Injuries are major setbacks for amateur and professional athletes. The recovery process from injury requires dedication to an early rehab process, followed through with highly functional, sports specific training. The decision to finally return to play (RTP) is complex, and we would like to share some thoughts on the topic here.
The narrative for decision making on RTP was initially always based on time. This was largely based on the tissue healing process. Looking specifically at soft tissue injuries, such as muscle or ligament, this process can be divided into three distinct healing phases, each generally occurring over a consistent time span. This process can take just 10 days to occur for mild injuries, but for more severe injuries it may take up to 8 weeks. Bones, tendons, and cartilage also have different healing time spans. So using time is a well proven method, but is it the holy grail of RTP? The old train of thought was that only once a tissue is completely healed in what is termed the remodelling phase (final phase), can an athlete return to their field of practice.
There is a new narrative on RTP in the modern sports world. Functional outcomes are showing to be extremely valuable in deciding on RTP rather than using pure time based decisions based on tissue healing. For example, initiating return to running post ACL reconstruction always started at 4-5 months. There is a body of research now to show that once the athlete can meet certain movement criteria (hops, single leg movements, strength tests, etc.) they are cleared to start a gradual running program. This can be as early as 3 months (although unlikely in most cases). The point is that functional based outcome measures may be more useful for RTP decision making.
Early tissue loading is another point of discussion regarding RTP. Current evidence suggests that early tissue loading in muscle strains may lead to earlier RTP than more conservative methods that rely solely on tissue healing times. For example, early active knee flexion within pain is beneficial to treating a hamstring strain; rather than waiting for the tissue to be in an ‘ideal state of healing’ for exercise to begin. This likely follows through with Wolfs Law, where tissue essentially adapts to the tensile forces placed on it. We would say that regardless of tissue state, the tissue will become stronger according to the demands placed on it. However, deciding what level of tensile force will be put through the injured tissue is key to allowing healing to occur.
We should also always be aware of the context. Each injury and individual is different, and will respond differently to loading. Also, different body tissues respond differently to load. For example, a reactive tendinopathy cannot be loaded into the point of pain as this will not allow for the tissue to settle down. A chronic tendinosis, however, can be loaded into pain as this would indicate enough force in the tendon to initiate a tissue regeneration response. Clinical decision making here is key.
The key question we need to ask ourselves is this: what is the most force that the injured tissue can handle NOW. And specifically regarding RTP, is the tissue resilient enough to handle the demands of the sport. A great way to think about RTP decision making is training load. Training load is mostly recorded as a function of internal and external loads. External loads are those that are imposed on the body, or stressors placed on the body. internal loads are the bodies response to those stressors, or stress reactions. An example of the ACL reconstruction athlete returning to play could be as follows: external stressors such as volume (distance run per session, time run per session, accelerations/decelerations per session, etc.); and internal stress reactions such as HR responses, local tissue response in the form of pain/inflammation/discomfort, local muscle soreness/fatigue, etc. How we quantify local tissue response is difficult, but sessional Rating of Perceived Exertion (sRPE) is a reliable way to do this. sRPE can be a great tool to monitor your athletes response to loading when deciding on RTP, as this would need to match the demands required for a normal match situation.
Some key concepts to think about when deciding on an athletes RTP are as follows. These are in depth topics that require detailed discussion:
- Control-chaos continuum (how much control does the athlete have over the movements and decision making when challenged with external stressors during rehab)
- Motor learning (how has the athlete relearnt movement, or is the movement under conscious control or subconscious control)
- Strength symmetry ratios (are there large deficits in the injured and uninjured limbs relative to specific movements)
- Sport specific demands (is the athlete resilient enough to withstand the forces required for their specific sport)
- Psychological readiness (is the athlete psychologically ready to return to the field)
In conclusion, RP decision making is complex, and requires in depth understanding of the demands of the sport. Clear functional outcomes should always be used, and clinical decision making makes the difference between too-early and too-late RTP.