Between 70 and 80 per cent of runners sustain a running-related injury in any given year. That is not a small statistical blip — it is the majority of people who lace up and head out the door. And yet most of those injuries are not the result of bad luck or fragile bodies. They are the result of how load is being managed, stride by stride, over months and years.
The encouraging part: the body rarely fails silently. Before a tendon becomes a tendinopathy or a stress reaction becomes a stress fracture, there are almost always earlier signals — patterns in how you move that a trained eye can identify and address. Some of those signals are things you feel. Others are things you can see, if you know what to look for.
Here are five of the most clinically significant ones.
1. Pain that arrives at the same point in every run
You know the one. Mile two, or perhaps the twenty-minute mark. Everything feels fine, and then it is not. The discomfort comes on at almost exactly the same moment each time you go out, settles if you slow down or stop, and returns on schedule the next run.
Runners often interpret this as a structural problem — something worn, something wrong with the tissue itself. Clinically, it is more often a load tolerance issue. Your tissues can handle a certain volume of cumulative stress before they begin to complain. When you consistently reach that threshold at the same point in a run, it tells us the tissue is under-recovered, under-conditioned for the demand being placed on it, or both.
This pattern is common in the Achilles tendon, the patellar tendon (the tendon just below the kneecap), and the proximal hamstring — all structures that absorb significant repetitive load and are slow to adapt when training increases too quickly.
What keeps it happening: Continuing to run through the threshold reinforces the cycle. The tissue never fully recovers between sessions, tolerance does not improve, and the onset point gradually moves earlier into each run. The window between "manageable" and "significant injury" closes faster than most runners expect.
What to do: Rather than resting entirely and returning to the same pattern, the goal is to gradually extend your load tolerance — through progressive loading of the tendon or muscle, addressing any contributing factors in your gait, and ensuring recovery between sessions is actually sufficient. A gait assessment will often reveal whether you are also asking the tissue to work harder than necessary due to a mechanical inefficiency.
2. One side tightening noticeably more than the other
After a run, or sometimes during one, you notice that the right calf or left hip flexor or one particular glute is consistently tighter than its counterpart. You stretch it, it releases, and the same side is tight again after the next session.
Asymmetry in post-run tightness is one of the clearest signals of asymmetrical loading — meaning one side of your body is doing more work than the other to produce the same forward movement. Over the course of a five-kilometre run, your foot strikes the ground roughly 2,500 times per side. If one side is absorbing or generating more force on each of those contacts, the cumulative difference in demand becomes significant.
The cause is rarely the tight muscle itself. More often it is a compensatory pattern — the hip on that side may not be extending fully, the ankle on the other side may have restricted dorsiflexion (the ability to bring your toes towards your shin), or there may be a meaningful difference in single-leg stability between the two sides.
What to do: Targeted stretching of the tight structure addresses the symptom but not the cause. A side-by-side comparison of your movement — ideally on video — will usually reveal where the asymmetry originates. From there, the intervention is specific: restoring range of motion where it is limited, building strength where it is insufficient, and giving your nervous system new movement patterns to draw on.
3. Knee pain on downhills or descending stairs
Running on the flat feels fine. Running downhill, or walking down a staircase the morning after a long run, produces a familiar ache at the front of the knee or just to the outside of the kneecap. It is a specific, directional pain — and it is a specific, directional signal.
Descending requires your quadriceps (the large muscles at the front of the thigh) to work eccentrically — contracting while lengthening, to control the rate at which your knee bends. When the gluteal muscles are not contributing adequately to hip control during this movement, the thigh tends to drift inward as the foot lands. This inward drift of the femur — the thigh bone — is called femoral adduction, and it increases the compressive load on the outer and front portions of the knee joint.
The result is often patellofemoral pain (pain around the kneecap, sometimes called runner’s knee) or iliotibial band syndrome (pain at the outer knee). Both are frequently attributed to the knee itself, but in the majority of cases, the origin is a hip control problem.
What keeps it happening: Strengthening the knee in isolation — through exercises like leg extensions — does not address the upstream cause. The glutes, particularly the gluteus medius and gluteus maximus, need to be strong enough and well-coordinated enough to control the hip during the stance phase of running. Without that, the knee continues to take excess load on every downhill stride.
What to do: A structured gluteal strengthening programme, combined with work on single-leg stability, is the primary intervention. It is also worth assessing your cadence — a slightly higher step rate reduces the braking forces your knee has to manage on each landing, and can provide meaningful relief while the strength work takes effect.
4. Shin or foot pain that improves mid-run, then returns afterwards
This one follows a distinctive pattern that runners often find confusing: the pain is present at the start of a run, then fades as you warm up and find your rhythm, then returns — sometimes more intensely — in the hours after you finish.
This warm-up-and-return pattern is a clinical hallmark of bone stress response — the stage before a stress fracture, where the bone is remodelling under load but has not yet developed a fracture line. The warm-up effect occurs because blood flow to the area increases as you run, temporarily reducing the pain signal. The post-run return reflects the inflammatory response as the tissue attempts to recover.
The most common sites are the tibia (the large bone in the lower leg, often called a shin splint location), the metatarsals (the long bones of the foot), and the navicular (a small bone on the inner arch of the foot). Navicular stress fractures in particular are often misdiagnosed or missed entirely, partly because the pain presentation can be vague.
What to do: This pattern warrants prompt clinical assessment. Running through a bone stress response significantly increases the risk of progression to a complete stress fracture, which requires a much longer period off running. Imaging — typically MRI — is needed to characterise the severity. Beyond load management, the underlying causes need addressing: training volume, footwear, surface, nutritional adequacy (particularly calcium and vitamin D), and running mechanics that may be producing excessive impact forces.
5. A hip drop you can see on video
Ask a friend to film you running from behind, or set your phone up at ground level while you run away from it. Watch the footage with attention on your pelvis — specifically, whether it stays level as each foot lifts off the ground, or whether one side drops noticeably as the opposite foot pushes off.
A visible drop of the pelvis towards the side of the lifted leg is called a Trendelenburg pattern. It indicates that the gluteus medius — the hip abductor muscle on the stance-side hip — is not generating enough force to keep the pelvis stable during single-leg support. During running, you are on one leg for approximately 60 per cent of every stride cycle. If the pelvis is dropping on every step, the cumulative impact on the lower back, hip, knee, and even ankle is considerable.
Runners with a pronounced hip drop commonly present with:
- Iliotibial band syndrome at the outer knee
- Patellofemoral pain (front knee pain)
- Greater trochanteric bursitis (outer hip pain)
- Low back pain during or after runs
- Recurrent hamstring strains on the dropping side
The hip drop is not itself a diagnosis — it is a movement pattern that places disproportionate demand on structures that were not designed to compensate for it.
What keeps it happening: Gluteus medius weakness does not resolve through general fitness. The muscle needs specific, progressive loading — particularly in single-leg positions that replicate the demands of running. Many runners with a hip drop are not weak in absolute terms; they lack the neuromuscular control to recruit the muscle quickly enough at foot strike.
What to do: A combination of targeted gluteus medius strengthening and running-specific stability work is the foundation. Video gait analysis allows a physiotherapist to track improvement objectively — the drop should visibly reduce as strength and control develop. Cueing changes to your running form can also help in the short term, though cues work best when the underlying capacity is being built simultaneously.
A note on what these signs share
Each of these five patterns reflects the same underlying principle: the body compensates until it cannot. Pain is not the first stage of injury — it is usually a later-stage signal that a compensation has been running quietly for some time. The earlier these patterns are identified, the more straightforward the intervention tends to be.
None of them require you to stop running entirely. They require you to run more intelligently — with a clear picture of what is happening in your movement, and a specific plan to address it.
See your gait. Understand what it’s telling you.
The Runner’s Body Check is a 50-minute clinical movement assessment — video gait analysis, single-leg loading tests, and a clear plan to keep you running. Available on ClassPass at both clinics.
Book Runner’s Body Check