TIME IS NOT ENOUGH ; A CRITERION-BASED APPROACH TO RETURN TO RUNNING
“So, when can I start running again?” This is a common question during the course of a lower extremity rehabilitation process and rightfully so. The stage at which a patient is able to return to the dynamic activity of running marks an important point in the rehabilitation process and is a key bench mark in the lead up to a gradual return to sporting activity. Unfortunately, the answer to this question is not such a simple one.
Throughout the course of this short blog I would like to lay out the thought process that goes through my mind as a clinician when I am faced with such a question and detail some of the nuances that go into making the appropriate decision for clearance to return to running. The crux of this hypothetical scenario will revolve around the return to running process for an individual who has undergone an ACL reconstruction, however the principles and criteria that are laid out apply across a myriad of post-operative knee procedures with the primary difference likely being the time course and rate of progression.
In many cases the 12-14 week mark is commonly put fourth in many post-operative protocols as the appropriate time to initiate a running progression, yet time alone is not a sufficient variable on which to base decision making, and we have good evidence in the literature that a return to running should be based on achievement of certain metrics and an individual’s ability to display specific bio motor qualities.
While time alone may not be sufficient to determine an athlete’s readiness to begin running it must certainly be a component in the decision-making process. The 12-week mark is often put forth as an appropriate time point second to consideration given to biological factors, namely graft healing. In the early post-operative period, the newly placed graft and points of bony fixation undergo a process of cellular proliferation which is characterized by a period of high tissue turn over, cellular and metabolic activity. During this period of high cellular activity mechanical properties of the tissue demonstrate their lowest resilience to stress and force and excessive forces during this period have the potential to negatively impact the integrity of the repair. Biology matters, but graft integrity and tissue healing should not be the only factors that are considered when determining an individual’s readiness to run.
A review conducted by Rambaud and colleges in 2018 found that only 20% of ACL-reconstruction (ACLr) studies used some form of testing battery or performance metrics to clear patients to return to run. Taking this into account with the vast amount of empirical evidence which suggests that individuals who return to sporting activity too soon or before they possess the sufficient physical and psychological faculties necessary to facilitate a successful return to sport, may be at as much as a fourfold greater risk to re-rupture should give us pause, and provide insight into the significance of having a concomitant criterion based approach to determine readiness for a return to running.
As such having a collection of clinical measures that take into account an individual’s ability to produce and absorb force in addition to various functional markers to gauge confidence, competency and capacity of the knee is vital in maximizing the success of the return to running process.
From a time perspective, the best available evidence suggests that it is reasonable to expect to begin a return to running program between 8- and 16-weeks post operation, but there are a number of clinical and physical expression measures that must also be considered. Below is a breakdown of the “raw materials”, for lack of a better word, and performance metrics based on the available literature that I utilize to guide my decision-making process in determining an individual’s readiness to run. While it is not perfect, there are points that can certainly be up for discussion, and it ultimately will remain fluid and tailored towards the individual I believe that this provides a good framework for maximizing success in the return to running process.
- Clinical
- Minimal to no pain at rest
- Full & Symmetrical knee extension
- 95% plus limb symmetry in knee flexion
- “Quiet knee” (trace to no effusion)
- Tolerant of all ADLs
- Force Metrics (isometric dynamometry)
- 75-80% Quadriceps Limb symmetry Index (LSI)
- 75-80% Plantar flexors (LSI)
- 75-80% Hamstring (LSI)
- Performance Metrics
- Hop Test >= 70% (LSI)
- Single Leg Squat >= 80% (LSI)
- 20+ Single Leg Heel Raises
- Has tolerated and accumulated sufficient volume to establish tissue tolerance in intensive/low impact elastic activities (March drills, ankling, pogos, skipping)
- Rambaud, A. J., Ardern, C. L., Thoreux, P., Regnaux, J., & Edouard, P. (2018). Criteria for return to running after anterior cruciate ligament reconstruction: A scoping review. British Journal of Sports Medicine, 52(22)
- Kyritsis, P., Bahr, R., Landreau, P., Miladi, R., & Witvrouw, E. (2016). Likelihood of ACL Graft rupture: Not meeting six clinical discharge criteria before return to sport is associated with a four times greater risk of rupture. British Journal of Sports Medicine, 50(15)
- Dauty, M., Menu, P., & Dubois, C. (2010). Effects of running retraining after knee anterior cruciate ligament reconstruction. Annals of Physical and Rehabilitation Medicine, 53(3)
- Muller, B., Bowman, K. F., & Bedi, A. (2013). ACL Graft Healing and Biologics. Clinics in Sports Medicine, 32(1)
Kevin McNamara, PT, DPT, CSCS
Physical Therapist
