Rehabilitation Principles of the Injured Runner

Acute Painful Phase

Patients often present in clinic unable to run due to the acute nature of their symptoms. They may be so sensitive that even basic movements of daily life, e.g., walking or sitting down in a chair, are painful. This amount of sensitivity can lead the injured runner to conclude that these low load activities are causing damage and they may become fearful of activity as a result. In these cases, initial loading may need to be isometric.

There are a myriad of physiological reasons why isometric loading can be beneficial to recovery. Isometric contractions can slow muscle atrophy and decrease edema. More importantly though, isometric loading, specifically of tendons, has been shown to be analgesic. This can be incredibly helpful to the clinician who needs to break the patient's association between activity and pain.

In addition to breaking the pain cycle, isometrics have an important role in restoring normal muscle recruitment. When a tissue is painful, its use is inhibited, and alternative motor recruitment strategies are used to accomplish functional activities. It is therefore necessary to restore normal motor recruitment before more loading can be commenced. Isometrics serve as the tool to restore this normal motor recruitment.

When putting this idea into practice, gym equipment can be a useful tool because it allows for very specific loading that can be adjusted right up to the edge of a patient's tissue tolerance. If the patient does not have access to gym equipment, body weight variations can be utilized to produce the desired load. Researchers have classically used five sets of 45 second isometric holds at 70% of one repetition maximum. This should be adjusted based on the patient's response. Since the goal of the exercise is to diminish symptoms, the patient experiencing those symptoms will be able to direct the load much better than the clinician. Autonomy should be granted to the patient to progress the load as tolerated once they have demonstrated understanding of the purpose of this exercise prescription.

Clinically, exercise choice will be dependent on the sensitivity of the patient and the tissue that needs to be loaded. That said, it can be beneficial to recreate running specific positions with the exercise prescribed. Conceptually, this loads the tissue similarly to actual running. It also provides a mental benefit for the patient who can start to extrapolate the exercise out to their eventual return to normal running.

Regardless of which tissue is injured, exercise of some type should be prescribed if only to start to restore the patient's confidence in their body. It is at this stage that a patient is most psychologically fragile. If the message that exercise is damaging is promoted, they will struggle to progress.

During this acute phase, modalities such as tape and cryotherapy, as well as massage and manual therapy, could be used to help decrease the reactivity of the tissue. ^. It is up to the experience of the practitioner, taking into account the beliefs of the patient, to determine the best use of these. Decreasing a patient's reactivity to load can help to facilitate their progression out of the acute painful phase and onto the progressive loading phase. Care should be taken to ensure that the application of these does not diminish the self-efficacy of the patient. Pain is a complex phenomenon, and ultimately, a patient must feel that they have control of their symptoms if they are going to confidently return to running. If they have to rely on external modalities consistently, they are not demonstrating faith that their body is robust enough to tolerate external stresses, which will, in turn, create a struggle to move forward to the next phase of loading.

Subacute Progressive Loading Phase

Once tissue sensitivity has diminished, progressive loading should be initiated to increase the tissue tolerance. At first, running load may still be too great to apply to the injured tissue. Therefore alternative loading strategies need to be used to progress the patient back to running.

Different loading protocols have been advocated by different groups. Specifically with tendons, the difference between concentric and eccentric load has been debated. Initially, eccentric exercise was advocated because of the “lengthening” strain on the tendon. This lengthening strain was hypothesized to encourage reorganization of damaged tendinous tissue and help return it to its preinjury structure. More recently, this idea has been called into question. In vivo studies of tendon mechanics have shown that the actual excursion of the tendon is not different based on the load placed on it. It is still true that higher loads can be produced with eccentric exercises. However, in a rehabilitation setting, these higher loads are rarely used; thus the clinical utility of eccentric exercise may be more limited than previously understood. Ultimately, the benefit of the load may not even be structural. Limited evidence supports the reversibility of pathological tissue changes; however, loading has still been shown to be beneficial. This is possibly due to improvements in cortical control and decreased muscular inhibition, which can help improve transmission of load through the injured tissue.

No matter what type of load is used, progression is dictated by the symptoms of the patient. Classic loading recommendations start with body weight and three sets of 15 repetitions. The weight is increased when the total volume of sets and reps can be tolerated without “disabling” pain. ^. It is liberating to both the patient and the clinician to know that exercise need not be pain free for it to be beneficial to the patient and that there is some evidence that suggests that painful exercise may be more beneficial. Clinically, it is helpful to set rules for acceptable levels of pain and pain behavior (see Box 11.1 ). These should be discussed with the patient and agreed upon based on the type of injury, the stage of healing, and the patient's past experiences with pain.

This provides room within a rehab program for discomfort, without the worry of reinjury. It also allows for patient autonomy so that they can make confident decisions about their daily activities and whether or not they are within their tissue's load tolerance. This promotes patient self-efficacy and confident return from injury.

Because running is a plyometric activity, this type of loading is the ultimate goal of the exercise progressions being provided. If a runner cannot tolerate hopping in the clinic, it is not realistic to expect that running will be successful. To advance, loaded double-leg exercises can be progressed to single-leg exercises. Single-leg exercises can be progressed to double-leg plyometric activities and from there to single-leg plyometric activities (see Fig. 11.1 ). By the time patients perform this, they are likely able to tolerate some volume of running, and a progressive training plan can commence. Progressing through these exercises is an ideal time to work on form and biomechanics, which will be addressed later in this chapter.