Start here: what to do
A CAR is one joint moving slowly through its biggest circle. Here is how to use it.
- Move one joint, hold the rest still. Pin the body part above the joint. Brace your trunk and squeeze your other fist. That tension and that stillness are what make it a CAR, not a lazy arm swing.
- Take 20 to 40 seconds per circle. Go that slow in each direction. Faster, and momentum drags the joint through spots you do not control. Slow is the whole point.
- Do a 6 minute morning round. Neck, shoulders, upper back, hips, knees, ankles. 1 to 2 circles each way per joint. Use moderate tension. A short round you do daily beats a long one you drop.
- Use it as a check, not a cure. Note which part of each circle feels stickiest. Note if the two sides differ, and if that gap grows over weeks. Film the same joints every 2 weeks from the same spot.
- Turn up the tension to train. After 4 to 6 weeks, pick 1 or 2 joints and push hard against your own movement. Do 2 to 3 circles each way. The circle will look smaller. That is right, not wrong.
- Get new range somewhere else. CARs keep what you have. New range comes from holding and loading the end of the range, from loaded work through the stiff part, or from contract and relax stretching. Check daily, train apart.
Hold the brand claims lightly. The base ideas are sound. Active range beats passive range, and end range should be loaded. But claims that a 40 second circle oils the joint or rebuilds tissue go past the proof. The wider method has support. The brand name does not add any.
Expect small circles. Done well, your circle shrinks. You just took away the borrowed movement from your back and hips. Judge it by control and by side to side gaps, not by how big it looks.
Safety. This is general coaching information, not medical advice. CARs should feel like effort, not pain. Stop for joint line pain, a painful click, or dizziness when you turn your head. Rehab and return to sport are your clinician's call. Get checked for pain that will not settle, swelling, a joint that gives way, numbness or weakness, or recent surgery or concussion.
Stand up and make an arm circle
Go on, actually do it. A big, lazy circle with your arm, the kind you'd make while yawning.
Congratulations: you've just trained almost nothing. Now do it again, and this time take forty seconds for a single revolution.
Brace your abdomen. Clench your opposite fist. Keep your ribcage completely still, deliberately resist your own movement, and take the shoulder to the outer edge of the range you can control in every direction.
Suddenly it's work, isn't it? That second version is a controlled articular rotation — a CAR — and the difference between those two circles is the entire method.
Same path through space, completely different exercise. Hold that thought, because it explains nearly everything else in this article.
By the end of this one you'll know how to perform a CAR properly, the cheats to watch for at every joint, how to scale the effort, and what the system behind the drill gets right and wrong.
Those five requirements are not stylistic. Remove any one of them and the drill quietly turns back into the lazy arm circle you started with.
Tension makes the movement active rather than passive, and active is what requests an adaptation at the outer range instead of merely visiting it.
Isolation makes sure the joint you're training is actually at its own limit, rather than borrowing range from a helpful neighbour.
The outer limit itself matters too. You're aiming for the edge of the range you can control — not your passive limit, and not a comfortable middle. The outer limit is where the adaptation is requested.
Slowness stops momentum from carrying the joint through sectors it can't control. And tracing the complete circle drags you through the sectors you'd otherwise conveniently avoid — which are precisely the informative ones.
One-line recap, borrowed from the coaching floor: tense everything, move one thing.
Two more cues that earn their keep: "slower than feels sensible", and "make it smaller and harder". If your circles obey all three, you're doing a CAR.
The whole idea in six lines
- A CAR is one joint moving slowly through its complete outer-limit circle while everything else stays still.
- Whole-body tension and joint isolation are what separate a CAR from an ordinary joint circle.
- They're excellent for assessment and maintenance, and comparatively weak for acquiring new range — despite usually being sold the other way round.
- A single repetition should take twenty to forty seconds. Speed lets momentum carry the joint through positions it doesn't control.
- The effort scales from a gentle morning check to a genuinely demanding high-tension effort — and most people never leave the lowest level.
- The surrounding certification system makes claims that outrun the published evidence. That doesn't make the drill itself less useful.
The drill comes from the Functional Range Conditioning system, and over the last decade it has become one of the most widely adopted mobility practices going (Spina, 2013). As you'll see, it deserves the adoption — just not always for the reasons on the poster.
The isolation problem
The most common execution error, by a wide margin, is failing to isolate the joint. It's worth understanding exactly how this happens, because it will happen to you.
Take the shoulder CAR. As your arm travels behind your body into internal rotation, you'll run out of shoulder range — and, without noticing, you'll continue the movement by flaring your ribcage and extending your spine (Neumann, 2016).
The arm keeps moving, so it looks like the exercise is working. In reality, the shoulder stopped at its limit some time ago, and your thoracic spine has quietly taken over the job.
Every joint has its own version of this trick:
- Shoulder Ribcage flare and lumbar extension substituting for the last portion of internal rotation. Keep the sternum still and the ribs down.
- Hip Pelvic tilt and lumbar movement substituting for hip extension and rotation. Use a wall behind the pelvis for feedback.
- Ankle Knee and hip movement disguising limited dorsiflexion. Fix the shin visually or against a surface.
- Thoracic spine Lumbar rotation substituting for thoracic rotation. Sitting on a bench with the knees squeezed together restricts the pelvis.
Which leads to a counterintuitive practical instruction: a proper CAR should look considerably smaller than you expect.
A well-executed hip CAR covers less visible ground than a sloppy one, because all the borrowed range has been stripped out. Small and honest beats big and borrowed, every time.
Can't tell whether you're cheating? Film it. The camera has no interest in your ego, and every compensation on that list is obvious on a screen.
What they're genuinely good for
Time for an honest appraisal, because this drill is better than some of the claims made about it and worse than others.
As an assessment tool, controlled articular rotations (CARs) are excellent. A daily sequence takes five or six minutes and tells you which joints are stiff, which sectors of each circle are uncomfortable, and where left and right differ (Kolber & Hanney, 2012; Ingram, 2015).
Because you repeat it every day, it's far more sensitive to change than a movement screen performed every few months (Bonazza, 2017). It needs no equipment, it can be filmed for comparison, and it costs precisely nothing.
It also highlights left-right asymmetry unusually clearly — and a side difference that grows over weeks is exactly the kind of thing you want to catch.
As maintenance, they're also strong. Most people have ranges they simply never visit — a shoulder that never goes into end-range internal rotation, a hip that never sees extension with rotation.
A CAR visits those forgotten ranges under tension every day, which preserves what exists. If you spend your working life at a desk, that alone is a solid reason to bother.
Combat athletes lean on hip and spine CARs for exactly this reason: their training loads some directions heavily and others never.
As a method of acquiring substantial new range? Much weaker — and this is exactly where the marketing outruns the method.
Meaningful range acquisition generally requires sustained end-range loading, progressive resistance through range, or PNF-style approaches (Afonso, 2021; Oranchuk, 2019; Sharman et al., 2006). All of them involve considerably more stimulus than a forty-second circle provides.
The honest caveat: someone starting from very little may see modest gains. For everyone else, the circle keeps the shop open; it doesn't build the extension.
A reasonable summary: CARs are for keeping and checking, not for getting. Use them daily for those purposes, and use loaded end-range methods when the goal is to increase what you have.
Keep and check with CARs; get with heavier tools. If you remember one sentence from this article, that's the one.
Joint by joint, level by level
What to watch for at each joint
Each joint has a characteristic sector where control is poorest, and a characteristic compensation used to hide it. Learn both and you'll stop being fooled by your own movement.
At the shoulder, the difficult sector is almost always internal rotation with the arm behind the body. It's the position overhead athletes lose first, and the one most people have never actively controlled in their lives (Wilk, 2011).
The tell is the sternum. If it lifts, the shoulder has stopped moving and something else is finishing the circle on its behalf.
At the hip, the difficult sector is extension combined with internal rotation — which happens to be exactly the position required in the late stance phase of sprinting. Pelvic movement disguises it completely, so the pelvis has to be fixed for the drill to mean anything.
If you sprint, for a living or for fun, take that hip sector seriously. It's the one most relevant to sprinting and the one most commonly restricted.
At the ankle, dorsiflexion combined with eversion is the sector that most limits squat depth and deceleration mechanics. It's easily masked by knee movement, which is why the shin stays fixed.
The thoracic spine likes to outsource its rotation to the lumbar segments below it, so fix the pelvis — often by sitting down. The wrist tends to be stiffest in ulnar deviation with extension, and hides it with forearm rotation, so pin the forearm against your body.
The cervical spine deserves particular care. Move it slowly and without force — and if combined rotation with extension produces dizziness, stop and seek clinical advice rather than working through it.
Scaling the effort, or why nothing is changing
If a CAR practice is producing nothing, the reason is almost always the same: it's being performed at the lowest tension level, indefinitely.
The intended mechanism here is irradiation — the phenomenon whereby tension generated elsewhere in the body increases the recruitment available at the working joint.
Clench the opposite fist, brace the trunk, generate whole-body tension, and the effort at the shoulder rises considerably. No external load required: you are the load.
That's why the opposite-fist cue from the very first exercise in this article matters. It looked like theatre; it's actually the mechanism.
- Level one, minimal tension: a morning check or an irritable joint. Assessment only, no training effect.
- Level two, moderate tension: the default for daily practice. Noticeable bracing and active resistance.
- Level three, high tension: substantial resistance to your own movement throughout. This is where control at the outer limit actually changes.
- Level four, near-maximal: very high tension, extremely slow, used for specific sectors and short exposures only.
Level one has its place — a gentle morning check, an irritable joint, early rehabilitation under a clinician's guidance. Just be clear that it's an assessment, not a training stimulus.
Level four is the other extreme: genuinely demanding, deliberately brief, and not a daily practice. Most of your useful work lives at levels two and three.
Want to know whether your tension is genuine? A level three shoulder CAR should be tiring after two or three repetitions.
If you can perform ten comfortably, you're at level one regardless of what you intended. The same movement at a different tension level is a different exercise.
Figure 4's caption deserves repeating: most people perform CARs at level one and wonder why nothing changes. Don't be most people.
Where they fit in your week
The time cost is so low that CARs can slot in almost anywhere. Three placements make sense.
One: a standalone daily practice, typically in the morning. Five or six joints, one or two repetitions in each direction, at level two. Six minutes, done.
Two: the first component of a warm-up. They prepare the specific joints the session will load, and they give you a read on how you're moving that day — an ankle or shoulder that feels off is worth knowing about before you're under a bar.
Weightlifters make this concrete: ankle and shoulder CARs before a session tell you whether today's catch positions are actually available.
Just don't mistake them for a complete warm-up. They don't raise temperature or build intensity, so the raise and potentiate stages still have to happen (Behm, 2016).
Three: inside a dedicated mobility session, at level three, alongside end-range isometrics and loaded work. Here they stop being a check and become a genuine training stimulus.
- Daily practice: 5 to 6 joints, level two, 1 to 2 repetitions each way, around 6 minutes.
- Warm-up: 2 to 3 relevant joints, level two, before the raise stage or immediately after it.
- Mobility session: 2 joints, level three, 2 to 3 repetitions each way, alongside loaded end-range work.
- Rehabilitation: level one, guided by a clinician, often the earliest movement a joint tolerates.
That last placement is a boundary as much as a slot. Everything else here is performance coaching for people who are not injured, and rehabilitation is a different job with different decision rules. If a joint is painful, swollen, unstable or giving way, if you are post-operative, if you are recovering from a concussion, or if you have failed hop or strength testing, the progression belongs to the clinician managing you, because criteria for advancing loading after injury are set by assessment rather than by the calendar (Chmielewski et al., 2006). Use CARs inside that plan, not in place of it.
An honest look at the system behind them
CARs come from Functional Range Conditioning, a certification system that has been genuinely influential — and that makes claims worth examining carefully.
The reasonable parts are substantial. Emphasising active over passive range is correct, and matches the evidence discussed elsewhere in this unit (Moreside & McGill, 2013). Loading end range is a sound principle.
It is worth being precise about what that evidence covers. It is direct for the general principles: active range training, end-range isometrics and PNF-style contract-relax methods have each been studied in their own right (Oranchuk, 2019). It is indirect for the branded drills. CARs, PAILs and RAILs have not been tested head to head against those general methods, so no claim that the trademarked version outperforms them is currently supported.
Treating mobility as a trainable capacity that needs progressive stimulus, rather than as passive stretching, is a genuine improvement on what came before. The clinical framing around joint health and progressive tissue loading is defensible too (Bohm et al., 2015).
The less reasonable parts concern specificity. Assertions about lubricating the joint, remodelling specific tissue structures, or producing particular cellular adaptations in response to a forty-second circle go well beyond what published research has demonstrated.
There's also a vocabulary problem. The system wraps existing concepts in proprietary terminology, which makes the ideas harder to evaluate against the wider literature rather than easier.
- Well founded, but indirectly Active range matters more than passive range; end range should be loaded; mobility requires progressive stimulus. The research behind those principles tested general methods rather than the branded drills.
- Reasonable but unproven specifics Claims about synovial fluid dynamics, joint capsule remodelling, and cellular responses to CARs specifically.
- Presentational issues Proprietary terminology for existing concepts, and certification-led dissemination that limits open critique.
- Practical verdict The drill is genuinely useful. Adopt it for assessment and maintenance without adopting every claim attached to it.
None of this is a reason to avoid the practice. It's a reason to use it for what it demonstrably does — which is quite a lot — and to source your range acquisition from methods with stronger supporting evidence.
Short version: take the drill, and hold the doctrine lightly.
The underrated part: CARs as a daily data source
Here's the most underrated application of the lot: the longitudinal record. Because a CAR is performed daily and takes under a minute per joint, it produces a continuous stream of information about how you're moving.
Film the same joints from the same camera position once a fortnight. Over three months, that comparison is far more informative than any single assessment, and it will show changes a periodic screen would miss entirely.
For an overhead athlete, that might mean spotting shoulder internal rotation quietly shrinking. For a lifter, it might be an ankle that no longer wants to give you your squat depth. Either way, you find out early.
- Fix a camera position and a body position, and film the same joints each time.
- Note any sector that is painful, sticky, or noticeably different from the other side.
- Track the asymmetries; a side difference that grows over weeks is worth investigating.
- Use the daily practice as a readiness check. A joint that feels different from usual is information about the session ahead.
- Take any new pain, catching or clicking with pain as a reason to seek assessment rather than to push through.
This is the strongest argument for the whole practice. Not that a forty-second circle transforms a joint — it doesn't — but that a daily two-minute check catches problems weeks before they become injuries, and costs almost nothing.
Think of it as flossing for your joints: quick, unglamorous, and mostly about catching trouble early.
Your six-minute morning routine
Six minutes, every morning, no equipment. This is the version worth actually doing, rather than the comprehensive version nobody sustains.
Six minutes is deliberately modest. A routine you do every day beats a perfect one you abandon by Thursday.
The sequence
- Cervical spine: 1 repetition each direction, very slow, level one to two.
- Shoulders: 2 repetitions each direction per side, level two, ribs down.
- Thoracic spine: 2 rotations each direction, seated with the knees squeezed.
- Hips: 2 repetitions each direction per side, pelvis fixed against a wall.
- Knees: 1 repetition each direction per side, hip held still.
- Ankles: 2 repetitions each direction per side, shin fixed.
What to pay attention to
- Which sector of each circle feels stickiest or requires the most concentration.
- Whether the two sides differ, and whether that difference is changing over weeks.
- Whether any position produces pain rather than effort or stretch sensation.
- Whether you can complete the circle without the compensations described earlier.
- How the joints feel relative to yesterday, which is useful readiness information.
Progressing the practice
After four to six weeks at level two, raise the tension on one or two priority joints to level three.
Expect the achievable circle to become visibly smaller. That's not a failure — it's correct. At higher tension, the borrowed range disappears.
A smaller, harder-won circle at level three is worth more than a big theatrical one at level one.
If you want range, not just maintenance
CARs will preserve what you have. If the daily assessment reveals a genuine restriction that actually matters, pair the practice with one of the following, because this is where the actual range gain will come from.
- End-range isometrics at the restricted sector, three times weekly.
- Loaded mobility work through the restricted range, twice weekly.
- PNF-style contract-relax work if passive range is genuinely limited.
- Progressive loading of the position within the main training programme.
Check daily, train separately. Keep the circles honest, and they'll keep you honest right back.
Sport applications
Overhead athletes benefit most from the shoulder CAR as a daily monitoring tool, since loss of internal rotation is an early and clinically relevant change that a daily check catches quickly (Wilk, 2011).
Combat sports athletes use hip and spine CARs to maintain ranges that training loads heavily in some directions and never in others.
Weightlifters find ankle and shoulder CARs useful for daily readiness assessment, since both joints directly determine whether the catch positions are available that day.
Field-sport athletes get value from hip CARs specifically at extension with internal rotation, the sector most relevant to sprinting and most commonly restricted.
Older adults and desk-based populations gain a great deal simply from visiting full joint ranges daily, since the ranges that are never used are the ones that quietly disappear (Levangie & Norkin, 2011).
Common mistakes
- Performing them without tension. A relaxed joint circle is not a CAR. Without whole-body tension the movement is passive and produces little adaptation at the outer range.
- Failing to isolate the joint. The single most common error. If the ribcage flares during a shoulder CAR or the pelvis moves during a hip CAR, the target joint stopped at its limit some time ago.
- Moving too fast. Momentum carries the joint through sectors it does not control, which defeats the purpose. One repetition should take twenty to forty seconds (Spina, 2013).
- Staying at level one forever. Minimal-tension circles are an assessment, not a training stimulus. If you can do ten comfortably, you are not training anything.
- Expecting them to produce large range gains. They maintain and assess well. Acquiring meaningful new range requires loaded end-range work, progressive resistance through range, or proprioceptive neuromuscular facilitation (PNF) methods (Afonso, 2021).
- Avoiding the uncomfortable sectors. The sticky part of the circle is the informative part. Athletes reliably shorten the circle to skip it.
- Forcing the cervical spine. It should be moved slowly and gently. Dizziness during combined rotation and extension is a reason to stop and seek advice, not to persist.
- Treating them as a complete warm-up. They prepare joints usefully but they do not raise temperature or build intensity. The rest of the warm-up still has to happen.
Coaching cues
- "Tense everything, move one thing."
- "Ribs down" for the shoulder.
- "Pelvis against the wall" for the hip.
- "Slower than feels sensible."
- "Make it smaller and harder."
- "Find the sticky part and stay honest about it."
- "Fight your own movement."
- "Check daily, train separately."
FAQs
What is a CAR?
A controlled articular rotation: One joint moved slowly through its complete outer-limit circle while the rest of the body stays still and under tension. The tension, the isolation and the slowness are what distinguish it from an ordinary joint circle.
How long should one repetition take?
Twenty to forty seconds for a full revolution. If it is faster than that, momentum is carrying the joint through positions it does not actively control, which removes most of the point.
Will CARs make me more flexible?
They will help you keep and use the range you have, and they may produce modest gains in someone starting from very little. They are not an efficient method for acquiring substantial new range, which generally requires loaded end-range work, progressive resistance through range, or PNF methods. Use CARs for assessment and maintenance, and source range gains elsewhere.
How often should I do them?
Daily is the standard recommendation and it is reasonable, because the time cost is very low and the assessment value comes from the repetition. Five or six joints at moderate tension takes about six minutes.
Why does my CAR look so small?
Usually because you have removed the compensations, which is a good sign rather than a bad one. A properly isolated hip CAR covers noticeably less visible ground than a sloppy one, because all the borrowed pelvic and spinal movement has been taken away.
Should CARs hurt?
No. Effort, concentration and a sense of stretch at the outer limit are expected. Pain, pinching at the joint line, or clicking accompanied by pain are not, and they warrant assessment rather than persistence. Dizziness during cervical rotation is a specific reason to stop and seek advice.
Is Functional Range Conditioning evidence-based?
Partly, and the distinction is worth making. The underlying principles, that active range matters more than passive range and that end range should be loaded, are well founded and consistent with the wider literature — but that is indirect evidence for the general method rather than direct evidence for the branded protocols. The more specific claims about joint lubrication, capsular remodelling and cellular responses to CARs go beyond what has been demonstrated, and no head-to-head trial has shown the trademarked drills to outperform ordinary mobility work. The drill is useful; not every claim attached to it is supported.
Can I use CARs as my warm-up?
As part of it, not as all of it. They prepare joints and provide a useful daily check, but they do not raise core temperature or build intensity towards the session. The raise and potentiate stages of a warm-up still need to happen.
Recommended videos
Each video below was chosen because it covers a specific part of this article in more depth than text alone allows.
Related reading on FitXplor
- 4.12 Active and Passive Mobility
- 4.14 End-Range Strength
- 4.15 Isometric Mobility
- 4.9 Understanding Range of Motion
- 4.2 The Joint-by-Joint Approach to Movement
- 4.6 The Shoulder Complex
- 4.5 The Hip: Mobility, Stability, and Power Transfer
- 4.10 Dynamic Stretching
References
Spina, A. (2013). Functional Range Conditioning system materials. Functional Anatomy Seminars.
Neumann, D.A. (2016). Kinesiology of the Musculoskeletal System, 3rd edition. Elsevier.
Levangie, P.K., Norkin, C.C. (2011). Joint Structure and Function: A Comprehensive Analysis, 5th edition. F.A. Davis.
Afonso, J. et al. (2021). Strength training versus stretching for improving range of motion: a systematic review and meta-analysis. Healthcare.
Oranchuk, D.J. et al. (2019). Isometric training and long-term adaptations: effects of muscle length, intensity and intent. Scandinavian Journal of Medicine & Science in Sports.
Moreside, J.M., McGill, S.M. (2013). Improvements in hip flexibility do not transfer to mobility in functional movement patterns. Journal of Strength and Conditioning Research.
Wilk, K.E. et al. (2011). Shoulder injuries in the overhead athlete. Journal of Orthopaedic & Sports Physical Therapy.
Kolber, M.J., Hanney, W.J. (2012). The reliability and concurrent validity of shoulder mobility measurements. International Journal of Sports Physical Therapy.
Ingram, L.A. et al. (2015). Quantifying upper limb motor impairment: reliability of range of motion assessment. Journal of Rehabilitation Research.
Bonazza, N.A. et al. (2017). Reliability, validity, and injury predictive value of the Functional Movement Screen. American Journal of Sports Medicine.
Behm, D.G. et al. (2016). Acute effects of muscle stretching on physical performance, range of motion, and injury incidence. Applied Physiology, Nutrition, and Metabolism.
Bohm, S., Mersmann, F., Arampatzis, A. (2015). Human tendon adaptation in response to mechanical loading. Sports Medicine - Open.
Sharman, M. J., Cresswell, A. G., & Riek, S. (2006). Proprioceptive neuromuscular facilitation stretching: Mechanisms and clinical implications. Sports Medicine, 36(11), 929–939. Read on PubMed
Chmielewski, T. L., Myer, G. D., Kauffman, D., & Tillman, S. M. (2006). Plyometric exercise in the rehabilitation of athletes: Physiological responses and clinical application. Journal of Orthopaedic & Sports Physical Therapy, 36(5), 308–319. Read on PubMed
Medical disclaimer. FitXplor publishes general performance and health education, not individualised medical advice. Nothing here diagnoses, treats or replaces assessment by a qualified clinician. Stop and seek assessment if you have pain that does not settle, swelling, instability, numbness or weakness, a recent injury, surgery or concussion, or if you are pregnant, under 18, or managing a medical condition or medication. Supplement, rehabilitation and mental-health guidance in particular should be reviewed with a qualified professional before you act on it.
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