What Causes Knee Pain When Going Down Stairs
Knee pain when descending stairs is most commonly caused by patellofemoral pain syndrome (PFPS), which produces retropatellar or peripatellar pain during activities that load the knee extensor mechanism, particularly stair descent. 1, 2
Primary Mechanism: Patellofemoral Pain Syndrome
Stair descent is the first activity to trigger knee pain as osteoarthritis and patellofemoral disorders develop - research demonstrates that the "using stairs" question is the earliest WOMAC pain item to score points as knee pain progresses from zero, occurring before walking, standing, or other activities 2
PFPS characteristically causes diffuse retropatellar and/or peripatellar pain during squatting, stair ambulation, and activities requiring knee flexion under load 1
The pain mechanism involves increased patellofemoral joint stress during the eccentric loading phase of stair descent, when the quadriceps must control knee flexion while bearing body weight 3, 4
Anatomic Location-Based Differential Diagnosis
Anterior Knee Pain (Most Common for Stair Descent)
Patellofemoral disorders including cartilage loss, subluxation/dislocation, and friction syndrome are the primary causes of anterior knee pain with stairs 5
Patellar tendinopathy commonly produces anterior knee pain during stair descent 5
Fat pad impingement syndromes and Hoffa's disease (enhancing synovitis >2mm in Hoffa's fat) correlate with peripatellar pain during stairs 5
Medial plicae can cause anterior knee pain aggravated by stair use 5
Other Anatomic Locations
Medial compartment osteoarthritis causes medial knee pain, particularly during weight-bearing activities like stair descent 5, 6
Iliotibial band syndrome produces lateral knee pain during repetitive knee flexion-extension 5
Critical Factors Contributing to Stair-Descent Pain
Biomechanical Factors
Kinesiophobia (fear of movement) is the strongest predictor of self-rated difficulty descending stairs in knee osteoarthritis patients (β = 0.607, p = .001), combined with pain explaining nearly 100% of self-reported difficulty 7
Interestingly, objective stair-descent kinematics and muscle strength deficits do NOT explain self-rated difficulties - the psychological component of pain and fear dominates the clinical picture 7
Patients with knee OA display altered lower extremity kinematics and longer stance time during stair descent compared to controls 7
Age and Activity-Related Patterns
Teenage girls and young women are more likely to have patellar tracking problems such as patellar subluxation and PFPS 8
Teenage boys and young men more commonly experience knee extensor mechanism problems like tibial apophysitis (Osgood-Schlatter) and patellar tendonitis 8
Active patients are more prone to overuse injuries including pes anserine bursitis and medial plica syndrome 8
Older adults predominantly experience osteoarthritis-related stair pain 8
Critical Pitfall: Referred Pain
You must exclude hip and lumbar spine pathology before attributing stair pain solely to knee pathology - this is a common diagnostic error 5, 6
Hip pathology commonly refers pain to the knee and should be evaluated if knee imaging is normal 5, 6
Lumbar spine pathology must be considered when knee radiographs are unremarkable and clinical evidence suggests spinal origin 1, 5
In adolescents with knee pain, slipped capital femoral epiphysis can present as referred knee pain during stair use 8
Diagnostic Approach Algorithm
Step 1: Initial Imaging
Obtain anteroposterior and lateral knee radiographs first to exclude fractures, osteoarthritis, osteophytes, and loose bodies 6
Include a tangential patellar view to assess patellofemoral alignment 6
Step 2: Advanced Imaging (If Radiographs Normal or Non-Diagnostic)
MRI without IV contrast is indicated if radiographs are normal or show only effusion and pain persists despite adequate conservative treatment 1, 6
MRI excels at identifying meniscal tears, ligamentous injuries, bone marrow edema, and Baker's cysts 6
Avoid premature MRI - approximately 20% of patients with chronic knee pain undergo MRI without recent radiographs, which is inappropriate 5, 6
Step 3: Evaluate for Referred Pain
Consider hip radiographs if knee examination and imaging are unrevealing 5, 6
Perform thorough clinical examination of the lumbar spine and hip before attributing symptoms solely to knee pathology 5
Treatment Implications
Exercise therapy targeting the knee (with or without hip strengthening) combined with education should be the primary intervention for patellofemoral pain causing stair-descent symptoms 1
Exercise therapy produces clinically important reduction in pain (MD -1.46 on 0-10 scale, 95% CI -2.39 to -0.54) and improvement in functional ability 4
Hip plus knee exercises may be more effective than knee exercises alone for reducing pain (MD -2.20,95% CI -3.80 to -0.60) 4
Supporting interventions including prefabricated foot orthoses, manual therapy, movement retraining, or taping should be tailored to individual patient needs and preferences 1
Address kinesiophobia directly through education and graded exposure, as fear of movement is the strongest predictor of self-rated stair-descent difficulty 7