Why Does My Knee Hurt When Running? Common Causes & How Physiotherapy Can Help
- Vicky Lewis-Baldy
- Jul 15
- 3 min read
Running is one of the best ways to improve fitness, strength and mental wellbeing, but knee pain is one of the most common issues runners experience. Whether you are training for your first 5K, preparing for a marathon, or simply enjoying regular runs, pain around the knee can be frustrating and may stop you from doing what you love.
The good news is that knee pain when running is often manageable with the right assessment, advice and rehabilitation plan.
At Hybrid Health Physiotherapy in Bath, we help runners understand why their knee hurts, what is causing the problem, and how to safely return to pain-free running.
Why does my knee hurt when I run?
Knee pain during running can happen for many different reasons. The knee is a strong and stable joint, but it relies on the muscles and joints above and below it — including the hips, pelvis, ankles and feet — to work effectively.
Common causes of knee pain in runners include:
1. Runner’s knee (patellofemoral pain)
One of the most common causes of running-related knee pain is patellofemoral pain, often referred to as "runner's knee".
This usually causes pain around or behind the kneecap and may feel worse with:
Running, especially downhill or on hills
Squatting or lunging
Walking downstairs
Sitting for long periods with your knee bent ("movie theatre sign")
Despite the name, runner's knee is not simply a problem with the kneecap. It is often linked to how the knee is loading during movement, including strength, control and running volume.
2. Increasing your running too quickly
A common trigger for knee pain is a sudden increase in training load.
Examples include:
Increasing mileage too quickly
Adding speed sessions or hills
Returning to running after a break
Increasing frequency of runs
Your body needs time to adapt to new levels of stress. Running itself is not harmful — but doing too much, too soon can overload tissues.
3. Hip and strength deficits
Although knee pain is felt at the knee, the cause is not always located there.
The muscles around your hips, particularly your glutes, play an important role in controlling your pelvis and knee position while running.
Reduced strength or control can contribute to increased stress around the knee.
A good running assessment looks at the whole movement pattern rather than just the painful area.
4. Tendon-related knee pain
The tendons around the knee can become irritated when they are exposed to more load than they can currently tolerate.
Common examples include:
Patellar tendon pain ("jumper's knee")
Often felt below the kneecap and can be aggravated by:
Running
Jumping
Squats
Stairs
Quadriceps tendon pain
Pain may be felt above the kneecap.
Tendon problems usually respond well to progressive strengthening rather than simply resting.
5. Previous injuries or surgery
Previous knee injuries, including:
ACL injuries
Meniscus injuries
Ligament injuries
Knee surgery
can affect how your knee moves and tolerates running.
A tailored rehabilitation programme can help rebuild strength, confidence and capacity.
Should I stop running if my knee hurts?
Not necessarily.
Many runners assume they need complete rest, but this is not always the best approach.
In many cases, modifying your training while gradually building strength can help you recover while maintaining fitness.
This might include:
Reducing running volume temporarily
Adjusting speed or hills
Adding strength exercises
Improving running technique
Following a structured return-to-running plan
The right approach depends on the cause of your pain.
How can physiotherapy help with running knee pain?
A physiotherapy assessment looks at more than just where your pain is.
At Hybrid Health Physiotherapy in Bath, we assess:
✅ Your running history and training load
✅ Strength and movement control
✅ Hip, knee and ankle function
✅ Previous injuries
✅ Your goals and activity requirements
From there, we create a personalised rehabilitation plan to help you:
Reduce pain
Build strength
Improve confidence
Return to running safely
Reduce the risk of future flare-ups
When should I see a physio about knee pain?
It is worth getting your knee assessed if:
Pain is stopping you running
Symptoms are worsening
Your knee is swelling
Your knee locks or gives way
Pain has lasted more than a few weeks
You keep getting the same problem returning
Early advice can often prevent a small issue becoming a longer-term problem.
Get back to running stronger with Hybrid Health Physiotherapy
Knee pain does not have to mean giving up running.
Whether you are training for an event, returning after injury, or simply want to run comfortably again, our experienced physiotherapists in Bath can help you understand your knee pain and build a plan to get you back doing what you enjoy.
Book a running injury assessment with Hybrid Health Physiotherapy in Bath today.
Comments