Shin splints

What it is

Medial tibial stress syndrome is a stress reaction in the bone along the inner border of the tibia, with contributions from the overlying muscle attachments. It sits on a continuum: bone stress reaction at one end and a frank stress fracture at the other, which is why the distinction matters clinically.

It is almost always a training error. Bone adapts to load but on a slower timescale than fitness improves, so a runner whose cardiovascular system can handle more mileage may have bone that cannot yet. The gap between what you can run and what your shins have adapted to is where this lives.

What it feels like

• Diffuse aching along the inner edge of the shin, over several centimetres rather than one point
• Sore at the start of a run, easing during, and worse afterwards
• Tender to press along the bone edge
• Progressing to hurting throughout the run and then during walking
• A single very tender point rather than a diffuse line, which suggests a stress fracture instead

What causes it

Most people have more than one of these at once, and they feed each other. Read the list looking for the two or three that sound like your week rather than for the one true answer — the ones that describe you are the ones worth acting on.

A rapid increase in impact load

More mileage, more speed, more hills, or a return after time off. Bone adaptation lags behind cardiovascular adaptation, and the mismatch is the mechanism.

Calf and foot muscle weakness

The calf and the muscles running along the inside of the shin absorb impact. When they fatigue or are weak, more force reaches the bone directly.

Excessive or poorly controlled pronation

A foot that rolls in excessively increases the traction on the muscle attachments along the tibia and changes the bending forces through the bone.

Hard surfaces and worn shoes

Running on concrete, or in shoes past their useful life, increases the impact per stride. Neither is the sole cause but both add to the total.

Low bone density and low energy availability

Under-fuelling relative to training load reduces bone quality, and in women it disrupts the menstrual cycle. Relative energy deficiency in sport is a major and frequently missed contributor to bone stress injuries.

Previous shin splints or stress fracture

A strong predictor of recurrence, partly because the underlying training pattern and biomechanics are usually unchanged.

Vitamin D deficiency

Associated with bone stress injuries in athletes and easily corrected. Worth checking in anyone with a recurrent problem.

High body weight relative to conditioning

Impact force scales with body weight. Someone returning to running at a higher weight than before is loading bone that has not adapted to that load.

Stride mechanics

Overstriding with a heavy heel strike increases the impact peak. Increasing cadence slightly reduces the load per step measurably.

Running through the early symptoms

The main reason a stress reaction becomes a stress fracture. Early symptoms are the warning that adaptation has been outpaced, and continuing removes the chance to respond.

Who tends to get it

• New runners and anyone returning after a break
• Military recruits and anyone starting a sudden high-volume programme
• Athletes with low energy availability or irregular periods
• Runners with weak calves or excessive pronation
• Anyone who has had shin splints or a stress fracture before

What makes it worse, and what settles it

The qFIT routine for this

Ready-made routineShin Splints Relief

qFIT already has this one built. It runs massage first, then stretching, then strength — the order that works on a body that is already sore — and every activity in it carries the reason it is there.

The button below opens your Checklist with this routine already selected, so instead of your whole list you land on just its Categories, Targets and Exercises, each with its checkbox, ready to tick as you work through them.

Have more than one problem? Tick yours under My Problems on My Profile and your Checklist's Routine list gains Recommended for my problems — every routine for the problems you picked, merged into one. Your picks stay private; that filter is the only thing they feed.

Get it checked if…

Focal point tenderness on the bone, night pain, or pain that worsens through a run suggests a stress fracture - stop running and image

And whatever the body part: chest pain or unusual breathlessness on exertion; a fever alongside the pain; unexplained weight loss; pain that is constant and unrelated to how you move; new numbness, weakness or loss of bladder or bowel control; or one calf that is swollen, warm and painful. Any of those, stop and get assessed.

How it usually goes

Most cases settle over four to eight weeks with load reduction and strengthening, and the recurrence rate is high in people who return to the same training pattern. Cross-training maintains fitness while the bone recovers, which makes the rest less costly than it feels. Pain that localises to one very tender point, that is present at rest or at night, or that hurts on hopping needs imaging for a stress fracture, which requires a longer and stricter break.

Prevalence basis: Sports medicine incidence data

This is general information, not a diagnosis, and it cannot examine you. If it matches you, use it to ask better questions of a clinician rather than to replace one.