Knee Pain: Causes, Diagnosis, Treatment and Exercise
Knee pain can show up in very different ways. You may feel pain around the kneecap when climbing stairs, along the outside of the knee while running, or directly below the kneecap when jumping. Your knee may hurt after a twisting injury, catch during movement, feel unstable, or gradually become stiff and uncomfortable over time.
These symptoms can all be described as “knee pain,” but they may represent very different problems.
Patellofemoral pain, meniscus injuries, ligament sprains, patellar tendinopathy, iliotibial band syndrome, osteoarthritis, and growth-related conditions such as Osgood-Schlatter disease can produce overlapping symptoms. Even the location of pain does not always identify exactly which structure is responsible.
That is why effective treatment begins with understanding what happened, where and when symptoms occur, what movements aggravate them, and how the knee functions during the activities that matter to you.
Understanding Knee Pain
The knee has to provide both mobility and stability while managing substantial forces during walking, running, climbing stairs, squatting, jumping, and changing direction.
Its function depends on more than the knee joint itself. The femur, tibia and patella interact with ligaments, menisci, tendons, muscles and other tissues to control movement and distribute load. Strength and movement at the hip, ankle and foot may also be relevant depending on the individual and the activity.
This helps explain why two people who both report “knee pain” may require very different approaches to assessment and rehabilitation.
For example, pain around the kneecap in a runner may behave very differently from joint-line pain following a twisting injury. Pain below the kneecap in an adult jumping athlete may involve the patellar tendon, while similar pain in a growing adolescent may involve the developing tibial tuberosity.
The goal of assessment is therefore not simply to locate a painful spot. It is to determine the most likely diagnosis, identify factors that are clinically relevant to that individual, rule out conditions requiring further investigation, and develop a treatment and rehabilitation strategy appropriate to the person's needs.
In This Article
Common Causes of Knee Pain
Knee pain can develop gradually from changes in activity and loading, or appear suddenly after a fall, twist, collision, or other injury. Age, activity level, sport, previous injuries, and the way symptoms behave all provide important clues. The following are some of the more common conditions we assess.
Patellofemoral Pain: Pain Around the Kneecap
Patellofemoral pain, sometimes called runner's knee, commonly causes pain around or behind the kneecap. Symptoms may increase with running, stairs, squatting, lunging, prolonged sitting, or other activities that place greater demands on the knee.
Despite the name, it is not limited to runners. Patellofemoral pain can affect people across a wide range of ages and activity levels. Rather than being caused by a single alignment or tracking problem, it is usually better understood by considering activity and loading, strength, movement, recovery, previous injury, and other individual factors.
Meniscus Injuries: Joint-Line Pain, Catching and Twisting
The menisci are two fibrocartilage structures that help distribute load and contribute to stability within the knee. Meniscus injuries can occur suddenly during twisting or pivoting movements, but meniscal changes can also develop gradually over time.
Symptoms may include pain along the inside or outside joint line, swelling, pain with twisting or deep knee bending, and sometimes catching or locking. Importantly, meniscal findings on MRI are common, particularly as we age, and do not always explain knee pain.
Many meniscus problems can initially be managed without surgery. However, a knee that becomes genuinely locked, significant trauma, or certain displaced or potentially repairable tears may require earlier orthopaedic assessment.
Knee Ligament Injuries: When the Knee Feels Unstable
The ACL, PCL, MCL and LCL help control movement and provide stability to the knee. Ligament injuries are more commonly associated with trauma, such as sudden changes of direction, awkward landings, collisions or direct blows to the knee.
Symptoms depend on the ligament and severity of the injury but can include pain, swelling and a feeling that the knee is unstable or may give way. Some ligament injuries respond well to rehabilitation, while others, particularly significant ACL injuries in people returning to demanding pivoting sports, may require consultation with an orthopaedic specialist.
Patellar Tendinopathy: Pain Below the Kneecap
Patellar tendinopathy, often called jumper's knee, typically causes localized pain in the patellar tendon, most commonly near the lower edge of the kneecap. It is particularly associated with sports involving repeated jumping, acceleration and rapid changes in loading.
Symptoms often increase as demand on the tendon increases. Rehabilitation focuses on managing aggravating loads while progressively rebuilding tendon and lower-extremity capacity. Complete rest is rarely the long-term solution because the tendon ultimately needs to tolerate loading again.
Iliotibial Band Syndrome: Pain Along the Outside of the Knee
Iliotibial band syndrome (ITBS) is a common cause of lateral knee pain, particularly in runners and cyclists. Pain typically develops along the outside of the knee during repetitive activity and may become progressively more noticeable as a run or ride continues.
ITBS is not simply the result of a “tight IT band.” Training load, running or cycling demands, strength, movement strategies and individual anatomy may all be relevant. Management commonly involves adjusting aggravating activity while progressively restoring strength and tolerance to the demands that triggered symptoms.
Osgood-Schlatter Disease: Knee Pain During Growth
In children and adolescents, pain around the knee needs to be considered in the context of skeletal growth. Osgood-Schlatter disease affects the developing tibial tuberosity, the bony prominence below the kneecap where the patellar tendon attaches.
It commonly appears during periods of rapid growth in young people participating in running, jumping and field or court sports. Pain and tenderness are typically localized over the tibial tuberosity and increase with activity.
Although the long-term outlook is generally very good, simply telling a young athlete to stop all activity is not always necessary. Appropriate load modification, progressive exercise and gradual return to higher-demand activity can help maintain physical capacity while symptoms are managed.
Knee Osteoarthritis: Pain and Stiffness Over Time
Knee osteoarthritis becomes more common with age, but an X-ray showing osteoarthritis does not automatically tell us how much pain or disability someone will experience.
Symptoms can include pain, stiffness, reduced movement and difficulty with activities such as walking, stairs or prolonged weight-bearing. Exercise, strengthening, physical activity, education and, where appropriate, weight management are central components of conservative care.
The goal is not to make an arthritic knee look different on an X-ray. It is to reduce symptoms, improve physical capacity and help the person remain engaged in the activities that matter to them.
A Diagnosis Is More Than the Location of Pain
These patterns can provide useful clues, but they should not be used for self-diagnosis. Pain around the kneecap does not automatically mean patellofemoral pain, and joint-line pain does not automatically mean a meniscus tear.
The history, mechanism of injury, age, activity demands, symptom behaviour and physical examination all need to be considered together.
How Knee Pain Is Assessed and Diagnosed
A good knee assessment begins before any physical tests are performed. Understanding how the problem started, how symptoms behave, and what activities have become difficult often provides some of the most useful diagnostic information.
Was there a sudden twist, fall, collision, or awkward landing? Did the pain gradually appear after increasing running distance, jumping, hiking, or another activity? Is there swelling, catching, locking, instability, or pain at night? Does the knee hurt during activity, afterward, or the following day?
Age and activity also matter. An adolescent athlete with pain below the kneecap presents a very different clinical picture from an older adult with gradually increasing stiffness or an athlete whose knee became swollen after a twisting injury.
The Physical Examination
The physical examination is guided by the history and may include:
Observation and movement: Looking at swelling, range of motion, walking, squatting, stepping, single-leg movements, or other activities relevant to the person's symptoms.
Palpation: Identifying areas of tenderness around the patella, joint lines, tendons, ligaments, tibial tuberosity, and other structures.
Joint mobility and range of motion: Assessing knee flexion and extension and determining whether movement is painful or restricted.
Ligament testing: Evaluating the ACL, PCL, MCL and LCL when injury or instability is suspected.
Meniscus testing: Combining joint-line tenderness, symptom history and provocative movements when a meniscal injury is being considered.
Strength and functional capacity: Assessing the quadriceps, hamstrings, hips and calf, along with functional tasks appropriate to the person's activity level.
Related regions: The hip, ankle, foot, lumbar spine or neurological system may also be examined when the history and clinical findings suggest they are relevant.
No single orthopaedic test should be expected to provide the entire diagnosis. Tests become more useful when their findings are interpreted alongside the history, symptom behaviour and overall examination.
Do You Need an X-Ray, Ultrasound or MRI?
Not everyone with knee pain needs imaging.
For many common knee problems, the combination of history and physical examination provides enough information to begin conservative management. Imaging becomes more useful when the diagnosis remains uncertain, significant trauma has occurred, fracture or another important condition is suspected, symptoms are not progressing as expected, or the result could change treatment decisions.
Different forms of imaging answer different questions. X-rays are useful for evaluating bone, fractures and osteoarthritis. Ultrasound can provide information about superficial tendons and other soft tissues. MRI provides more detailed imaging of structures such as the menisci, ligaments, cartilage and bone marrow.
It is also important to remember that an abnormal imaging finding is not automatically the cause of pain. Meniscal changes, cartilage changes and osteoarthritis can sometimes be found in people who have relatively few symptoms. Imaging therefore needs to be interpreted alongside the clinical examination rather than in isolation.
When Knee Pain Needs Further Investigation
Most knee pain is not an emergency, but certain presentations deserve more immediate assessment. Significant trauma, inability to bear weight, major or rapidly developing swelling, a knee that is genuinely locked and cannot fully straighten, substantial instability following injury, or suspected fracture should be evaluated appropriately.
Fever, pronounced redness or warmth, unexplained persistent night pain, systemic illness, or neurological or vascular symptoms also require further investigation because they may indicate something other than a routine musculoskeletal knee problem.
The purpose of assessment is not simply to give the painful structure a name. It is to determine what is most likely causing the problem, whether further investigation is necessary, and what needs to change to help the person regain function.
Treating Knee Pain: From Symptom Relief to Rehabilitation
There is no single treatment for knee pain because there is no single cause. Treatment should reflect the diagnosis, severity of the condition, activity demands, and the individual's goals.
For many knee problems, the objective is not simply to make the pain disappear temporarily. Effective rehabilitation should help restore movement, strength, confidence, and the physical capacity needed for everyday life, work, recreation, or sport.
Start by Managing What Is Aggravating the Knee
When knee pain develops, people are often faced with two extremes: continue pushing through the pain or stop activity completely. In many cases, neither approach is ideal.
Temporarily modifying activities that significantly aggravate symptoms can allow the knee to settle while maintaining as much activity as possible. This might mean reducing running distance, limiting repeated jumping, changing training frequency, temporarily modifying squat depth, or substituting cycling or another better-tolerated activity.
The goal is usually load management rather than complete avoidance of movement. As symptoms and physical capacity improve, activity can be progressively increased.
Manual Therapy as Part of a Broader Strategy
Manual therapy can sometimes help reduce symptoms or improve movement tolerance, particularly when pain or mobility limitations make exercise and normal activity more difficult.
At Kinetic Health, manual treatment may include techniques from Motion Specific Release (MSR), an integrated approach developed by Dr. Brian Abelson that combines soft-tissue procedures, joint mobilization, and other hands-on techniques with functional assessment and exercise.
Treatment is selected according to the individual examination rather than applying the same protocol to every person with knee pain. Depending on the findings, treatment may involve the knee as well as clinically relevant areas of the hip, thigh, lower leg, ankle, or foot.
The purpose of manual therapy is not to mechanically “put the knee back into place,” break up scar tissue, or correct a universal biomechanical fault. Its value is determined by the response. Does the person move more comfortably? Has useful range of motion improved? Can they perform an exercise or functional task more effectively?
When manual therapy produces a meaningful change, it can help create an opportunity to progress rehabilitation. It should support active treatment rather than replace it.
Exercise and Progressive Loading
Exercise is one of the most important components of rehabilitation for many common knee conditions.
The specific program depends on the diagnosis. Someone recovering from a ligament injury may have very different requirements from a runner with patellofemoral pain, an older adult with osteoarthritis, or an adolescent with Osgood-Schlatter disease.
Rehabilitation may progressively address:
Mobility: Restoring comfortable knee movement when flexion or extension is limited.
Strength: Developing the quadriceps, hamstrings, hips, calf, and other muscles important for the individual's activities.
Functional control: Progressing from basic movements to squatting, stepping, lunging and single-leg tasks.
Load tolerance: Gradually increasing the amount and intensity of activity the knee can tolerate.
Higher-demand movement: Reintroducing running, jumping, landing, acceleration and changes of direction when appropriate.
Sport or activity-specific capacity: Preparing the person for the actual demands they will face when they return to work, recreation or sport.
Progress is not determined by pain alone. Range of motion, strength, swelling, movement quality, functional performance, confidence, activity tolerance and the response during and after exercise can all help guide progression.
Rehabilitation Should Match the Person
Two people with the same diagnosis may not need the same rehabilitation program.
A recreational walker with knee osteoarthritis has different goals from a basketball player recovering from an ACL injury. A runner preparing for a marathon has different demands from someone who simply wants to climb stairs comfortably again.
This is why rehabilitation should become increasingly specific to the activities the person wants to return to.
The goal is not merely to complete a collection of exercises. It is to progressively rebuild enough physical capacity that the knee can once again handle the demands being placed upon it.
When Is Surgery Considered?
Many common knee problems can initially be managed conservatively, but surgery is appropriate in some circumstances.
Certain fractures, significant ligament injuries, displaced or potentially repairable meniscal tears, advanced joint disease, and other structural problems may warrant orthopaedic consultation. A genuinely locked knee or significant instability following trauma may also require more urgent investigation.
At the same time, an abnormal MRI does not automatically mean surgery is necessary. The decision should consider the diagnosis, symptoms, functional limitations, activity goals, response to appropriate conservative care, and the individual's preferences.
The objective is not simply to treat an image. It is to help the person regain the greatest possible level of comfortable, confident function.
Moving Forward with Knee Pain
Knee pain can be frustrating, particularly when it begins to interfere with walking, exercise, work, or the activities you enjoy. But pain does not automatically mean that the knee is seriously damaged, nor does an abnormal finding on an X-ray or MRI necessarily determine what you can or cannot do.
The first step is understanding what type of knee problem you are dealing with and how it is affecting you. A thorough assessment can help distinguish between common conditions such as patellofemoral pain, meniscus injuries, ligament injuries, patellar tendinopathy, iliotibial band syndrome, osteoarthritis, and growth-related conditions such as Osgood-Schlatter disease.
From there, treatment can be individualized. For many knee conditions, this means finding the right balance between managing aggravating activities and continuing to move, while progressively rebuilding mobility, strength, and physical capacity. Manual therapy may be incorporated when it produces a useful change in symptoms or movement that helps support rehabilitation.
Recovery is also about more than becoming pain-free. The larger goal is to develop a knee you can use with confidence, whether that means climbing stairs, returning to running, hiking in the mountains, playing a sport, or simply moving comfortably through everyday life.
At Kinetic Health, our approach is to determine what is clinically relevant to the individual, establish realistic goals, and build a treatment and rehabilitation strategy around the activities that matter most to them.
References
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Medical Disclaimer
The information provided on the Kinetic Health website, including articles, videos, exercises, and other educational resources, is intended for general educational and informational purposes only. It is not a substitute for individualized assessment, diagnosis, or treatment by a qualified healthcare professional.
Musculoskeletal conditions and injuries vary from person to person. Exercises, self-care strategies, or other information presented on this website may not be appropriate for every individual or condition.
If you have new, severe, worsening, or unexplained symptoms, or are unsure whether an exercise or treatment approach is appropriate for you, consult an appropriately qualified healthcare professional.
Use of this website does not establish a practitioner-patient relationship with Kinetic Health or any of its healthcare providers.
For urgent or potentially serious symptoms, seek appropriate medical attention.
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