By Nicolas Desjardins, PhD in Natural Medicine · DBA(c) · Master’s in Neuroscience (in progress), designer of the Q-Technology system. Nicolas Desjardins is not a medical doctor. October 2026.
Lire cet article en français : Ton squat bloque ? Ce n’est peut-être pas qu’une question de mobilité
The short answer. When your squat gets stuck above parallel, people blame your ankles and hips, and tell you to stretch. Mobility matters: ankle dorsiflexion is one of the factors research associates with squat depth. But a review published in Physical Therapy (Weppler and Magnusson, 2010) reports that, according to most studies, the range gained after one session, or after 3 to 8 weeks of stretching, is mostly explained by modified sensation, an increased tolerance, rather than by a longer muscle. In other words, your available range also depends on what your nervous system accepts. During the Test Posture Parfaite, we don’t measure your squat: we look at how your body organizes itself, before and while you wear the circuit.
You’ve been stretching for months. Your squat hasn’t moved.
You know the routine. Couch stretch before the WOD, ankle against the box, roller on the calves, ten minutes of mobility you never skip. And yet, by the third thruster, the wall ball, the overhead squat, it’s the same story: heels that want to lift, a chest that dives, a pelvis that rotates to one side at the bottom.
You keep hearing it: not flexible enough, stretch more. Sometimes that’s true. But if you’ve been stretching seriously for months without getting any lower, the question deserves to be asked differently. Maybe it isn’t a length problem. Maybe it’s an access problem.
What research links to squat depth DOCUMENTED
- In 101 healthy adults (64 men, 37 women), Kim et al. (2015) compared ranges of motion, strength and squat depth. In men, ankle dorsiflexion with the knee bent and hip flexion were associated with depth, and together explained about 44% of its variation. In women, it was ankle dorsiflexion with the knee straight and the strength of the ankle dorsiflexors, for about 32%.
- In 20 healthy people, Gomes et al. (2022) filmed back squat depth. It was associated with ankle dorsiflexion in the lunge test, knee bent (r = 0.69), and with none of the other measures tested. Achilles tendon stiffness and the ankle’s passive resistance to stretch had no evident influence on depth.
What to remember: ankle dorsiflexion shows up in both studies. But in Kim et al.’s model, the two measures retained explain only about 44% of the differences in depth in men and 32% in women: more than half lies elsewhere. Flexibility doesn’t explain everything.
When you stretch, does your muscle actually get longer? DOCUMENTED
What the Weppler and Magnusson review says (2010, Physical Therapy). During a stretch, the muscle really does lengthen, thanks to its viscoelastic properties, but that lengthening is transient. To explain the range gained after a single session, and after 3- to 8-week programs, most studies point to modified sensation: this is the sensory theory. The authors note that the mechanical effects of longer programs, beyond 8 weeks, had not yet been evaluated.
What a more recent meta-analysis shows (Behm et al., 2021, Sports Medicine). Across 11 studies and 14 measures in healthy adults, a single bout of passive stretching on one side also produced moderate increases in the passive range of joints that were not stretched. You stretch one leg, and right afterwards, the other has gained range too. The abstract doesn’t settle the mechanism.
What to remember: range isn’t only a length. It’s also a tolerance, and a tolerance is a sensation: it runs through your nervous system.
The neuroprotective brake: our hypothesis about what’s blocking you HYPOTHESIS
We think that at the bottom of the squat, under load, the nervous system only opens the range it judges controllable. When the body’s organization is unstable, with a pelvis that tilts, one shoulder higher than the other, one side that gives way on stability tests, it would pull the brake. We call it the neuroprotective brake.
This hypothesis is consistent with the sensory theory of stretching, but it doesn’t follow from it automatically: the studies above are about stretching and tolerance, not about the brake, and not about our circuits. The brake is a working hypothesis, and it may be wrong.
If it’s right, it changes the question you ask yourself. You’re not plateauing. You’re compensating. And you don’t release a brake by pulling harder on the cable.
What we look at during the test, and what we don’t promise
What we don’t promise: a squat depth, a load, a PR. The test doesn’t measure your squat, or the range of your ankle or hip, and it doesn’t replace your coach’s eye on your technique.
What we look at, before and while you wear the circuit, during the Test Posture Parfaite (fifteen minutes, with a certified tester, no equipment):
- the tilts of the pelvis and shoulders on three planes, in centimeters;
- neck rotation, scored out of 7 on each side;
- strength and stability tests, right and left, holding or giving way.
If it shows nothing, the test is refunded. To understand what we mean by perfect posture, read our definition.
What we observe OBSERVATION: while the circuit is worn, we observe a postural correction during the test: tilts decrease, neck rotation evens out, tests that gave way now hold.
Functional assessment, non-medical · Before/after protocol · Observations from internal tests · Individual results vary · Not a medical claim.
Our hypothesis HYPOTHESIS: the passive resonant circuit removes nothing and blocks nothing. It gives the nervous system a coherent, stable reference. Whether that reference releases the brake at the bottom of your squat is something we have not measured. This is a hypothesis about the mechanism, and it may be wrong.
Support, not cure. While you wear the circuit, the effect is there. Take it off, and you’re back where you started, like glasses: you wear them, you see; you take them off, you don’t.
Passive circuit: no substance. Check with your federation.
FAQ
Should I stop stretching to improve my squat?
No. Stretching increases range, that’s established. The Weppler and Magnusson review is about why: in the short term, mostly through increased tolerance rather than a longer muscle. Keep what works for you, and also look at what your nervous system accepts.
Does the ankle limit squat depth?
It is one of the factors associated with depth, in 101 adults (Kim et al., 2015) as in 20 people doing the back squat (Gomes et al., 2022). But it doesn’t explain everything.
What is the neuroprotective brake?
It’s our hypothesis: under load, the nervous system would only open the range it judges controllable. It is not an established fact, and it may be wrong.
Will the circuit make me squat deeper or heavier?
We don’t promise that. The test measures neither your squat depth nor your load. It shows your tilts, your neck rotation and your strength and stability tests, before and while you wear the circuit. Functional assessment, non-medical · Individual results vary.
Can I wear it in competition?
Passive circuit: no substance. Check with your federation.
How can I check for myself?
Book a Test Posture Parfaite: fifteen minutes, €33, with a certified tester, no equipment. You compare before and after, on your own body. If it shows nothing, it is refunded.
Before you add ten more minutes of stretching to your routine, see how your body compensates: book your Test Posture Parfaite, refunded if it shows nothing.
Sources
- Weppler CH, Magnusson SP. Increasing muscle extensibility: a matter of increasing length or modifying sensation? Phys Ther. 2010;90(3):438-449. https://doi.org/10.2522/ptj.20090012
- Behm DG, et al. Non-local Acute Passive Stretching Effects on Range of Motion in Healthy Adults: A Systematic Review with Meta-analysis. Sports Med. 2021;51(5):945-959. https://doi.org/10.1007/s40279-020-01422-5
- Kim SH, Kwon OY, Park KN, Jeon IC, Weon JH. Lower extremity strength and the range of motion in relation to squat depth. J Hum Kinet. 2015;45:59-69. https://doi.org/10.1515/hukin-2015-0007
- Gomes J, Neto T, Vaz JR, Schoenfeld BJ, Freitas SR. Is there a relationship between back squat depth, ankle flexibility, and Achilles tendon stiffness? Sports Biomech. 2022;21(7):782-795. https://doi.org/10.1080/14763141.2019.1690569
