You’re on a trail at Horsetooth, halfway through your run, and you feel it again, that sharp pull, deep ache, or pain behind knee when bending. You stop, stretch, maybe even shake it out, but it lingers.
You’re not alone. We see this kind of pain all the time here in Fort Collins, especially in runners, hikers, and CrossFit athletes who push hard and expect their bodies to keep up.
It might show up as:
• A sudden pinch when you kneel
• A tight pull when squatting at the gym
• An ache that flares up after long bike rides down the Poudre trail
The pain might not be coming from where you think. And if you’ve tried foam rolling, stretching, or even resting with no luck, it’s time to dig deeper.
Let’s talk about what’s really going on—and how you can fix it.
5 Causes of Pain Behind Knee When Bending (And the Knee Exercises to Make it Better!)
If pain behind your knee keeps showing up when you’re bending, squatting, or stretching, something deeper is likely going on.
As sports physical therapists here in Fort Collins, we often see this with runners training for the Horsetooth Half or hikers prepping for long days in Rocky Mountain National Park.
Let’s dig into five of the most common reasons behind-the-knee pain appears, and more importantly, how physical therapy can help you treat it and get back out there without setbacks.
Baker’s Cyst: The Hidden Swelling Behind the Knee
A baker’s cyst forms when fluid builds up behind the knee joint. This fluid-filled sac causes swelling, stiffness, and that distinct pressure or dull ache when bending.
You might feel:
• A bulge behind the knee when you extend it
• Tightness or pain when you squat or climb stairs
• Trouble bearing weight or straightening the leg fully
This condition often links to other knee issues like meniscus tears or arthritis. As physical therapists, we guide you through exercises that encourage blood flow and reduce swelling without making things worse.
Start with:
• Gentle heel slides
• Quad sets with a towel under the knee
• Calf pumps for fluid movement
Don’t try to push through the pain. The key is managing inflammation and addressing any underlying cause contributing to fluid buildup.
Hamstring Tendonitis: The Overuse Injury You Don’t Feel Until You Sit
If you sit a lot during the week but train hard on weekends, hamstring tendonitis might be behind your pain. This overuse injury causes burning pain or soreness at the top of the hamstring, where it attaches behind the knee.
Symptoms usually include:
• Pain behind the knee when bending
• Soreness after runs, especially on hills or trails
• Tenderness during a physical exam
Hamstring tendonitis commonly affects runners increasing mileage too quickly. In physical therapy, we focus on strengthening the surrounding muscles like your glutes and core to take pressure off the hamstrings.
Try these:
• Glute bridges with resistance
• Standing hamstring curls using your own body weight
• Single-leg deadlifts with a light kettlebell
If your knee hurts when bending, don’t wait for it to get worse. We’re ready to help you move better, feel stronger, and take control of your recovery.
Schedule your FREE Discovery Call or Get More Information today, or call us at (970) 500-3427 to schedule your evaluation.
Meniscus Tear: That Clicking or Popping Sound Isn’t Just Annoying
The meniscus is a piece of connective tissue that acts like a shock absorber between your thigh bone and shin. A meniscus tear can cause sharp pain or a popping noise behind the knee when bending, especially with a twisting injury.
Common signs:
• Very sharp pain during a deep bend or pivot
• Knee locks up or catches during movement
• Swelling that comes and goes
If you felt sudden pain during a game of pickup soccer or while trail running near Lory State Park, this might be the issue. Not every meniscus tear needs surgical treatment.
With sports physical therapy, we help you build strength and mobility with:
• Controlled weight-bearing exercises
• Balance and proprioception drills
• Strengthening the quadriceps tendon and surrounding muscles
Improved stability can keep you active and help prevent future knee injuries.
Patellar Tendon Strain: Why Knees Hurt After a Hard Workout
The patellar tendon connects your kneecap to your shinbone. If it’s inflamed, every squat, jump, or lunge increases your knee pain and strain.
You might be dealing with:
• Jumper’s knee (patellar tendinitis)
• Pain just below the kneecap, spreading behind the knee
• Difficulty bearing weight after intense leg workouts
This issue often stems from excess weight on the knee joints during high-impact moves. We commonly see it in CrossFit athletes and volleyball players here in Fort Collins.
In therapy, we work on:
• Eccentric quad strengthening
• Step-downs and step-ups to build knee control
• Proper jumping mechanics to reduce stress
We may also recommend knee pads or elastic bands for added support as you recover.
Posterior Cruciate Ligament Injury: The Ligament You Didn’t Know You Could Damage
The posterior cruciate ligament, or PCL, stabilizes the back of the knee joint. When injured, it can create posterior knee pain that flares up while going down stairs or during deceleration.
Signs include:
• Pain behind the knee when bending or bearing weight
• Feeling like the knee is unstable or gives out
• Swelling and discomfort after activity
Through a full physical examination, we’ll confirm the injury and set up a safe rehab plan. Strengthening the surrounding muscles is key to long-term recovery.
Helpful movements include:
• Wall sits to activate the quads
• Controlled straight leg raises
• Core exercises to reduce force transferred to the knee
You’ll want to avoid high-impact activity until you’re ready to move confidently again.
When Your Knee Hurts, Find Answers
If your knee hurts when bending, you don’t have to just deal with it. Whether you’re training for the FORTitude 10K or climbing Arthur’s Rock, addressing the real source of the pain is key.
Targeted physical therapy doesn’t just relieve pain—it helps you move better, stay active, and avoid future injuries.
Find Real Help For Knee Pain and Injuries
At Up and Running Physical Therapy, We Treat the Root Cause
If your knee pain keeps showing up when you bend, run, or even just walk through Old Town on a weekend, it’s time to stop guessing and start healing.
At Up and Running Physical Therapy, we take a deep dive into your movement, strength, and injury history to uncover the real cause of your pain.
We use thorough physical examinations and sport-specific assessments to find what’s holding you back. Whether it’s a meniscus tear, patellar tendon irritation, or tight surrounding muscles, we identify the root problem and tailor your recovery to your goals.
We Work With Athletes, Runners, and Active Adults Every Day
If you train for races, hit the trailheads often, or lift heavy in the gym, your body demands a different approach than standard rehab.
We focus on performance-oriented physical therapy that not only reduces pain but improves how your entire body moves.
You won’t find cookie-cutter treatment plans here. Instead, we create custom sessions with:
• Advanced hands-on techniques to restore mobility
• Strength training programs to build stability and reduce joint pain
• Return-to-sport planning so you feel ready, not hesitant
We work with your goals in mind. Whether you’re preparing for the Blue Sky Trail Marathon or want to hike Greyrock without pain, we’re ready to help you get there.
We Help You Move With Confidence Again
Pain behind the knee, sharp pain during squats, or a dull ache that just won’t go away can wreck your confidence. We understand how frustrating it feels to rest, stretch, and still not feel better.
Our approach focuses on:
• Teaching you how to move without flaring things up
• Using active rehab strategies that fit into your lifestyle
• Building resilience so you stay strong long after therapy ends
This is your recovery. We’re here to guide you through every step.
Let’s Get You Moving Without Pain
If your knee hurts when bending, don’t wait for it to get worse. We’re ready to help you move better, feel stronger, and take control of your recovery.
Schedule your FREE Discovery Call or Get More Information today, or call us at (970) 500-3427 to schedule your evaluation.
