Running feels simple. One foot in front of the other, a steady rhythm, the freedom of forward motion. Yet beneath that simplicity lies a complex interplay of muscles, joints, load, and repetition — and even small imbalances can quietly build into injury over time.
Many runners assume injuries happen because they trained too hard or pushed too far. Sometimes that’s true. But more often, problems develop gradually through subtle movement patterns, training habits, or recovery gaps that go unnoticed until discomfort becomes impossible to ignore.
Physiotherapy offers a clearer lens into why these injuries occur. It looks beyond the pain itself to understand how the body moves, adapts, and responds to stress. From overuse strain to biomechanical inefficiencies, the real causes are often more predictable — and more preventable — than most runners realise.
The physiotherapy perspective
Running is a high-impact, repetitive activity that puts significant demand on the musculoskeletal system. From a physiotherapy perspective, injuries rarely stem from a single bad step.
Instead, they are usually the result of an imbalance between the load placed on the body and the body’s capacity to handle that load.
Treatment isn’t just about rubbing the sore spot; it’s about identifying the weak link in the kinetic chain and progressive reloading.
1. The “too much, too soon” rule
The most common cause of running injuries is errors in training load. Tendons and bones need time to adapt to new stresses.
- Rapid mileage increase: Increasing weekly volume by more than 10% frequently leads to overuse injuries.
- Intensity spikes: Adding hill sprints or speed work without a solid aerobic base.
- Inadequate recovery: Muscles repair themselves during rest. Without it, micro-trauma accumulates into a clinical injury.
2. Biomechanical inefficiencies
While there is no “perfect” running form, certain movement patterns increase the risk of specific injuries:
- Overstriding: Landing with the foot too far in front of the centre of gravity. This creates a “braking” force that sends high impact through the shins and knees.
- Dynamic valgus: When the knee collapses inward during the stance phase, often caused by weak hip abductors (gluteus medius).
- Crossover gait: Running as if on a tightrope, which places excessive strain on the IT band.
3. The capacity gap (strength and mobility)
Running is essentially a series of single-leg hops. If your muscles aren’t strong enough to stabilise your joints, the “shock” is absorbed by non-contractile tissues like bone and cartilage.
| Common Weakness | Resulting Injury |
| Weak Glutes | Runner’s Knee (PFPS) / IT Band Syndrome |
| Weak Calves | Achilles Tendinopathy / Plantar Fasciitis |
| Poor Ankle Mobility | Shin Splints |
| Weak Core | Lower Back Pain / Hip Impingement |
4. Structural adaptation
Connective tissues like tendons have a different blood supply and metabolic rate than muscles. While your heart, lungs, and muscles might feel ready for a marathon after six weeks of training, your tendons and bones can take months to densify. This lag often leads to stress fractures or chronic tendinosis.
Key risk factors for running injuries
- Prior injury is a significant risk factor.
- Age matters: Older runners are more likely to experience soft-tissue/tendon issues (due to reduced tissue quality), while younger runners are more likely to experience bone or joint problems.
- Training behaviour and technique: Sharp changes in load, downhill/uphill changes, an abrupt switch in surfaces, or over-striding can all increase injury risk.
- Other factors: Nutrition, sleep, recovery, medication and overall tissue health also play a major role.
What to do when a running injury occurs
- Do a simple running assessment: look for things like excessive knee-drift (femur internal rotation and adduction) and landing too far ahead of your body (over-striding) as these increase joint and bone load.
- Calf muscle strengthening (especially soleus + gastrocnemius) is critical for running: they generate very large forces and so need strong, targeted rehab.
- If you must reduce running, avoid full rest for too long: completely “switching off” a running tissue may reduce its capacity further (stress-shielding). Where safe, maintain some load and build capacity progressively.
How to prevent bone-stress injuries (BSIs)
BSIs occur when the bone’s micro-damage repair process is overwhelmed by loading.
Here are five practical tips to minimise BSIs:
- Avoid big spikes in load – aim to increase training gradually rather than suddenly jumping kilometres or intensity.
- Volume before intensity – increase how much you run before increasing how fast or how hard you run; bones tolerate volume better than sudden high intensity.
- Schedule recovery/rest – include regular rest days and blocks of reduced load (or cross-training) to allow adaptation.
- Introduce new surfaces/terrains slowly – e.g., trail vs road, uphill vs flat; changes in environment alter loading patterns.
- Technique tweaks – increasing step cadence by around 5-10% (thereby reducing stride length) – can reduce impact loads and help protect the lower limb.
Final thoughts
Running injuries are rarely random. They develop when movement patterns, training load, and recovery fall out of balance over time.
Physiotherapy helps identify these hidden pressures early, guiding runners towards better mechanics, smarter progression, and stronger resilience.
With greater awareness and the right support, running can remain not just sustainable — but consistently rewarding.
Book an appointment with one of our experienced physiologists today for a comprehensive assessment and customised treatment plan.
