Hamstring injuries are some of the most common in sport. We frequently see these injuries occur in soccer, football, as well as track and field in addition to other sports which require quick accelerations and decelerations at high-speed. Prevalence ranges from 8-25% depending on the sport. A recent observational study reported 50% occurrence in elite level soccer players. These sports frequently put high eccentric (muscle lengthening) forces on this muscle, increasing likelihood of injury.
Your hamstrings comprise of three primary muscles: semitendinosis, semimembranosis and biceps femoris. It is the biceps femoris that accounts for approximately 80% of these injuries when it comes to running. A major contributing factor to this could be the large range of length and tension the hamstring muscle-tendon unit is put under during the running nature of these sports. During sprinting, for example, all three of your hamstrings produce peak muscle-tendon force at the same time during the terminal (at the end) swing phase of gait. This is commonly when runners injure this tissue. Other risk factors are age, hamstring weakness and previous injury.
Here are two videos of elite athletes caught in the action:
- Joey Altidore at 2014 World Cup (Pardon the potential language barrier. This is a great example however)
- As you can see here, starting the video at 45 seconds, Altidore injures himself when he heads the ball while his left hip/leg is flexed forward. Not only is his hamstring tissue in a position to produce peak force, nodding his head down to hit the ball creates a greater global posterior chain (back of his body) tissue lengthening, creating more tension.
- Thierry Henry Changing Direction
- In this example, Henry is running at top speed, changes direction, pushes off his right foot driving his hip and knee up into terminal swing and immediately falls to the ground in pain.
Preventing Hamstring Injuries
Research shows that it is possible to minimize the frequency of hamstring injuries. Training your hamstrings eccentrically, lengthening muscle and decelerating movement, has been most effective. Particularly, utilizing the Nordic eccentric hamstring exercise has been shown to reduce occurrences in male soccer players by 70%. This specific activity has also shown to improve overall length of the biceps femoris fascicles, improving flexibility. This was done over a 6 week period of 100 repetitions per week. Typically when referring to muscle length, in this case hamstrings, it is the chronic effect of lengthening (strengthening or stretching) that produces a meaningful change- meaning, doing this exercise once or for two weeks will likely not produce measurable change in length, prevent injury and therefore not your desired result.
Take a look at PEAK’s video of the Nordic Hamstring Curl
Developing this slow eccentric deceleration strength, and there are many ways to do so, is a great skill for developing general preparedness, strength and length of the hamstring tissue as well as adds power in your engine. You should not neglect your sport specific training and preparation, however. Likely you will need both in prevention and movement specific training for sport.
The best way to reduce the risk of hamstring injuries is improving tissue length, overall strength, resistance to fatigue and capacity. In running sports, improving tolerance to running, sport specifcifity as well as improving eccentric hamstring strength is essential to feel better, move better and perform better.
- Schache A, Dorn T, Blanch P, Brown N, Pandy M. Mechanics of the human hamstring muscles during sprinting. Medicine and science in sports and exercise. 2011;44(4):647–58. https://www.ncbi.nlm.nih.gov/pubmed/21912301. Accessed January 6, 2017.
- Prior M, Guerin M, Grimmer K. An evidence-based approach to hamstring strain injury. 1(2). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3445075/?log$=activity. Accessed January 6, 2017