Why does your knee feel tight when bending?

A tight or stiff feeling in your knee when bending it — whether squatting, sitting down, or walking up stairs — can be frustrating and even painful. Many people experience this sensation, where the knee feels tight when bending, making activities challenging.

Your knee is a complex hinge joint, supported by bones, cartilage, ligaments, tendons, and muscles. If any of these structures are irritated, inflamed, or injured, you might notice symptoms like stiffness, reduced mobility, or discomfort when bending your knee.

Recognizing that your knee feels tight when bending can be the first step towards finding effective treatment options. Let’s explore some of the most common causes of this issue and how physical therapy can help.

What causes knee tightness or stiffness when bending?

If your knee feels tight when bending, several factors could be contributing to the problem:

Joint stiffness from inactivity or overuse
Staying in one position too long (like sitting at a desk) or overdoing an activity (like squatting or climbing) can cause fluid buildup or muscle tension that limits movement.

Osteoarthritis
Over time, the cartilage that cushions your knee may wear down. This causes the bones to rub together, leading to inflammation, stiffness, and pain when bending or straightening your knee.

Tendinitis or Tendinopathy
Inflammation or degeneration of the tendons around the knee — such as the quadriceps or patellar tendon — can cause tightness that’s especially noticeable with movement.

Meniscus Injuries
A torn meniscus (the C-shaped cartilage inside the joint) can limit your knee’s ability to move smoothly and may create a sensation of tightness, clicking, or locking.

Ligament Sprains or Injuries
Ligaments like the ACL, PCL, or MCL help stabilize the knee. If stretched or torn, they can contribute to stiffness, swelling, or a feeling of instability.

Baker’s Cyst
This fluid-filled cyst forms behind the knee and can create tightness or fullness that worsens when bending or extending the leg.

Bursitis
Inflammation of the bursae — small fluid-filled sacs that reduce friction — can make movement painful and reduce the knee’s range of motion.

Postural imbalances or weak supporting muscles
If your glutes, hips, or calves are weak or tight, the knee may compensate, leading to stiffness or tension with bending.

Referred pain
Issues in the hip or lower back can sometimes cause pain or tightness felt in the knee, especially when the nerves are involved.

Symptoms that may accompany knee tightness

In addition to the stiffness in knees when bending, you might also notice:

• Swelling or puffiness around the joint
• Clicking, popping, or grinding
• A “locked” sensation or limited range of motion
• Warmth or redness
• A dull ache after activity or while resting
• The feeling that “my knee feels tight” even without sharp pain

These symptoms can help your physical therapist determine the underlying cause and design a plan that targets the specific issue.

How physical therapy can help a knee that feels tight

Physical therapy can address both the root cause of your stiffness and the symptoms themselves. Here are some of the techniques a PT may use:

Manual therapy
Hands-on techniques such as joint mobilization, soft tissue massage, or myofascial release can reduce restrictions in the knee and surrounding muscles.

Stretching and flexibility work
Your therapist may guide you through stretches for the quads, hamstrings, calves, and IT band — all of which influence knee mobility.

Strengthening exercises
Targeting the hips, glutes, and quadriceps can improve joint support and reduce mechanical stress on the knee.

Joint mobilization and manipulation
Small, controlled movements of the joint can improve range of motion. In some cases, more advanced techniques (like joint manipulation) can provide quick relief from stiffness.

Therapeutic ultrasound or electrical stimulation
These modalities may be used to reduce inflammation, improve blood flow, and promote healing in deeper tissues around the knee.

Movement training and activity modification
Your PT may analyze how you walk, squat, or climb stairs and provide feedback or modifications to reduce strain and improve alignment.

When to seek physical therapy for knee tightness

If your knee stiffness is lasting more than a few days or is affecting your ability to move comfortably, it’s time to get help. Early treatment can prevent further damage and help you avoid surgery or chronic pain down the line.

Most patients in New York can begin PT without a referral — and at Lattimore PT, you can usually be seen within 24–48 hours.

Find relief from knee tightness at Lattimore PT

If your knee feels tight when bending, the team at Lattimore Physical Therapy is here to help. Our Rochester-based therapists use evidence-based techniques to uncover the cause of your knee stiffness and build a plan that supports strength, mobility, and long-term recovery.

Don’t let a stiff knee slow you down. Schedule an appointment and get back to doing what you love — without hesitation.