How to rehabilitate your hamstring strain injury
Author: Leo Bell (Physical Performance Coach)
In Part 1 and Part 2 of this series we identified the risk factors precursor to hamstring strain injury and the appropriate exercise selection to mitigate those risks. However, despite our best efforts to prevent hamstring strains, there is a possibility they will still occur due to non-modifiable risks such as age and previous injury. Therefore, in this final part of the series we will discuss how we rehabilitate a low grade hamstring strain, and the special considerations in returning to athletic performance.
Acute Stage (0-48hrs)
The age old first aid practice of ‘RICER’ (Rest, Ice, Compression, Elevation, and Refer) still applies in the acute management of hamstring strain injury. This aims to reduce the secondary damage imposed by the acute-inflammatory response to the injured site. If left alone, an increased amount of swelling and inflammation into the muscle tissue will pronounce damage and muscle soreness, and extend healing time as it will take longer to subside. Apply ice for 10-20 minutes every 2 hours for the first 12-24 hours post injury, and maintain compression throughout the 48 hour period to minimise the secondary damage. Avoid consumption of alcohol as this will exacerbate inflammation and bleeding of the injured site, and will consequently disrupt the rehabilitation. After this period, the athlete should see a Physiotherapist to assess the grade of the injury.
Sub-Acute Stage (3-7days)
Following the initial management, the athlete should be ready to commence some level of exercise rehabilitation. Conventional hamstring rehabilitation begins with an isometric exercise (hamstring bridge) in a shortened position (90deg knee bend). This exercise is progressed throughout the range of motion at the knee. The criteria to progress is an absence of pain during this exercise and walking. The reasoning behind this is because pain can induce inhibition of the muscle. This is a protective mechanism, to avoid strain of the affected area. However, an issue with this is that it limits the ability to progress in the early stage of rehab. Additionally, a lack of stimulus for the hamstrings will lead to a chronic inhibition of the muscle group, and increase the risk of recurring hamstring strain injury. Despite this, we still utilise the hamstring bridge to assess and compare clinical signs such as pain, strength and power with the unaffected leg to monitor the asymmetry of the injured leg.
A more accelerated approach advised by the Hamstring Injury Research Group commence with isotonic exercises and regress or progress according to how the individual responds. The following are the hamstring exercises that we use during this early stage:
- Double Leg Hamstring Bridge 1-3 sets x 10-15 repetitions
- 45 Degree Double Leg Hip Extension 1-3 sets x 8-12 repetitions
- Double Leg Eccentric Slide Leg Curl 1-3 sets x 4-8 repetitions
- Straight-line run-throughs; 1-3 sets x 10 repetitions x 50m at a tolerable pace
As I have formerly mentioned in part 1 and part 2, peak eccentric strength and fascicle length are significant determinants of hamstring strain injury. Therefore the integration of eccentric-biased exercises are a cornerstone of successful hamstring rehabilitation for those physiological and structural adaptations to occur. Additionally, the introduction of straight-line running (no matter how slow) is also important in the loading of affected and unaffected soft-tissue. These exercises are then progressed once the athlete has tolerated them (4/10 or less pain), throughout a full range of motion.
- Single Leg Hamstring Bridge 1-3 sets x 10-15 repetitions
- 45 Degree Single Leg Hip Extension 1-3 sets x 8-12 repetitions
- Single Leg Eccentric Slide Leg Curl 1-3 sets x 4-8 repetitions >> if tolerated progress to Nordics 1-2 sets x 4 repetitions
- Lumbo-Pelvic Mobility Exercises
- Running Mechanic Drills at low velocity
- Lateral steps, Side to Side, Grapevines at low velocity 5 x 10m
- Straight-line run-throughs; 1-3 sets x 10 repetitions x 50-100m at a tolerable pace
- Fartlek (walk-jog) curve-linear; progress total volume
These exercise progressions gradually increase the difficulty and demand of the hamstring group. If the single-leg eccentric slide is tolerated by the athlete, they are then progressed to the Nordic hamstring exercise (NHE). The NHE is most effective in developing peak eccentric strength and fascicle length. Additionally, the NHE will provide a strong stimulus to restore neural activity and excitability which is otherwise lost due to inhibition. The inclusion of lumbo-pelvic mobility and running mechanic drills are used to reinforce positive behaviours during running and protect the athlete from adopting biomechanics that may promote strain on the hamstrings. By the end of the week the athlete may be able to establish a tempo which they feel they can comfortably run in a straight line. This may be reported as a percentage of their maximal effort (e.g. 50%). From this we are able to prescribe intermittent type training to introduce some aerobic conditioning. The inclusion of simple change of direction and Fartlek style running in a curve-linear (S-curve) pattern allows other muscle groups (calves, adductors) to be loaded alternatively to straight-line running, increase overall training load, and has been shown to reduce hamstring strain injury recurrence. This also assists in the avoidance of overuse injuries such as tendinopathies and helps maintain a regular training-stress balance.
Reconditioning Phase (7-14days)
Once the athlete is beginning to clear these clinical signs, they must improve their hamstring’s capacity to withstand increased internal and external loads. As a practitioner and athlete, the mindset should be focussed on returning to performance in better condition than prior to their injury. This should strongly consider the physical demands of the athletes sport. Otherwise they will return deconditioned and perform poorly in a competitive environment. Strengthening exercises should continue to progress to increase the overall strength, speed and endurance capacity of the hamstrings. The following can be included in addition to the previous examples:
- Rack-pull or Trap-bar Deadlift 2-3 sets x 6-8 repetitions at starting light weight
- Lunge 2-3sets x 6 repetitions starting at bodyweight
- Fast eccentric leg curl on fitball 2 sets x 6 repetitions
- Double leg broad jump 2 sets x 4 repetitions
- Introduce acceleration and decelerations – Run 5m + Decelerate 5m x 4 repetitions (progress Run in 5m increments e.g. 10m Run, 5m decelerate)
- Progress Running Tempo and Volume using MAS and game parameters
- Increase change of direction angle and intensity, Y-Cut + T-Cut 5 x 10m
- Low to moderate level training skill and technical drills (e.g. modified kicking distance, no contested work)
Functional Phase (14-21days)
By this stage of the rehabilitation the muscle tissue healing should be complete and pain free. The athlete should be returning to full training, whilst still being mindful of maximal speed efforts in drills. Before a return to competition the athlete should be able to demonstrate equal strength and power qualities between the injured and uninjured leg, ideally within 10% asymmetry. Within a professional setting, practitioners use a NordBoard to assess peak and average eccentric strength, as well as compare left to right. A simpler method would be a single leg hamstring bridge endurance test – the athlete performs as many repetitions as possible on each leg to compare their strength-endurance capacity. Power qualities can also be observed during a single leg bounding test; the athlete can perform one single leg bound, and a triple bound before comparing distances from left to right. Depending on which is the injured leg, there may have already been a pre-existing discrepancy in this performance test due to dominant versus non-dominant leg. Despite this, it is still important information that can compare the functional capacity of the rehabilitated leg. Additionally, athletes will need to have expressed maximal velocity either in training or in a controlled running drill before they are cleared to return to play. Whilst professional sporting clubs have access to GPS technology, this can also be achieved by performing a timed run over a pre-determined distance and calculating the speed using meters per second, or a fitness watch (e.g. Garmin) has the capacity to capture maximal velocity. Furthermore, athletes must demonstrate the muscular and aerobic endurance required at competition level. For Australian Rules football, this requires the player to be able to cover 11-15km with 30% at a high intensity (>15km/h) and intermittent sprint efforts (>25km/h). This type of game parameters session is often completed 7 days before the athletes planned return to play to ensure they are capable of withstanding the rigours of the sport and return to normal training load. If the athlete is able to demonstrate maximal capacity near symmetrical attributes to the uninjured leg, without pain or tightness, then they are cleared to return to play. The following exercises are used during this phase to improve the functional capacity of the hamstrings:
- RDL 2-3 sets x 6-8 repetitions
- Split-squat 2-3 sets x 6 repetitions
- Nordics 3 sets x 4 repetitions
- Prone Glute-Ham Raise 2 sets x 8 repetitions
- Sled Push resisted accelerations 4 x 10m
- Sprinting/Flying Starts 4 x 20m accelerate – 20m hold – 20m decelerate
- Full Training
Once the athlete has returned to play it is important to remain diligent in the maintenance of their hamstrings to prevent recurring injuries. History of hamstring strain injury significantly increases the risk of re-injury, so an increased effort must be maintained to remain injury free. Exercises targeting all aspects of the hamstrings functional anatomy are important to ensure nothing is going overlooked. This includes the use of hip and knee-dominant exercises to get proximal to distal, medial to lateral loading of the muscles and tendons. Additionally, the athlete should have regular high speed exposures; performing one maximal speed effort on a weekly basis to maintain the capacity of the hamstrings to contract at high velocity and maintain training load.
Early exercise intervention has been shown to improve rehabilitation outcomes by reducing time-loss to training and return to play. Furthermore, the appropriate implementation of eccentric-biased exercises will maintain a neuromuscular stimulus and prevent chronic inhibition, which will reduce the chances of recurring injuries. Lastly, gradually progressing the athlete workload towards a return to play is important in ensuring they are fully prepared for competition and avoiding acute spikes in workload that will put them at risk.
Hamstring rehabilitation is modifiable depending on the type of athlete, their chosen sport and the mechanism of injury. If you have experienced a hamstring strain, seek an expert on how to best return to sporting performance.