Everybody trains the hardware. Muscles, tendons, joints. Sometimes the hardware is fine and the software has the brake on. Square One is how you find out which one you are looking at.
The 90-Second Teaching
Your athlete's brain asks one question on a loop. Am I safe? It reads every position, every head turn, every foot strike, every color and sound in the room, and files each one as safe or threat. When the answer comes back threat, it pulls a brake. The brake looks like tightness, lost range, sloppy feet, bad balance, a lift that stalls at a number the kid should clear, or pain. The body is not broken. It is protecting itself.
Square One is a system built by Shawn Sherman for finding the inputs the brain has labeled a threat and clearing them one layer at a time. A light, quick muscle test reads the brain's answer. A brief hold in the position it does not trust shows the brain the position is fine. Then you test again. Every clear is one layer off the onion.
The physiology under it is not controversial. Pain and tightness are protective outputs, not tissue reports.[1][2] The brain weighs eyes, inner ear and body sense together to decide how to stand and move.[3] What has never been studied in a trial is Square One itself. So the question for your building is not whether the brain works this way. It does. The question is who in your room is going to learn the test, on which kids, and in what order.
1.The Problem
You have a kid who stretches every day. Soft tissue work. Extra warmup. The mobility block you wrote for him in August. He is still tight in September. At some point you have to admit the answer you keep repeating is not the answer.
Everyone trains the hardware. That is the right first answer and it fixes most kids. But there is software running all of that hardware, and the software can hold a muscle at a length on purpose. Stretching something that is being held does not change the reason it is being held.
Everyone trains the muscles, the joints. You work on your ligaments and
tendons, you work on your flexibility, but what if those things aren't
necessarily the problem? You hammer those issues, but there's a chance
it's not those things. What if it's the software that runs all of those
things?
Scott Leech, voice note, 2026-07-28.
That is the whole reason this page exists. If tightness is largely a sensation the nervous system produces, then a kid who does not change after weeks of stretching is not a hardware problem. He is a software problem, and you need a way to ask the software what it is protecting. Square One is the cleanest way I have found to ask.
2.What It Is
Credit first. Square One is Shawn Sherman's system. Penn State exercise physiology, ran a performance studio outside Chicago, first movement specialist for the Chicago Cubs from 2004 to 2009. He came up through Muscle Activation Techniques and built Square One in 2008 after a stuck client got better when Sherman did the opposite of what his training said to do. I took the course in June 2026 in a room of six coaches. I am not affiliated with Square One and I make nothing if you sign up. I just think it is one of the best things I have taken in a long time.
The premise is binary. The brain reads every input and every position as safe or threat. No third option. When it reads a threat it inhibits motor output to protect the structure, and the body compensates around the hole. Sherman's line for what he is actually doing: he is not trying to change outcomes. He is clearing reasons to compensate, and the brain does the rest.
Full output is allowed
- What you see
- Range, strength, speed and balance the hardware is capable of.
- What the test shows
- The muscle grabs. Fast, solid, abrupt stop. A pass.
- What happens next
- Nothing. Move to the next input. Load the pattern.
Protective output, on purpose
- What you see
- Tightness, lost mobility, poor coordination, balance problems, a stalled lift, test anxiety, compensation patterns, pain.
- What the test shows
- The muscle yields. Soft, slow, no grab. A fail. Anything that is not a clean 100 is a fail.
- What happens next
- Feed the position. Recheck. Clear one layer. Keep following the trail.
Hardware and software
Muscles, tendons, ligaments and joints are the hardware. The nervous system is the software that runs them. Sherman's own recommended framing for a client who already trains is exactly the one I use with my kids: everything you have done so far is a tissue approach, and what we are adding is the neurological layer on top. Not a replacement. Everybody still needs the hardware.
Two levels, one framework
Level 1 · the vestibular and visual reset
Simple on purpose. Sherman's point is that the head and eye map is not the hard part. The hard part is developing your hands as a muscle tester, and Level 1 gives you a small enough map to get reps on the test without a heavy mental lift.
Level 2 · the proprioceptive reset
More detail, more customization, harder. Sherman's advice to the room was to master Level 1 first. The three sensory systems are linked, so organizing one tends to organize the others.
The head and eye map, the indicator setups and the session order are in The Field Card below, for Insiders only. The hands-on skill is the course. Sherman's site: square1system.com
3.The Inputs
Everything is an input. Sherman says it and the postural control literature backs it. Your brain combines what the eyes report, what the inner ear reports, and what the feet and joints report, and it shifts how much it trusts each one depending on which is reliable in the moment.[3] That is the version I give my athletes.
If you were unconscious in the hospital, we could fold you up like a
pretzel. Your body has large ranges of mobility and flexibility
available. And if there was ever somebody trapped under a car, you'd be
able to lift the car. So you have this level of strength you can tap
into, but the nervous system is holding you back. Part of it is for your
own protection.
Scott Leech, voice note, 2026-07-28.
Vision
Where am I, where am I going, am I safe. The horizon is the primary reference for orientation, and the brain assumes body stability matches horizon stability. Threat triggers: poor horizon perception, inconsistent eye dominance, head and neck restrictions, an uneven surface, old injuries.
Vestibular
Inner ear. Tells the brain where the head is, which way is up, and how fast the body is moving through space. Coaches wait for a kid to say the room is spinning. That is not the bar. It can be doing its job badly and quietly and still be producing a protective response.
Proprioception
Receptors in the feet, muscles, ligaments, tendons and joints report joint position, ground reaction force, weight distribution and direction. Every foot strike is another chance for the nervous system to learn or to protect. When it does not trust the report, you get less power and more guessing.
Color, sound, load, breath
A kid can be clean on a movement and lose it when a specific color enters the environment, when a bar goes on his back, or when he has to hold his breath. Those are inputs too. Sherman's go-to triggers to surface history are a squat, a cough, and eyes closed.
Neural stacking: think browser tabs
Movement never happens in a vacuum. On Friday a kid sprints, tracks the ball, keeps his balance, reads a defender and makes a decision at once. Neural stacking adds those layers back deliberately: eye movement, head movement, a balance challenge, a cognitive task, another pattern. Compensations that hide during a clean single-pattern test show up once the layers stack.
If you've got one tab open, it's easy. You open five tabs, it's still
manageable. You open fifteen tabs, everything starts to slow down. The
nervous system works the same way.
Scott Leech, voice note, 2026-07-28.
This is also why the vision work in our warmup overlays sometimes does nothing for a kid. You can train the drill all you want. If the threat was never identified and cleared, the training does not stick.
You can do all the vision training you want, but if you don't identify
and then clear threats, you're not getting the full benefit out of that
training.
Scott Leech, voice note, 2026-07-28.
4.What the Research Says
Straight answer on the evidence. There is no peer-reviewed trial of Square One. None. Everything Sherman shows you is a demo, a case, or a before-and-after on video, and he says so himself. He calls objective markers the biggest gap in his own game. So this section does not prove the system. It tells you which pieces of the physiology under it are settled, which are supported, and which are contested, so you know what you are standing on when a parent or an AD asks.
1 · Pain is a protective output, not a damage meter
Fifteen years of pain science education rests on one reframe: pain is produced by the brain when it concludes the body needs protecting, and it tracks perceived threat more closely than it tracks tissue state. That is the same premise Square One runs on, and it is the mainstream view in pain research, not a fringe one.
Moseley GL, Butler DS. Fifteen years of explaining pain: the past, present, and future. J Pain, 2015. PubMed ↗2 · Tightness is mostly sensation
Muscle does lengthen under a stretch, but the length change is transient. The lasting gain in range after a stretching program is better explained by a change in the sensation of stretch, meaning the nervous system tolerates more. Tight is not always short. Sometimes tight is held.
Weppler CH, Magnusson SP. Increasing muscle extensibility: a matter of increasing length or modifying sensation? Phys Ther, 2010. PubMed ↗3 · The brain shuts muscles down to protect a joint
After knee injury, swelling or surgery, the quadriceps cannot be fully activated even when the muscle is healthy. The inhibition is reflexive, driven by altered sensory input from the joint, and it can last for years. This is a documented case of software turning down perfectly good hardware for protection.
Rice DA, McNair PJ. Quadriceps arthrogenic muscle inhibition: neural mechanisms and treatment perspectives. Semin Arthritis Rheum, 2010. PubMed ↗4 · Eyes, inner ear and body sense are weighed together
Standing still is a feedback loop that combines visual, vestibular and proprioceptive input, and the brain reweights the three when one becomes unreliable. Take the visual reference away or make the floor move and the weighting shifts. The three-input model Sherman teaches is the standard model of postural control.
Peterka RJ. Sensorimotor integration in human postural control. J Neurophysiol, 2002. PubMed ↗5 · Cognitive load changes landing mechanics
Athletes who scored lower on reaction time, processing speed and visual attention at baseline landed with higher knee abduction moments and ground reaction forces on a drop jump. The brain's processing capacity showed up in the knee. Neural stacking is a training version of this finding.
Herman DC, Barth JT. Drop-jump landing varies with baseline neurocognition: implications for anterior cruciate ligament injury risk and prevention. Am J Sports Med, 2016. PubMed ↗6 · After a concussion the stack costs more, for longer
Concussed adolescents walked with worse balance control when a cognitive task was added, and the dual-task deficit persisted across two months of follow-up even as single-task walking looked normal. A kid can look fine in a drill and fall apart the moment he has to think and move at once.
Howell DR, Osternig LR, Chou LS. Dual-task effect on gait balance control in adolescents with concussion. Arch Phys Med Rehabil, 2013. PubMed ↗7 · Eye and head screens catch what a balance test misses
A brief vestibular and ocular motor screen, built on smooth pursuit, saccades, convergence, the vestibulo-ocular reflex and visual motion sensitivity, separated concussed athletes from healthy controls with good accuracy. The eye and head inputs Sherman starts with are the same inputs concussion medicine reaches for first.
Mucha A, Collins MW, Elbin RJ et al. A brief Vestibular/Ocular Motor Screening (VOMS) assessment to evaluate concussions: preliminary findings. Am J Sports Med, 2014. PubMed ↗8 · The muscle test is the contested part
Here is where you need to be honest. Sherman borrowed neuro-response muscle testing from kinesiology and says so. One review of more than 100 studies found good reliability and validity for manual muscle testing in neuromusculoskeletal patients, with the caveat that its full validation still needs better trials. A later review found that technique, duration and force vary widely across practitioners and that most studies never report them. Translation: the test can work, the practitioner is the instrument, and a sloppy tester gets sloppy answers.
Cuthbert SC, Goodheart GJ. On the reliability and validity of manual muscle testing: a literature review. Chiropr Osteopat, 2007. PubMed ↗ · Conable KM, Rosner AL. A narrative review of manual muscle testing and implications for muscle testing research. J Chiropr Med, 2011. PubMed ↗9 · The brain can change output without the tissue moving
Twelve weeks of mental contractions, no physical training, raised little finger abduction strength by 35 percent and elbow flexion by 13.5 percent, with a measurable rise in the cortical signal driving the muscle. Sherman's claim that a client can visualize a joint action he is not allowed to perform and still clear it is not as strange as it sounds.
Ranganathan VK, Siemionow V, Liu JZ, Sahgal V, Yue GH. From mental power to muscle power: gaining strength by using the mind. Neuropsychologia, 2004. PubMed ↗Read that stack as a coach, not a scientist. The premise is settled. The inputs are settled. The cost of stacking is supported. The test is the part you have to earn, and Sherman tells you that in the first hour.
5.The Test
The whole system rides on one question. Does it grab?
A neuro-response muscle test is a brain test, not a strength test. Sherman's contrast: a handheld dynamometer gives you a number, a manual 1-to-5 strength grade gives you an opinion, and neither one is what he is reading. He is reading transmission speed. How fast does the signal get there when load arrives? The load itself is light, somewhere around 2 to 8 pounds, placed abruptly and held for about a second. A pass is a fast, solid grab that stops you cold. A fail is soft, slow, yielding.
What a pass and a fail actually look like
Sherman's rule is that 99 is a fail, 47 is a fail, 12 is a fail. You then map and clear off that. Wait too long before loading and the muscle spindle takes up the slack and hands you a false pass. Push too hard and you are strength testing. The skill is the feel, and he is blunt about it: you will be bad at it on half the people on day one, and it is like riding a bicycle. Reps fix it.
I was the demo
On day one Sherman put me on the table next to another coach to teach the room about calibration. My fails were dramatic. On a 1-to-100 scale a failing side on me read like a 10 against a solid 100. On Jason the fails were subtle, a 90 against 100, barely a fail. He told the room to go get their hands on Jason for practice, because I was too easy.
Two things I took out of that. First, I walked in a D1 strength coach who lifts every day and my own nervous system had positions it did not trust. Strong is not the same as safe. Second, you have to recalibrate on every person, every time. If Sherman expects a pass he pushes a little harder to try to prove himself wrong. If he expects a fail he goes a little lighter to check his own bias. Prove an obvious fail and an obvious pass first, or you are guessing.
Kill the storyteller
This is the discipline that separates Square One from every corrective exercise seminar you have sat through. The instinct when a test fails is to explain it. Tight lat. Weak glute. Old ankle sprain. Sherman's answer is that you are not smart enough to know that, and neither is he. His name for the mindset is the IDIOT procedure: I'm an idiot, you're an idiot, so ask better questions. You do not diagnose why. You interview the nervous system with pairs. Right versus left. Up versus down. You read the answer, you feed the safe side, and you check your work.
The one rule I would tattoo on a new coach's forearm: never use the injured area as the indicator. The indicator is a global test that passes neutral and is pain free. It is a gauge, not the thing you are fixing.
6.The Loop
A session is one loop, repeated. Find it, feed it, check it. Every pass through is one layer. Here is the shape of it. The step-by-step version with the map and the test setups is The Field Card in section 7.
- Indicator. A global test, arm or leg or trunk, that passes in neutral and is pain free. Not the injured area. This is your gauge.
- Input. Move a joint, the head, or the eyes into a position. At Level 1 that is a head or eye position with a nasal breath. At Level 2 it is a single joint action off the gait map.
- Test. Does the indicator still grab? If it does, that input is safe. Move on. If it goes soft, the brain just told you that position is a threat.
- Intervene. A brief isometric into the failed position, a few seconds, intent over end range. Visit the position. Show the brain it does not need to avoid it.
- Recheck. Re-test the exact position that failed. Pass means one layer cleared. Skipping this step is the number one beginner miss, because without it you cannot tell whether you did anything.
The onion
Pain is usually the top of a stack of compensations built over time, layer on layer, sometimes for years. Your job is not to guess how many layers there are. Your job is to clear as many as you can this session and keep following the trail. Sherman's honest numbers from the floor: one to five sessions per trigger, one to three is common, and it is hardly ever one shot, one kill. Older, more injured, longer history means more layers. Every time, you check again, because the next layer is not always the same one.
One question people have is how long will it take to see results? And
the honest answer is you don't always know. Because Square One doesn't
necessarily chase pain. We identify and clear the compensatory patterns
that may be contributing to it.
Scott Leech, voice note, 2026-07-28.
Two stories from the course that changed how I load kids
135 triggered. 225 did not.
Sherman told the room about training in Matt Van Dyke's garage. A bodyweight squat triggered, so they cleared it. They put 135 on the bar and it triggered again. Van Dyke was shocked. They cleared 135. Then they went to 185 and 225 and nothing triggered. Same pattern, slightly different weight, and Van Dyke's max was over 400, so the next place it would likely show up is the 5RM range where recruitment changes and the lifter starts to cheat. The rule that came out of it: start light, clear the pattern, then do your normal work. Check again at 85 to 95 percent. Otherwise leave it alone.
The Texas defensive back and the wrist he was hiding
Van Dyke brought Sherman in to work with the Texas football staff before COVID. One player was a top defensive back, one of the fastest kids in the country, projected first or second round. He could only quarter squat. Sherman's indicator failed on head left, he localized it, and the answer came back as the right wrist. Not the knee, not anything the staff expected. He cleared the wrist fifteen times in a row, which does not happen by chance, and the kid went from a quarter squat to a full pistol squat in one session. Two months later it came out that the kid had been hiding a wrist and elbow injury from the staff the whole time, scared it would cost him playing time. The nervous system was not hiding it. History comes out of the body if you ask it the right way.
7.The Field Card
This is the part I said I would not put on a web page. It is here because you are an Insider and I want you to be able to follow a session start to finish. These are my own notes from the weekend, cleaned up so a coach who has never seen the system can run the steps in order. Two warnings before you start. One, the hands still come from the course. You can read every word below and still be bad at the test on day one, because the test is a feel. Two, read Red Flags first. Stenosis, acute concussion, and anything the athletic trainer has not cleared do not go on your table.
The card, on one screen
- Pick an indicator.A muscle test on an arm, a leg, or the trunk. It has to pass in neutral and it has to be pain free. Never the sore spot.
- Calibrate on this person.Prove one obvious pass and one obvious fail before you read anything. Their effort is a 2 or 3 out of 10. Your push is light, quick, and calm.
- Give one input.One of the six head positions or the four eye positions. Add a sniff through the nose on the hold.
- Test.Does it still grab? Grab means safe. Soft means threat. Anything that is not 100 is a fail.
- Feed the failed position.Hold an easy isometric into that exact position for 2 to 5 seconds. Intent over range.
- Recheck the same position.Same body position, same input. Pass means one layer cleared. Skipping this step is the number one beginner mistake.
- Add a trigger and go again.Squat, cough, eyes closed, a light bar. Whatever surfaces the next layer.
- Get them up and walk.Three minutes. Let the brain integrate it. Recheck one functional marker.
Step 1 · Pick an indicator
An indicator is your gauge. It is a global muscle test that passes in neutral and does not hurt. You are going to run every input against it and watch whether it holds or gives. It is never the injured area. Here are the four I use, in the order I reach for them.
A · Straight-leg internal rotation (the one Sherman likes most)
Setup. Pull the heel gently so the leg stays long. Roll the foot inward toward the other leg. Find the soft end of the range first, then push a little further. Compare left to right.
What you say. "Keep your leg straight. Hold it here. Do not let me turn it." Cue about a 2 out of 10 effort.
What you feel. A hard, abrupt stop means it grabbed. A soft, mushy give means it failed. Sherman's note: the right foot is restricted on most people regardless of handedness, so do not read a right-side fail as a mystery.
The cheat. The athlete goes hard with the whole leg instead of holding the rotation. Slow him down. Rotation first, then resist.
B · Shoulder rotation test (the manual calls it the TRAPP test)
Setup. Start where you know he passes: arm out at about 90 degrees, no rotation, arm supported so he is not fatiguing. Press down abruptly. Feel the grab. That is your baseline. Now break the plane: take the arm just past 90, rotate the thumb all the way around so it points at the sky, keep the elbow locked, and press down again.
What you say. "Really rotate. Keep rotating as you stop me. The more you rotate, the less force I have to use." If he shrugs, have him unshrug and redo it.
What you feel. Snappy grab on the good side. Absent or soft grab on the failing side.
The cheat. Athletes will not stay in the rotated position. It feels unstable, so they come out of rotation and push. Do not reward that with a pass. Reset the rotation and go again. If his eyes drift to the same side on both reps, hold a finger in front of his face and say "look at my hand." That eye drift is a layer you will clear later.
C · Lat pull-out test (everybody is bad at it and it rarely hurts)
Setup. Elbow locked. Full internal rotation. Have him pull the bicep into his rib cage. You pull straight out to the side while he holds. Sherman teaches three directions off the same setup: straight out, forward while he pulls back, and up and away at 45 degrees. Find the one he passes and the one he fails. The one that fails cleanly is your usable test today.
What you say. "Lock the elbow. Squeeze the arm into your ribs. Do not let me pull it away."
The cheat. A soft elbow. Have no tolerance for it. Cue the triceps. And do not let him clamp the arm tight against his side, that makes him artificially strong.
D · Trunk rotation test (keeps him on the table, also a strength test)
Setup. Support the ribs, get the pelvis neutral, then push the knees across to one side while he holds them in the middle. Both sides. Sherman also runs the trunk through its big six on the table: bend forward, bend back, side bend right and left, rotate right and left. One of the six is usually the sick one.
Rule for any test you invent. Pull away from midline while he works toward midline. Think in 90 degree angles so you can reproduce it. Never test into a shortened end range. You can hurt somebody there.
Step 2 · Calibrate on this person
Every athlete, every time. Before you read a single input, prove one obvious pass and one obvious fail so you know what his grab feels like and what his give feels like. Sherman's rule of thumb for the force is ounces, not pounds, and the same light force works on a 150 pound receiver and a 300 pound tackle. Short, stout guys are the hardest to read. Long levers are the easiest. Wait until he engages, then load abruptly. If you wait more than about half a second the muscle spindle takes up the slack and hands you a false pass. If your read is muddy, go lighter, not harder. Full intensity, quick, calm.
Step 3 · The Level 1 map
Ten inputs. Six head positions, four eye positions. Add a sniff through the nose on each hold. Run each one against your indicator and write down what happens. Nothing else changes. Same indicator, same force, same body position. Only the input changes.
| # | Input | How you set it | Its opposite |
|---|---|---|---|
| 1 | Head down | Chin toward chest. On the table, lift the head off the ground. | Head back |
| 2 | Head back | Look up and back. On the table, press the head into the ground. | Head down |
| 3 | Turn right | Rotate the head to the right, eyes come along. | Turn left |
| 4 | Turn left | Rotate the head to the left. | Turn right |
| 5 | Lean right | Right ear toward right shoulder. | Lean left |
| 6 | Lean left | Left ear toward left shoulder. | Lean right |
| 7 | Eyes up | Head still. Eyes only, look at the ceiling. | Eyes down |
| 8 | Eyes down | Head still. Eyes only, look at the floor. | Eyes up |
| 9 | Eyes right | Head still. Eyes only, look right. | Eyes left |
| 10 | Eyes left | Head still. Eyes only, look left. | Eyes right |
| + | Sniff | A nasal breath on every hold. Breathing is 24/7, so you clear it as a threat too. Sherman also touches the ribs and adds a mouth breath as a trigger. |
Learn the opposites cold. Sherman's joke in the room: what is the opposite of right? Left. Of up? Down. You will be reading pairs all session, and the pairs map to four directions of locomotion: up, down, right step, left step. Head turns and head-off-the-table are your proof points.
Step 4 · Read the answer
One side passes, the other fails
Turn right grabs, turn left goes soft. That is a preference, which is compensation. Feed the failed side with the input it needs and recheck. The safe side is your ally: give more of that signal and the other side picks it up.
Both sides fail
Turn right and turn left both go soft. In Level 1 you give both sides the input and recheck. If it will not clear, it is probably a Level 2 piece (a specific joint action), and that is the course, not this page.
Do not guess the fix from the fail
A right lock does not mean the answer is on the left. Sherman calls it a 50/50 proposition. Turn off the storyteller. Test the opposite, test the pair, read what the body says.
Everything passes
Add a trigger and run the map again. If it is still clean, get him up and check the functional markers. Some athletes are clean on the table and fall apart under a bar or a cough.
Step 5 · Feed the failed position
Sherman's phrase is feed the problem. Put the athlete into the exact position that failed and have him hold an easy isometric there for 2 to 5 seconds. Often a couple of seconds is enough. Intent matters more than end range. Active or passive does not matter much. You are showing the brain the position is available and nothing bad happens. A sniff through the nose on the hold. Sherman also gives a self-cue the kid can do as homework: head up and snap, a quick contraction into the position.
Step 6 · Recheck
Same indicator. Same body position. Same input that failed. If it grabs now, you cleared one layer. If it does not, your first suspect is you, not the athlete. Sherman's order of suspicion: practitioner error first, strange case second. You did not track his eyes, he softened, you pushed too hard. Then check the pair. After a head-up intervention, recheck both up and down.
Step 7 · Add a trigger and go again
A trigger is anything safe that surfaces the next layer. It reveals history. It does not create it. Run the map, clear what fails, then add one of these and run the map again.
- Eyes closed plus a cough. Sherman's go-to stack and mine.
- A bodyweight squat. Then the same squat with a head turn.
- Hands on the ribs, mouth breath. Neutralizes breathing as a threat.
- A light bar. The Van Dyke rule. Clear the empty bar and 135 before you load. Check again in the 5RM range.
- Whatever he already does. His stretch, his foam roll, his arm care, his prehab. If any of it fails the test, it is not helping him. Clear it so his nervous system tolerates it.
Step 8 · Get him up
After five or ten layers, stand him up. Three minute walk. Ten squats. A slumped-over breather. Let the brain integrate what you just did. This is the step that keeps a concussion kid from getting dizzy, and Sherman says he cannot remember the last one who did once he added the walk-arounds. Then recheck one functional marker from your intake.
Session one, in order
This is the intake I wrote down at the course. It fits in a period.
- Screen range and pain.Hip internal rotation. Shoulder internal and external rotation. The standing big six for the back. Any pattern that hurts, and exactly when: up the stairs or down, lead leg or trail leg. Video the ugly version.
- Hips on the table.Flexion, extension, lateral both ways, rotation both ways. Indicator against each.
- Shoulders on the table.Flexion, extension, internal, external, abduct, adduct.
- Vision.Track left and right, track up and down, head still with eyes moving, head rotating with eyes tracking, convergence, near-far, a few saccades.
- Stand him up and check the functional stuff.Squat, push, pull, rotation. Whatever he has to do on Friday. Run the indicator against each one and clear what fails.
Advanced loops from my notes (once the basics are clean)
RDL loop. Four eye positions by six head positions is 24 combinations on a hinge. Balance, speed, and load are the last resort triggers, not the first.
Squat head-turn loop. Check neutral. If it fails, check up and down, fix it, check neutral again. Then squat with a head turn and ask whether it is still a threat. Check neutral one more time.
Rehab loop. Check that his treatment, his arm care and his prehab are not themselves threats. Look ahead and make sure the exercises you are about to prescribe will not be threats either.
Foot on the table. Hook-lying, foot rolled in. Push the foot back out and find which side breaks. If one breaks, run eyes up, down, left, right, map it, intervene, and re-test in the exact position he failed.
What I say to a kid before the first test
Your muscles and joints are the hardware. Your brain is the software running them. I am going to put you in a few positions and give you a light push. Your job is a 2 out of 10. Just do not let me move you. If your brain likes the position, you will stop me easy. If it does not, you will feel it go soft and so will I. That is not you being weak. That is your brain telling on itself, and it is exactly what we came here to find.
The five to remember every day
- Run the loop. Never skip the recheck. Re-test the exact position that failed.
- Does it grab? Brain test, not strength. Light, abrupt, about a second. Wait for engagement, then load.
- Calibrate every person, every time. Prove an obvious fail and an obvious pass first, or you are guessing.
- Kill the storyteller. Do not diagnose why. Interview right and left, up and down. Pain-free indicator. Never the injured area.
- General, light, layers. Not perfection. Breathe, squat, walk. Minimal effective dose. Resilience is the goal, and you will be bad at this first. Reps.
8.Red Flags and Your Lane
Sherman spent a full block on the one thing that scares him, and you should know it before you touch a kid. This is educational material for coaches. It is not medical advice, and none of it replaces your athletic trainer or the kid's doctor.
| Situation | What Sherman does | What that means for you |
|---|---|---|
| Spinal stenosis | Refers out. The one condition he has seen get worse, four to six cases since 2015. Clearing compensation can stack the spine straighter and compress the nerve more. | Do not run this on a kid or a coach with diagnosed stenosis. Age is not a filter. His most recent case was an active man in his fifties. |
| Concussion history | Expects peaks and valleys. Uses movement snacks, short walk-arounds, and leans on eye and head work. Expects the same trigger to fail again after clearing. | Never in the acute window. Never without the AT. Expect repeats and keep sessions short. |
| Post-surgery, PT, diagnosis | Asks what is contraindicated and works inside it. Clears the athlete's existing rehab so the nervous system tolerates it, and checks new exercises for threat before prescribing. | Stay in the PT's lane. Ask what is off limits. If your prescribed prehab is itself a threat, it is not prehab. |
| Severe structural damage | A torn meniscus client felt dramatically better in session one, then her knee lit up in session two as she compensated less. Surgery moved up. Less compensation revealed how bad the tissue was. | Feeling better is not the same as being fixed. Do not talk a kid out of surgery he needs because a test cleared. |
| Non-disclosure | Explicit consent up front: if this hurts, tell me. He overstates the risk and understates how much he can help. | Say it out loud before you start. A high school kid will hide an injury to protect his snaps. |
Sherman's consent framing on a hard case, in his words: overstate the risk, understate how much you can help. Use it.
9.The GW Way
Here is where I land. Seven rules. This is the part of the page that is mine, and it outranks anything above it.
- Hardware first. Always.Run the stretch, the soft tissue, the warmup block. That is the right first answer and it fixes most kids. Square One is not a replacement for a weight room. It is the layer on top.
- Weeks of the hardware answer with no change is a software question.Stop repeating a failed answer. That kid goes to the table, not to another mobility block.
- It sits upstream of the screen.Our four-item screen and the competency gate tell you how a kid moves. Square One asks why the brain is limiting him. A kid who fails the single-leg squat and does not change with correctives is the kid this is for.
- Clear before you load.Light bar first, clear the pattern, then work. Recheck at the top of the 5RM range. This is the Van Dyke garage rule and it costs you ninety seconds.
- Stack the layers the way the game does.Eyes, head, balance, a decision, a color. The cognitive overlays in our warmup exist for this reason. Clean alone is not clean.
- Never promise a timeline.One to three sessions per trigger is common and nobody knows how many layers a kid is carrying. Say that plainly. A coach who sells a date is guessing.
- The test is earned, not downloaded.The Field Card gives you the map and the order. The course gives you the hands, and the hands take thousands of reps to trust. Start on a coach or a teammate, not on your best player. Take the course before you make this part of your program.
How I explain it to the kids
The version I give my players is the version you read in section 3. Hardware and software. Hospital bed, car. Am I safe on a loop. The eyes, the inner ear, the GPS in the feet. Browser tabs. The onion. A 16-year-old gets all of it in ninety seconds, and the payoff is that he stops saying he is tight and starts telling you when. Which positions. Which days. Which drills. That list is information nobody else can get for you.
Who it is for
Not a football-only tool. Athletes, obviously. The kid with test anxiety who tightens up before every max out. Tactical people. Anyone in pain. Anyone whose hardware is fine and whose output is capped anyway. Sherman's favorite two clients are an elite athlete with one hiccup and the worst of the worst, because the change is easy to see on both. Athletes almost always feel it. A kid who never pushes his body may not feel anything even when you moved the needle, which is exactly why you keep a functional marker on him.
★Bonus · The AD Pitch
I paid for this course with school money and then had to justify it after the fact. Learn from that.
I signed up, I'm doing this course called Square One, which is kind of
like an RPR something like that. It's $1,500, and I put it on the
school, and thankfully they purchased it before asking me any
questions. But then they were like, hey, we need to justify every
purchase. Can you justify going to this course? And it didn't have
CEUs attached to it, so I had to come up with some BS.
Scott Leech, voice note, 2026-05-27.
Here is what I should have walked in with, and what you will walk in with.
- Name the problem in their language. Not "nervous system reset." Say: we have kids who do not respond to stretching and corrective work, and right now our only next step is to refer them out or wait. This gives us a next step in-house.
- Bring functional markers, not theory. Sherman's own quick set: straight-leg raise with internal rotation, shoulder internal rotation, neck rotation, squat depth, plus any pattern that hurts. Video the ugly version. Video the after. An AD understands a before-and-after clip. He does not understand a muscle spindle.
- Run a 21-day trial on three kids. That is the trial window Sherman uses in his own practice. Pick the kid who has been tight since August, the kid coming back from a concussion who is cleared but not right, and your best player with one nagging thing. Three success stories on day one, then the money conversation is easy.
- Frame it as software on top of hardware. Nothing you already bought gets replaced. The racks, the plates, the AT, the PT all stay. This is the layer we did not have.
- Do the NIL math if you have NIL. One starter at $100K sitting out a game costs more than the course. At the high school level swap NIL for the kid you cannot replace on Friday night. Same math, same case.
And get the CEU question answered before you buy, not after. If your district requires continuing education credit to spend on a course, ask the provider in writing. I did not, and I spent an afternoon writing a justification memo I could have skipped.
10.Objections and Questions
This is applied kinesiology. Isn't muscle testing woo?
Part of it is borrowed from kinesiology, and Sherman tells you that in the first hour, which is more than most neuro seminars will do. The literature on manual muscle testing is split: one large review found good reliability and validity in neuromusculoskeletal patients, and a later review found that force, duration and technique vary so widely that many results cannot be compared.[8][9] What is not in dispute is the physiology under it: protective inhibition is real and documented, and pain and tightness are outputs.[4][1] Sherman's own guard against fooling yourself is the part I trust: prove an obvious fail and an obvious pass on every person before you read anything, calibrate against your own bias, and never explain a result you did not test.
How is this different from RPR?
Sherman frames Square One as a framework, not a competing modality. His words: a framework to test any thought, any idea you have. You can plug RPR into it, or MAT, or chiro, or the athlete's existing rehab, and check whether each one reads as safe. The difference is the test. RPR gives you a reset without a way to prove it worked on this kid, which is the same buy-in problem Sherman says team coaches hit. Square One makes you check your work every time.
Can I just do the head and eye positions off a reel?
You can do the positions. You cannot do Square One, because Square One is the test and the recheck, and those are the parts you cannot learn from a phone or from the Field Card above. Without the test you are guessing which position is a threat, and without the recheck you cannot tell whether you did anything. Sherman's self-reset, a few minutes of moving every joint through its positions with a nasal breath, is a fine thing to teach a team as a morning routine. It is not the system.
Will it make my kids faster or stronger?
No trial says so and I am not going to say so. What it does is remove a brake. A kid whose brain stops guarding a position gets to use the range and strength he already built. That can look like a big jump on the day, the Texas kid went from a quarter squat to a pistol squat in one session, but the hardware still has to be there. Software on top of hardware. Not instead of.
How long does a clear last?
Sherman calls it semi-permanent. Once a trigger is cleared it tends to stay cleared for a while, and how long depends on the person and the stress that comes next. Life keeps adding inputs and new triggers form. The upside is that a nervous system that has been through the process gets more resilient and takes a bigger stressor to build the next trigger. Nobody can honestly promise more than that.
So stretching is bad now?
No. Hardware first, always. Stretching changes how much stretch an athlete tolerates, and that is useful.[2] The lesson is not stop stretching. The lesson is stop repeating a failed answer. When weeks of it change nothing, that is information, and it points somewhere else.
Can I run this on the whole team?
Not the test, not with one set of hands and sixty kids. Sherman's own answer for big groups is a related tool that applies the inputs without testing, and he is honest that the cost is you cannot prove it worked. My answer is triage. Team-wide, the head and eye overlays live in the warmup and the self-reset can be a morning routine. The table is for the three kids the hardware answer failed.
§Glossary
If you are newer to the neurology side, these are the terms used throughout this page.
- Safe or threat
- The binary read the brain makes on every input and position. Threat produces protective output. There is no third option in the model.
- Compensation
- The work-around the nervous system builds when it reads a position as a threat. Layers of it stack over time. Pain usually sits on top of the stack.
- Hardware and software
- Hardware is muscle, tendon, ligament, joint. Software is the nervous system running them. Square One is a software approach layered on hardware training, not a replacement for it.
- Indicator
- A global muscle test, arm or leg or trunk, that passes in neutral and is pain free. The gauge you read to see how the brain answered an input. Never the injured area.
- Neuro-response muscle test
- A light, abrupt load of about one second, read as pass (the muscle grabs) or fail (it yields). A brain test of signal speed, not a strength test. Borrowed from kinesiology.
- Input
- Anything the brain processes: a head or eye position, a joint action, a color, a sound, a load, a breath, a cough. Every input can be a threat.
- Trigger
- An input that surfaces a layer already written in the body. A squat, a cough, eyes closed. Triggers reveal history. They do not create it.
- Intervention
- A brief isometric into the failed position, a few seconds, intent over range. Shows the brain the position does not need to be avoided.
- Recheck
- Re-testing the exact position that failed after the intervention. The step that proves you did something. The most common beginner miss.
- Layer, or the onion
- One cleared compensation. Sessions clear several. Nobody knows how many a given athlete carries.
- Neural stacking
- Adding inputs on top of a movement on purpose: eye movement, head movement, balance, a cognitive task, another pattern. Compensations hidden in a single clean pattern show up under the stack.
- Vestibular system
- The inner ear apparatus that tells the brain where the head is, which way is up, and how fast the body is moving. Can be doing its job badly without producing dizziness.
- Proprioception
- Body position sense from receptors in feet, muscles, tendons, ligaments and joints. Reports joint angle, ground reaction force, weight distribution and direction.
- Horizon perception
- The brain's primary visual reference for orientation. It assumes body stability matches horizon stability.
- Arthrogenic muscle inhibition
- Reflexive shutdown of a muscle by altered sensory input from an injured or swollen joint, even when the muscle itself is healthy. Documented after knee injury.[4]
- Dual-task cost
- The drop in movement quality when a cognitive task is added. Measured as the percentage change from single-task performance.
- Level 1 and Level 2
- Level 1 is the vestibular and visual reset: head positions, eye positions, a nasal breath. Level 2 is the proprioceptive reset: single joint actions mapped to gait and the squat.
- Spinal stenosis
- Narrowing of the spinal canal or nerve openings, usually from degeneration or bone growth. The one condition Sherman refers out because clearing compensation can worsen nerve compression.
Deeper Reading
References
- Moseley GL, Butler DS. Fifteen years of explaining pain: the past, present, and future. J Pain, 2015;16(9):807-813. PubMed ↗
- Weppler CH, Magnusson SP. Increasing muscle extensibility: a matter of increasing length or modifying sensation? Phys Ther, 2010;90(3):438-449. PubMed ↗
- Peterka RJ. Sensorimotor integration in human postural control. J Neurophysiol, 2002;88(3):1097-1118. PubMed ↗
- Rice DA, McNair PJ. Quadriceps arthrogenic muscle inhibition: neural mechanisms and treatment perspectives. Semin Arthritis Rheum, 2010;40(3):250-266. PubMed ↗
- Herman DC, Barth JT. Drop-jump landing varies with baseline neurocognition: implications for anterior cruciate ligament injury risk and prevention. Am J Sports Med, 2016;44(9):2347-2353. PubMed ↗
- Howell DR, Osternig LR, Chou LS. Dual-task effect on gait balance control in adolescents with concussion. Arch Phys Med Rehabil, 2013;94(8):1513-1520. PubMed ↗
- Mucha A, Collins MW, Elbin RJ, Furman JM, Troutman-Enseki C, DeWolf RM, Marchetti G, Kontos AP. A brief Vestibular/Ocular Motor Screening (VOMS) assessment to evaluate concussions: preliminary findings. Am J Sports Med, 2014;42(10):2479-2486. PubMed ↗
- Cuthbert SC, Goodheart GJ. On the reliability and validity of manual muscle testing: a literature review. Chiropr Osteopat, 2007;15:4. PubMed ↗
- Conable KM, Rosner AL. A narrative review of manual muscle testing and implications for muscle testing research. J Chiropr Med, 2011;10(3):157-165. PubMed ↗
- Ranganathan VK, Siemionow V, Liu JZ, Sahgal V, Yue GH. From mental power to muscle power: gaining strength by using the mind. Neuropsychologia, 2004;42(7):944-956. PubMed ↗
Talk About It Inside
Got a kid who has not changed since August? A concussion kid who is cleared but not right? Trying to write the justification memo for your AD before you buy the course? Drop it in the Insiders thread. I answer every one.