Mobility progressions for rehab: What we learn from Functional Range Conditioning

In a world of training systems and methodologies, “mobility training” as we see it in the world of social media is one of the more controversial and misunderstood. You’ll see opinions ranging from “just get strong, nothing else matters” to “don’t touch a weight until you have all the mobility prerequisites.” Neither is inherently wrong, but when working with complex, dynamic systems like humans, the truth often lies somewhere in the middle. Within that middle, mobility training can range from various 10 second stretches and a couple rounds on a foam roller to dedicated hour long routines.

This article will discuss training systems like the Functional Range Conditioning (FRC) model, specifically as relates to isolating and improving local joint capacities, and how I’ve come to implement it on the clinic floor.

Birds’ eye view of Functional Range Conditioning

Functional Range Conditioning, at its essence, can be seen as an isolated joint training system that often trains a joint at its end range of motion through isometric or quasi-isometric efforts.

One of the key components of this conceptual model is the idea of “workspace”: the amount of space a joint can explore through all of its degrees of freedom. We can also understand this as the total range of motion of a joint. Controlled articular rotations (CARs) are exercises where we take a joint through its entire range of motion, and the size of a CAR will often provide a visual representation of workspace.

When reverse engineering an athlete’s physical demands back to fundamental constraints, one that we can address in the clinic is their available workspace. Do they have, at a minimum, the ability to position their joint(s) as necessary for sport or the terminal task? This is the first question we’ll often ask ourselves with mobility training.

The second question is whether the athlete has the ability to produce or manage forces relevant to sport or the terminal task in these positions.

We can then explore the isolated, end range training options offered by FRC, breaking down the workspace into the individual degrees of freedom that we can isolate and train (e.g., shoulder flexion, extension, abduction). The rationale behind isolated end range training is similar to that of isolating the knee extensor mechanism with leg extensions in rehab, as opposed to solely using compound exercises: we’re reducing the potential for compensation and trying to funnel loading specifically towards our desired adaptation.

Clinicians must be on guard against getting lost in the weeds of the myriad of new trainable qualities to prioritise. Otherwise, they risk going on an endless chase towards “perfecting” a CAR or increasing range of motion instead of prioritising an athlete’s initial goals. Focusing solely on end range training has limited integration with real world demands. Merely doing leg extensions is unlikely to help us run, jump or change directions unless we complement those extensions with running, jumping or changing directions.

While FRC can be incredibly effective in rapidly expanding range of motion, most athletes don’t come to us with the sole goal of improving range of motion. Rather, they are struggling with a certain task.

Being able to relate and intertwine mobility milestones back to the desired task makes a good clinician or coach. This is a framework I use when deciding whether and when to apply an FRC lens in tandem with traditional strength & conditioning across the rehab timeline.

Controlled articular rotations over the rehab timeline

We begin by categorising our rehab goals into early, mid and late stages. Early stage rehab is where we’ll often see painful limitations to and potential asymmetries in our passive and active ranges of motion. Early stage goals usually centre on restoring pain free motion and normalising active:passive ratios. The traditional approach to early stage rehab taught in many physiotherapy schools emphasizes passive stretching or advising the client to rest –  both of which ignore what an athlete can still do in order to maintain the rest of their physical capacities.

Mid stage rehab is where we typically address asymmetries in force output in key muscles or affected joints. Through a traditional approach, this is where we would incorporate strength & conditioning principles in order to progressively overload injured tissues.   

Late stage rehab addresses return to sport. Traditional approaches reincorporate speed, impact and chaos via plyometrics, change of direction, sprints, and gradual re-exposure to practise, among other activities.

Our look into the FRC toolbox begins with understanding controlled articular rotations. CARs have become a ubiquitous part of mobility training practices and serve many different needs throughout the rehab pipeline.

Every rehab school will stress the importance of active range of motion. During a CAR, the clinician isolates a patient’s joint and mindfully takes it through its entire range of motion. At their core, CARs are a way to access active range of motion in a way that allows the patient to nearly perform a self assessment and learn about their current movement capacities. It’s another way of placing control over the rehab process back into their hands.

In most cases, CARs start in the very early stages of rehab as a way to clear inflammation, facilitate healing (as necessary) and maintain current movement capacities.

As we progress further into rehab, I’ll typically use CARs (potentially adding physical constraints) to address any compensations the patient may have already developed in response to the injury. Being aware of and cleaning up some of these stress shielding strategies is often my initial step to ensure I can effectively drive loading towards injured tissue.

During later stages of rehab I’ll use CARs, again with the potential of loading, to explore the outer pockets of range of motion, where patients may be more likely to reinjure.

Progressing mobility training at each stage of rehab

Mobility and its relevance in overall programming boils down to movement options. Throughout the rehab continuum, we aim to influence an individual’s movement options to facilitate clinical success. The three time based phases of rehab map on to overarching goals. In the early stages, we want to create movement options. During the middle stages, we curate movement options; and then in the late stages we focus on cultivating movement.

Early rehab: (re)Creating movement options

Here we often use setups that place the injured tissue in a position just shy of aggravating the symptoms, then slowly ramping isometric effort of that tissue. This lets us place injured tissue on a loading continuum as soon as possible, maintaining contractile quality and signalling for adaptation from early on.

More importantly, we take advantage of isometric loading strategies and their well known effect of providing temporary pain relief whenever possible, opening up movement availability towards the terminal task. We select specific exercises as the terminal tasks that lack chaos compared to sport but, depending on the injury, may contribute to continued participation in practice or sport.

For example, in early stages, anterior knee pain (patellofemoral, tendon related, etc.) may be so aggravated that it limits knee flexion range of motion during testing, to say nothing of the patient’s ability perform a squat pattern exercise. In this case, I’ll pair low load long duration PAILs (i.e., a lengthened side isometric) for knee flexion with a split squat, which is the terminal task exercise. The rationale is to start adapting the compromised tissue (anterior knee) with the potential bonus of reopening the door to a more relevant exercise, even if only temporarily.

Note that PAILs are named by the position the patient is training. For example, during knee flexion PAILs we’re training in knee flexion despite working the knee extensors.

	Exercise	Intensity	Sets x Reps x Time	Notes
A1	Knee flexion LLLD PAILs	Pain free	3 x 2 x 30s	60s total, decreased individual hold time and increase volume around pain response
A2	Split squat ISO hold		3 x 6 x 5s

A frequent upper body example is rotator cuff related shoulder pain limiting horizontal pressing variants like bench press or push ups. The clinical indication is painful limitations of shoulder internal rotation and, potentially, pain limited force output with shoulder external rotation.

In early stage rehab, this is often the primary focus, so I’ll often use these as a “main lift.”

	Exercise	Intensity	Sets x Reps x Time	Notes
A1	Shoulder internal rotation LLLD PAILs	Pain free	3 x 2 x 30s	60s total, decreased individual hold time and increase volume around pain response
A2	Bench press	Pain free	3 x 10-12	Focus is on accumulating pain free volume

Functional range conditioning in early rehab initiates the reacquisition of movement options through repeated exposures, with the goal of lasting improvement to painfully limited range of motion. In contrast to a more traditional approach emphasizing rest, this allows the athlete to maintain as much of their physical capacities as possible by remaining active, often leading to a quicker restoration of range of motion.

Pairing FRC movements with a more relevant task helps us keep the individual engaged in the rehab process and, more importantly, reminds practitioners to not get lost in the weeds chasing range of motion. The goal remains the goal.

Mid rehab: Curate movement options

As healing begins and active pain responses diminish, a sense of normalcy returns to the patient’s system, so my goal shifts towards (re)building optionality, with the end goal of decreasing risk of reinjury. I typically have two implementation strategies: short / long pairing, and isolated / integrated pairing.

Both strategies rely on isolated end range training options to funnel loading to injured tissue; and to accumulate appreciable time under tension in the end ranges, where patients may be more susceptible to reinjury.

The advantage of these over traditional exercise options is mainly in the ability to isolate and force time under tension in these weaker zones.

Short / Long

The underlying goal of short / long pairing is to build degrees of freedom so the patient develops an abundance of movement options, therefore protecting them from over-relying on a single option to complete a task. Building this mobility provides a buffer for the demands of sport and activity.

This strategy involves pairing exercises that focus on end range force production on both sides of the target joint. The lengthened tissue will accumulate maximal levels of strain to expand range of motion. The paired shortened tissue input builds active control over those newly expanded ranges of motion.

Take a mid-stage hip impingement, where range of motion increased on the clinic plinth, but the patient’s limitation remains when we try to load those ranges of motion in a deep squat, or in the sport of jiu-jitsu. The low load PAILs variant from the early stages progresses to maximal effort PAILs in hip flexion. The eccentric quasi-isometric nature of the holds induces a maximal effort stimulus on the shortened side, as well.

Whereas PAILs efforts are isometric end range contractions on the lengthened side, RAILs are the opposite, targeting shortened side tissue For the shortened position, we start the process with passive range holds in hip flexion.

	Exercise	Intensity	Sets x Reps x Time	Notes
B1	Hip flexion PAILs/RAILs	Max effort	3 x 1 x 8s	Decrease intensity, increase time in presence of pain
B2	Hip flexion passive range hold		3 x 6 x 5s	30s total, decrease hold time, increase rep count depending

Building on the example of rotator cuff related shoulder pain, let’s now look at the overhead position. The indication is when both passive and active range of motion has been restored into overhead flexion, but loading limitations still persist. Along with our typical cuff related rehab work, once the patient has a level of control over the target range of motion we’ll progress to passive range holds as the shortened position input. We can also progress from the yielding isometric to a concentric effort with a lift off.

Unless this range of motion limitation is the sole focus, I tend to use these as a secondary or tertiary exercise.

	Exercise	Intensity	Sets x Reps x Time	Notes
C1	Shoulder flexion PAILs/RAILs	Max effort	3 x 1 x 8s	Decrease intensity, increase time in presence of pain
C2	Shoulder flexion passive range lift off		3 x 8-12

Isolated / Integrated

The underlying goal of isolated / integrated pairings is to bridge the gap to terminal goals and coordinate the patient’s very controlled and isolated movement qualities back into global movement strategies. Isolated inputs still have their place, due to their ability to funnel loading towards the qualities we want to address, but we need more. Training those movements only in isolation will not prepare the patient to repeat those movements at the same level of quality in the complex, chaotic landscape of movement.

Returning to the hip impingement example provides us with pairings like a squat variant with a hip internal rotation PAILs / RAILs. This pairing occurs in the early stages where range of motion is still quite limited, or with a hip flexion lift off in the later stages. The isolated input homes in on the persistent deficits that still need improvement, while the integrated input guides the system to explore and recalibrate.

	Exercise	Intensity	Sets x Reps x Time	Notes
A1 (early example)	Hip internal rotation PAILs/RAILs	80%	4 x 1 x 10s	Decrease intensity, increase time in presence of pain
A1 (later example)	Hip flexion passive range lift off		4 x 8
A2	Squat		4 x 6	Focus towards heavier loads, if tolerated

With the rotator cuff related shoulder pain example, the pairing could be a half kneeling landmine press (if the patient is still limited in full overhead flexion) with the lift off.

	Exercise	Intensity	Sets x Reps x Time	Notes
B1	Shoulder flexion passive range lift off		3 x 8-12	Option to load if needed
B2	Half kneeling landmine press		3 x 8-12

While most rehab models will introduce heavier loading in this stage to address strength deficits or asymmetries, an FRC lens allows us to identify and specifically address any persistently deficient movement qualities through accessory lifts or a paired exercise.

The goal is not only to rebuild an athlete who is as strong as they were pre-injury, but one who moves better than before.

Late rehab: Cultivate movement options

Late stage rehab is often very case- and individual specific, and comes with the understanding that many general population patients may not need to progress into some of the more aggressive examples described here. The goal for this phase is to layer resiliency onto movement options, such that variables like intensity, speed, and chaos aren’t associated with immediate reinjury risk.

The main factors we’ll discuss are supramaximal force, and speed at end range.

Supramaximal force

The focal points in late stage rehab are ensuring that the injured tissues are able to tolerate high levels of strain and manage those forces as the patient fails into end ranges. Patients should perform these exercises slowly, as the intent is to lose position only as the external load overcomes their own output. An important prerequisite, then, is tolerance to maximal effort isometric loading at end range.

Under the FRC umbrella, these exercises are often classified as ENGs (eccentric neural grooving). Like the name suggests, the focus here is entirely eccentric.

For anterior shoulder instability, the ENG focuses on the classic shoulder external rotation, horizontal abduction position.

Two ways we can implement this are purely in isolation (video 14, 15) or, once the patient has built the capacities, setting the movement up to fail into a previously injurious position. The example shown here is with the Americana shoulder lock in jiu-jitsu, which forcefully brings an opponent’s shoulder into external rotation (video 16). Whenever relevant and possible, I like to use a partner assisted setup specific to the injury position itself (video 17).

Experiencing and tolerating this position specific failure can also offer a degree of psychological readiness as we look at full return to sport.

	Exercise	Intensity	Sets x Reps x Time	Notes
B1	Shoulder external rotation ENG		4 x 4-6
B2	Supine dumbbell internal rotation		4 x 15-20	Very case specific, as this was the exercise that caused initial subluxation. Goal is to accumulate reps at fatigue

End range speed

Many of the strategies discussed earlier involved slow, controlled ramping of effort, which can provide a safer entry point to loading. One final point to consider on this loading continuum is velocity. Injuries can happen much quicker than the 5-10 second window we’re using for the maximum effort isometrics, and end range velocity variants are how I like to funnel power and rate of force development qualities towards injured tissue.

Naturally, the prerequisites for exploring these options are tolerance to both maximal effort isometrics at end range, and tolerance to supramaximal failure into end range.

One way to introduce end range velocity in isolation is via ballistic isometric efforts at end range – essentially, a ballistic PAILs. Knowing that we have access to maximal effort contraction at end range, instead of a slow ramp, we use a spike of isometric effort to force local tissues to rapidly stiffen. Similar to early stage rehab, this setup allows the patient to self regulate both the amplitude of force and the rate with which they generate it, depending on tolerance. The use of a live force trace can provide some biofeedback and help encourage a quick spike in loading instead of a gradual ramp.

Following a similar pattern, once the patient can tolerate ballistic efforts at end range, I may progress into catch variants to quickly fail into end range. Like the name suggests, these involve taking a fully relaxed limb into end range and rapidly producing eccentric force to stop at the target length. These can be a planned deceleration (video 20) or, later, an unplanned reactive deceleration (video 21, 22)

I’ll often program end range velocity similar to how I might use any dynamic effort or plyometric effort. End range contrasts are a common route.

	Exercise	Intensity	Sets x Reps x Time	Notes
A1	Bench press		3 x 3-5
A2	Shoulder external rotation loaded catch		3 x 6

As in the middle stages, I’ll often still use short / long or isolated / integrated pairings when programming these, depending on intended outcome. Because of its hyper-isolated nature, a key advantage to applying FRC in late stage rehab is our ability to stress test and ensure that the injured tissue is able to handle previously injurious forces in previously injurious positions.