Are You At Risk For A Hamstring Injury?

If you’ve ever injured a hamstring you know how difficult the recovery process can be.  Knowledge is power! The more we know about the causes of this injury, the better we can prevent them in the future.  This article looks at what recent research tells us about hamstring injury risk factors and prevention strategies.

The hamstrings are a group of 3 muscles (biceps femoris, semi-membranosis, semi-tendinosis) located on the back portion of our thighs.  They help us extend our hips and flex our knees.

Hamstring strain injuries can be a challenge for athletes and clinicians due to their high incidence rate, slow healing and persistent symptoms. These injuries are common in sports that involve sprinting – such as soccer, track, rugby and football, and also in sports involving end range ballistic movements such as martial arts (1).  Occurring in both recreational and professional sports, these injuries can result in substantial time lost from sport and commonly recur (2).

Hamstring Injury Risk Factors

The high incidence of hamstring muscle strain-type injuries and potential associated costs has resulted in a substantial amount of research into the factors related to such injuries. Two recent systematic reviews have been completed in an attempt to collate the evidence around risk factors for hamstring injuries (2)(3).

The 1st systematic review sought to determine the risk factors associated with hamstring muscle injury.  This review concluded there were 7 positive risk factors for hamstring injuries:

[accordion] [acc_item title=”Person’s Age”]Athletes of older age tend to be at a higher risk of a hamstring injury.[/acc_item] [acc_item title=”Previous Hamstring Injury”]Represents a risk factor for future injury.[/acc_item] [acc_item title=”Quadriceps Peak Torque (strength)”]Concluded to be a risk factor for hamstring strain injury during concentric contractions, but not eccentric.[/acc_item] [acc_item title=”Other Injuries”]There is a relationship between a history of ACL reconstruction and recurrent hamstring injury, and a history of calf muscle strain (more than 8 weeks previously) with a new hamstring strain.[/acc_item] [acc_item title=”Size of Previous Hamstring Injury on MRI”]Those with an injury volume of > 21.8 cm3 are 2.3x more likely to be reinjured, while injury transverse size measurements > 55% of the total cross-sectional-area are 2.2x more likely to re-injure.[/acc_item] [acc_item title=”Leg Length Discrepancy”]A functional discrepancy of > 1.8 cm is a risk factor for hamstring strain.[/acc_item] [acc_item title=”Type of Activity”]68% of hamstring strains occur while performing running activities, while the greatest severity of injury occurred during kicking-type activities (2).[/acc_item] [/accordion]

The 2nd Systematic review looked at risks associated with re-injury of a hamstring injury.  Unfortunately, no clear conclusions on risk factors for hamstring re-injury could be made.  However, they were able to show that the recurrence rate of a hamstring injury lies between 13.9-63.3% up to 2 years after the initial injury (3).

It should also be noted that hamstring re-injury is usually more severe than the first which, emphasizes the need for a comprehensive rehabilitation program and a deeper focus on preventative strategies with pre-sport training and conditioning (4).

Hamstring Injury Prevention

Eccentric exercises show promise in preventing hamstring injury (4).  An eccentric exercise is simply lengthening the hamstring muscle while it is loaded and contracted.

Nordic Exercise for Hamstring Injury Prevention

Nordic Exercise for Hamstring Injury Prevention

The exercise utilized is called the Nordic Exercise, and is performed with a partner. One person begins in the kneeling position, while the training partner applies pressure to the kneeling athlete’s heels/lower legs to ensure that the feet stay in contact with the ground. The kneeling athlete then slowly lowers their torso toward the ground to maximize hamstring loading eccentrically. The athletes performing the exercise were asked to touch their chest to the floor, while allowing their arms/hands to buffer the fall. Subsequently, the athlete was asked to return back to the starting position by using their hands to minimize loading in the concentric phase. Each athlete performed 27 sessions of the Nordic Exercise over the course of 10 weeks (4).

Nordic Exercise protocol for hamstring injury prevention:

  • Week 1 – 1 session per week, 2 sets, 5 reps;
  • Week 2 – 2 sessions per week, 2 sets, 6 repetitions;
  • Week 3 – 3 sessions per week, 3 sets, 6-8 reps;
  • Week 4 – 3 sessions per week, 3 sets, 8-10 reps;
  • Weeks 5 to 10 – 3 sessions per week, 3 sets at 12 reps, 10 reps, and 8 reps, respectively;
  • Weeks 10+ – 1 session per week, 3 sets, 3 at 12 reps, 10 reps, and 8 reps, respectively.

This study found that performing this exercise decreased the rate of overall, new, and recurrent acute hamstring injuries (4).

Note: please do not attempt any exercise program without speaking to a health care professional.  If you have suffered a hamstring injury or suffer one in the future, please see a health care professional to guide you through the proper treatment.  There are specific manual therapies and rehab strategies that can reduce your recover time and lower your risk of re-injury.


  1. Heiderscheit B et al. Hamstring Strain Injuries: Recommendations for Diagnosis, Rehabilitation, and Injury Prevention. Journal of Orthopaedic & Sports Physical Therapy 2010; 40(2): 67-81.
  2. Freckleton G & Pizzari T. Risk Factors for Hamstring Muscle Strain Injury in Sport: A Systematic Review and Meta-Analysis. British Journal of Sports Medicine 2013; 47: 351-358.
  3. de Visser HM, Reijman M, Heijboer MP et al. Risk Factors of Recurrent Hamstring Injuries: A Systematic Review. British Journal of Sports Medicine 2012; 46: 124-130.
  4. Petersen J, Thorborg, K, Nielsen MB et al. Preventive Effect of Eccentric Training on Acute Hamstring Injuries in Men’s Soccer: A Cluster-Randomized Controlled Trial. American Journal of Sports Medicine 2011; 39: 2296-2303.