Hamstring Injury Prevention

Hamstring Injury Prevention

Hamstring injuries, whether they be muscle tears or strains, are some of the most common to occur in sport, being especially prominent in football and rugby as well as many track and field disciplines, especially sprinting. Being able to prevent these injuries can mean players remain fit to play and even more importantly for a football or rugby club, games and premierships can be won, time lost to injury can mean money lost. Flywheel training provides an effective tool which covers the many facets of preventing hamstring injuries

The prevention of hamstring injuries is a multi-factorial challenge. Firstly, it’s important to understand why they occur. Factors such as fatigue, lumbo-pelvic stability, previous injury history, flexibility and posture as well as environmental factors such as playing surface can all play a part. However the greatest risk factors include a lack of eccentric strength and shortened muscle fascicle length, both of which can be helped by eccentric training on the kBox.

Research (1)  performed in Australia studied elite football players and the rate of hamstring injuries taking into account eccentric knee flexor strength and fascicle length of the long head of biceps femoris. The group of players with the lowest levels of hamstring injury possessed muscle fibres that were “strong and long” 

Hamstring Strengthening

By strengthening the hamstrings, they become more resistant to strain however care needs to be taken not to cause overuse injuries as strengthening can cause shortening and tightening, limiting flexibility. Shorter muscle fascicles are at greater risk of tearing due to overstretching. This is where eccentric strengthening using the kBox is such an effective method, the muscles are strengthened while lengthening during the contraction and the low impact nature of the device limits potential overuse injuries.  The use of eccentric hamstring strengthening is the most researched and accepted method of preventing hamstring injuries, reducing the risk of primary and secondary injuries. It can result in a change of the muscle physiology, even lengthening the biceps femoris long head muscle fibres. 

Emphasis for football players must also be placed on explosive power to provide strength during movements such as kicking and sprinting. Performing squats  and lateral squats on the kBox are an effective way of targeting the muscles that are required for sprinting, kicking and cutting. Any strengthening program should be accompanied with an appropriate stretching routine.

Developing lumbo-pelvic stability

It’s not only the hamstrings that need strengthening. Adjacent joints should be considered such as the glutes, adductors and quadriceps which can be worked in co-contraction with the hamstrings.  All of these muscles can be targeted using the kBox which provides various attachments and settings for different training requirements. Weakness in the hip extensors during sprinting can cause increased risk of hamstring injuries and deficits in explosive strength can also increase the risk of injury.Poor coordination of stabilising muscles around the pelvis can cause compensatory activation of agonists and antagonists. There is an equal need for hip extensor and knee flexor strength. All players should be assessed for right to left asymmetry as an imbalance can lead to an increased injury risk.

Player workload

Managing a player’s workload can be difficult, especially during the football season with so many matches, sometimes including representative duties in addition to  club fixtures. The same challenge is seen during competitive track and field season, trying to manage increasing training load in preparation for competition season. While it has been shown that a high training load can be protective in elite football, it is important not to exceed this threshold, causing injury. A large and rapid increase in training during times of increased frequency of matches and tournaments can cause increased risk of hamstring tear. By incorporating flywheel training into a strength and conditioning regime, players are able to make welcome strength gains without spending further time on the pitch and in a more efficient manner due to the ability for the kBox to deliver higher levels of resistance.

How does flywheel training fit into this?

By using a flywheel device such as the kBox, players are able to perform exercises to improve the explosive strength required for sprinting as well as eccentric loading that can strengthen the hamstrings while lengthening muscle fascicle length, preventing injuries resulting from muscle shortening. 

The very same device delivers a platform to perform glute strengthening, providing pelvic stability. All done in a low impact, efficient manner, avoiding overuse injuries from repetitive strain and limiting the workload required by players, supplementing their training routine perfectly.

Hamstring rehabilitation

Unfortunately some hamstring injuries are unavoidable but the goal of rehabilitation is to regain strength and function in order to prevent recurring injuries. Flywheel training is incredibly popular with physiotherapists working in sports rehabilitation as it offers a low impact and controllable method of delivering strength training. With the kBox, the amount of resistance and speed of movement can be predetermined to allow a gradual progression of loading of the muscle as the athlete builds their strength and range of movement. Eccentric training, a method that the kBox is known for championing, is an important element of muscle rehabilitation, as it determines control, landing technique and change of direction ability.



  1. Timmins RG, Bourne MN, Shield AJ, et al
    Short biceps femoris fascicles and eccentric knee flexor weakness increase the risk of hamstring injury in elite football (soccer): a prospective cohort study British Journal of Sports Medicine 2016;50:1524-1535.
  2. Buckthorpe M, Wright S, Bruce-Low S, et al
    Recommendations for hamstring injury prevention in elite football: translating research into practice British Journal of Sports Medicine 2019;53:449-456. https://bjsm.bmj.com/content/53/7/449


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kBox4 Active

Our entry level model for the serious personal trainer or demanding home user. The perfect tool in strength and rehabilitation at our lowest price point.

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