Hamstring injury management

[Warrimoo]

Hamstring strains are the most common non contact injuries sustained in all football codes and the incidence hasn’t changed significantly over the last 50 years or so despite extensive research into treatment and prevention. With the recent spate of hamstring injuries in the NRL I’d like to discuss causes , treatment and prevention of hamstring injuries.
Firstly a brief rundown of the anatomy . There are 3 hamstring muscles -biceps femoris (which has a long and short head), semimembranosis and semitendinosis. These muscles flex the knee and extend the hip. Even though the maximum load on these 3 muscles is roughly the same when the extended knee starts to flex (especially when sprinting), it is the long head of the biceps which is torn in the majority of cases. This is because the groups of muscle fibres (fascicles) of the biceps femoris long head are shorter than the other hamstring muscles and are more likely to tear when stretched . In fact the long head of biceps increases in length up to 12% when sprinting.
Hamstring tears can occur in the muscle,tendon or junction of the muscle and tendon. The higher the tear ,in general, the longer the recovery time as it usually involves the tendon (which has a relatively small blood supply. ) Scar tissue can form in these tears (from 6 weeks post injury up to even 6 months afterwards) and this can compromise the biomechanics of the area.
MRI is the modality of choice when assessing hamstring tears and helps when deciding when to return to the field. If you return despite an abnormal MRI (such as persistent oedema) there is an increased chance of re-injuring the same hamstring.The risk of re-injuring the same hamstring within a month or so of returning from a hamstring injury is fairly high because it takes 3 to 6 months to regain full strength in the injured hamstring.
Treatment for hamstring tears is fairly straightforward but it is the prevention of hamstring tears which generates the most discussion in the medical fraternity . I’ll discuss the best options in my next post .

 

[JenEagle]

Thanks very much. Unfortunately I’m a long time hamstring injury person myself.
I have just recovered from a grade 2. Took about 7 weeks.

 

[Waz13]

Over 50 hammy injuries in the nrl this year through 10 rounds.

 

[WiseyEagle]

In my athletic days under 13's I could run 100 metres in under 13 seconds and 200 metres under 30 seconds. Never had a hammy go in those days. These days, me skipping 10 metres would be a hammy hazard.

 

[The Who]

Hamstring strains are the most common non contact injuries sustained in all football codes and the incidence hasn’t changed significantly over the last 50 years or so despite extensive research into treatment and prevention. With the recent spate of hamstring injuries in the NRL I’d like to discuss causes , treatment and prevention of hamstring injuries.
Firstly a brief rundown of the anatomy . There are 3 hamstring muscles -biceps femoris (which has a long and short head), semimembranosis and semitendinosis. These muscles flex the knee and extend the hip. Even though the maximum load on these 3 muscles is roughly the same when the extended knee starts to flex (especially when sprinting), it is the long head of the biceps which is torn in the majority of cases. This is because the groups of muscle fibres (fascicles) of the biceps femoris long head are shorter than the other hamstring muscles and are more likely to tear when stretched . In fact the long head of biceps increases in length up to 12% when sprinting.
Hamstring tears can occur in the muscle,tendon or junction of the muscle and tendon. The higher the tear ,in general, the longer the recovery time as it usually involves the tendon (which has a relatively small blood supply. ) Scar tissue can form in these tears (from 6 weeks post injury up to even 6 months afterwards) and this can compromise the biomechanics of the area.
MRI is the modality of choice when assessing hamstring tears and helps when deciding when to return to the field. If you return despite an abnormal MRI (such as persistent oedema) there is an increased chance of re-injuring the same hamstring.The risk of re-injuring the same hamstring within a month or so of returning from a hamstring injury is fairly high because it takes 3 to 6 months to regain full strength in the injured hamstring.
Treatment for hamstring tears is fairly straightforward but it is the prevention of hamstring tears which generates the most discussion in the medical fraternity . I’ll discuss the best options in my next post .

Nice introduction to Silvertails, Doctor.
The rest of we posters are going to have to list our content quality because credible information is not our strong suit!

 

[Warrimoo]

The prevention for hamstring strains is a very interesting area and there has been a bit of conf

 

[Dion Johnson]

Over 50 hammy injuries in the nrl this year through 10 rounds.

I see they are looking at the amount of time with the ball in play contributing to hamstring injuries, Hammers injury the ball was in play for 20 minutes without a stoppage.

 

[Warrimoo]

Just a few definitions before I continue . There are 3 different types of muscle contractions:Concentric where the muscle shortens and contracts (like the first half of a biceps curl), eccentric where the muscle lengthens and contracts (like the 2nd half of a biceps curl); and isometric where the muscle contracts but the length stays the same (eg planking).

It is well documented that eccentric exercises involving the hamstrings have a protective effect against hamstring strains .This is undisputed . The best ones in my opinion are the one leg Romanian dead lift and the Nordic hamstring curl .

Let's now talk torque because this is central to the understanding of the mechanism of hamstring strains and their prevention . Torque is the rotational force of a muscle . It is best measured with a state of the art isokinetic dynamometer (which should be a staple of any professional football club which is serious about minimising hamstring injuries). The angle of maximum torque for knee flexion is around 30 degrees . This means that the hamstrings exert their maximum force when the knee is flexed 30 degrees . After a hamstring tear this angle of maximum torque for the knee increases usually to about 40 degrees. This means that the hamstring is more vulnerable to tears as they tend to occur at much smaller angles than this . Furthermore it takes 3 to 6 months to regain the pre-injury knee flexion torque so the player is vulnerable to more tears up until this time.

However , you always have to consider muscles in pairs or groups. The quadriceps (which extends the knee) opposes the hamstring and the hamstring to quadriceps torque ratio is a key measurement in the prevention of hamstring strains. In general a 60% H/Q maximum torque ratio for knee flexion at low the medium angle velocities is a minimum for professional athletes. In someone with recurrent hamstring strains you'd want that ratio around 80% . You'd also want as high a ratio as possible at angles below 30 degrees.

The glutes also play a very important part. They help the hamstrings extend the hip. This is why a lot of sprinters have large glutes. I haven't seen any studies on the subject but I suspect that the volume of the glutes has an inverse relationship to the risk of hamstring injuries. The other beneficial effect of strong glutes is the ability of them to stop forward tilting of the pelvis which is another risk factor for hamstring strains.

It is very important not to concentrate solely on the hamstring when it comes to hamstring strain prevention. Core strength is equally important. The best exercise for this in my opinion is the Swiss ball curl. Another study has shown that eccentric hamstring exercises such as the one leg Romanian dead lift and the Nordic curl can be more effective in building hamstring strength when they are performed under fatigue .This resulted in the conclusion that there is a neuromuscular component involved in building hamstring strength. I recommend that these exercises be performed at the end of training sessions.

The other very important components of hamstring injury prevention are Plyometric exercises including jumping and landing techniques . HAM sprints are also beneficial. Unequal leg lengths should be addressed. A difference in leg lengths of greater than 1.8cm results in a 4 fold increase in the risk of hamstring injuries. The effect of faulty running mechanics however has been overstated .

There is no doubt that fatigue plays a role in hamstring injuries . I recall a study which showed that the majority of hamstring injuries occur towards the end of the 1st and 2nd halves .I saw a news report tonight where Cameron Munster blamed the spate of hamstring injuries in the NRL on the faster pace of the game. I agree with him to an extent (I recommend getting rid of the absolutely ridiculous 6 again rule as it is a blight on the game). However you have to accept a certain level of fatigue in a professional football match as it's just a variable that is out of your control.

In summary I don't think that enough time and energy is invested into the prevention of hamstring injuries. All players should have their H/Q torque ratios recorded in the off season and have individually strength programs implemented which should be reviewed at regular intervals.

 

[The Bagman]

Just a few definitions before I continue . There are 3 different types of muscle contractions:Concentric where the muscle shortens and contracts (like the first half of a biceps curl), eccentric where the muscle lengthens and contracts (like the 2nd half of a biceps curl); and isometric where the muscle contracts but the length stays the same (eg planking).

It is well documented that eccentric exercises involving the hamstrings have a protective effect against hamstring strains .This is undisputed . The best ones in my opinion are the one leg Romanian dead lift and the Nordic hamstring curl .

Let's now talk torque because this is central to the understanding of the mechanism of hamstring strains and their prevention . Torque is the rotational force of a muscle . It is best measured with a state of the art isokinetic dynamometer (which should be a staple of any professional football club which is serious about minimising hamstring injuries). The angle of maximum torque for knee flexion is around 30 degrees . This means that the hamstrings exert their maximum force when the knee is flexed 30 degrees . After a hamstring tear this angle of maximum torque for the knee increases usually to about 40 degrees. This means that the hamstring is more vulnerable to tears as they tend to occur at much smaller angles than this . Furthermore it takes 3 to 6 months to regain the pre-injury knee flexion torque so the player is vulnerable to more tears up until this time.

However , you always have to consider muscles in pairs or groups. The quadriceps (which extends the knee) opposes the hamstring and the hamstring to quadriceps torque ratio is a key measurement in the prevention of hamstring strains. In general a 60% H/Q maximum torque ratio for knee flexion at low the medium angle velocities is a minimum for professional athletes. In someone with recurrent hamstring strains you'd want that ratio around 80% . You'd also want as high a ratio as possible at angles below 30 degrees.

The glutes also play a very important part. They help the hamstrings extend the hip. This is why a lot of sprinters have large glutes. I haven't seen any studies on the subject but I suspect that the volume of the glutes has an inverse relationship to the risk of hamstring injuries. The other beneficial effect of strong glutes is the ability of them to stop forward tilting of the pelvis which is another risk factor for hamstring strains.

It is very important not to concentrate solely on the hamstring when it comes to hamstring strain prevention. Core strength is equally important. The best exercise for this in my opinion is the Swiss ball curl. Another study has shown that eccentric hamstring exercises such as the one leg Romanian dead lift and the Nordic curl can be more effective in building hamstring strength when they are performed under fatigue .This resulted in the conclusion that there is a neuromuscular component involved in building hamstring strength. I recommend that these exercises be performed at the end of training sessions.

The other very important components of hamstring injury prevention are Plyometric exercises including jumping and landing techniques . HAM sprints are also beneficial. Unequal leg lengths should be addressed. A difference in leg lengths of greater than 1.8cm results in a 4 fold increase in the risk of hamstring injuries. The effect of faulty running mechanics however has been overstated .

There is no doubt that fatigue plays a role in hamstring injuries . I recall a study which showed that the majority of hamstring injuries occur towards the end of the 1st and 2nd halves .I saw a news report tonight where Cameron Munster blamed the spate of hamstring injuries in the NRL on the faster pace of the game. I agree with him to an extent (I recommend getting rid of the absolutely ridiculous 6 again rule as it is a blight on the game). However you have to accept a certain level of fatigue in a professional football match as it's just a variable that is out of your control.

In summary I don't think that enough time and energy is invested into the prevention of hamstring injuries. All players should have their H/Q torque ratios recorded in the off season and have individually strength programs implemented which should be reviewed at regular intervals.

This is really informative and interesting information. Thanks Warrimoo!

 

[globaleagle]

No Hammie problems for Jamie Chapman!

https://www.news.com.au/sport/nrl/one-of-the-great-origin-tries-nrl-world-loses-it-for-jaime-chapman-stunner/news-story/429a0cd0491d0aa805f2fc745accc9eb

NSW 1-0 v Qld..!