Patellofemoral pain syndrome (PFPS) is one of the most common knee complaints in young active adults, particularly women and runners. It is characterised by pain around or behind the kneecap (patella) that is provoked by activities that increase patellofemoral joint (PFJ) contact stress: stair climbing/descent, squatting, running, prolonged sitting (cinema sign), and kneeling. Unlike osteoarthritis, PFPS occurs in younger people and the pathology is in the PFJ mechanics rather than articular cartilage degeneration.
PFJ Mechanics and Why Certain Activities Hurt
The patellofemoral joint carries very different loads depending on knee flexion angle:
- At full extension (straight leg): minimal PFJ contact force
- At 30-60 degrees of knee flexion (stair climb, moderate squat): PFJ contact force 3-4x body weight
- At 90+ degrees of knee flexion (deep squat, getting up from low chair): PFJ contact force up to 8x body weight
This explains why PFPS patients have pain on stairs but not on flat level walking -- the PFJ load on level walking is relatively low, while stair climbing provokes the high-flexion, high-PFJ-force position.
Walking Cane Role in PFPS
Flat-level walking rarely requires a cane in PFPS because the PFJ load during level walking is generally tolerable. The cane is most relevant in two specific situations:
- Stair descent: Descending stairs provokes PFJ pain more than ascending (eccentric quadriceps loading increases PFJ force in descent). A cane used on the handrail side allows the upper limb to absorb some of the load during descent, reducing knee flexion force
- Prolonged walking with accumulated fatigue: As PFPS patients fatigue, their gait mechanics deteriorate (increased knee valgus, altered hip mechanics) that worsens PFJ load. A cane provides stability when gait mechanics are most compromised
PFPS is Fundamentally Different from Osteoarthritis for Cane Use
The key differences:
- PFPS patients are typically young (teens to 40s) and the condition usually responds to physiotherapy (VMO strengthening, hip strengthening, patellar taping, load management) over months. A cane is a short-term support tool while rehabilitation progresses, not a long-term mobility aid
- The pain pattern in PFPS is activity-specific (stairs, squatting) rather than generalised. The cane is needed specifically for painful activities, not for all walking
- Appearance considerations are particularly acute in young PFPS patients who may be reluctant to use a walking aid
PFPS and Cane Use: Summary
| PFPS Situation | PFJ Load | Cane Role |
|---|---|---|
| Level walking | Low | Not usually needed |
| Stair ascent | High | Cane or handrail to offload; cane on handrail side |
| Stair descent | Very high (eccentric) | Cane or handrail essential; most painful activity |
| Prolonged walking, fatigued gait | Moderate-high (deteriorated mechanics) | Cane for stability as mechanics deteriorate |
Explore the DaiWalk cane collection. Related: Walking Cane for Knee Osteoarthritis | Walking Cane on Stairs
