From Injury To Field: How To Combine Rehabilitation & Athletic Programming
The goal of rehabilitative programming is to stress healing tissue while athletic programming strives to optimize healthy tissue. The most frequently overlooked aspect of therapy is the rehabilitation plan. Therapists usually set short term goals in the initial assessment, but scrolling through any clinician’s patient notes will typically show “Progress” under the PLAN subheading. This fly by the seat of your pants approach often leads to sup-optimal results, poor patient recovery and decreased retention.
To understand how to program for rehabilitation, it is important to understand the basics of tissue healing and injury timeframes. Depending on the tissue that is injured, a standard timeframe of tissue healing will occur. These timeframes can vary significantly based on many factors, including the size and severity of the injury. Below are general healing guidelines for various tissues within the body.
There are many factors that influence tissue healing. Based on wound healing studies, the following factors have been shown to impact the tissue repair process.
To the clinician dealing with an injured patient, we must understand how these factors can alter the course of healing as it affects our rehab programming and plan of care. For example:
- Age has been shown to delay the healing response in seniors during each phase but not the quality of the tissue
- Diabetes affects tissue healing in many ways including hypoxia, prolonged inflammation from free radicals, dysfunctional angiogenesis, and impaired collagen synthesis
- Alcohol alters the proliferative phase of healing, negatively impacting collagen production even in small doses
- Smoking slows healing through decreased blood flow and peripheral vasoconstriction, leading to tissue hypoxia
This is one reason why it is important to conduct a thorough history, including medical conditions and medications, and screen for any red flags.
Characteristics of the Injury
There is more or less healing potential depending on the area of the body affected. For example, a hamstring muscle may heal faster if the injury is more distal, and does not affect the musculotendinous junction. Although both fall under muscle healing guidelines, these injuries are not considered equal in terms of recovery. Another example is in the meniscus, which has blood supply to the peripheral third of the tissue. With better vascularity in that region, there is a greater healing potential.
Injury timelines may be classified according to the tissue (muscle, tendon, ligament, bone), but there are certain pathologies that will have specific prognoses. For example, adhesive capsulitis (frozen shoulder) can last up to two years and progresses through 3 distinct phases. Although you may classify an injury under certain tissue healing guidelines, the pathology itself will dictate the prognosis.
Surgical intervention will also change the timeline, although tissue healing guidelines are still applicable. For example, surgical repair of a Gr. III ACL tear will follow the tissue healing guidelines for ligaments, but there are factors specific to an ACL reconstruction that must be incorporated into a rehabilitation program. In addition, these considerations are modified in response to individual patient factors (such as pain, strength, ROM, medical history, etc).
Phases of Rehabilitation
The phases of rehabilitation are not distinct but rather overlap. To progress from one stage to the next is not as simple as determining the timeframe from the injury, however these timeframes are essential in understanding the normal physiological response of healing tissue. The rehabilitation process is like cooking, preparing the ingredients are the first step (acute phase), cooking the ingredients are the second step (subacute) and putting them together to create a meal is the third step (chronic). As with cooking, these phases overlap. You may have vegetables already cooking while you prepare the meat. Similarly, the acute phase and subacute phase overlap as inflammation subsides while fibroblasts begin laying down new collagen.
Acute (< 4-6 days)
Also known as the Inflammation Phase, the acute phase is characterized by the use of the RICE, PRICE or POLICE principles. The POLICE method is more recent and stands for protect, optimal loading, ice, compression, and elevation. Optimal loading of injured tissue can mean immobilization (as in a fracture) or gentle active or assisted movements. Inflammation is incredibly complex and involves a cascade of many biochemical processes. These include hemorrhage and inflammation, secondary edema formation, pain and muscle spasm, and hematoma or substrate organization.
Subacute (4-21 days)
As inflammation subsides, the clinician must adequately stress the tissue without overdoing it. This is usually accomplished through low resistance and high repetition exercises. During the subacute phase, any bleeding that has clotted and formed a hematoma begins to be reabsorbed. Fibroblasts begin synthesizing granulation tissue and laying down fragile, disorganized Type III collagen. Throughout this phase, gentle loading of the tissue will start to remodel collagen fibers. They begin to thicken and align themselves in the direction of tissue stress.
Above, granulation tissue is shown on the left and is magnified on the right. The dark lines that branch throughout the tissue are fragile Type III collagen that will eventually be replaced by stronger Type I collagen.
Chronic (21 days – 12 months)
During this stage, tissue remodelling occurs and collagen fibers are capable and more appropriately oriented to withstand tensile stress. The chronic phase is the most poorly executed stage by rehabilitation professionals, partly due to the lack of formal education provided in PT school. In our opinion, the chronic phase should be transitioned to an athletic, strength-based periodization program with specific modifications based on the initial injury. The first 2.5 months are crucial after injury because it is during this period that collagen can be remodelled easily. Type III collagen is synthesized during the subacute phase and the quality of that collagen is the main difference in the chronic stage of healing, where weaker Type III collagen transitions into stronger Type I collagen. Type I collagen can be seen below with its characteristic striped band appearance and thicker fibers. Notice how these fibers are well aligned in the direction of tensile stress applied to the tissue.
There is a balance between production and degradation of collagen, yet the type III collagen responds favourably to increased tensile stress. Adhesions can occur if this tensile stress is not applied. During the first 2.5 months, collagen forms weaker hydrogen bonds with other collagen fibers. These weaker bonds allow for the remodelling changes during the subacute and chronic stages. After 3.5 months, collagen forms stronger covalent bonds, making it less responsive to change. In cooking terms, you need to heat the food for an appropriate amount of time or risk burning it, at which point it is much more difficult to produce a quality meal.
Throughout these phases, indicators to progress rehab include the amount of pain, swelling and fatigue. If exercise or movement increase these factors, then activity is being progressed too quickly. Transition to subsequent phases of the rehabilitation program depend on individual criteria, outcome measures, functional tests, soreness, and tissue healing guidelines.
Another method of structuring a rehabilitation program is through a five phase model:
These five phases occur in a step-wise manner and are based on tissue healing principles. As mentioned above, each injury will be unique and may require an accelerated progression through each phase. For example, research supports an accelerated rehabilitation program for Gr. 1 and 2 lateral ankle sprains. As with many injuries, a significant overlap is necessary between each phase as long as the progression is logical and systematically applied.
The phases of a strength and conditioning program have been layed out in the essential book Periodization Training for Sports by Tudor Bompa. In his book, Bompa explains the foundations of strength periodization and programming for various sports. The following is a brief summary of the most applicable phases that must be understood by the rehabilitation professional in order to get an athlete back to play.
Phases of Strength Periodization
1. Anatomical Adaptation (AA)
The anatomical adaptation phase is the starting point for both novice and elite athletes. It’s role is to prep the body for future training cycles by establishing a minimum strength level in the muscles and connective tissue (tendons and ligaments), as well as to provide a base of aerobic conditioning. The layout of this phase must progress from a high number of exercises and repetitions, low loads, and shorter rest to higher loads and lower training volume. Typically, circuit training is used during this phase as well as body weight exercises for novice athletes. This phase is essential to reduce the risk of injury and to set a solid foundation for athletic performance. The anatomical adaptation phase should last for 6-10 weeks in novice athletes and 2-4 weeks in elite athletes in order to allow the structural adaptations to occur within connective tissues.
2. Hypertrophy (Hyp.)
Once the body is prepared, the next phase is the hypertrophy phase. The goal is to increase muscle size (cross-sectional area) and the energy storage system within the muscles. Doing so provides a better foundation for the body to recruit more muscle fibers. This phase is not essential because most sports require relative strength without an increase in overall muscle mass. Therefore, many programs will transition directly from the anatomical adaptation phase into the maximum strength phase.
3. Maximum Strength (MxS)
Whereas the previous phases focused on the structural adaptations needed as a foundation for strength training, the maximum strength phase is primarily concerned with harmonizing the relationship between the central nervous system (CNS) and peripheral nervous system (PNS). There are four main ways to develop maximum force in the body; this phase focuses on the first three:
1. Intermuscular Coordination – defined as the ability of the body to coordinate firing of the specific muscles within the body that are needed to produce a movement (i.e. jumping). Technique training performed explosively with low-moderate load and multiple repetitions is essential for intermuscular coordination (developed in Maximum Strength-I Phase). When intermuscular coordination is optimized, muscle firing is more efficient and fewer motor units are used to perform the same movement.
2. Intramuscular Coordination – involves synchronization, recruitment and rate coding. Synchronization is the ability to contract motor units simultaneously. Recruitment and rate coding are arguably more important for maximum strength. Recruitment is very similar to synchronization but instead deals with the ability to recruit motor units simultaneously. The more muscle units recruited, the more forceful the contraction. Rate coding is the ability to increase the firing rate of the motor units involved. This is typically involved in power training with high force production in minimal time.
3. Disinhibition of Inhibitory Mechanisms – receptors within muscle, such as the golgi tendon organs, inhibit muscle activation if tension in the muscle is too high. These receptors along with other CNS inhibitors, become disinhibited through neuromuscular training allowing alpha motor neurons to fire at a higher rate.
4. Hypertrophy – this has been done in the previous phase in order to increase the cross-sectional area of the muscle.
Training maximum strength requires two separate sub-phases: submaximum load method and maximum load method.
It is recommended that novice athletes, with less than 1-2 years experience, follow the submaxmum load method before progressing to the maximum load method. The goal of this phase is to recruit fast twitch muscle fibers of the prime muscles involved in sporting movements by using explosive concentric contractions with heavy loads (70-100% of 1RM).
Because the training loads during the maximum strength phase are based on the percentage of the athletes 1RM, it is crucial to establish an estimate of the 1RM. It is likely not appropriate to test an absolute 1RM for an athlete following an injury, even in the chronic stage, however a submaximum load (5RM – 10RM) can be used instead based on this chart:
Energy System Training
4. Conversion to Specific Strength (Conv.)
The conversion to specific strength phase is where sport specific training takes precedence. This phase is characterized by energy system training that is dependent on the energy requirements of the sport. Therefore, effective programming for this stage is dependent on the clinician’s ability to understand the sporting demands. The previous three phases can be thought of as the basis for athletic performance in any sport, whereas this phase is the conversion of that foundational training to the specific requirements needed during competition.
Training for conversion to specific strength requires either power training, muscular endurance training or a combination of both depending on the sport. Movement training should be very specialized and sport specific.
Power is the rate of producing force, expressed as P = F x V (force times velocity). Power is extremely important for any sport that involves speed, agility and explosive movements. These sports include track and field, team sports, and racket sports. Having a lot of muscle mass won’t help athletic performance unless those muscle fibers can be used to apply force quickly. Power training helps accomplish this by increasing rate coding, which is the discharge rate of the motor units. Thus, power training targets the CNS and fast twitch muscle fibers. Exercise selection during this phase should be few and highly specific to the movements required of the sport, with an emphasis on applying high force in the shortest amount of time. Because power depends on the development of both strength and speed, it should be trained in two distinct subphases.
Phase 1 of power training occurs during the maximum strength phase because increasing recruitment of fast-twitch muscle fibers occurs with loads of >70% of the 1 rep maximum (1RM).
Once the body learns to more effectively recruit fast twitch fibers, phase 2 of power training shifts to increasing the discharge rate of those muscle fibers (rate coding). This is accomplished by moving lighter loads (50-60% of 1RM) in the shortest amount of time. Exercises include agility and speed drills, plyometrics and olympic lifts.
Muscular Endurance Training
Training for endurance sports require different physiological demands and therefore necessitates different training methods. During longer duration events, the CNS preferentially recruits slow twitch Type 1 fibers due to the sub-maximal loads placed on the muscles. This allows the body to become more efficient at utilizing fat as fuel instead of depleting glycogen stores. Depending on the sport, endurance training should incorporate these principles:
- Strength training with higher reps and low-moderate loads that are greater than sporting demands
- Train for long-duration muscular endurance
- Alternate training with short-duration power endurance to target Type IIa and IIx fibers that are recruited when fatigued
- Maximum strength is needed to recruit more motor units to complete a task (i.e. increased force during swim stroke)
- Increase loads gradually from 2.5-5% per microcycle
- Exercise selection and number of repetitions should be specific to the sport (i.e. 50,000 strides for marathon runners or 200 non-stop strokes in swimming)
- Muscular endurance should be trained for short duration, medium duration or long duration depending on the sport
Demands of Sport and Annual Plan
The phases of strength periodization will depend on the competitive demands of the specific sport. Clinicians typically don’t see patients for over a year, so periodization training over multiple athletic seasons is usually the responsibility of the strength and conditioning coach. This becomes more important as the athlete transitions from the conversion phase into the competitive phase, which involves a maintenance (Maint.) program, and a compensation phase (Compens.) before transitioning to the off-season. However, periodization principles are important in each phase of athletic programming, for each microcycle, and for specific skills such as agility and plyometrics. Below are some examples of how to apply periodization principles depending on the phase.
Cohesive Programming for Rehab and Athletics
As shown in the graph above, the most overlap between the rehabilitation program and athletic periodization program is the anatomical adaptation phase, hypertrophy phase and maximum strength phase. Typically, the more sport specific phases are transitioned from the therapist to the strength coach, however this is not always the case. When programming for return to sport, the phase of competition when the injury occurred as well as the phase where the athlete wishes to return must be considered. Depending on the sport, there may be specialized return to sport programs such as the throwers ten program in baseball and similar programs in overhead sports.
Whereas progression through the rehabilitation program is dependent on tissue healing timeframes and specific milestones reached, the athletic program is based on periodization principles, sporting demands, and energy systems. Both of these phases allow adaptations to safely occur over time.
For rehab professionals, the ANALYSIS and PLAN part of a SOAP note should be much more detailed in the initial assessment and modified accordingly depending on individual progress. As discussed, the following aspects should be included in a well designed treatment plan:
- Stage of recovery (acute, subacute, chronic)
- Phase of athletic programming
- Number of days/weeks/months since injury (included every treatment session)
- Prognosis based on tissue healing and specific injury
- Anticipated number of treatment sessions per phase
- Specific impairments based on pathology and stage of recovery (pain, ROM, location of injury, etc)
- Return to sport goals
- Sporting demands (energy system, phase of competitive season)
Unfortunately, many times we see a patient who has been dealing with a nagging problem for many months. In this case, the tissue healing guidelines are more difficult to apply because we aren’t seeing them from the beginning during the acute stage. Not only is the diagnosis more difficult to establish but the prognosis can vary dramatically depending on the problem. More often than not, the issue is due to muscular imbalance, postural issues, ROM restrictions, failure to accommodate to load and/or nerve sensitivity. The last two points are especially important. Failure to accommodate to load is a very common issue and is caused by increased stress that exceeds tissue tolerance, such as with a sudden increase in activity. Nerve sensitivity is another issue that is receiving more attention due to its complex involvement with pain processing and persistent pain states. Although beyond the scope of this article, nerve sensitivity is a likely culprit in many conditions even during the initial stages of rehabilitation. In fact, increased nerve sensitivity (also known as peripheral sensitization) has been shown to occur within a few hours after an injury and can progress into central sensitization and persistent pain.
Overall, as the rehabilitation plan transitions into the chronic phase, the more influence strength and conditioning principles and athletic programming should have in the patients plan of care. Perhaps the drop-off in patient retention that is commonly seen in therapy is partly due to the poor execution of the chronic phase of a rehabilitation program. Maybe the value added from a physical therapist during this last phase is not up to par compared to a strength and conditioning coach. Many rehabilitation clinics do not have access to strength and conditioning equipment that is mandatory in an athletic training facility. If physical therapists want to direct a patient throughout the entire rehabilitation process, than they must understand both aspects of programming or else refer them to someone who does. Both rehabilitation and strength and conditioning principles are crucial in guiding an athlete from injury to field.