FEATURED ARTICLE • MUSCULOSKELETAL PHYSIOTHERAPY
Knee Pain: Types, Common Causes, Assessment & Physiotherapy Management
Knee pain is a common musculoskeletal complaint. The location of pain can provide useful clinical clues, but pain location alone cannot establish a diagnosis. A structured history and physical examination are essential.
Introduction
Knee pain may arise from the patellofemoral joint, menisci, ligaments, tendons, bursae, muscles, or other surrounding tissues. Rehabilitation should be individualized according to the underlying presentation, symptoms, function and goals.
1. Anterior Knee Pain (Front of the Knee)
Anterior knee pain is felt around or behind the kneecap. It is commonly associated with activities that repeatedly load the patellofemoral joint, such as stairs, squatting, running, and prolonged sitting with the knee bent.
Common Causes
- Patellofemoral pain syndrome
- Patellar tendinopathy
- Patellofemoral cartilage-related disorder
- Quadriceps or patellar loading-related problems
Key Features
- Pain around or behind the kneecap
- Pain during stairs, squatting, running or jumping
- Pain after prolonged sitting may occur
- Pain commonly aggravated by repeated knee flexion
2. Medial Knee Pain (Inside of the Knee)
Medial knee pain is experienced on the inner side of the knee. It can come from structures such as the medial meniscus, medial collateral ligament, medial compartment of the knee joint, or tissues around the pes anserine region.
Common Causes
- Medial meniscal injury
- Medial collateral ligament (MCL) injury
- Medial-compartment osteoarthritis
- Pes anserine bursopathy/tendinopathy
Key Features
- Pain along the inner side of the knee
- Twisting or loaded bending may aggravate pain
- Medial joint-line or soft-tissue tenderness may be present
- Swelling may occur depending on the condition
3. Lateral Knee Pain (Outside of the Knee)
Lateral knee pain occurs on the outer side of the knee. It is often related to repetitive loading during running or other activities, but meniscal, ligament, and joint problems can also contribute.
Common Causes
- Iliotibial band-related pain
- Lateral meniscal injury
- Lateral collateral ligament (LCL) injury
- Lateral-compartment osteoarthritis
Key Features
- Pain on the outer side of the knee
- Symptoms may increase with running or repetitive loading
- Twisting may aggravate symptoms in some conditions
- Localized lateral tenderness may occur
4. Deep Knee Pain (Inside the Joint)
Deep knee pain is perceived within the knee joint rather than at a superficial area. It may be accompanied by stiffness, swelling, catching, or crepitus depending on the underlying joint or intra-articular problem.
Common Causes
- Knee osteoarthritis
- Meniscal pathology
- Synovial irritation
- Loose bodies or other intra-articular disorders
Key Features
- Deep aching pain within the joint
- Stiffness or restricted movement
- Swelling or effusion may occur
- Crepitus, catching or other mechanical symptoms may occur
5. Pain Below the Knee (Upper Tibia / Below the Kneecap)
Pain below the kneecap is usually felt around the patellar tendon, tibial tubercle, or upper shin. The pattern is often related to repetitive running or jumping loads, although the cause can vary with age and activity level.
Common Causes
- Patellar tendinopathy
- Osgood-Schlatter disease in growing adolescents
- Activity-related tibial or soft-tissue disorders
Key Features
- Pain below the kneecap or around the tibial tubercle
- Pain may increase with jumping or running
- Localized tenderness may be present
- Often related to repetitive loading
6. Posterior Knee Pain (Back of the Knee)
Posterior knee pain is felt behind the knee and may present as aching, tightness, fullness, or swelling. Muscular, meniscal, cyst-related, and other posterior knee conditions can produce this pattern.
Common Causes
- Baker's cyst
- Hamstring or gastrocnemius-related injury
- Meniscal pathology
- Other posterior knee disorders
Key Features
- Pain or fullness behind the knee
- Tightness or swelling may occur
- Deep knee flexion may aggravate symptoms
- A feeling of fullness can occur with a popliteal cyst
7. Generalized Knee Pain (Around the Knee)
Generalized knee pain refers to discomfort spread across several areas of the knee rather than one clearly localized spot. It may occur with osteoarthritis, inflammatory conditions, or activity-related overload and is usually assessed alongside stiffness, swelling, and functional limitations.
Common Causes
- Knee osteoarthritis
- Inflammatory arthritis
- Overuse or load-related pain
- Less commonly, infection or other systemic conditions
Key Features
- Diffuse pain around the knee
- Stiffness and/or swelling
- Reduced range of motion
- Reduced tolerance for walking or other activities
8. Ligament-Related Knee Pain (Instability)
Ligament-related knee pain is commonly associated with an injury to one of the major knee ligaments and may be accompanied by instability or a feeling that the knee is giving way. It often follows a traumatic event, particularly during sports or twisting movements.
Common Causes
- ACL injury
- PCL injury
- MCL sprain
- LCL sprain or combined ligament injury
Key Features
- History of trauma may be present
- Knee may feel unstable or give way
- Swelling may occur after significant injury
- Difficulty with pivoting, cutting or sports may occur
Physiotherapy Assessment of Knee Pain
A physiotherapy assessment should be individualized and should not rely on pain location alone.
- History: onset, mechanism, duration, aggravating/relieving factors, previous injury, activity changes and functional limitations.
- Pain and symptoms: location, intensity, 24-hour behavior, stiffness, swelling, locking, clicking and giving way.
- Observation: gait, alignment, swelling, bruising, muscle wasting and movement strategy.
- Range of motion: active and passive knee flexion/extension and relevant hip and ankle mobility.
- Strength and motor control: quadriceps, hamstrings, hip muscles and functional lower-limb control.
- Palpation: relevant joint lines, tendons, bursae, ligaments and surrounding soft tissues.
- Special tests: use condition-specific tests when clinically indicated and interpret them with the history and examination.
- Functional assessment: sit-to-stand, squat, stairs, walking, running, jumping, balance or sport-specific tasks.
Physiotherapy Management: General Principles
- Patient education and reassurance based on the clinical presentation.
- Appropriate activity and load modification while maintaining tolerable movement.
- Progressive strengthening, commonly targeting the quadriceps and relevant hip musculature.
- Mobility exercises when clinically relevant restrictions are present.
- Balance, coordination and functional movement training.
- Manual therapy may be used as an adjunct when appropriate, alongside active rehabilitation.
- Gradual progression toward work, exercise, running or sport-specific goals.
- Medical or specialist referral when red flags, major trauma or suspected serious pathology are present.
Red Flags and Referral
- Major trauma with suspected fracture, dislocation or significant ligament injury.
- Acute substantial swelling after trauma, especially with inability or marked difficulty bearing weight.
- Hot, markedly swollen knee with fever or systemic illness.
- Unexplained persistent or worsening pain, significant night pain or systemic symptoms.
- New calf swelling, warmth, redness or unexplained calf pain, particularly with risk factors for thrombosis.
- True locking, recurrent giving way or major functional loss.
Educational Clinical Case Study
Case: A 24-year-old recreational runner reports gradual anterior knee pain for six weeks. Symptoms increase with downhill running, stairs and repeated squats. There is no major traumatic event and no significant swelling.
Example approach: Assess symptom behavior, training load, knee and hip strength, movement control and functional tolerance. Management may include education, temporary load modification, progressive strengthening and a graded return to running according to examination findings and response.
Quick Clinical Comparison
| Pain Location | Examples of Causes | Clinical Clues |
|---|---|---|
| Anterior | Patellofemoral pain, patellar tendinopathy | Stairs, squatting, running, prolonged sitting |
| Medial | Meniscus, MCL, medial OA, pes anserine disorders | Medial tenderness; twisting/loading |
| Lateral | IT band-related pain, lateral meniscus, LCL | Running/loading; lateral tenderness |
| Deep | OA, meniscus, intra-articular disorders | Deep ache, stiffness, swelling/mechanical symptoms |
| Below patella | Patellar tendinopathy, Osgood-Schlatter | Jumping/running; inferior patellar pain |
| Posterior | Baker's cyst, hamstring/gastrocnemius disorders | Posterior fullness or flexion pain |
| Generalized | OA, inflammatory arthritis, overuse | Diffuse pain, stiffness/swelling |
| Instability | ACL/PCL/MCL/LCL injuries | Trauma, giving way, swelling, pivoting difficulty |
Key Takeaways
- Knee pain location can guide clinical reasoning, but it is not diagnostic by itself.
- Different pain locations have different possible causes and clinical patterns.
- Complete history and physical examination are essential.
- Rehabilitation should be individualized and progressed according to symptoms, function and goals.
- Red flags and significant traumatic or systemic presentations require appropriate medical referral.
Medical disclaimer: This article is for physiotherapy education and general information. It does not replace an individual examination, diagnosis or treatment plan.