Muscular strains are very common injuries affecting athletic and active people. Unfortunately, there are many misconceptions and misunderstandings as to why these injuries occur and how we can prevent them. As always, we’re going to use the published, peer reviewed literature to help dispel some of the myths…
Concentric and Eccentric Muscle Contraction
In order to understand how hamstring muscles function during activity, it’s essential that you understand the different types of muscular contraction that occur.
When we run, the hamstring is responsible for both a concentric and an eccentric contraction. The eccentric contraction occurs as the hamstring slows our leg during the swing phase. The concentric contraction occurs after our foot contacts the ground, helping to propel us forward. Injury to the hamstring muscle usually occurs during the late swing phase of the running stride and / or during footstrike, when the hamstring muscle is switching from an eccentric to a concentric contraction.
See the picture above. In order to slow the left leg during the end of the swing phase (to prepare for ground contact) the hamstring muscle in green must eccentrically contract. In other words, it is lengthening while it contracts. This is when the muscle can be susceptible to injury.
An interesting study published in the Scandinavian Journal of Medicine and Science in Sports spent 4 years looking at elite soccer teams in Iceland and Norway. What they found was that those athletes who followed a stretching program saw no reduction in the incidence of hamstring strain. Those teams using an eccentric hamstring strengthening program showed a significant reduction in hamstring strain.
Tight Hamstrings and Hamstring Strain
Numerous studies have now shown us that hamstring strain injuries are not usually caused by muscular tightness but are more attributed to weakness. Specifically, hamstring muscles that are weak during eccentric contraction (the swing phase of running) are more prone to strains. You can then understand why stretching the hamstrings will only help to make them longer or “looser” but will not prevent hamstring strain necessarily.
Hamstring Strengthening Exercises
To give the hamstrings more eccentric strength, the athlete needs to train them eccentrically. Several studies have examined the usefulness of the “nordic lower” exercise. Repeatedly, it has been found to be helpful in reducing hamstring strains in athletes and is why it is included in the “FIFA-11” program. This exercise eccentrically trains the hamstring muscle so that it can withstand aggressive lengthening and deceleration of the leg during the swing phase of running.
As always, these recommendations are to educate the reader. Before implementing new exercise we suggest that you consult with a suitable practitioner who can decipher your risk of injury and the suitability of this exercise for you. This exercise is primarily used for the prevention of hamstring strains. If you have a strained hamstring you likely require treatment before thinking about prevention of re-injury.
Treatment in Burlington for Hamstring Strain
Our Chiropractic and Physiotherapy clinic in Burlington offers various ways to treat hamstring injuries. In acute cases, laser therapy is usually the best treatment. It reduces pain, inflammation and allows for tissue healing. In chronic stubborn cases, active release or graston technique should work the best. For more information or to get some guidance as to the best approach for you, give us a call! 905.220.7858 firstname.lastname@example.org
Sangnier S, Tourny-Chollet C. Comparison of the decrease in strength between hamstrings and quadriceps during isokinetic fatigue testing in semiprofessional soccer players. Int J Sports Med 2007: 28; 952-957.
Arnason A, Andersen TE, Holme I, Engebretsen L, Bahr R. Prevention of hamstring strains in elite soccer: an intervention study. Scandinavian Journal of Medicine & Science in Sports. 2008: 18; 40-48.
Croisier JL, Ganteaume S, Binet J, Genty M, Ferret JM. Strength imbalances and prevention of hamstring injury in professional soccer players. The American Journal of Sports Medicine 2008: 36(8); 1469-1475.
Gioftsidou A, Ispirlidis I, Pafis G, Malliou P, Bikos C, Godolias G. Isokinetic strength training program for muscular imbalances in professional soccer players. Sport Sci Health 2008: 2; 101-105.
Greig M, Siegler J. Soccer specific fatigue and eccentric hamstrings muscle strength. Journal of Athletic Training 2009: 44(2); 180-184.
Nordic Lower exercise – as seen at www.fifa.com; “The 11”.