Nordic Hamstring Training

Original Editor - User: Matt Huey

Top Contributors - Matt Huey, Kim Jackson and Lucinda hampton  

Introduction

In the field of sports physiotherapy, muscle injuries are not uncommon. A large proportion is taken up by the so-called hamstring injuries. According to Manier et al., this injury is among the most common in football, rugby, and American football. In their publication, the authors Diemer et al. describe a proportion of 5-15% and a reviewed trauma rate of 4-68% in sport. However, the authors Biz et al. raise the figure to 25% and give an average recovery time of 9 days. This is based on the severity of the injury and the patient's activity level. A descriptive epidemiological study by Gudelis et al. collected data on non-contact injuries of the hamstrings in a sports club from Barcelona.

In the period from 2007 to 2017, a total of 538 hamstring injuries were registered in the club. According to the authors, that's 1.29 injuries per 100 players per year (a total of 17 sports). Thus, this injury represents a potential source of danger in sport physiotherapy.

One way to prevent hamstring injuries could be the Nordic hamstrings. Several studies have given an indication of a reduction in the susceptibility of hamstrings to injury after preventive training, as Raya-Gonzalez et al. reported in a systematic review.

The Hamstrings

The hamstrings or ischiocrural muscles form part of the dorsal thigh muscles. It works antagonistically to the quadriceps femoris muscle in the knee joint and synergistic in the hip joint with the gluteal muscles. Hamstrings consist of the semimembranosus muscle, the semitendinosus muscle, and the biceps femoris muscle. They all have a common origin at the ischial tuberosity, with the exception of the caput brevis of the biceps femoral muscle. This part originates at the linea aspera (labium laterale) femoris. Approach of the semimembranosus and semitendinosus muscles are located at the pes anserinus and the attachment of the biceps femoris is located at the caput fibulae. The innervation of all three muscles occurs via the tibial nerve (L5-S2). Here, the short biceps head is again an exception, with an innervation via the fibular nerve (L5-S2).

Hamstring Injury

Hamstring injuries describe an injury to the ischiocrural muscles caused by an overstretching or overload even in sports. Kuske et al. described three degrees of injury.

Grade	Presentation
Grade 1	Mild pain or swelling, non-appreciable tissue disruption, no or minimal loss of function
Grade 2	Identifiable partial disruption of tissue with moderate pain and swelling, leading to loss of function
Grade 3	Complete disruption or tear of the musculotendinous unit with severe pain and swelling and lack of function

Rehabilitation depends on the athlete's current activity level and the level of return to performance.

Nordic Hamstring Training

Nordic Hamstring Training is used to strengthen the ischiocrural muscles. The lower leg of the patient/exerciser is fixed. Now the athlete lowers the upper body, with his hips extended, eccentrically forward, like a plank. At the beginning, the athlete will usually lack strength and will have to support himself with his hands. In the later course, the Athlete should return to the original position without the use of the hand under the power of the ischiocrural muscles. (Schneider, 2020).

However, the training can also be carried out with knee curl devices, as the ischiocrural muscles are also trained here (Jäger, 2012). Here, however, the executing athlete has no further core activity. In general, there are several variations, which are briefly presented below:

1. Eccentric training with leg fixation
2. Eccentric training with leg fixation and theraband to help with eccentric forces
3. Eccentric training with explosive push-off activity
4. Eccentric training with concentric return movement of the body

Nordic hamstring training is a complex and demanding training and is therefore more likely to be used therapeutically in the sports sector and less often in physiotherapy practice. The burden should be progressively increased (Alt et al., 2022).

Literature Research

To answer the question of what effect preventive Nordic hamstring training has on the risk of hamstring injuries, the PubMed database was used at the beginning (27.05.2023). The search terms were "Nordic Hamstring" and "Prevention". At the beginning of the research, no further filters were used to get a general overview. A total of 138 results were presented as search results. The "Timeline" filter was then used and a value of 5 years was set. Thus, all studies published before 2018 are excluded. After that, 105 results remained. In order to further narrow down the results, the filters are "Meta-Analysis"; "Systematic Review"; "Guidelines" and "Randomized Controlled Trial" were used and the results were reduced to 30. Now these 30 studies have been fundamentally tested for initial inclusion criteria and exclusion criteria. [Furthermore, the databases PEDro and the Cochrane Library were searched. Due to similar results with PubMed, these platforms were no longer included.] The criteria are listed below:

Inclusion criteria

  - It's about the prevention of hamstring injuries

- Isolated Nordic Hamstring Training Application

- Subjects are athletes and have not previously had a hamstring injury

- Age between 16-40 years

- Full free text

Exclusion criteria

- Use of combination treatments

- Patients are younger than 16 years or older than 40 years

Benefits

Several studies have found benefits in utilizing Nordic Hamstring training to decrease the incident of hamstring injuries in soccer players. One study had male soccer players doing a Nordic Hamstring curls twice a week for four weeks and found it increased knee flexor eccentric strength. Other studies have found decreases in the incident of hamstring injuries in male soccer players when Nordic Hamstring curls are incorporated into their training. It must noted, that even thought there is a recorded decrease in the hamstring injuries, the severity of the injuries were unchanged.

Equipment

Relatively little additional equipment is needed to perform this exercise and depends on someone's ability to perform it.

What is needed:

• A place to secure the feet (another person or a loaded barbell)
• Pad (provides comfort to the knees)
• Band (this can be uses to provide a counter resistance when building strength)
• Box (another item that could be used for someone building their strength)

Training

The Nordic Hamstring curl is a challenging exercise and even seasoned athletes may struggle to perform a full repetition. There are levels to building up strength to be able to perform a full repetition. Keep in mind that it does take some to build strength. Pick a level that you feel the most comfortable starting with. All levels will start with the same position, in the kneeling position with the heels/feet secured. Work to maintain an upright position with each level. If you are finding you are having to bend at the hips to perform it, you may need to regress until your strength comes up.

Level 1 Rocking

Many people begin at this level. In the starting position, lean forward as far as you feel comfortable while keeping the torso, hips and thighs in alignment. You should feel your hamstrings contract as they hold you from falling forward. Then using your hamstrings return to the starting position.

Level 2 Assisted

This levels uses a form of assistance to allow the person to go further. 2 options that people could do, depending on what they have available. One is using a sturdy surface, such as an exercise bench or box, in front of them. As they go further into the range, reach your arms out to the box to assist in returning back to the start position. To progress, use a shorter box so that you are going further into the range.

Another option is using a resistance band around the chest and secured to a sturdy surface behind you. As you go further into the range, the band provides a counter resistance to assist in returning back to the starting position. To progress, use a smaller/less resistant band.

Level 3 Eccentric

In the starting position, lower yourself down as slowly as you can. Use your hands to catch yourself and to assist with returning back to the starting position

Level 4 Full

In the starting position, lower yourself until you are just above the floor. You can have your hands at your side or behind your back. Then return to the starting position while maintaining the upright position from the thighs to your torso. This can be further progressed by holding a weight.