Hamstring injuries are multifaceted and complex in nature. More often than not, it is a combination of variables that lead to a sprain or strain. Hamstring injuries are the most common soft tissue injury in sports that involve high speeds. From the research, we know that previous hamstring injuries are the biggest predictor of a future sprain, and as such, prevention is better than a cure!
To best prevent hamstring injuries in sport, we need to:
- Have a good foundation of knowledge surrounding anatomy and physiology
- Have a good understanding of exercise programming, exercise selection and periodisation
- Understand the concept of load and how we can balance our training load with recovery and avoid overtraining
- Understand the effect of proper sprint training and running mechanics in athletic populations
This blog and the attached video series; aims to be your starting block for this information. In reading this, you should have the tools and knowledge to go out and implement the basics of hamstring injury prevention. AND, if you are serious about training athletes, this information can be a launching point for you to dig deeper into training the hamstring to both optimize performance and reduce your athletes’ chances of injury.
The hamstring group is made up of three muscles, the biceps femoris, semimembranosus, and semitendinosus.
All three muscles originate from the ischial tuberosity of the pelvis and attach to either the tibia or fibula (depending on the muscle). Together the hamstrings act to extend at the hip and flex at the knee. The most important thing to note about the anatomy of the hamstrings is that they are bi-articulate, meaning; they cross two joints. As such, the length and action of the hamstrings are directly affected by movements from the hip and the knee. This helps us classify exercises as either hip dominant or knee dominant. This piece of information is extremely important when it comes to exercise selection. To ensure we train the hamstring at a number of different length and positions, we want to include a balance of both hip and knee dominant exercises. Exercises that are hip dominant will train the hamstring at the more proximal end (closer to the origin/pelvis) and knee dominant exercises will train the hamstring at the distal end (closer to the insertion/knee).
Well balanced training programs focused towards injury prevention will incorporate a variety of hip and knee dominant exercises, including both single leg and bilateral, done at a variety of muscle lengths and muscular contraction speeds. This ensure strength throughout the entire length of the hamstring at various joint angles, to protect against the rigors of sprinting, kicking and accelerating.
HIP DOMINANT TRAINING
As previously stated, hip dominant exercises will train the hamstring closer to the proximal end of the hamstring (hip joint). The video below demonstrates three hip dominant exercises that we believe give you the biggest bang for your buck in terms of both hamstring development, injury prevention mechanisms and athletic performance. These exercises will train the hamstring at long lengths, have great eccentric loading of the hamstring musculature and integrate the entire posterior chain into the movement.
KNEE DOMINANT TRAINING
Knee dominant exercises will train the hamstring closer to the distal end of the hamstring (knee joint). The video below will again demonstrate exercises that provide a mix of both heavy eccentric and concentric contractions. As stated in the video, exercises such as the Nordic curl and razor curl have been heavily touted as ‘must do’ exercises for hamstring injury prevention. Although I wouldn’t consider them to be 100% necessary, they have been shown to have significant affects on reducing hamstring injury rates. This is due to the fact that they increase the fascicle length of the hamstring tissue. Why is this important? Research indicates that shorter fascicle lengths, especially of the biceps femoris, decreases the risk of hamstring injuries. As such, exercises that are purely eccentric (Nordics/razor curls/slide outs) have been shown to increase both the eccentric strength of the hamstring and increase the fascicle lengths and therefore decrease the risk of hamstring injuries occurring.
Like nordics and razor curls, sprint training has also been shown to change the muscular architecture of the hamstrings. Regular sprint training has been shown to increase the fascicle length of the hamstring group just as much as the ever-hyped-up nordics and razor curls. This is why when it comes to hamstring injury prevention, dedicated sprint training will always be king. Not only does sprint training have a protective mechanism for the hamstrings, it also has performance benefits for speed, power and acceleration qualities.
However, if you are going to sprint, ensure you are getting the most out of it. Sprint training should have a focus on developing technique; through appropriate sprint mechanic drills and positional exercises. Poor max velocity running technique (excessive lumbar extension or pelvic drop) is a recipe for hamstring injuries, so if you’re not sure how to coach high speed running mechanics or how to fix poor positions, then hire yourself a sprint coach. In addition to focusing on technique, you need to ensure appropriate rest periods are being adhered to, so that your speed session doesn’t turn into a conditioning session. 1-2 minutes rest per 10m sprinted is a great place to start.
Understanding the basics of load management is crucial to reducing not only your risk of a hamstring injury, but a vast majority of soft tissue, chronic overuse and joint injuries. Acute and chronic fatigue often play a role in the breakdown of athletes and subsequent soft tissue injuries.
ACUTE FATIGUE = Is a reduction in muscular power output and force production as a result of insufficient rest or recovery. Acute fatigue is basically short-term fatigue as the result of a single session or a small number of training sessions.
CHRONIC FATIGUE = Is reduction in performance as a result of more long-term fatigue. Insufficient recovery and/or prolonged intense or high-volume training can cause chronic fatigue of both the peripheral and central systems.
Both acute and chronic fatigue are both risk factors for soft tissue injuries. As such, we need to understand how:
- Periodise our training and incorporate recovery to reduce chronic fatigue
- Schedule and plan training sessions to avoid certain training methods (such as sprint training) whilst under acute fatigue
Acute fatigue is at times unavoidable. In fact, acute fatigue is a direct result of our training stimulus. If we were to avoid acute fatigue all together, that would mean never providing a training stimulus hard enough to achieve supercompensation (see graph below).
As such, instead of avoiding acute fatigue, we need to plan for it. To relate it back to hamstring injuries, this means scheduling our training week or block to ensure exercises that have the highest amount of neural fatigue (sprint training, power training and heavy strength training) should be done following periods of rest, so we are the best prepared to execute them. As a general rule, to reduce your risk of a hamstring injury, you should avoid sprint training following; heavy strength training (especially when there is a heavy eccentric component) and avoid doing back to back sprint training sessions.
Finally, when it comes to reducing your risk of a hamstring injury – we also need to avoid large spikes in our training volume. Large spikes in training, whether it be a spike in overall running load (distance) or distance run at high speed (high speed running metres) – have been shown to increase the likelihood of soft tissue injuries. As such, when returning to sport from a break or injury, running loads should be gradually increased. This is the general concept of load management. Planning training volumes to ensure we are not suddenly doing too much work and causing dangerous high levels of acute fatigue to the system.
Load management is a complex topic. What has been discussed in this article is merely a short breakdown of some general concepts that will hopefully give you some direction when it comes to planning your training week or making decisions about how much training you should be doing.
- Ensure you have a well-balanced strength training program in the gym. This program should train the hamstring via both hip and knee dominant exercises and utilize Nordics or other eccentric biased training, to increase fascicle length and prevent against injury.
- Sprint training is the king of hamstring injury prevention. Understand how to improve top speed mechanics and follow correct sprint training protocols to optimize performance.
- Grasp the basics of load management. Constantly training to fatigue and under recovering is a recipe for soft tissue injuries. Utilize your recovery and avoid large spikes in training loads.
- Organise your training week to avoid sprint training under acute fatigue. High speed running should be performed whilst the CNS and peripheral systems are fresh, so plan accordingly.
Written By Coach Ben Andrews
Ms. Ex. Sc.