Knees and calf pain


Common causes of severe knee pain

Share on PinterestEither direct or gradual trauma can cause knee pain.

The Arthritis Foundation lists the knee as one of the most injury-prone joints.

The overall structure and components of the knee increase the risk for certain types of injury, which can cause pain and prevent full function.

Common knee injuries occur because of tears in one of the three main ligaments of the knee.

These are:

  • the anterior cruciate ligament (ACL)
  • the medial collateral ligament (MCL)
  • the posterior cruciate ligament (PCL)

Injuries to these ligaments are common in athletes.

A sudden twisting motion or change in direction can injure the ACL. This is one of the most common knee injuries.

People tend to injure the PCL with direct impact to the area, such as a car crash or football tackle. A direct blow to the knee can lead to MCL damage.

Ligament injuries often require surgery.

Knee trauma can also lead to injuries as a result of overworking or overstretching a tendon. Inflammation, tendinitis, or ruptures can cause knee pain. Engaging in activities that involve the tendons can cause tendon injuries, such as running, jumping, and lifting heavy items.

Patellar tendinitis is the term that describes irritation and inflammation of the patellar tendon in the knee. A severely ruptured tendon usually requires surgical repair.

Less severe cases can be treated with a rigid support called a splint that keeps the knee in a fixed position during the healing process.

Knee bursitis

An injury that inflames the bursae can lead to bursitis. The bursae are small, fluid-filled sacs that cushion the outside of the knee joint and make it possible for tendons and ligaments to glide easily over the joints.

A sudden blow to the front of the knee can injure the bursae. Alternatively, damage can occur if people spend a lot of time on their knees without protection. Bursitis can lead to swelling, warmth, pain, and stiffness in the knee.

Most people can resolve the symptoms of bursitis with therapy and oral medications, such as non-steroidal anti-inflammatory drugs (NSAIDs). Therapy can include rest, ice, elevation of the limb, and splinting.

People with serious bursitis might require steroid injections. Individuals will not normally need surgery to make a full recovery and will normally achieve full function with proper management and treatment.


Trauma from a fall or collision can cause fractures in the bones of the knee.

The knee contains several bones that can break, including the kneecap, also known as the patella.

Individuals with osteoporosis or other degenerative disorders that weaken bones can fracture their knee simply by stepping off a curb in the wrong way. Serious fractures require surgery, but some people with a knee fracture need only physical therapy.

Dislocated kneecap

Some injuries can cause the kneecap to move out of place.

Often, a doctor can replace the kneecap without issue. An X-ray can identify any accompanying fractures in the area. The individual may have to use a splint to allow the soft tissue around the patella to heal and regain strength. Occasionally, a person will require surgery to prevent further dislocations.

A dislocated knee is a rare but dangerous injury and differs from a dislocated kneecap. It takes a highly powerful blow to cause this type of damage. Though reversible, dislocation of the knee is extremely painful.

The doctor must reduce the dislocation and ensure that there are no further injuries. Injuries to the blood vessels and nerves around the knee are common with this injury, and it can be limb-threatening and life-threatening.

A doctor will almost always recommend surgery to repair the damaged structures in a knee dislocation. It can take about 6 weeks to heal from a dislocated kneecap.

This a medical emergency and requires immediate clinical attention.

Osteoarthritis of the Knee

Alternative remedies
Nutritional supplementation (glucosamine and chondroitin are the most common forms of this) is helpful to some patients though the science on this is not entirely supportive of their effectiveness.

There are some studies to suggest that acupuncture can decrease the pain associated with osteoarthritis of the knee.

Looking for a “light duty” alternative to heavy manual labor is one good approach for coping with osteoarthritis of the knee. Many patients who work at desks find that prolonged sitting in one position is associated with stiffness and pain upon first arising so periodically standing stretching or moving the knee through an arc of motion can be helpful at minimizing this “start-up” pain.

Adaptive aids
For some patients particularly those who cannot tolerate surgical interventions for medical or other personal reasons use of a cane crutches or a walker can be of use.

For more information about arthritis contact the Arthritis Foundation ( For more information about orthopedic surgery contact the American Academy of Orthopedic Surgeons (

Condition research
Medical researchers continue to look into the causes and best treatments for symptoms of osteoarthritis of the knee which is very common and sometimes disabling.

Pharmaceutical research
There is considerable research being done into the medical management of osteoarthritis. Recently increasing awareness of the complications and problems associated with use of non-steroidal anti-inflammatory drugs (NSAIDs) including effects on the kideys the stomach and the heart.

Surgical research
There is considerable research being done studying the surgical approaches for this condition including newer approaches for total knee replacements; one of these the minimally-invasive quadriceps sparing approach appears to help patients recover more quickly and with less pain than traditional approaches to knee replacements.

Other surgical interventions including osteotomy (cutting and re-orienting the bones around the knee) and arthroscopy (using a surgical camera and small motorized shavers to “clean up” the raw bone ends) also are topics of surgical research relevant to patients with knee arthritis.

Summary of knee arthritis

  1. Osteoarthritis of the knee is common and can result in severe pain and disability; as a result of this condition several hundred thousand people each year in the U.S. undergo total knee replacement.
  2. Mostpeople with osteoarthritis of the knee can be managed without surgery.
  3. The cause of osteoarthritis of the knee is not known but some risk factors include obesity severe knee trauma and genetics.
  4. There are many other kinds of arthritis that can affect the knee; it is important to make sure that the correct diagnosis is made as some of these other conditions are treated very differently.
  5. Thediagnosis of osteoarthritis of the knee is usually very straightforward and is made in almost all cases by a physician taking a thorough history performing a physical examination and getting x-rays with the patient standing up.

Joint pain

Pain in just 1 joint

Knee pain

The knee joint is probably the most frequently damaged joint and is particularly vulnerable as it takes the full weight of your body.

But knee pain is not always a joint problem. Learn about the most common causes of knee pain and what you should do.

Inflammation of the joint lining

If you have injured the joint recently and it suddenly becomes painful again, the thin layer of tissue lining the joints and tendons may be inflamed, a condition called traumatic synovitis.

It usually does not cause any redness or heat.

You should be able to manage injury-related swelling at home with anti-inflammatory medicines, such as ibuprofen, an icepack and rest.

Gout or pseudogout

If the skin over the joint is hot and red, and the pain comes in repeated attacks, the cause is likely to be either gout or pseudogout.

Both of these are types of arthritis.

Gout usually affects the joint of the big toe first before affecting other joints.

It’s important to correctly diagnose gout, as treatment will prevent future attacks of joint pain and disability.

Pseudogout is similar to gout, but usually affects the knee joint first.

See your GP if you think you have gout or pseudogout.

Damage to the cartilage at the back of the kneecap

Knee pain that feels worse when you go up or down stairs could be a sign of a damaged kneecap, called chondromalacia patellae.

This should not cause any redness or heat around the knee.

The cause is not understood, but it can be linked to overuse of the knee.

You can treat this problem yourself with anti-inflammatory medicines, such as ibuprofen, an icepack and rest.

Bleeding into the joint space

If you have recently had an injury to the knee joint, such as a torn ligament or knee fracture, it may cause bleeding into the joint spaces. This is known as haemarthrosis.

This is more likely to happen if you take anticoagulants, such as warfarin.

Signs of haemarthrosis are:

  • swelling of the knee
  • warmth
  • stiffness and bruising, which occur soon after the injury

Go to A&E immediately for treatment if you have a very swollen knee following an injury.

Less common causes

Sudden pain in a joint is less commonly caused by:

  • a fracture – read about a broken arm or wrist, broken leg, broken ankle or hip fracture
  • reactive arthritis – which usually develops after an infection and tends to affect young adults
  • psoriatic arthritis – a type of arthritis that affects up to 1 in 5 people with psoriasis
  • rheumatoid arthritis – which can start in just 1 joint, with the pain coming and going
  • Osgood-Schlatter’s disease – swelling and tenderness over the bony bump just below the kneecap

Rarely, the cause may be:

  • septic arthritis – a serious health condition that causes a painful, hot, swollen joint that you will not be able to move (sometimes with a high temperature); see your GP urgently or go to A&E
  • haemophilia – an inherited illness that affects the blood’s ability to clot
  • a tropical infection
  • cancer
  • crumbling of the bone (avascular necrosis) – caused by a lack of blood supply
  • repeated dislocation of the joint

What causes pain behind the knee?

It may be important to work closely with a doctor to diagnose pain in the back of the knee, as some causes require long-term treatment to heal completely.

Possible causes for pain in the back of the knee include:

Leg cramps

Share on PinterestLeg cramps commonly cause pain behind the knee.

Cramps are when muscles become too tight. This tightness may be because the muscle is doing too much work without being stretched. If it is stretched and still cramps, the muscle may simply be overused.

Overuse syndrome can affect different areas of the knee. A person might feel a cramp in the thigh or calf near the knee.

The sensation resembles a sudden, painful spasm of the muscle. The pain may last seconds or minutes and can range from uncomfortable to severe.

Other possible reasons for leg cramp include:

  • dehydration
  • infection such as tetanus
  • liver disease
  • excess toxins in the blood
  • nerve problems

Women who are pregnant may also experience leg cramps as a normal side effect of pregnancy.

Some people who often experience leg cramps may find relief through regularly stretching their calves. Also, they can try shortening their stride to put less strain on the knee and surrounding muscles.

Baker’s cyst

A Baker’s cyst is a pocket of fluid that builds up in the back of the knee, leading to pain and swelling.

Baker’s cysts may not be noticed at first, as small cysts do not typically cause pain. However, as the cyst grows, it may shift the surrounding muscles or put pressure on tendons and nerves, causing pain.

Baker’s cysts may grow to about the size of a table tennis ball. People with Baker’s cysts often feel pressure in the back of the knee, which may cause a tingling sensation if the cyst is hitting a nerve.

In most cases, Baker’s cysts are not a cause for concern, but treatment can relieve the symptoms.


Osteoarthritis is a condition that wears down the cartilage of the joints over time. This condition can easily cause pain in the back of the knee.

People with osteoarthritis in the knee may display other symptoms, such as loss of motion or difficulty bending the knee. Inflammation in the joint may make it stiff and painful. This discomfort may also be felt anywhere around the knee.

Other forms of arthritis that could be causing the pain include autoimmune diseases, such as lupus and rheumatoid arthritis.

Runner’s knee

Share on PinterestRunner’s knee is when the cartilage in the knee joint wears down.

Runner’s knee is the wearing down of the cartilage in the knee joint. When the cartilage is gone, the bones of the knee rub together. Typically, this causes a dull, aching pain behind the knee.

Other symptoms of runner’s knee include:

  • the knee giving out or buckling randomly
  • weakness in the knee and leg
  • restricted movement in the leg and knee
  • crackling or grinding feeling when the knee bends

Hamstring injury

A hamstring injury is a tear or strain in one or more of the muscles in the back of the thigh.

These muscles include:

  • the biceps femoris
  • semitendinosus
  • semimembranosus

A hamstring strain happens if the muscle is pulled too far. It may tear completely from being pulled too much and can take months to heal fully.

Hamstring injuries may be more common in athletes who run fast and in bursts, such as those who play basketball, tennis, or football.

Meniscus tears

The meniscus is a piece of cartilage on either side of the knee. Twisting motions while squatting or bending the leg may tear this cartilage. Many people hear a pop when they tear their meniscus.

The pain from a meniscus tear may not show up at first but worsen over the next couple of days.

Meniscus tears often cause other symptoms, including:

  • loss of knee motion
  • weakness and fatigue in the knee and leg
  • swelling around the knee
  • the knee giving out or locking up when used

Surgery may be required if a meniscus tear is severe and does not heal on its own.

ACL injuries

The anterior cruciate ligament or ACL is a band of tissue that runs through the front of the knee joint, connecting the bones and helping to keep the knee joint stable.

ACL strains often happen from sudden stops or changes in direction. Similarly to meniscus tears, a strain in the ACL may cause a popping sound, followed by pain and swelling.

A torn ACL is a well-known, serious injury, often side-lining an athlete for a long time. Torn ACLs usually require reconstructive surgery.

PCL injuries

Share on PinterestPCL injuries may occur because of a traumatic injury. Surgery and rest are usually recommended treatments.

The posterior cruciate ligament or PCL plays a similar role to the ACL, though it is less likely to be injured than the ACL.

PCL injuries may happen during traumatic events, such as falling directly on to the knee from a height or being in a car accident. With enough force, the ligament may tear completely.

PCL injuries cause symptoms including:

  • knee pain
  • stiffness in the knee if bending
  • trouble walking
  • swelling in the knee

Completely resting the knee may help a PCL strain to heal. A severe PCL injury may require surgery.

Deep vein thrombosis (DVT)

A thrombosis is a blood clot, and a DVT occurs when a clot happens in the veins deep within the leg.

Many people who have a DVT feel more pain when they stand up. Nevertheless, they may feel pain in their leg and knee at most times.

Other symptoms of DVT may include:

  • skin that is red or warm to the touch
  • swelling in the area
  • fatigue in the affected leg
  • prominently visible surface veins

Risk factors for DVT can include being overweight, being older, and smoking. People who lead sedentary lifestyles may also experience DVT.

DVT needs medication and care, as it can become more serious if the clot breaks loose into the bloodstream.

Common causes of pain in the back of the knee:

Pain behind or in the back of the knee is relatively common. The pain behind your knee can be sharp and severe; or mild and dull. In some of you, the pain in the back of the knee started after a sports injury. For others, the pain behind the knee began after bending down or even occurred at rest.

Pain in the back of the knee can occur with or without swelling or a feeling of fullness. Most causes of pain in the back of your knee are straightforward, and others might need urgent attention. In this post, we will review some of the most common causes of pain in this region of your knee.

What’s behind your knee? A brief anatomy lesson.

The back of the knee is a complicated area. There are several critical structures back there. From a functional perspective, we have many muscles, such as the hamstring and calf muscles. The hamstrings start at the pelvis, cross the back of the knee, and attach to your tibia or shin bone. The calf muscles start on the back of your thigh bone or femur, cross the knee and form the achilles tendon, which attaches to your heel.

From the Medical Media Group.

Behind our knee, we have critical structures such as the popliteal artery and the nerves to the leg. The nerves are the peroneal nerve and the tibial nerve. The peroneal nerve is a troublemaker sometimes. It doesn’t cause pain in the back of your knee but can cause pain elsewhere. We discuss the peroneal nerve elsewhere on this page.

Most people think their knee joint is in the front. But the back of our knee goes further back than we think. The attachment of both the medial and lateral meniscus is in the back of the knee. These meniscus attachment points are called roots. Root tears can be a cause of severe knee pain which may start in the back of your knee. We cover root tears of the meniscus in this post.

There is cartilage on the bones in the back of the knee. Osteoarthritis can start back there, so the first sign of osteoarthritis could be pain in the back of your knee.

Many of these structures in the back of the knee are capable of causing pain. Because of the complicated anatomy, a proper examination, Xrays, and perhaps an MRI will be useful in determining which structure could be the cause of your pain. Once the cause of the pain is determined, the best possible treatment can be recommended.

Below we are going to cover some of the more common causes of pain behind your knee.

First, we will list the potential causes of pain behind your knee, then we follow through with a more detailed discussion of each potential cause of pain.

  • Swelling due to a Bakers cyst: A Bakers cyst is a common cause of swelling and pain behind your knee.
  • Root tears of the meniscus
  • Hamstring injury: usually occur higher in the thigh.
  • Tears of the posterior horn of the medial meniscus
  • Deep vein thrombosis — or a blood clot in the back of your leg
  • Overuse syndromes in runners and athletes.- usually causing a grinding or snapping in the back of the knee.
  • Osteoarthritis: probably the most common cause of pain. Often due to swelling and inflammation.
  • Nerve pain- the pain of sciatica can radiate to behind your knee

DVT: Deep vein thrombosis can cause pain in the back of your knee and calf

Deep vein thrombosis or DVT can cause pain in the back of your knee… but the pain is not often isolated to the back of the knee. There is usually calf pain, calf swelling and perhaps thigh pain too. A DVT is not a common cause of pain and swelling, but I list it first because it can be a worrisome cause of pain.

Usually, the pain from a DVT will also occur in the back of your calf or your inner thigh. While not impossible, the pain can be isolated to just the back of your knee. Most people with a DVT will also have swelling in their calf or leg. In people who are obese, swelling of the leg is not uncommon so swelling alone does not mean you have a DVT.

People who are at risk for a DVT include people who are obese, have cancer, chronic diseases, and those of you who recently traveled and sat still for hours/days while recovering from illness, injury, or surgery. We do not know the exact incidence of people walking around with a DVT. People who recently had surgery are at an increased risk for a DVT. If your calf is tender and swollen and the back of your knee hurts, you need to see your doctor urgently or go to an emergency room.

Meniscus tears and pain behind your knee

Root tears of the meniscus are prevalent. The “root” of a meniscus is where the meniscus attaches to the shin bone or tibia. Much like a tree roots into the ground, the meniscus has a firm, deep attachment to your bones as well.

Sadly, over the years, these attachment points or roots can weaken. A common story is that you bent down or knelt and felt a pop in the back of the knee. Later that day or two days later, your knee is swollen, and the pain is very severe. The root of the meniscus tore in this situation because it had degenerated from decades of activity.

The pain from root tears often subsides over the next few weeks to months. By the time you see a doctor, and they order an MRI, the pain is often starting to improve. This post below goes into far more detail about root tears as the cause of pain in the back of your knee.

The meniscus is a shock absorber. When the root of the meniscus tears, the meniscus no longer works as a shock absorber. Therefore, following a root tear, you may develop stress fractures or stress reactions. That is why the pain worsens a few days after you felt the pop.

This post goes into detail about how root tears cause these stress fractures and how they can be treated. This is usually a situation where you have very severe pain and require crutches for support. As I have talked about elsewhere, root tears will often cause a significant stress reaction or a stress fracture. When root tears lead to a stress reaction, the pain will often move from behind the knee to the inner side.



On some occasions, we need to consider surgery to repair these root tears… but this is not usually necessary.

Pain behind the knee in runners

Overuse syndromes are prevalent in runners. Most runners are going to experience an overuse injury during their running careers. The most common cause of pain behind the knee in runners is due to a hamstring strain. Hamstring strains that occur around the knee tend not to be as painful or as chronic as those that occur up higher in the buttock region.

Runners should consider shortening their stride and increasing their cadence, as well as avoiding hills for a few weeks. In most cases, this approach should enable a painful hamstring to settle down.

A less common cause of pain in the back of the knee in a runner is bursitis that occurs where a few tendons cross over and therefore rub against each other. The pain is usually associated with a grinding or snapping sensation as you squat down. The grinding sensation is due to the hamstring tendons being irritated from rubbing against each other.

Some believe the location of this friction might be due to one of your calf muscles rubbing along one of the hamstring muscles in the back of the knee. This has also occurred in some patients after a hamstring ACL reconstruction. Surgical treatment is rarely necessary for this situation.

In runners, the pain in the back of the knee will usually subside with a change in their running style (shorter stride, higher cadence) and workout schedule. Physical therapy may be useful, as well.

Bakers cyst and pain in the back of the knee

A Bakers cyst is a fluid-filled pocket in the back of the knee. Bakers cysts are a common cause of painful swelling. If the cysts are small, they do not create much discomfort.

A Bakers cyst can grow larger. If a cyst becomes large, it can put pressure on the muscles, blood vessels, and nerves behind the knee and can cause discomfort. Most people with a Bakers Cyst will also have osteoarthritis.

In most instances, treatments to diminish the swelling associated with arthritis will help reduce the pain and swelling from the cyst. In the majority of cases, these cysts are not dangerous. An ultrasound can usually tell if you have a simple cyst versus something more complex that warrants further evaluation with an MRI. If the Bakers cysts are huge, then one treatment alternative is to have the fluid drained. While that will result in relief of pain, the fluid might come back again.

Read more about a Bakers cyst.

Osteoarthritis and pain in the back of the knee

Osteoarthritis is a widespread cause of pain behind your knee. Some of you might also note that you have a loss of motion and can not fully bend the knee. The pain from arthritis can be due to inflammation of the structures behind the knee. That irritates the lining or inside of the knee joint and makes the joint stiff and painful.

If osteoarthritis is causing pain in the back of the knee you might note that the pain can refer up the back of the thigh, or down into the calf. Many of you with arthritic knee pain will benefit from wearing a compression sleeve or brace. You will also find that gentle stretching, an ice pack, or a warm compress can help calm arthritic pain.

If the pain does not improve over a few days, consider seeing your doctor to look into why the back of your knee hurts.

Hamstring Injuries

Hamstring injuries are a prevalent injury in sports. Hamstring injuries usually occur higher and in the back of the thigh up near the pelvis. We discuss hamstring injuries and some of the difficulties in managing them here and here. It is possible to injure the hamstring near the back of your knee too.

Usually, the pain from a distal hamstring injury is about 4-6 inches above your knee. The pain from a lower hamstring injury will be most severe immediately after the injury and start to improve within a few weeks. It is important to begin stretching the hamstrings as soon as you tolerate it to prevent stiffness.

Nerve Pain

Nerve pain can be present in the back of the knee. Nerve pain generally radiates to the back of the knee from higher up the leg or buttock area. The nerves are rarely a cause of pain that is isolated to the back of the knee and doesn’t radiate anywhere else.

Pain in the back of the knee is common but can be non-specific. There are many reasons why the back of your knee might be bothering you. I hope you find this short guide useful in determining the possible causes of your pain.

Disclaimer: this information is for your education and should not be considered medical advice regarding diagnosis or treatment recommendations. Some links on this page may be affiliate links. Read the full disclaimer.


16th October 2018 By Mr. Sam Rajaratnam FRCS (Tr. & Ortho)

Because your knees bear the body’s weight and are subject to movement in a number of planes they can be quite vulnerable to trauma and to conditions resulting from trauma and wear and tear.

There are a number of different types of condition which can cause pain to the back of the knee. These include strains or tears to the muscle or tendons, damage to the ligaments, damage to the cartilage within the knee joint, excess fluid in the knee or blood vessel problems.

The information given below will give you an indication of the problem you may be having, but is not intended that you diagnose yourself. Also this guide is intended for pain behind the knee itself; if your pain is part of general joint pain there will be other reasons for this and you should consult a doctor.


The shallow depression formed at the back of the knee is called the popliteal fossa; it is formed at the junction of the femur and tibia. There is a muscle here on the floor of the popliteal fossa which is the deepest muscle of the knee joint. It works on the femur to rotate it on the tibia when walking. Through the popliteal depression a bundle of muscles (the semimembranosus, semitendinosus and biceps femoris) run from the pelvis to the knee and attach to the tibia and fibula respectively by tendons. These three muscles are collectively called the hamstring muscles, and function to extend the leg and bend the knee.

At the back of the lower leg the calf muscles are composed of the gastrocnemius and soleus muscles which flex the leg at the knee and flex the ankle via the achilles tendon.

Pain behind the knee when walking or running

The cause of pain at the back of the leg behind the knee could be hamstring tendonitis. This is caused by the tendons of the hamstring becoming inflamed, often due to overuse of the hamstring muscles, but the pain will subside after rest and first aid centred on the ‘RICE’ method (Rest, Ice to reduce the swelling, apply a Compression bandage and Elevate the knee).

If you notice a sudden sharp pain in the back of the thigh when undergoing vigorous exercise this may be due to a pull, partial tear or tear of the hamstring, and is due to overloading the muscle. This type of injury is most often treated by a doctor. A similar pain in the calf may be due to gastrocnemius tendonitis.

A tenderness behind the knee, felt when rotating the leg inwards in the act of walking could denote an injury to the popliteus muscle. A cold pack applied for 10 minutes every hour for the first day after injury can alleviate the symptoms.

All the muscles at the back of the leg can be subject to cramp. This is a common condition and occurs when a muscle goes into spasm. The symptoms are a tightening of the muscle accompanied by pain. Amongst other causes, it could be due to dehydration, muscle fatigue or a restriction of the blood supply to the affected muscles. Cramp is not serious and can be relieved by relaxing, massaging and stretching the affected muscle.


Ligaments are strong, flexible, fibrous and elastic connective tissue which connect one bone to another, provide stability and support joints. They do not connect muscles to joints, that is done by the tendons.

The ligaments of the knee comprise the medial and lateral collateral ligaments, on the inside and outside of the knee respectively, which give sideways stability to the knee joint, and the anterior and posterior cruciate ligament at the front and back of the knee. There is also a patellar tendon, which is really a ligament, which attaches the bottom of the patella to the top of the tibia.

A sudden severe pain or ‘popping’ sound accompanied by swelling and a feeling of looseness of the joint and instability

This may be due to damage to one of the knee ligaments, and is commonly seen as a result of sports injuries concerned with a sudden impact, twisting or over stretching. If the ligament is torn or twisted it is a sprain (equivalent to a strain in a muscle or tendon). If you suspect a damaged ligament you should comply with the ‘RICE’ procedure, but not immobilise the joint as there is a risk of stiffness and possible muscle atrophy. The injury should be clinically assessed, and may need surgery.

Pain behind the knee when bending it or pain and stiffness below the kneecap

Although not behind the knee, the patellar tendon can be overloaded and torn by repetitive actions such as jumping, running or kicking. This is called patellar tendonitis, and can get progressively worse as the the torn tendon swells and becomes weaker. Again the RICE formula should be applied, and your doctor should be consulted.

Pain, swelling and a bony lump below the kneecap, typically in children or adolescents

The patellar tendon can also be a factor in both Osgood-Schlatter’s Disease and Sinding-Larsen-Johansson Syndrome, where it become inflamed at its attachments to bones during growth spurts together with inflammation of the growth plates. This typically occurs in children or adolescents and often heals of its own accord, but your doctor may prescribe physiotherapy, knee protection or other measures.


In the knee joint the ends of the femur and tibia are enclosed within a synovial joint. This synovial joint has a synovial capsule enclosing both the articular cartilage on the end of your femur and tibia, and the synovium. The synovium contains loose connective tissue, blood vessels, lymphatic vessels and cells which produce synovial fluid to lubricate the joint.

A swelling at the back of the knee and calf causing pain, and a feeling of tightness when straightening the leg

This may be due to a Baker’s Cyst, which is an accumulation of synovial fluid in the popliteal fossa. The synovial fluid is over-produced, due often to a trauma to the knee or in conditions such as arthritis. The cyst may clear up on its own, but if not it is advisable to visit the doctor.
Swelling in the knee joint due to extra synovial fluid being produced also occurs due to accidental damage to the knee or when osteoarthritis is present.


There are two triangular, or wedge shaped, pieces of cartilage in the synovial joint which are called menisci. One lies on the inside, or medial side, of the knee, and one on the outside or lateral side. They act as shock absorbers between the femur and tibia, the end surfaces of which also have a cartilage covering called articular cartilage. At the front of the synovial joint is the patella which is an oval bone protecting the front of the joint and lined internally with cartilage.

A popping sensation behind the knee or pain and stiffness at the side of the knee

May be the result of a torn meniscus, particularly the posterior horn of the meniscus. This can often occur due to an impact or twisting sports injury, and is more likely as one gets older and the meniscus becomes worn. Pain might not be evident until some time after the injury occurred. RICE may temporarily alleviate the symptoms, but the tear will often require a surgical procedure.

Discomfort, aching and tightness in the knee, grating and pain behind the kneecap when bending the knee or when it is exercised after a period of rest

May be due to chondromalacia patella. In this condition the cartilage on the underside of the patella softens and deteriorates. Some people are able to ignore the condition, but it will not improve and will probably need surgery. Sometimes an unstable flap of surface cartilage may cause this pain, and may be curable with simple keyhole surgery and a chondroplasty.

Pain and stiffness. A grinding sound when the knee is bent. Perhaps swelling of the knee and a feeling of instability

These are often the symptoms of arthritis. Although there are many different forms of arthritis, osteoarthritis is the most common. It is more likely to affect women than men, and, if it occurs, it is more prevalent after middle age. It is caused by erosion of the articular cartilage within the synovial joint, so that the bone of the femur and tibia come into contact and rub against each other causing pain and inflammation. Osteoarthritis is often due to normal wear and tear over a period of time, although injury, repetitive activity, obesity and genetics can also be factors. There is no cure for osteoarthritis, and, although various methods can temporarily mollify the symptoms, surgery is the only permanent solution to eliminate pain and increase mobility.


The popliteal artery and its accompanying vein are major blood vessels at the back of the knee. The artery branches off from the large femoral artery which runs down from the top of the leg, and divides into several other significant blood vessels around the distal end of the femur and proximal ends of the tibia and fibula. The popliteal vein follows the path of the artery and carries blood back to the heart.

Aching, cramp, tiredness or numbness at the back of the knee and calf

Is most likely due to Popliteal Artery Entrapment Syndrome, where the artery becomes compressed due to pressure on it from the muscles and tendons around the knee. The blood supply to the artery is reduced or cut off. This can occur due to overuse or because of athletic activity, particularly if the calf muscles and muscles around the artery become over-developed due to exercise. Normally the artery will simply recover, but if the problem is persistent medical help should be sought.

Pain, tenderness, warm or red skin or a swelling behind the knee

May be the indication of a blood clot in the popliteal vein. This is also called a thrombosis, and the block would restrict the circulation of blood in your leg. More importantly a clot could form an aneurysm, which is an abnormal bulging in the vein walls, and could lead to a pulmonary embolism. If you suspect you have a blood clot it is imperative that you see a doctor as soon as possible. Your body can eventually break up small clots, but you may be sent for a CT scan to investigate the blood clot and given a prescription for blood-thinning medication.


If you are at all worried about any symptoms you experience, and certainly if you suspect a blood clot, you should consult your doctor. In addition any knee pain, swelling or reduced mobility that lasts for more than 48 hours needs a doctor’s opinion.

What causes calf muscle pain?

A variety of conditions and situations can cause calf pain, including:

1. Muscle cramp

Share on PinterestMuscle cramps in the calf are a common complaint for those who exercise frequently.

Calf muscle cramps are usually temporary but can cause significant pain and discomfort.

Causes of calf muscle cramps include:

  • dehydration
  • a loss of electrolytes through sweating
  • lack of stretching
  • prolonged physical activity
  • weak muscles

2. Muscle strain

A calf muscle strain occurs when the muscle fibers in the calf tear either partially or completely.

The symptoms will vary depending on the severity of the strain, but most people will experience sudden, sharp pain and tenderness at the calf muscle site.

3. Arterial claudication

A person may experience calf pain due to narrowing or blockages in the arteries that supply blood flow to the legs. This is known as arterial claudication.

Arterial claudication may cause pain while walking, as this movement requires blood to flow to the lower legs.

If the blood has difficulty moving due to narrowing (claudication), a person may experience calf pain.

A person with arterial claudication will experience no discomfort at rest, but pain after a few minutes of walking.

4. Neurogenic claudication

Neurogenic claudication occurs when the nerves that go to the legs are pinched, affecting their ability to communicate with the lower legs.

Neurogenic claudication is often due to a condition called spinal stenosis.This condition occurs when the bones in the spinal column narrow, placing extra pressure on the nerves. Sciatica is one example of neurogenic claudication.

In addition to calf pain, neurogenic claudication symptoms include:

  • pain while walking
  • pain after prolonged standing
  • pain that also occurs in the thighs, lower back, or buttocks
  • pain that usually improves when a person leans forward at the waist

A person may also experience calf pain from neurogenic claudication when at rest.

5. Achilles tendinitis

The Achilles tendon is a tough, fibrous band that connects the calf muscle to the heel bone.

If a person’s calf muscles are especially tight, this may put extra pressure on the Achilles tendon. As a result, a person can experience calf pain.

People are more likely to experience Achilles tendinitis if they have recently started an exercise program or they perform repetitive exercises.

Frequent stretching can often help to reduce symptoms.

6. Compartment syndrome

Share on PinterestPersistent pain in the calf should be addressed by a doctor.

Compartment syndrome is a painful condition that can occur in the calf muscle or in both legs, usually after a person has experienced a trauma or severe injury.

It occurs when excess blood or fluid builds up underneath a band of tough tissues in the body that cannot stretch very well. This fluid places extra pressure on the nerves and blood vessels in the lower leg, causing pain, swelling, numbness, and tingling.

Another form of compartment syndrome is chronic or exertional compartment syndrome. This type occurs when a person experiences pain while exercising.

Symptoms associated with chronic compartment syndrome include numbness, visible bulging or enlarging of muscles, or trouble moving the foot.

7. Diabetic neuropathy

Diabetic neuropathy is a condition that occurs when a person experiences nerve damage related to diabetes.

Frequently high blood sugar levels can damage the body’s nerves, usually beginning with the hands and feet.

Sometimes, the tingling and numbness can cause shooting pain and discomfort that radiates to the calf muscles.

8. Plantar fasciitis

Plantar fasciitis is a condition that affects the plantar fascia tissue located on the bottom of the foot.

If the calf muscles are too tight, a person may be more likely to experience plantar fascia because the calf muscles cannot support the foot.

The most common symptoms of plantar fasciitis are foot pain when waking and difficulty flexing the foot.

9. Varicose veins

Varicose veins are enlarged veins that often bulge from the legs and may look like cords. They develop when damaged valves in a person’s veins allow blood to backflow.

Factors that contribute to varicose veins include:

  • age
  • a family history of varicose veins
  • hormone fluctuations
  • pregnancy
  • obesity
  • lack of physical activity

Varicose most commonly appear in the legs and can cause pain, throbbing, cramping, and aching.

10. Deep vein thrombosis

Deep vein thrombosis (DVT) is the result of a blood clot that forms in one of the veins in the leg. This condition can cause severe pain and affect blood flow to the legs.

People are more likely to develop DVT if they have been sitting for long periods, such as on a flight, or if they have high blood pressure or blood clotting disorders.

Symptoms of DVT include calf pain that usually gets worse when standing or walking. A person’s leg may also swell and have a red or inflamed area due to the problems with blood flow.


As Chiropractors, Osteopaths and sports therapists, the ProBack team are responsible for more than just back pain but for the mechanical components of the whole body; how they align and interact is key to understanding how any pain evolves including pain in the leg and pain in the calf.

We see many patients whose leg and calf pain is a direct result of nerve compression within the back known as Sciatica, most commonly this involves shooting pain down the leg often extending into the calf, however sometimes the pain occurs as just calf pain without additional symptoms. Often this occurs as sudden calf pain or can be described as a shooting pain in the calf.

Alternative causes for pain in the leg or calf can be brought on by many different things, with symptoms ranging from mild to severe. Often leg and calf pain is caused by a certain activity or a result of a direct injury without obvious causes, yet there may be a more complicated problem related to a bio-mechanical issue as a result of stresses and strains on the body.

Causes of Leg & Calf Pain

Many causes of leg and calf pain are due to localised inflammation; unless a large and unusual force has been exerted on those tissues, then it is likely that it is a repetitive strain that has caused the issue. In these cases, there are likely to be one or more additional mechanical issues in the chain from lower back to the foot that are causing dysfunction in the muscle tissues. Causes of leg or calf pain can include:

  • Dropped Arches

Dropped or dysfunctional arches (flat feet) can happen as a result of the arches not forming properly or becoming stiff due to the overwhelming strain caused by walking on hard surfaces like concrete. Local inflammation of tissue in the foot is often known as plantar fasciitis – which we can treat by mobilising the joints in the feet and giving the correct advice on footwear and potentially orthotics.

  • Muscle Strains

Muscle strains very commonly affect the legs or calves, usually as a result of an excessive force damaging the tendons around joints. If you have a muscle strain you may have swelling or pain in and around the joint area where the muscles connect into the bones; you my experience stiffness in the leg when trying to move the area.

  • Ankle/Knee Tendinitis

This condition is particularly common in athletes, as the ankle and knee absorb force constantly during strenuous activity. You may get ankle or knee tendinitis as a result of weaker muscles in the legs, for example the hamstrings or thigh muscles, as this puts greater stress and strain on the knee and ankle.

  • Baker’s Cyst

Baker’s Cysts commonly occur from arthritis in the knee or from a sports injury, it is a form of swelling behind the knee. While this can originally cause pain in the knee, if a Baker’s Cyst ruptures this causes swelling and a sharp pain in the calf.

  • Compartment Syndrome

This condition can affect ‘compartments’ in the body, for example the leg or arm, and usually happens because of a sudden trauma, like a road accident. Trauma can result in bleeding and swelling within the muscles and can cause symptoms such as severe pain, tenderness or tightness. While acute compartment syndrome may need surgical intervention, chronic compartment syndrome can cause cramping or swelling during exercise which can improve with rest.

  • Shin Splints

Shin splints can, again, occur as a result of injury from exercise as a result of more intense weight bearing on the legs. Examples of intense weight bearing include; running on a hard surface, or rapidly increasing training distances over a short space of time. The pain can vary in severity from a dull ache to more severe pain during exercise and occurs over the shinbone.

  • Lower back or neck misalignment

Lower back or neck misalignment can cause referred pain into the legs, this can be as a result of overcompensating with the legs during load bearing, or from a disc injury that may be causing symptoms such as sciatica. This can cause sensations such as pain down the back of one or both legs, weakness, tingling or pins and needles.

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