Dealing with Pain Behind the Knee

Three weeks into training for my first century ride, something started hurting behind my left knee. Not sharp pain, just a persistent ache that got worse over days. Ignored it. Made it worse. Spent a month off the bike learning what I should have researched before it became a problem.

Common Causes in Cyclists

Posterior knee pain shows up frequently in cycling, usually connected to bike fit or overuse. The mechanics of pedaling put specific stresses on structures behind the knee.

Saddle too high: When your saddle is positioned too high, you hyperextend at the bottom of the pedal stroke. The hamstring tendons where they attach behind the knee take extra strain. This is probably the most common cause in cyclists who recently raised their saddle or bought a new bike.

Hamstring tendinopathy: Overuse inflammation where the hamstring tendons connect to the tibia. Develops gradually. Gets worse with continued riding. Rest and reducing saddle height usually help.

Baker’s cyst: A fluid-filled pouch behind the knee. Sometimes develops from other knee issues. Creates a feeling of tightness and sometimes visible swelling. Not specifically cycling-related but can be aggravated by riding.

My Experience

Turned out my saddle was 8mm too high after a recent adjustment. I’d raised it chasing more power, then ignored the warning signs. Lowered it, rested for two weeks, and the pain resolved. Could have avoided the whole thing with a proper fit check.

When to See Someone

Sudden sharp pain deserves immediate attention. Swelling or redness behind the knee is concerning. Pain that persists despite rest and fit adjustments warrants professional evaluation.

A sports medicine doctor or physical therapist who understands cycling can identify whether the issue is muscular, tendon-related, or something else. Generic advice to “just stretch” often misses the actual problem.

Fit Adjustments That Help

Lower the saddle 3-5mm and ride easy for a week. Note any changes. The hamstrings should engage smoothly without excessive stretch at the bottom of the stroke. Your leg shouldn’t lock out.

Cleat position matters too. Cleats pushed too far forward put more stress on the posterior chain. Moving them back can relieve some pressure.

Saddle fore-aft position affects hamstring engagement. Too far back and you’re overreaching on each stroke.

Off-Bike Management

Ice after rides during active inflammation. Anti-inflammatory medication short-term if needed. Stretching the hamstrings gently, not aggressively. Foam rolling the posterior thigh, avoiding direct pressure on the tender area behind the knee.

Strengthening the hamstrings through controlled exercises helps long-term. Nordic curls, Romanian deadlifts with light weight, eccentric movements. Stronger muscles handle cycling stress better.

Returning to Riding

Come back gradually. Easy spins before hard efforts. Flat routes before climbs. If pain returns during a ride, stop and reassess. Pushing through posterior knee pain usually makes it worse and extends recovery time.

I came back too fast the first time and regretted it. Second attempt, I took three weeks of easy spinning before any intensity. That worked.

Prevention Going Forward

Get a proper bike fit, especially after equipment changes. Increase training load gradually rather than in jumps. Pay attention to early discomfort before it becomes actual pain. Strengthen off the bike with exercises that target hamstrings and glutes.

Posterior knee pain is common enough in cycling that most experienced riders have dealt with it at some point. The good news is it usually resolves with appropriate rest and fit correction.