Failure of Anterior Cruciate Ligament reconstruction (ACLr) currently sits at a rate of ~25-30% when accounting for ipsilateral & contralateral injuries in the young sub-elite athlete. Additionally less than 1/4 of athletes appear to be succeeding in fulfilling their expectation of returning to sport within a 12 month time frame. Within Australia, the prominent graft selection of choice by the orthopaedic community is the hamstring graft. As previously outlined in part 1 of this blog, the selection of a hamstring graft (whilst entirely appropriate in many population groups) does not come without its own unique circumstances of morbidity and implications. For the rehabilitation professional, it is pivotal that a tailored approach is utilised from the early stages of the athletes journey to assist in achieving an optimal outcome. Gone are the days of 'protocol driven' rehabilitation and long gone are the days of 'time driven' progression throughout rehab. Much of part 1 outlined the role that eccentric hamstring strength had in the success or failure of the hamstring graft ACLr, with a mixture of evidence based information and clinically driven anecdotes that have led to my own interpretation surrounding this clinical picture. Part 2 is going to be dedicated towards the rehabilitation process, sharing my experiences, lessons and recommendations for optimising rehabilitation.
5 PHASES OF REHABILITATION
To understand how to optimise the rehabilitation process it's important as the rehabilitation clinician to establish a fundamental system reverse engineering what a fully rehabilitated athlete looks like back to the day they leave the operating theatre. During this process, outlining an 'outcomes based approach' for progression will help you identify the physical qualities that you deem necessary for the athlete to move further into their journey. For our rehabilitation process there are clearly defined objectives in each phase of rehabilitation, these are:
Protection Phase = Tissue Healing
Load Introduction Phase = Establish Load & Key Lift Patterns
Strength Accumulation Phase = Return to Run
Training Integration Phase = Return to Team Training
Return to Performance = Return to Play & Return to Perform
Figure 1: Outcomes Based Approach to Rehab Progression
When we outline the outcomes for each phase, this then dictates the entry criteria into the next phase of rehab and subsequently, the interventions that the clinician will implement. Commonly, this aspect of rehabilitation tends to be forgotten, with many clinicians placing their thought and energy into developing interventions, without giving the time of day to establish the context that surrounds the intervention. What is left is a rehab program that lacks substance and meat and is rather filled with 'stuffing'. This is why I am a fan of what I describe as a 'bottoms up' approach to rehabilitation, allowing for the flexibility that multiple interventions can lead to the outcomes that are dictated by the clinician.
Figure 2: Bottoms Up Rehab Approach Pyramid
Figure 3: Forming Rehab Interventions
By outlining your rehabilitation interventions in this way, you are able to always understand where you are; where you have come from and where you are heading. In this light we recognise that during a long term rehab journey, athletes never truely leave a particular phase of rehabilitation but rather build upon what they had previously achieved, this is what I call, 'building the stairway'. A practical example in the case of the ACLr athlete is that once they have achieved full range of motion and nil swelling within their knee, whilst not an active front of mind piece of attention, we are always maintaining this mantra throughout the rest of the rehab process. This comes into fruition primarily whenever an athlete suffers a setback, to which most do... There will always be periods where an athlete may deal with an increase in effusion in response to increased loads, so we must prepare athletes, both physically and in their behaviour patterns in order to manage this as they arise. In this light we are able to adequately educate and prepare athletes for later stages of their journey by arming them with the tools necessary to manage any speed bumps along the road.
Additionally, by having clear and robust phases for athletes to progress through it gives them a sense of connection, triumph and success as they navigate their way back to performance (whatever performance may mean to them). 12 months can feel like a long time if an athlete is so 'session-centric' that they feel like they are just repeating the same thing 3 times per week for 52 weeks. By breaking things down it allows them to always feel like there is purpose behind each day, building towards the next... They are in essence, building their stairway back to optimal health.
Figure 4: Building The Stairway
With this context in mind we can establish that in order to outline the best interventions for the athlete we need to classify and define what the athlete needs during each phase of their rehabilitation. This is critical as we move on to the actual purpose of this blog, which is to outline the stepped progression in the reconditioning of the hamstrings post hamstring graft ACLr .
For the hamstring graft ACLr, the most important consideration in the protection phase is the knowledge that the athlete has suffered a G4 muscle tendon lesion in the process of harvesting the graft tissue. For this reason we as practitioners must be gentle with our hamstring loading and respect the donor site healing. Personally I like to restrict any specific hamstring loading for the first two weeks post surgery to promote scarring around the distal hamstring insertion site.
Prior to outlining an appropriate progression stream, it is important to understand the streams at which we as rehab professionals will be aiming to reconditioning the athlete. We can do this by breaking down hamstring rehabilitation by two pillars:
Contraction type - Isometric, Concentric or Eccentric (& Integrations)
Position - Knee dominant or Hip dominant (& Integrations)
Figure 5: Classifying Hamstring Rehab Interventions
Once initial healing has occurred, my main principles are placing the athlete in a position whereby they are in control of the load exerted upon them rather than external loads dictating what is sent through the distal hamstrings. In light of this my starting point for distal hamstring load is isometric in inner ranges, gradually working to outer range and through more concentric and eccentric progressions.
Below is an example of a non-exhaustive list of rehab progressions that may be utilised with an athlete during the protection phase (once the initial 2 week healing has passed). It is important to note that progression through this stream is competency based.
Figure 6: Example Protection Phase Progression Stream
Video 1: Hip Bridge - Unloaded Hammy Slide
It is important to consider our overarching phase goals during the protection phase of reducing effusion, restoring gait and quadricep muscle activation. The benefits that hamstring reconditioning in this phase largely centres around allowing the athlete to properly restore the swing phase of their gait cycle via a strong active knee flexion moment.
There are no specific exit criteria in relation to hamstring strength that I utilise in the protection phase.
LOAD INTRODUCTION PHASE
When the athlete transitions into the Load Introduction phase, we must have the future in mind which will aid in the development of our rehab interventions. Foreshadowing that the end of this phase will dictate a graduation to returning to run, we can reverse engineer that the role of our reconditioning is centred around developing muscle capacity that will tolerate our early stages of returning to run.
With this in mind, fundamental themes of our hamstring reconditioning include:
Maintaining a strong hip extension pattern
Isometric knee dominant yielding
Strong concentric knee flexion
In this phase I will aim to develop the following streams:
Isometric ground based yielding (Supine Bosch Hold Stream)
Concurrent hip extension & isometric knee flexion (Hip Bridge Stream)
Concentric Knee Flexion (Hamstring Curl Stream)
Introduce Eccentric Stimuli (Slider Stream)
Figure 7: Example Load Introduction Phase Progression Stream
Video 2: Supine Bosch Hold (30 deg)
Video 3: Hamstring Slider (DL Eccentric)
Outcome measures that I utilise in the load introduction phase involve a series of Isometric strength markers at differing joint angles utilising the Vald Performance Nordbord, as well as Hamstring Bridge (Foot Elevated Hip Bridge) capacity testing.
STRENGTH ACCUMULATION PHASE
The strength accumulation phase can be identified the meat and vegetables of ACLr rehabilitation. As rehab professionals, we must expose athletes to maximal torque production in this phase in order to overcome lasting elements of neuromuscular inhibition. This phase also allows us the opportunity to chase physiological adaptations such as increased fascicle length, increased tendon cross-sectional area and re-organisation of collagen tissue as the initial healing process should well and truely be finished.
Primary principles I utilise in this phase are to challenge the hamstrings in an integrated manner, whereby external loads & forces (such as gravity) are dictating the load placed upon the hamstring complex rather than letting the athlete dictate loading.
Figure 8: Example Strength Accumulation Phase Progression Stream
It is important to recognise that with the athlete returning to run in this phase, in tandem with a linear progression of eccentric loading, weekly periodisation of hamstring load becomes of paramount importance. One strategy which can be implemented is the dosage of the heaviest eccentric load, separated from the athletes speed based run and placed prior to a lower risk type run such as a volume run in order to minimise risk of hamstring injury.
Outcome measures that I utilise in the Strength Accumulation phase involve a series of Isometric & Eccentric strength markers at differing joint angles utilising the Vald Performance Nordbord, as well as Isokinetic Concentric Strength.
Video 4: Harop Curl
Video 5: Band Assisted Nordic Fall
Video 6: GHD - Glute Ham Raise
TRAINING INTEGRATION & RETURN TO PERFORMANCE PHASE
The Training Integration & Return to Performance Phase have a large focus on developing rate of force development and building resilience towards the more chaotic demands that sport places upon the body. Breaking down the role of the hamstrings in protecting the ACL, as previously outlined in part 1 of this series, we can identify there is a large eccentric contraction and braking force that the distal hamstrings produce to protect the ACL during deceleration. Similarly a rapid yielding isometric contraction is seen in high speed running and change of direction moments.
For this reason, our interventions should be geared towards rapid force production and there should be a positional re-organisation component in order to maximise the bodies integration strategy with the trunk and pelvis.
Figure 9: Example TI & RTP Phase Progression Stream
Video 7: GHD - Bosch Hold + OH MB Slam
Outcome measures that I utilise in the remaining two phases involve building on a series of Isometric & Eccentric strength markers at differing joint angles utilising the Vald Performance Nordbord, as well as Isokinetic Concentric Strength.
Hamstring reconditioning post ACLr involves an intricate relationship between allowing the donor site to heal, developing localised capacity of knee flexion in multiple contraction types, integrating hip and knee dominant patterns to develop architectural changes and co-ordination of the pelvic and trunk systems to maximise efficiency of loading. Utilising a phased rehab system and a multi-factorial intervention selection process we can create a progression stream that ensures the athlete is robust upon their return to sport and reduce the risk of ACL & hamstring re-injury.
If you are interested in learning about systemising the clinical progression and business scalability involved with athletic rehabilitation. The Athletes Authority ACL Mentorship might be the perfect piece of PD for you.
Yours in Rehab