NCAA Division I Football summer training.

The Order of Concurrent Training Does not Affect Soccer-Related Performance Adaptations.

The role of neuromuscular inhibition in hamstring strain injury recurrence.

Hamstring injuries: risk assessment and injury prevention.

Which screening tools can predict injury to the lower extremities in team sports?: a systematic review.

Neuromuscular training improves performance and lower-extremity biomechanics in female athletes.

The effects of plyometric vs. dynamic stabilization and balance training on power, balance, and landing force in female athletes.

Methodological approaches and rationale for training to prevent anterior cruciate ligament injuries in female athletes

Does eccentric training of hamstring muscles reduce acute injuries in soccer?

Eccentric hamstring muscle training can prevent hamstring injuries in soccer players.

Acute hamstring injuries in Swedish elite football: a prospective randomised controlled clinical trial comparing two rehabilitation protocols.

The post The Nordic Ham Curl: A Staple Exercise for Athletes appeared first on Bret Contreras.

If you train in a garage gym, then chances are you resort mostly to squat and deadlift variations for leg development. While many lifters, especially those who train at commercial gyms, would be much better off if they went this route and solely focused on progressive overload with squat and deadlift variations, at least for a certain period of time, there are times when adding in leg isolation movements is a good idea. Feeling the burn and acquiring a pump is good for muscular hypertrophy, especially when performed in tandem with heavy compound lifting, and all bodybuilders do it.

The problem is, performing leg extension and leg curl movements is not always easy in the garage gym setting. Many in this circumstance resort to sissy squats and Nordic ham curls, which is perfectly fine, but there are indeed ways to perform isolated knee flexion and extension exercises in the garage gym. Granted, specialized equipment is often needed, but the point of this article is to showcase some ideas and spark creativity. With some ingenuity, chances are that you can figure something out in your garage gym just like we did.

I sometimes throw a couple of sets of a couple of these exercises in at the end of a heavy leg workout to add additional time under tension and metabolic stress.

Here are pics of the individual movements:

Band Leg Extensions off the GHD

Gliding Leg Curls

Band Lying Leg Curls

Single Leg Band Lying Leg Curls

Supine Band Leg Extensions

Leg Extensions off the Reverse Hyper

Band Seated Leg Curl

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