The knee is the largest joint in the body and one of the hardest working. It carries your body weight with every step, absorbs impact when you run or climb stairs, and bends and straightens thousands of times a day. It is no surprise that knee pain is one of the most common reasons people walk into a physiotherapy clinic.
At our Juhu clinic, we see knee pain in all age groups: college athletes and morning joggers along the promenade, office professionals who sit for hours, gym-goers pushing their limits, and older adults whose joints have simply worked hard for decades. The pain may feel similar from person to person, but the cause is often very different, and that difference decides which treatment works.
This guide covers five of the most common causes of knee pain we treat, what they typically feel like, and how physiotherapy helps each one.
1. Osteoarthritis (Cartilage Wear)
What it is: Osteoarthritis develops when the smooth cartilage covering the ends of the bones gradually thins and roughens. It is the most common cause of long-term knee pain in adults over 40, although past injuries and excess body weight can bring it on earlier.
What it feels like:
- Stiffness in the morning or after sitting for a while
- Pain when climbing stairs, standing up from a low seat, or walking long distances
- A grinding or creaking feeling in the joint
- Occasional swelling after activity
How physiotherapy helps: Many people believe that arthritic knees need rest, but the opposite is usually true. Guided movement keeps the joint nourished and the surrounding muscles strong enough to share the load. Treatment combines pain-relieving manual techniques, mobility work, and progressive strengthening of the thigh, hip, and calf muscles. You can read more about how we approach arthritis physiotherapy and how it helps people stay active and independent.
2. Patellofemoral Pain Syndrome (Runner’s Knee)
What it is: Patellofemoral pain syndrome occurs when the kneecap does not glide smoothly in its groove at the end of the thigh bone. Weak hip and thigh muscles, tight quadriceps, or poor foot and knee alignment are common reasons for this.
What it feels like:
- A dull ache around or behind the kneecap
- Pain that worsens with running, squatting, climbing stairs, or sitting with bent knees for long periods
- Sometimes clicking or grinding around the kneecap
How physiotherapy helps: Treatment focuses on correcting the way the kneecap tracks. This means strengthening the hips and quadriceps, stretching tight muscles, improving movement control, and adjusting training habits. Many of our patients with this problem are runners, and structured care for running injuries also looks at footwear, running technique, and training load so the pain does not return.
3. Meniscus Injury
What it is: The menisci are two C-shaped pieces of cartilage that cushion the knee and help stabilise it. They can be torn suddenly through a twisting movement, such as pivoting while the foot is planted, or they can gradually wear down with age.
What it feels like:
- Pain along the inner or outer edge of the knee
- Swelling that develops over a day or so
- Catching or locking sensations
- Difficulty fully straightening or bending the knee
- Pain when twisting or squatting deeply
How physiotherapy helps: Many meniscus problems, especially smaller or degenerative tears, respond well to physiotherapy without surgery. Treatment reduces pain and swelling first, then restores movement, then builds strength and control around the joint so the meniscus is protected. If your knee locks completely or does not improve with rehabilitation, we will guide you on when a further medical opinion is appropriate.
4. Ligament Injuries (Including ACL Tears)
What it is: Ligaments are strong bands that hold the knee stable. The anterior cruciate ligament (ACL) is the one most commonly injured, typically during football, cricket, badminton, or other sports involving sudden stops, jumps, and changes of direction.
What it feels like:
- A sudden pop or tearing sensation at the time of injury
- Rapid swelling
- The knee feeling unstable or giving way, especially when pivoting or changing direction
- Difficulty putting full weight on the leg soon after the injury
How physiotherapy helps: Whether you choose surgery or a non-surgical route, rehabilitation is essential. It restores movement, rebuilds strength, and retrains balance and control, then gradually prepares the knee for return to sport. Our dedicated ACL rehabilitation programme follows a structured, milestone-based progression so that you return to activity when the knee is truly ready, not just when it feels better.
5. Overuse, Muscle Weakness, and Training Errors
What it is: Not every painful knee has a structural injury. Very often, the cause is overload. Sudden increases in exercise, heavy squats or lunges with poor technique, muscle imbalances, and long periods of inactivity followed by intense activity can all irritate the tendons and tissues around the knee. Patellar tendon irritation, sometimes called jumper’s knee, is a common example.
What it feels like:
- Pain just below the kneecap, especially when jumping, squatting, or pushing up from a squat
- Soreness that builds during or after exercise
- Tenderness when pressing on the tendon
How physiotherapy helps: We assess your movement and training habits to find what is overloading the knee, then treat the irritated tissue and correct the cause. For regular exercisers, gym injury physiotherapy focuses on technique, load management, and recovery. Longer-term, a structured strength and conditioning programme builds the strength and resilience that protect the knee from repeat problems.
How Do We Find the Cause of Your Knee Pain?
Because these causes can feel alike, an accurate assessment is the foundation of good treatment. A typical assessment includes:
- A detailed history of when the pain started, what makes it better or worse, and any previous injuries
- Examination of knee movement, swelling, and tenderness
- Special tests for ligaments and meniscus
- Assessment of hip, ankle, and foot strength and alignment
- Observation of how you walk, squat, and step
- Guidance on whether scans or further medical opinions are needed
This whole-body view matters because the knee is often the victim of a problem elsewhere in the leg or hip.
When Knee Pain Needs More Than Physiotherapy?
Most knee pain improves well with the right rehabilitation. However, in advanced joint damage, some people eventually need a knee replacement. In those cases, physiotherapy remains just as important, before surgery to prepare the joint and muscles, and afterwards to restore walking and function. Our team supports patients through knee replacement rehabilitation so that recovery is safe and steady.
Please see a doctor urgently if you have severe pain after a fall or twisting injury, cannot put weight on the leg, notice obvious deformity, or have a hot, red, swollen knee with fever.
Simple Tips to Look After Your Knees
- Stay active. Gentle movement such as walking, cycling, or swimming keeps knees healthy.
- Strengthen your hips and thighs. Strong muscles protect the joint.
- Increase exercise gradually. Avoid sudden jumps in distance, speed, or weight.
- Warm up properly. Prepare the joints and muscles before activity.
- Wear supportive footwear. Worn-out shoes change how force travels up the leg.
- Watch your technique. Keep your knees tracking in line with your toes during squats and lunges.
- Do not ignore persistent pain. Early treatment is faster and simpler than treating a long-standing problem.
Conclusion
Knee pain can come from many sources, including cartilage wear, kneecap tracking problems, meniscus tears, ligament injuries, and simple overuse. The right treatment depends on identifying which one is behind your symptoms, and that is exactly where a careful physiotherapy assessment makes a difference.
At Juhu Physiotherapy, we assess the full picture behind your knee pain and create a personalised plan to reduce pain, restore strength, and get you back to the activities you enjoy. If knee pain is slowing you down, book an assessment with Juhu Physiotherapy and take the first step towards moving comfortably again.
