Hamstring strains are among the most common athletic injuries, particularly in sports like football, soccer, and other sports that involve high speed running and kicking. Dancers are also highly prone to hamstring strains, with 34 percent reporting at least one incident of acute hamstring strain.3 Once an athlete has suffered a hamstring strain, the risk of being re-injured is high, resulting in lost training and competition time, and affecting the athlete’s career and quality of life.
The rate of recurrent hamstring injuries in athletes ranges from 12 to 63 percent, with the highest risk being the first month after return to play (RTP), and elevated risk for 12 months after RTP.2 Much research has been devoted to reducing hamstring injuries after RTP. Data has revealed interesting findings about some underlying conditions that may predispose an athlete to hamstring injury.
The hamstrings are actually a group of three long muscles, the semitendinosus, semimembranosus, and biceps femoris, that cross over two joints, acting at the knee as flexors, and at the hip as extensors. Due to the hamstrings’ multifaceted anatomy, hamstring injuries should not be given a one-size-fits-all treatment, but should be evaluated and treated on a case-by-case basis.
Brukner1 identifies three elements that may influence different types of hamstring injuries:
Type of activity: Injuries incurred during sprinting vary from injuries from high kicking, sliding and sagittal splits. Injuries from high speed running more often involve the biceps femoris long head, while movements that lengthen the hamstrings often affect the free proximal tendon of semimembranosus.
Muscle tendon architecture: Some athletes may be predisposed to hamstring injury due to a structurally small or narrow aponeurosis of the biceps femoris long head.
Referred pain: Sometimes hamstring pain may originate from the lumbar spine, fascial injury or the gluteal muscles, and not from an injury to the hamstring itself.
While hamstring injuries are an inherent risk of training and competition that athletes understand and accept, research using advanced technology is uncovering issues in other areas of the body that interfere with optimal movement mechanics, setting an athlete up for injury.
Some risk factors3 that may predispose an athlete to recurrent hamstring injuries include:
Unequal leg length: Even a very slight difference in length is enough to affect movement mechanics.
Shortened optimal muscle length: The length at which optimal force is generated may be shorter for injured hamstrings, altering knee flexion torque.
Poor flexibility: Tight hamstrings may play a role in optimal knee flexion torque and may be more vulnerable to strains.
Imbalanced bilateral hamstring strength: Strength imbalances can affect coordination and impede performance.
Insufficient warmup: Warm muscles are more elastic and less subject to strain. Many hamstring strains occur early in play.
Fatigue: Many injuries also occur late in play, after muscles have been overworked.
Low back pain: Lumbar disorders can affect pelvic position and may increase hamstring tension.
Sciatic neural tension: Compressed nerves affect muscle tension and movement mechanics.
Muscle fiber composition: Type II fast twitch fibers are more prone to muscle strain than type I, which are typically more dominant in the hamstrings. Some athletes genetically have a higher ratio of Type I, and vice versa.
Age: Older players have a higher risk of hamstring strain.
Poor trunk stabilization: A weak or imbalanced core negatively affects upper body stability, which can compromise lower extremity performance.
Unless deficiencies are uncovered and addressed, an athlete will return to play with the same mechanisms in place that contributed to the initial injury, putting them at higher risk for re-injury.
An injured athlete, especially at the elite level, is highly incentivized to return to play as quickly as possible. Nevertheless, sending an athlete back to play before all of their issues have been addressed may extend the total time they are out of play in the long run. Recurring injuries can permanently ruin an athlete’s career, especially when fear of re-injury begins to affect their in-play psyche.
Since there is little evidence to suggest that any single treatment strategy will be more effective than another, the sports medicine practitioner will have to rely on experience and the evidence at hand to determine an appropriate treatment regimen.
Some progressive treatment therapies include:
Biomechanical assessment and retraining: Computer-based movement analysis and treatment can identify mechanical deficiencies and provide a virtual environment for correcting them.
Neurodynamic assessment and treatment: Assessing and treating the area of the lumbar and sacral spine can release trapped and compressed nerves that affect hamstring dynamics.
Strengthening of the lumbar spine and core: Trunk dynamics play a huge role in sports, and weakness and imbalances are the root cause of many sports injuries.
Hamstring strengthening with eccentric emphasis: Exercises that focus on faster contraction speeds at longer muscle length prepare the hamstrings for real-time play.
Running gait retraining and running overload training: A thorough gait analysis followed by gait retraining corrects mechanical deficiencies. High speed running overload in the later stages of rehab prepares the muscles for in-play sprints.
Yoga-based stretching and relaxation: Relaxed total body stretching optimizes muscle tension at the joints while enhancing muscle flexibility, reducing strain risk.
Injection therapies: Injections in the lumbar region to reduce pain and inflammation can promote healing and relieve neural tension.
The sports medicine specialists at NYDNRehab have the expertise, equipment and technology required to analyze, treat and correct mechanisms that increase your risk of recurrent hamstring injury. Do not return to play until you have visited the best sports medicine professionals in NYC, to ensure you remain injury free and on the playing field for years to come.
1. Brukner, P (2015). Hamstring injuries: prevention and treatment—an update. British Journal of Sports Medicine, 49, 1241-1244.
2. Brukner, P et al., (2014). Recurrent hamstring muscle injury: applying the limited evidence in the professional football setting with a seven-point programme. British Journal of Sports Medicine, 48, 929-938.
3. Liu et al. (2012). Injury rate, mechanism, and risk factors of hamstring strain injuries in sports: A review of the literature. Journal of Sport and Health Science, 1(2), 92-101.