Knee pain during exercise: causes and gradual loading

Patellofemoral pain is a condition with pain at the front of the knee, in and around the kneecap [2]. The Norwegian medical handbook Legehåndboka describes it as pain at the front of the knee that is assumed to be due to the muscles that control the kneecap not working well enough, so that control of the kneecap becomes poorer when the knee moves [3].

The condition particularly affects young athletes [2]. Pain on the outside of the knee in runners is a different condition, called iliotibial band friction syndrome [4]. You can also read about runner's knee and jumper's knee.

NHI describes dull, aching pain behind, around or under the kneecap. The pain typically comes with running, jumping, stairs, especially downwards, and squatting [2]. Many also feel stiffness after the knee has been bent for a long time, and pain after long periods of sitting, for example on car or bus journeys [2]. Some experience a feeling that the knee gives way [2].

It may initially affect one knee, but often both knees become involved over time [2].

The condition is most often caused by overload or uneven loading of the joint between the kneecap and the thigh bone. Weakened thigh muscles, congenital foot malalignment and a lot of activity without accustomed progression can contribute [2]. These are associations described in the sources, and they do not mean that a single factor explains the complaints in each individual.

Gradual adaptation to sport-specific activities and an adapted training plan are regarded as important for avoiding setbacks with overuse injuries in general [4].

The diagnosis is made on the basis of the history and a clinical examination [2][3]. X-ray and other imaging usually show no abnormality in the knee and are in some cases used to rule out other causes [2].

The international guide suggests that the assessment covers the history, pain level, fear of movement, expectations and knee function. The examination looks at strength in the hip and knee, movement pattern and how much load the knee tolerates [1].

A British guide from 2024 is based on a systematic review, patients' experiences and clinical reasoning. Knee-based exercise receives the strongest recommendation, and exercise for both hip and knee also receives a high recommendation. Education about the condition should underpin all measures [1].

Prefabricated foot insoles are also recommended, but with low certainty of effect. Manual therapy for the lower limb may have an effect on function, but not on pain. Tape can be used as an addition when there is a lot of pain or irritability [1]. NHI describes the effect of taping, bandages and orthoses as uncertain [2].

Physiotherapy is regarded as effective treatment, and strengthening of the thigh muscles and stretching of the back of the thigh are mentioned as central [2].

The guide says that the dose of exercise should be adapted to pain and irritability. If the knee tolerates loaded bending poorly, more emphasis is first placed on hip exercises. If the measure has no effect, it should be reconsidered after at least six weeks [1].

NHI describes offloading by avoiding activities that trigger pain, for example deep squats, running on hard surfaces and plyometric jumps. The offloading can last several months [2]. For runners and cyclists, relative rest is described, that is, replacing painful activities with others rather than stopping completely [4].

Mild cases often resolve on their own. Many improve with reduced load and rehabilitation, but for some the complaints can become long-lasting. NHI points out that there are no good long-term studies [2]. Surgery is regarded as a last resort and is only relevant after 12 to 24 months of rehabilitation without effect [2].

The diagnosis is made on the basis of the history and a clinical examination [2]. If the complaints do not improve, or you are unsure what the cause is, you can have the knee assessed by a doctor or physiotherapist. The guide recommends that measures are reconsidered after at least six weeks without effect [1].

A physiotherapist can examine the knee, strength and movement pattern and make a plan for gradual rehabilitation adapted to your pain. You can read more about physiotherapy, and if you are a runner you will find information about running injuries and running analysis.

What is patellofemoral pain syndrome?

A condition with pain at the front of the knee, in and around the kneecap. It particularly affects young athletes [2].

Do I have to stop training when my knee hurts?

Not necessarily. The guide adapts the exercises to pain and irritability [1], and NHI describes relative rest, where painful activities are replaced with others [4]. Offloading of activities that trigger pain can still last several months [2].

Do I need an X-ray or MRI of the knee?

Imaging usually shows no abnormality in the knee with this condition. It is used in some cases to rule out other causes [2].

Which exercises are recommended for pain at the front of the knee?

The guide gives knee exercises its strongest recommendation and also recommends hip and knee exercises. Which exercises and what dose are suitable depends on pain and how much the knee tolerates [1].

Does tape or insoles help?

The guide recommends prefabricated foot insoles with low certainty of effect, and tape as an addition when there is a lot of pain [1]. NHI describes the effect of taping, bandages and orthoses as uncertain [2].

The article about sports injuries describes first aid and gradual rehabilitation more generally. You can find more articles in the overview of articles.

This article was written by Dr.Dropin Fysikalske and is based on the sources listed below. It gives general information and does not replace an examination by a healthcare professional.

The websites were accessed and read on 22 October 2026.

1. Neal BS, Lack SD, Bartholomew C, Morrissey D. Best practice guide for patellofemoral pain based on synthesis of a systematic review, the patient voice and expert clinical reasoning. Br J Sports Med. 2024. Link

2. Patellofemoralt smertesyndrom (Patellofemoral pain syndrome). NHI.no. Last updated 1 March 2022. Link

3. Alvestad M. Patellofemoralt smertesyndrom (Patellofemoral pain syndrome). Legehåndboka, Norsk elektronisk legehåndbok. Revised 2 July 2025. Link

4. Idrettsskader, utholdenhetsidretter (Sports injuries, endurance sports). NHI.no. Last updated 6 October 2020. Link