Hamstring Strain: Prevention & Rehabilitation (Part 2)

Hamstring Strain Prevention

Nordic Hamstring exercise

In a recent study Peterson et al, (2011) added the Nordic hamstring exercise to conventional pre season soccer exercise programs and showed it to be beneficial in reducing injury rates in soccer. The Nordic hamstring exercise is a partner exercise. The athlete starts in a kneeling position, with his torso from the knees upward held rigid and straight. A training partner applies pressure to the athlete’s heels/lower legs to ensure that the feet stay in contact with the ground throughout the movement. The athlete then attempts to resist a forward-falling motion using his hamstring muscles to maximize loading in the eccentric phase. The participants were asked to brake the forward fall for as long as possible using the hamstrings. The athletes were asked to use their hands to buffer the fall, let the chest touch the surface, and immediately get back to the starting position by pushing with their hands to minimize loading in the concentric phase (Mjolsnes et al, 2004).

Nordic Hamstring Exercise Start

Nordic Hamstring Exercise StartNordic hamstring exercise EndNordic hamstring exercise End

Peterson et al (2011) used 942 soccer players who performed the Nordic hamstring exercise in a progressive 10 week program during pre season that was added to their conventional training program. They compared injury rates between players that performed the Nordic hamstring progressive exercise program (table below) and those that did not.

Week

Sessions

Sets

Reps

1

1

2

5

2

2

2

6

3

3

3

6-8

4

3

3

8-10

5-10

3

3

12-10-8

They found that injury rates were reduced by 85% when compared to the control group who did not perform the eccentric protocol. The 10 week protocol was made progressive to reduce the negative effect of delayed onset of muscle soreness (DOMS). This study showed that adding in the Nordic hamstring exercise alone to conventional pre season training programs reduced hamstring injury rates.

The most consistently thought of explanation for the beneficial role of eccentric exercises for the hamstring muscle group in preventing injury and re injury is that they cause a shift in the optimum angle for eccentric torque generation, to longer hamstring muscle lengths which can protect against hamstring injuries and re-injuries. Peak muscle-tendinous force and strain for the hamstring muscle group occurs during the terminal swing phase, just before ground contact, and it is suggested that it is in this period of the stride cycle that the bi-articular hamstrings are at the greatest risk of injury. It is therefore suggested that eccentric muscle strength training should be performed at longer muscle-tendinous lengths, mimicking movements and muscle length occurring at both the knee and the hip (Thorborg, 2012).

Hamstring Strain Rehabilitation

Soft Tissue Mobilisations

Hunter (2004; 2007) soft tissue mobilisations around the injured lesion and transverse glides across the healing tissue during passive and active movements of the muscle to promote collagen alignment and promote pliability of scar tissue formation. Rushdon and Spencer (2011) found that hamstring muscle extensibility and ROM improved greater when a static end range transverse medial glide technique was applied to the biceps femoris muscle for a period of 30 seconds along with a physiological stretch. When compared to a physiological stretch alone. A group of expert clinicians gathered together (Orchard et al, 2008) about their clinical expertise in dealing with muscle strain injuries. They agreed upon ice being very beneficial and early mobilising of the soft tissue and active movements within pain be commenced even <24 hours post injury. Ice applied for 20 mins after every rehabilitation session is also recommended.

Exercise 

In recent studies that have compared different rehabilitation protocols after acute hamstring strain injuries which showed good results in both time to return to play and re injury rates. Askling et al (2013) performed a study that compared two different rehabilitation protocols for acute hamstring strains. They used 75 male and female football players that had clinical signs of an acute hamstring injury. They separated the subjects into two different protocols. These were a L protocol which included exercises to put load onto the hamstrings during maximal dynamic lengthening. The exercises involved movements of the hip and knee with eccentric muscle actions. The C protocol consisted of conventional concentric and stretching rehabilitation exercises. Both protocols started 5 days post the injury with regular follow ups and progressions in load and speed of the exercises. Their results showed that the L protocol had a significantly shorter (28 days) return to play when compared with the C protocol (51 days). Also there was only one re injury between both groups which happened to a subject from the C protocol.

Slider et al (2013) also compared two different but heavily supported rehab programmes for hamstring strains. They separated 25 subjects who had a hamstring injury within 10 days and involved in sports, into a progressive agility and trunk stabilization (PATS) group and progressive running and eccentric strengthening (PRES) groups. They found both rehab protocols to be efficient in return to sport times and both had low re injury rates a year post return to sport participation with 2 in PATS group and 2 in the PRES group.

Sherry and Best (2004) also compared two different rehabilitation protocols. They had 24 athletes separated into: static stretching, isolated progressive hamstring resistance exercise and icing (STST) and progressive agility and trunk stabilization exercises and icing (PATS) groups. Their interventions lasted for 2 months on return to sport, with 3 sessions a week. The STST group had a 54% re injury rate whereas the PATS group had no re injuries within 16 days of returning to sport. With the STST group also showing a significant increase in re injury rates a year post returning to sport with 70% compared to 7.7% in the PATS group.

The exercises that were used in the most beneficial rehabilitation protocols were:

‘The Extender’. Stabilise the thigh of the injured leg with the hip flexed approximately 90° and then perform slow knee extensions to a point just before pain is felt. Twice every day, three sets with 12 repetitions

‘The Extender’. Stabilise the thigh of the injured leg with the hip flexed approximately 90° and then perform slow knee extensions to a point just before pain is felt. Twice every day, three sets with 12 repetitionsThe extender 2

‘The Diver’. The exercise should be performed as a simulated dive, that is, as a hip flexion (from an upright trunk position) of the injured, standing leg and simultaneous stretching of the arms forward and attempting maximal hip extension of the lifted leg while keeping the pelvis horizontal. Once every other day, three sets with six repetitions.

‘The Diver’. The exercise should be performed as a
simulated dive, that is, as a hip flexion (from an upright trunk position)
of the injured, standing leg and simultaneous stretching of the arms
forward and attempting maximal hip extension of the lifted leg while
keeping the pelvis horizontal. Once every other day, three sets with six repetitions.diver 2

‘The Glider’. The exercise is started from a position with upright trunk, one hand holding on to a support and legs slightly split. All the body weight should be on the heel of the injured leg with approximately 10–20° flexion in the knee. The motion is started by gliding backward on the other leg and stopped before pain is reached. The movement back to the starting position should be performed by the help of both arms, not using the injured leg. Once every third day, three sets with four repetitions

‘The Glider’. The exercise is started from a position with
upright trunk, one hand holding on to a support and legs slightly split.
All the body weight should be on the heel of the injured leg
with approximately 10–20° flexion in the knee. The motion is started
by gliding backward on the other leg and stopped before pain is reached. The movement back to the starting
position should be performed by the help of both arms, not using the
injured leg. Once every third day, three sets
with four repetitionsslider 3

Hamstring curl on swiss ball

Hamstring curl on swiss ballhamstring curl 2

 

Single leg glute bridge

Single leg glute bridgebridge 2

Eccentric knee extensions

Eccentric knee extensionsbridge towel 2

Brughelli and Cronin (2007) suggest alternative eccentric exercises to the Nordic hamstring exercise due it being an open chain exercise that is bilateral which could cause one leg to take more the strain than the other leading to asymmetries. Also that it is a single joint exercise whereas the hamstrings are bi-articulate that is stretched over the hip flexion and knee extension. It would be more specific to perform multi-joint eccentric exercises that involve more muscle groups working together. Brughelli et al (2009) showed the functional eccentric exercises below to be effective in returning an Australian rules football player who had three previous muscle strain injuries confirmed by MRI (grade II and III muscle strain injuries) to his right hamstring (long head of the biceps femoris) over the previous four years. Playing every game in the subsequent season injury free and the exercises also altered the optimum angle of peak torque of the knee flexors and extensors.

Malliaropoulos et al (2012) also recommend exercises that also incorporate both hip and knee concentric and eccentric actions due to the bi articular nature of the hamstring muscle group. Also active lengthening of the hamstring muscles may occur both in the late swing phase (open kinetic chain) and during late stance phase (closed kinetic chain) of sprinting. This suggests that open and closed kinetic chain exercise should be included in prevention programmes. The hamstrings lengthen under load from 45% to 90% of the gait cycle (swing) absorbing imposed mechanical energy, and then shorten under load from late swing through stance to reuse this energy. Therefore, they strongly advise to use of Stretch Shorten Cycle exercises and combine them with isolated eccentric exercises in open or closed kinetic chain in order to replicate hamstring function.

Eccentric Backward Box Drops

Eccentric Backward Box Dropsback drop 2

Eccentric loaded lunge drops: The trainee rises up onto his or her toes while taking a lunge stance, with or without resistance. He or she then quickly drops onto the ground with his or her feet landing flat and balanced. Then he or she will resist the downward forces into a deep lunge position while maintaining good posture

Eccentric loaded lunge drops: The trainee rises up onto his or her toes while taking a lunge stance, with or without resistance. He or she then quickly drops onto the ground with his or her feet landing flat and balanced. Then he or she will resist the downward forces into a deep lunge position while maintaining good postureeccenric loaded lunge 2

Single leg RDL with alternating toe touches

Single leg RDL with alternating toe touchesSingle leg RDL with alternating toe touches 2

Other exercises include double and single leg dead lifts and Romanian dead lifts, Eccentric split stance zerchers and eccentric leg curls.

Stretching

The results of intervention studies (Arnason et al., 2008; Askline et al, 2013; Sherry and Best, 2004) and one randomised controlled trial (van Mechelen et al., 1993) question whether flexibility reduces hamstring injuries. A non-randomised intervention involving contract-relax hamstring stretches in elite Scandinavian soccer teams failed to reduce injury rates which were statistically indistinguishable from those of teams that declined to follow the program (Arnason et al., 2008). In a randomised comparison of two rehabilitation programs, Sherry and Best (2004) compared a progressive agility and trunk stabilisation approach to one that involved isolated strengthening and stretching of injured muscles. The strengthening and stretching was particularly ineffective as it resulted in significantly more injuries in the 1 year follow-up period than the alternative program. In Askling et al (2013) study they found that there C protocol which included contract relax stretching showed increased re injury rates when compared to their L protocol that involved no static stretching.

However in Malliaropoulos et al (2004) study they investigated the effect of the stretching component of rehabilitation in 80 athletes who had sustained acute hamstring injury. Their study compared two rehabilitation programmes in which the only difference was the number of stretches performed. Each stretching session consisted of a static stretch to mild discomfort applied to the hamstrings for 30 seconds and repeated four times. One of the groups had one session per day while the other group had four stretching sessions per day. The results showed that the group that performed four stretching sessions per day regained their range of motion more quickly and had a shorter rehabilitation period, with both differences being statistically significant.

Castellote-Caballero et al (2012) showed that a neural mobilization slider technique on the sciatic nerve was effective in significantly improving passive SLR range of motion after only a week which included 3 sessions, in 14 football players. The subjects sat with their trunk in thoracic flexion (slump) and while maintaining that posture, they performed alternating movements of knee extension/ankle dorsiflexion with cervical extension, and knee flexion/ankle plantar flexion with cervical flexion. Subjects performed these active movements for approximately 60 s and repeated them 5 times.  Neurodynamic slider technique could perhaps be more effective at reducing injury rates than static stretching due to 16% of hamstring injuries showing no signs of muscle damage on MRI (Mendiguchia et al, 2012).

Return to Play

With signs of damage on MRI still being shown after full rehabilitation programs and no signs of symptoms on clinical examination it seems important to utilize progressive running sessions into rehab to assess how the hamstrings are functioning and also whether people are able to return to sport. Progressive running programs were utilized in Slider et al, (2013) study which is shown in the table below.

Level

Acceleration Distance (m)

Constant Speed 75% of Max (m)

Deceleration distance (m)

1

40

20

40

2

35

20

35

3

25

20

25

4

20

20

20

5

15

20

15

6

10

20

10

When the subjects were able to complete a level 3 times pain free they were progressed to the next level. This programme tests out the hamstrings when they are most vulnerable to injury during acceleration and deceleration in high speed running.

Another way of doing this could be to the subject run 90 metres with the first 30 m being acceleration, middle 30 m being constant speed and final 30 m to deceleration. The acceleration and deceleration distances can then be reduced and constant speed distance being increased keeping the exercise to 90m long to progress the exercise, this is utilized by THFC.

A test devised by Askling called the Askling H test involves performing a SLR with the knee kept in full extension and ballistic hip flexion is performed. If the subject showed signs of pain or lack of subjective confidence when performing the test it was positive. It was utilized in their 2013 study where if the test was positive rehab was continued for another 5 days. This could have contributed to their low re injury rates, which could suggest that this test should be utilized when determining whether a player is fully able to return to sport.

Conclusion

Hamstring strains are still very prevalent and a massive problem to people participating in sport. However in recent years promising research has been shown to be effective in reducing hamstring strain injury and re injury rates. It seems to suggest that the most effective rehabilitation and prevention protocols include eccentric training with trunk musculature training included instead of concentric and stretching training. In this piece I’ve included some of the exercises that were in the most successful protocols along with progressive running drills and a progressive nordic hamstring exercise protocol for the prevention of hamstring strains.  I hope you have enjoyed reading this and comments about your experiences with hamstring strains and rehab protocols would be very welcome. With thanks to Tim Campkin: @timcampkin89 for being my model in the pictures and Paul Starrs: @starrs89 for his input.

Reference List

Arnason, A., Andersen, T.E., Holme, I., Engebretsen, L. and Bahr, R. 2008. Prevention of hamstring strains inelite soccer: an intervention study. Scand J Med Sci Sports, 18(1):40–8.

Askling, C.M., Tengvar, M. and Thorstensson, A. 2013. Acute hamstring injuries in Swedish elite football: a prospective randomised controlled clinical trial comparing two rehabilitation protocols. Br J Sports Med, 00:1–8.

Brughelli, M. and Cronin, J. 2008. Preventing Hamstring Injuries in Sport. Strength and Conditioning Journal, 30 (1), 55-64.

Brughelli, M., Nosaka, K. and Cronin, J. Application of eccentric exercise on an Australian Rules football player with recurrent hamstring injuries. Physical Therapy in Sport10, 75–80.

Castellote-Caballero, Y., Valenza, M.C., Martín, L.M., Martos, I.C., Puentedura, E.J. and Fernández-de-las-Peñas, C. 2012. Effects of a neurodynamic sliding technique on hamstring flexibility in healthy male soccer players. A pilot study. Physical therapy in sport, 1 (7).

Malliaropoulos, N., Papalexandris, S. and Papalada, A. 2004. The role of stretching in rehabilitation of hamstring injuries: 80 athletes follow up. Medicine Science Sports and Exercise36:756-759.

Mjølsnes, R., Arnason, A. and Østhagen, T. 2004. A 10-week randomized trial comparing eccentric vs. concentric hamstring strength training in welltrained soccer players. Scand J Med Sci Sports, 14:311–17.

Mueller-Wohlfahrt, H.W., Haensel, L., Mithoefer, K., Ekstrand, J., English, B., McNally, S., Orchard, J., van Dijk, C.N., Kerkhoffs, G.M., Schamasch, P., Blottner, D., Swaerd, L., Goedhart, E. and Ueblacker, P. 2013. Terminology and classification of muscle injuries in sport: The munich consensus statement. Br J Sports Med,  47(6):342-50.

Petersen, J., Thorborg, K. and Nielsen, M.B. Preventive effect of eccentric training on acute hamstring injuries in men’s soccer: a cluster randomized controlled trial. Am J Sports Med39:2296–303.

Sherry, M.A. and Best, T.M. 2004. A comparison of 2 rehabilitation programs in the treatment of acute hamstring strains. J Orthop Sports Phys Ther34(3):116–25.

Slider, A., Sherry, M.A., Sanfilippo, J., Tuite, M.J., Hetzel, S.J. and Heiderscheit, B.C. 2013. Clinical and Morphological Changes Following 2 Rehabilitation Programs for Acute Hamstring Strain Injuries: A Randomized Clinical Trial.

Thorborg, K. 2012. Why hamstring eccentrics are hamstring essentials. Br J Sports Med46, 7.

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1 Comment

  1. Thanks so much ! A splendid article.

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