Hamstring strain injuries are common in sports and thus time to return to sport and secondary prevention become a particular concern. Two studies have looked at the comparison of two rehabilitation protocols in acute hamstring injuries in elite athletes (footballers, sprinters, and jumpers). Both studies show the effectiveness of the rehab protocols by evaluating time needed to return to full participation in training and return to match play. The two rehabilitation protocols were one in which focused on loading the hamstring during extensive lengthening with eccentric muscle actions (muscle active when lengthening/stretched). The other rehab protocol consisted of conventional exercises with a less emphasis on lengthening the hamstring.  

Each protocol consisted of 3 exercises that the first exercise focused on increasing flexibility, exercise 2 focused on a combination of strength and trunk/pelvis stabilisation and exercise 3 was more of a specific strength training exercise.

Lengthening Rehabilitation Protocol Exercisers:

1. The Extender

2. The Diver

3. The Glider

Conventional Rehabilitation Protocol Exercisers:

1. Stretching contract/relax

2. Cable-pendulum

3. Pelvic lift

*  Description of exercises can be found in the below articles.

The results of the two studies show that the choice of rehabilitation protocol has significant impact on return to training and match play. The findings of the study show that a rehabilitation protocol that consists mainly of lengthening type of exercises are more effective than the conventional protocol when returning to full training and match play. An explanation of the results is that typically after a hamstring injury, there is an avoidance of voluntary activation of the hamstring, and this limits hamstring load during lengthening exercises. This may lead to eccentric hamstring weakness (weakness when the muscle is stretched). So, an explanation of the positive results of the lengthening rehab protocol could be that the type of exercises included in this protocol was beneficial in voluntarily activating the injured hamstrings compared to the conventional program and thus includes eccentric strengthening. Another explanation is that the exercises in the lengthening protocol mimicked the particular action of injury, thus strengthening the muscle in the action of injury. 

What does this mean for Physiotherapy?

By adopting rehab protocols that consists of lengthening exercises it will improve rehabilitation efficiency after acute hamstring injury. This means a quicker time to the return to full training and match play for clients.

By Sam Lee, student at Exercise Thought.

References 

Askling, C., Tengvar, M., Tarassova, O., & Thorstensson, A. (2014). Acute hamstring injuries in Swedish elite sprinters and jumpers: a prospective randomised controlled clinical trial comparing two rehabilitation protocols. British Journal Of Sports Medicine, 48(7), 532-539. https://doi.org/10.1136/bjsports-2013-093214 (Askling et al., 2014)

Askling, C., Tengvar, M., & Thorstensson, A. (2013). Acute hamstring injuries in Swedish elite football: a prospective randomised controlled clinical trial comparing two rehabilitation protocols. British Journal Of Sports Medicine, 47(15), 953-959. https://doi.org/10.1136/bjsports-2013-092165 (Askling et al., 2013)

Additional article in support:

Severini, G., Holland, D., Drumgoole, A., Delahunt, E., & Ditroilo, M. (2018). Kinematic and electromyographic analysis of the Askling L-Protocol for hamstring training. Scandinavian Journal Of Medicine & Science In Sports, 28(12), 2536-2546. https://doi.org/10.1111/sms.13288