The four mobility gaps that show up under load — and how to prep before your event

Most athletes describe it the same way. Something feels tight, they stretch it, it loosens for an hour, and then it comes back — usually the week of the event they have been training for.

Here is what we see in the office. Tightness that keeps returning is rarely a short muscle. It is usually a joint that has lost part of its normal range, plus a body that has quietly learned to borrow that range from the joint next door. At an easy pace you never notice. Under real load — a sprint, a landing, a heavy single, the ninth game of a Saturday tournament — the borrowing shows up as a knee that caves in, a low back that takes over, or a shoulder that pinches overhead.

Four restrictions account for most of what walks through our door: single-leg control, ankle range, hip rotation, and mid-back extension. Below is what each looks like when it is missing, a test you can honestly do at home, and what to do about it — followed by what a real pre-event warm-up should accomplish, and why the week of a race is the wrong time to chase big changes.

Why movement has to be tested under load

Plenty of athletes pass every stretch test on the floor and still move poorly on the field. Range you have while lying down is not the same as range you can control while your body weight lands on one leg. That gap — between range you own and range you can actually use — is where most non-contact injuries live.

So the tests below are weight-bearing, or close to it. Each one asks a joint to move while something else is asking it to hold steady. Do them fresh rather than after a hard session, and compare left to right. The side-to-side difference usually tells you more than any absolute number does.

1. Single-leg control: the knee that caves in

Almost everything in sport happens on one leg. Running is a chain of single-leg landings. Cutting, kicking, pushing off in pickleball, coming down from a jump — one leg at a time. When the muscles on the outside of the hip cannot keep the pelvis level, the thigh rolls inward and the knee drifts toward the midline. Coaches call it the knee cave; clinically it is a dynamic valgus pattern.

What it looks like: a hip that drops as you run, kneecap pain that shows up late in a run or a game, an ankle you keep rolling, or a pelvis that feels like it is rocking side to side on long efforts.

The self-test. Stand facing a mirror on one leg, hands on your hips, and slowly bend the standing knee until the other heel taps the floor about six inches in front of you. Do five. Watch three things: does the knee stay stacked over the middle of your foot, does the opposite hip stay level, and does your torso stay upright? A knee that drifts inward, a hip that dips, or a trunk that leans to catch you are all the same finding.

What to do. This is a strength and control problem far more than a stretching one, and it responds well. Split squats, slow step-downs from a low box, single-leg deadlifts with a light weight, and banded or side-lying work for the outer hip — two or three sessions a week, done with control rather than speed. Our article on the outer-hip muscle behind knee cave and hip drop walks through the pattern in more detail.

2. Ankle range: the quiet one

Ankle dorsiflexion — driving your knee forward over your toes with the heel down — is the restriction most athletes have and almost nobody tests. It limits how deep you can squat without your heels lifting, how well you absorb a landing, and how far your body can travel over the foot in a running stride. When the ankle will not give you the range, the knee, hip, or low back has to.

Old sprains are the usual culprit. An ankle rolled in high school and never fully rehabbed often keeps a stiff joint for years, long after the swelling is a memory.

The self-test. The knee-to-wall test. Put your foot about a hand’s width (four to five inches) from a wall, keep the heel flat on the floor, and drive your knee straight forward to touch the wall. If you can, slide the foot back and try again until you find your limit. Then do the other side. Most athletes want roughly four inches of clearance, but the comparison matters more than the number — more than a half-inch difference between sides is worth addressing.

What to do. Loaded range beats passive stretching here. Slow knee-to-wall reps with the heel pinned down, calf raises through the full range including the very bottom, and a bent-knee calf stretch for the deeper calf muscle. If the joint feels blocked rather than tight, hands-on work to restore the glide at the ankle often opens more range in one visit than a month of stretching. Our piece on what a properly rehabbed ankle sprain looks like explains why the stiffness outlasts the injury.

3. Hip rotation: where rotational sport gets paid for

Golf, pickleball, tennis, baseball, soccer, and every lift with a twist in it need the hip to rotate underneath a loaded leg. When hip rotation is limited on one side, that rotation has to come from somewhere, and the low back is the closest volunteer. The lumbar spine is built for a few degrees of rotation per segment. Ask it for thirty, over and over, and you get the ache that arrives on the back nine or on day two of a tournament.

What it looks like: low back tightness after rotational sport, a pinch in the front of the hip when you squat deep or sit cross-legged, one side of a swing or serve that never feels as free as the other.

The self-test. Sit tall on a bench or the front edge of a chair, knees bent, feet flat. Keeping the thigh still, swing one foot outward away from the midline — that rotates the hip inward. Then swing it toward the opposite ankle to rotate the hip outward. Compare left to right for range and for feel: a hard block or a sharp pinch at the front of the hip is a different finding than a soft stretch, and worth having looked at. Our overview of the pinch at the front of the hip covers when that one matters.

What to do. Ninety-ninety hip rotations on the floor, moving slowly side to side and lifting the knees so it is active rather than a slump; adductor rock-backs; and rotational work with a band or a light medicine ball so the new range gets used against resistance. Range you cannot control at speed will not survive the first real swing.

4. Mid-back extension: the one shoulders and necks pay for

The mid-back, or thoracic spine, is where overhead motion actually comes from. If it cannot extend and rotate, the shoulder blade never sets up properly and the shoulder joint runs out of room — so the athlete arches the low back to get the arms overhead, or grinds the shoulder into the last few degrees it does not have. Overhead throwers, swimmers, and anyone pressing a bar overhead feel it first. So do the athletes who train after eight hours at a screen.

Ribs are part of this. A mid-back that will not extend usually comes with ribs that are not moving much, which is also why some athletes cannot find a full breath at the top of an interval. Our article on the rib restriction that makes breathing feel tight covers that overlap.

The self-test. Stand with your back against a wall, heels a few inches out, and flatten your low back to the wall by tucking the pelvis slightly. Hold that flat back, then raise both arms overhead and try to touch your thumbs to the wall with the elbows straight. Thumbs reach easily and the low back stays flat? Good. If the low back peels off the wall or the elbows bend to get there, that range was coming from your lumbar spine, not your mid-back.

What to do. Foam-roller extensions over the mid-back, open-book rotations on your side, wall slides done slowly with the ribs down, and a few minutes of deliberate breathing where you feel the lower ribs widen. Hands-on care to the stiff segments makes the exercise work faster; the exercise is what makes it hold.

Every joint that stops moving hands its job to a neighbor. The neighbor is usually the part that hurts.

What a real pre-event warm-up should accomplish

A warm-up has four jobs, and fixing your mobility is not one of them. It should raise your temperature, restore access to the ranges your sport needs today, wake up the pattern you are about to use, and rehearse the intensity you are about to ask for.

• Raise temperature first. Five to ten minutes of easy movement — jogging, biking, skipping, sport-specific footwork.
• Move, don’t hold. Dynamic work through the ranges you just tested: leg swings, knee-to-wall reps, hip rotations, open books, walking lunges with a reach. Long static holds right before a power effort tend to dull output for a while — save those for afterward.
• Load one leg. A few slow step-downs or split squats per side predict how you will land far better than any stretch does.
• Rehearse the speed. Two or three build-ups at or near race pace, or a handful of progressively heavier warm-up sets. The nervous system wants a preview, not a surprise.

And nothing new on event day. No drill you have never done, no new shoes, no first-ever deep soft-tissue session an hour before the gun.

The week before: what to do and what to leave alone

Here is the honest part. The week of an event is not when mobility changes. Real range change takes weeks of consistent loaded work — that is simply how tissue and motor control adapt. What the last week can do is make sure you have full access to the range you already own, and that you arrive rested.

• Do keep training, cut the volume, and keep a few short touches of intensity so you do not go flat.
• Do run your mobility work daily but briefly — ten minutes on the ranges your sport actually needs.
• Do treat sleep, food, and hydration as part of the training, because for that week they are the training.
• Don’t chase a new range, add a new lift, or test a max.
• Don’t book your first aggressive soft-tissue or mobility session two days out. If you want hands-on care before an event, have it five to seven days out so any soreness has cleared.

The right window for the four restrictions above is the four to eight weeks before a season or a goal event, not the taper. If you are reading this on the Thursday before a Saturday race, warm up well, race, and put the assessment on next week’s calendar. And if mobility work and stretching still sound like the same thing, our piece on why stretching more doesn’t restore range is worth ten minutes.

When it isn’t a mobility gap

Restrictions are common and mostly mechanical. Some things are not, and they belong with a physician or your athletic trainer rather than a mobility drill:

• Pain that started with a real injury — a fall, a collision, a pop you heard or felt.
• Pain at night or at rest that wakes you or does not settle when you stop moving.
• Numbness, tingling, or genuine weakness in an arm or a leg.
• A joint that locks, catches, or gives way underneath you.
• Swelling that keeps coming back, or fever alongside joint pain.

Push through those and no warm-up will save you. Route them properly and you usually get back to sport sooner, not later.

How we test it in the office

An assessment at The Spine Studio in Cottleville is forty minutes of watching you move — single-leg control, ankle range, hip rotation, mid-back extension, and then the movement your sport actually demands, under load. Dr. Andersen uses hands-on care to restore motion where a joint is stuck, then builds a short Corrective Exercise program so the range you gain has strength behind it and still shows up in week six, not just on the table.

We work alongside your coach, your athletic trainer, and your physician rather than around them — they see you far more often than we do. If you compete anywhere around St. Charles County, whether that is Katy Trail miles, a Saturday tournament, a meet, or a barbell goal, our sports chiropractic care in Cottleville page explains what the process looks like start to finish.