Keyword: anterior cruciate ligament injury, athletic rehabilitation, periodization

Of the 250,000 anterior cruciate ligament (ACL) injuries documented each year in the USA, approximately 65% of these injuries require reconstructive surgery. Appropriate rehabilitation after ACL reconstruction can give predictably good outcomes, with return to previous levels of activity and high knee function. Periodization training is used at all levels of sports training and is a method to design resistance training programmes (1). Whether conceptualized and directed by coaches, or by athletes themselves, competitors structure their training in a cyclic fashion, enabling athletes to best realize their performance goals. This blog explores this concept further. 

The return to sport and  play of athletes after an injury must progress through the recovery of strength, neuromotor control, and cardiovascular training with consideration of different psychological aspects. A different approach must  focus on factors including motor control, progressive development of strength and cognition should be considered during sports rehabilitation .

What is periodization in rehabilitation?

Periodization is the planned manipulation of training variables (load, sets, and repetitions) to maximize training adaptations while minimizing fatigue and injury. It is relevant to the optimization of muscle strengthening, athletic qualities, and neurocognitive qualities of athletes during rehabilitation after injury (2). 

Periodized training is a safe method of training for healthy athletes, as well as those in pain or following an injury (1).There are yet to be been randomized controlled trials in this topic, however the ideas in this blog may stimulate further suitable studies investigating the application of periodization in rehab. Various models of periodization exist, with the two most common being linear and nonlinear (3).

• Linear periodization adjusts exercise volume and load across a series of predictable phases or mesocycles. This stepwise progression from one training stage to another based on intended goals is similar to advancing a rehabilitation protocol from one stage of recovery to the next. 
• Non-linear periodization, on the other hand, involves a more frequent change of volume and load within a mesocycle.

Practical applications

Day to day, sport physical therapists use periodization, commonly in postoperative “protocols” that serve as rudimentary forms of periodization over short time frames. An example would be the postoperative progression of an athlete recovering from ACL reconstruction.The initial post-operative phase of rehabilitation focuses on pain and swelling management, restoration of range of motion, quadriceps recruitment, and normalizing gait mechanics. Once an athlete meets these goals, they can begin a periodized resistance training program. 

The injury-induced reduction in physical and mental function associated with sports training and competition infers that it is illogical that a single recovery strategy and/or a generic one-size-fits-all approach would address a player’s recovery requirements (4). Alternatively, a framework where strategies are sequenced systematically at independent time points to match the source of physiological stress, alongside consideration to favorable adaptation, might be a preferred approach in sports. In line with this, strength and conditioning coaches and rehabilitation specialists may select better ways to control fluctuations in the competitiveness of individuals and teams, in addition to the already well-established variations in traditional training components (i.e. volume and intensity). Monitoring will help physical therapists and coaches to detect unexpected adaptations in the athletes’ fitness traits and adjust rehab and training loads according to these measured responses.

The neurocognitive mesocycle

It is well known that the vast majority of non-contact injury events occur while athletes are cognitively distracted, attending to complex visual demands or environmental stimuli. This suggests that neural mechanisms may directly contribute to the athlete’s ability to safely interact with the dynamic sport environment. Neurocognitive tasks, such as those measuring reaction time, processing speed, visual memory, and verbal memory, are well established in the neuropsychology literature as indirect measures of cerebral performance (5).

Situational awareness, arousal, and attentional resources of the individual may influence several areas of neurocognitive function, affecting the complex integration of vestibular, visual, and somatosensory information needed for neuromuscular control. Over the course of rehabilitation following injuries, excitability of the motor cortex for quadriceps and other contractions decreases, This neuroplastic disruption progresses until altered motor strategies potentially become the norm. Subsequent restoration of baseline function then becomes a must against maladaptive neuroplasticity developed in the wake of altered central nervous system (CNS) input and motor output compensations. A most interesting and widely unexplored aspect of implicit learning in rehabilitation is its connection with anticipation and decision-making (6). This may be important in the late stages of rehabilitation, when athletes are approaching the return to sport phase.

Take home message

Having a basic understanding of periodization theory may be helpful / important for sports rehabilitation specialists. Such an understanding can help sports medicine teams to better interact with the competitive mindset of athletes, their coaches, and their goals. Sports rehabilitation specialists become more able to skillfully plan rehabilitation programs that then progress toward the realization of the patients’ treatment goals.

Authors: Georgios Kakavas PT OMT PhD (1, 2) and Florian Forelli PT PhD (3, 4, 5)

1 University of Thessaly, Volos, Greece

2 Fysiotek Spine and Sport Laboratory, Athens, Greece

3 Orthosport Rehab Center, Domont, France

4 Clinic of Domont, Domont, France

5 SFMKS Lab, Pierrefitte sur Seine, France

References

1.Kakavas G, Forelli F, Malliaropoulos N, Hewett TE, Tsaklis P. Periodization in Anterior Cruciate Ligament Rehabilitation: New Framework Versus Old Model? A Clinical Commentary. International Journal of Sports Physical Therapy. 2023 ;18(2):541-546. DOI: 10.26603/001c.73035. PMID: 37020434; PMCID: PMC10069386.

2.Kakavas G, Malliaropoulos N, Bikos G, et al. Periodization in anterior cruciate ligament rehabilitation: a novel framework. Med Princ Pract. 2021;30(2):101-108. 10.1159/000511228 

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