Understanding Joints

Why is it important to understand your joints?

Understanding your joints helps you choose appropriate activities and recognize symptoms that warrant a doctor’s visit. Joint pain is common: in a survey conducted in Herne, Germany, the estimated proportion of people aged 40 and older who had experienced joint pain in the past 12 months was 67.4%. This estimate took into account the age and gender distribution of the city’s population.¹

A knee that cracks when climbing stairs, a stiff shoulder in the morning, or a sore hip after a walk can be cause for concern. There are several possible explanations for these symptoms. Joint noise alone is not enough to identify an injury; pain, swelling, and difficulty moving guide the evaluation.

Many joint problems can improve with appropriate care. For example, exercise generally helps people with knee osteoarthritis reduce their pain and perform their daily activities more effectively.²

Here's what research teaches us about joints:

• Movement affects metabolic processes in cartilage: this tissue derives most of its nutrients from synovial fluid, the fluid found inside movable joints. In ponies, fluid collected after a week of exercise promoted the production of certain cartilage components in culture more effectively than fluid collected after a period of rest in the stable. This experimental result does not indicate healing in humans.^{3, 4}
• Changes visible on imaging can also occur without pain. A review of studies in people without back pain estimates that structural changes in the discs—known as degenerative changes—occur in 68% of people by age 40. It estimates that disc bulges occur in 40% of people by age 30. Discs are the cushions between the vertebrae, the bones of the spine; a bulge is a significant protrusion beyond the disc’s normal outline. These imaging findings must be evaluated in light of the patient’s symptoms.⁵
• Exercise can help reduce pain and improve daily activities. In a 2015 review on knee osteoarthritis, exercise programs reduced pain by an average of 12 points out of 100 and improved physical function by 10 points out of 100, compared with groups that did not exercise, immediately after the program.²

This guide explores what joints are, how they work, and how to keep them healthy. You will also understand when it is helpful to consult a physiotherapist to optimize your mobility and reduce pain.

What is a Joint?

A joint is a connection between bones that provides a stable link and, depending on its type, allows for movement. Some joints move a great deal, such as the shoulder. Others move very little or remain immobile, such as the sutures between the bones of the skull.⁶

Joints allow for a full range of motion: walking, running, grasping objects, turning the head, and bending the fingers.

The movable joints of the knee, hip, and shoulder have surfaces covered with cartilage, a smooth tissue that facilitates sliding. Ligaments connect the bones. A sac, called the joint capsule, contains synovial fluid. Fibrous and cartilaginous joints have a different structure.

How a joint functions also depends on the muscles that move it and the nerves involved in controlling its movement. An injury, inflammation, or stiffness can disrupt this function. The evaluation examines these factors together, because pain does not necessarily indicate a problem with a single structure.

What Are the Different Types of Joints?

Joints are classified into three groups based on their structure: synovial, fibrous, and cartilaginous. Synovial joints have a cavity containing fluid; fibrous joints are connected by strong fibers; and cartilaginous joints are connected by cartilage. Their range of motion depends on their shape and location.⁶

Synovial Joints: The Most Mobile

Synovial joints allow for movements whose range varies depending on their shape. This range is called the range of motion. A space between the bones contains synovial fluid and is enclosed by a capsule. The knee, shoulder, hip, wrist, and ankle are examples of synovial joints.

These joints have bone surfaces covered with articular cartilage, a fibrous capsule surrounding them, and ligaments that limit and control movements. The synovial fluid inside lubricates the surfaces and nourishes the cartilage.

Synovial joints come in several forms. Spheroidal joints, such as the hip and shoulder, have a ball-shaped surface that moves in multiple directions. Hinge joints, such as the elbow and, most notably, the knee, allow for bending and straightening—known as flexion and extension. Pivot joints allow for rotation, such as between the first two vertebrae of the neck. Others are flat and allow for sliding, such as saddle joints (e.g., the base of the thumb) or condylar joints with an oval surface (e.g., the wrist).

Fibrous Joints: Maximum Stability

Fibrous joints are connected by dense fibrous tissue and allow little to no movement. Instead, they provide stability and protection. The sutures of the skull are the best-known example: the bones are so tightly joined that they barely move.

The fibrous ligament connecting the lower ends of the tibia and fibula—the two bones of the lower leg—allows for slight movement near the ankle. The fibula is also known as the peroneal bone. This ligament helps hold the bones together when weight is placed on the ankle.

Cartilaginous Joints: The Compromise

Cartilaginous joints are connected by cartilage. Some have limited mobility; others are immobile. Symphyses contain fiber-reinforced cartilage, known as fibrocartilage. The joints between the vertebral bodies, along with their discs, are examples of this: their small movements combine to allow the spine to move.

Hyaline cartilage, the other type of cartilage found in these joints, forms a more homogeneous tissue. In particular, it connects the first rib to the sternum, the bone in the center of the chest. Cartilaginous joints thus provide connections whose flexibility and function vary depending on the region.

Now that you know the types of joints, let's look at how mobile joints work in daily life.

How Do Joints Work?

Movable joints function thanks to the sliding cartilage surfaces, the synovial fluid that lubricates them, the ligaments that guide movement, and the muscles that move the bones. The joint capsule surrounds the joint cavity. These components work together to provide both mobility and stability.

Articular Cartilage: The Gliding Surface

Articular cartilage covers the ends of bones in a synovial joint. It allows the bones to slide against each other with minimal friction.

Cartilage also helps distribute forces and absorb some of the energy from impacts. The underlying bone plays a role in this response. Tests on horse tissue measured the energy absorbed by these two tissues during impacts; their behavior depended, in particular, on the extent of the damage. Cartilage and bone therefore respond together to a load.⁷

Articular cartilage does not have blood vessels. Nutrients, primarily from the synovial fluid, pass through it by diffusion: they move from areas where they are more concentrated to those where they are less concentrated. Cartilage also contains water that moves as it compresses and relaxes.^{3, 8} An experiment in ponies showed that exercise could alter the effect of their synovial fluid on cartilage cultured in the laboratory.⁴

Synovial fluid: lubricant and source of nutrition

Synovial fluid is a fluid that contains water and components derived from the blood, as well as substances produced by the cells of the joint. The synovial membrane lines the inside of the joint capsule. Its cells contribute to the composition of the fluid, which facilitates gliding and exchange with the cartilage.⁹

Synovial fluid contains, among other things, hyaluronic acid and lubricin. Hyaluronic acid contributes to its viscosity; lubricin helps lubricate the surfaces. Their interactions influence how the fluid behaves under load. It also contains nutrients and growth factors—substances that influence cell activity.⁹ In the experiment with ponies, certain growth factors tended to increase after exercise, but the concentration of hyaluronic acid remained unchanged.⁴

In this experiment, the fluid was collected after one week of exercise or rest in the stable. The researchers then added it to cultured cartilage for four days. The fluid associated with exercise promoted the production of glycosaminoglycans—components that retain water in cartilage—and reduced their release. This animal study does not measure the amount of fluid produced in humans or its long-term changes.⁴

Ligaments: control and stability

Ligaments are bands of fibrous tissue that connect one bone to another. They have two main roles: to stabilize the joint and to limit excessive movements that could cause injuries.

Ligaments vary depending on the joint. In the knee, the two cruciate ligaments and the two collateral ligaments primarily limit forward and backward movement, lateral movement, and certain rotations. A stretched or torn ligament is called a sprain. This can result in instability, but instability does not occur after every sprain.

Ligaments can withstand movements that put them under tension. In laboratory studies, repeated loads combining compression, flexion, and rotation caused cumulative damage to the anterior cruciate ligament of the knee. These findings shed light on a possible mechanism of injury; they do not mean that everyday movements gradually damage all ligaments.¹⁰

The joint capsule: the protective covering

The joint capsule is a fibrous structure that surrounds the synovial joint. Its outer layer is strong and protects the joint. Its inner layer, the synovial membrane, produces certain substances in the synovial fluid.

The capsule and ligaments contain nerve receptors that play a role in proprioception—the perception of the body’s position and movement. This information combines with input from the muscles and skin to guide movement.⁶ A review of fourteen studies, primarily focused on the knee, describes a less accurate perception of movement in people with osteoarthritis. Changes in the receptors of the posterior cruciate ligament may contribute to this; their exact role remains to be determined.¹¹

When a joint is injured or inflamed, the joint capsule can become stiff and contract. This is what happens in conditions such as shoulder capsulitis (frozen shoulder), where the joint capsule tightens and severely limits movement.

Now that you understand the structures, let's explore the role of cartilage and synovial fluid in joint health.

What is the role of cartilage and synovial fluid?

Cartilage facilitates gliding and distributes forces, while synovial fluid lubricates the surfaces and contributes to nutrient exchange. Movement and loads influence these exchanges, though they are not the sole driving force behind them.

Cartilage: Interactions with Fluid

Articular cartilage normally contains neither blood vessels nor nerves. Its cells, called chondrocytes, receive most of their nutrients from the synovial fluid. This exchange also allows waste products from their metabolic activity to be removed.³

Diffusion transports, in particular, small molecules such as glucose and oxygen. The water movements that accompany the compressions can facilitate the transport of certain larger molecules. Their effect depends on the load, its duration, and the properties of the cartilage.⁸

Nutrient exchange continues at rest: it does not stop between movements. Laboratory studies also show that sustained compression and repeated compressions do not have the same effect on the transport of molecules. Movement remains beneficial, but a greater load does not automatically mean better nutrition.⁸

Synovial fluid: more than just a lubricant

Synovial fluid plays a role in the exchange of glucose, oxygen, and other small molecules needed by cells. It also contains chemical signals, including growth factors. These signals contribute to cellular responses and interactions with neighboring tissues.

Viscosity refers to a liquid’s resistance to flow. The viscosity of synovial fluid changes depending on the rate at which it is deformed: it can become less viscous when subjected to faster shear. The interactions between hyaluronic acid and lubricin contribute to this complex behavior.⁹

Inflammation can alter the composition of the fluid and be accompanied by a buildup of fluid in the joint. This buildup contributes to swelling. A warm, swollen, and painful joint requires prompt medical attention to determine the cause.¹²

The importance of regular movement

Walking, biking, and water exercises offer different ways to stay active on a regular basis. They engage the muscles and joints; the choice depends on comfort, ability, and preference. For people with knee osteoarthritis, exercise programs can help reduce pain and improve daily activities.²

An injury or excessive stress can contribute to changes in the joints. Osteoarthritis, however, depends on several factors: age, previous injuries, weight, heredity, and the joint’s biological responses. It does not result simply from a volume of movement that exceeds a universal threshold.^{13, 14}

Pain or an injury can cause a person to move less. The resulting loss of strength and confidence can then make it harder to get back on track. Gradual movements and tailored exercises help build strength and confidence in one's movements.

Now that we understand how joints stay healthy, let's look at what can go wrong.

What are common joint problems?

Common joint problems include osteoarthritis, bursitis, instability, and stiffness. Osteoarthritis affects several tissues within the joint; bursitis involves a small sac of fluid near the joint. Instability causes a feeling of lack of support, while stiffness limits movement. Pain can also result from inflammatory arthritis or an infection.

Osteoarthritis: Changes in Multiple Joint Tissues

Osteoarthritis can affect the cartilage, the underlying bone, and the synovial membrane. Visible changes do not always correspond to the severity of the pain. A person may have changes visible on imaging without significant pain. For knee osteoarthritis, therapeutic exercise can reduce pain and improve physical function.²

Osteoarthritis can cause pain during certain activities and stiffness after a period of inactivity. Movement can relieve stiffness, while unusual exertion can temporarily worsen symptoms. The course of the condition varies from person to person.

Osteoarthritis is not solely a function of age. Mechanical stresses interact with cellular responses and the body’s ability to repair tissues.¹³ Previous injuries, being overweight, and genetics are among the risk factors.¹⁴ Our comprehensive guide to physical therapy outlines the steps involved in an evaluation and possible treatment options.

Spinal discs also have a significant genetic component. Studies of twins have shown that differences in physical exposure at work and during leisure activities account for less of the changes in the discs than previously assumed. This complements the role of age and other factors; these disc-related findings do not apply to all joints.¹⁵

In osteoarthritis, pain depends not only on the tissues but also on how the nervous system processes signals. A review describes an imperfect correlation between X-rays and symptoms, as well as sensitization phenomena—an increased response of the nervous system to stimuli.¹⁶ Explanations of pain must therefore take into account the individual and their specific situation.¹⁷

In a cohort of 3,369 people followed for six years, most individual lumbar findings on magnetic resonance imaging (MRI) were not associated with greater future pain. However, among individuals who were pain-free at baseline, five or more findings were associated with an additional increase of 1.21 points out of 10, compared with no findings. This group-level association alone does not predict an individual’s course of the disease.¹⁸

Bursitis: inflammation of the protective cushions

Bursitis is the inflammation of a bursa, a small, flat, fluid-filled sac that helps skin, muscles, tendons, and ligaments glide smoothly over bones. Bursae reduce friction around joints.

Shoulder bursitis affects a deep bursa located near the tendons. Superficial bursitis is most commonly described in the elbow and in front of the knee; other bursae are found near the hip, pelvis, and heel.¹⁹ Bursitis can cause pain during movement or upon touch, swelling, and sometimes warmth or redness.

Bursitis can result from repeated pressure or friction, a direct blow, an inflammatory condition, or an infection. A warm, swollen bursa—especially when accompanied by a fever or general malaise—requires prompt medical evaluation. When the situation allows for physical therapy, treatment may include modifying activities that cause irritation and gradually resuming normal activities.¹⁹

Joint Instability: A Feeling of Lack of Support

Joint instability can involve both ligament laxity and difficulty controlling movement. Excessive laxity is called laxity. In some cases, the joint may become completely dislocated (a dislocation) or partially dislocated (a subluxation). A feeling of the joint giving way does not always mean that a bone has moved out of place.

Symptoms may include a feeling that the joint is loose, pain during certain movements, and swelling after activity. Repeated sprains warrant an evaluation of stability, balance, and strength.

A study of 32 people who had previously suffered an ankle sprain found greater laxity in those who reported persistent instability than in those without instability.²⁰ Treatment may include balance, movement control, and strengthening exercises based on the measured difficulties. The 2021 clinical guideline specifically recommends proprioception and neuromuscular control exercises for persistent ankle instability: these exercises improve positional awareness and muscle coordination.²¹

Joint Stiffness: Loss of Range of Motion

Joint stiffness manifests as a loss of range of motion. It can be caused by a thickening of the joint capsule (as in capsulitis), by osteoarthritis, or by prolonged immobilization following an injury.

The duration of morning stiffness helps distinguish osteoarthritis from certain inflammatory forms of arthritis—conditions in which inflammation affects the joint. Brief stiffness after rest may be a symptom of osteoarthritis; prolonged stiffness warrants a medical evaluation. Duration alone is not sufficient to make a diagnosis.²²

Stiffness can make movements more difficult and lead to avoidance. Gradual movements help improve mobility and build confidence, while taking into account any necessary restrictions following an injury or surgery.

Understanding these common problems helps identify when to seek professional help. Now, let's look at how physiotherapy can assist.

How does physiotherapy help joints?

Physical therapy helps improve mobility, strength, and activities that are limited by a joint problem. The physical therapist assesses your symptoms and abilities, then works with you to select exercises, provide advice, and, if necessary, use manual techniques. The expected results depend on the specific problem being treated.

Improved Mobility

Physical therapy can be aimed at improving your range of motion, depending on your needs. Joint mobilizations are movements performed by the physical therapist while you relax your muscles. They can be part of the treatment for a stiff joint.

For capsulitis, also known as frozen shoulder, a 2018 review found that certain mobilization techniques had favorable effects on range of motion and pain. The techniques and the quality of the studies varied widely; therefore, the authors could not establish a definite and consistent effect. Mobilization techniques can be incorporated into a treatment plan that includes exercises.²³

Active exercises complement this work: you perform the movement yourself. For example, you can practice raising your arm or bending your knee within an appropriate range of motion. The follow-up tracks the progress that is relevant to your activities.

Protective Muscle Strengthening

Strength training builds the muscles’ ability to perform tasks and control movement. The exercises engage the muscles and joints; their difficulty can be adjusted based on your abilities. For kneeosteoarthritis, a 2015 review estimated an average improvement in pain of 12 points out of 100 immediately following an exercise program, compared to no exercise.²

The exercises target the muscles and movements that are causing problems. For the knee, they can work the quadriceps at the front of the thigh and the hamstrings at the back. For the shoulder, they can target the rotator cuff—a group of muscles that control arm movement—and the muscles that control the shoulder blade.

The 2024 Cochrane update includes 139 trials. Compared with no treatment, usual care, or limited information, exercise improves pain by an average of about 13 points out of 100 and physical function by about 13 points out of 100 immediately after the program. Confidence in these results is low to moderate, and the magnitude of the perceived change remains uncertain. Some trials report more adverse effects: the amount and difficulty of the exercises should be adjusted based on the individual’s response.^{2, 24}

Pain relief

Manual techniques, such as muscle massage and joint mobilization, can influence the nervous system’s responses. A scientific model proposes reactions at the tissue, spinal cord, and brain levels. The spinal cord is the nerve cord located within the spine that transmits messages between the brain and the body. The exact mechanisms remain to be clarified; this model alone does not demonstrate the effectiveness of a technique.²⁵

Heat can help relax tense muscles or tissues. Cold may provide temporary relief for some people. Place a barrier between your skin and the source of heat or cold, and stop using it if it increases your discomfort. TENS refers to a device that delivers an electrical current through electrodes placed on the skin.

In a trial involving 101 workers who had been experiencing lower back pain for more than three months, the group that participated in intense aerobic exercise—which works the heart and lungs—showed improvement after twelve weeks. Their average pain score dropped from 6 to 2 on a scale of 10; difficulties with daily activities and the distance between their fingers and the floor when bending forward also decreased. The passive treatment group showed no statistically significant improvement. These before-and-after analyses alone are not sufficient to quantify the superiority of exercise between the groups.²⁶ The clinical value lies in developing an appropriate exercise regimen and strategies for managing symptoms between sessions.

Injury Prevention

A consultation can also help you prepare to resume sports or take on a demanding job. The physical therapist will assess your current abilities and discuss your past injuries to recommend a tailored training plan.

A physical therapist can help you practice the movements required for your sport or job. They can recommend exercises to build strength, balance, and endurance, as well as adjustments that make certain tasks more comfortable. This preparation does not guarantee that you will not get injured.

To learn more about the full role of physiotherapy, consult our guide to physiotherapy.

Beyond professional treatment, you can also protect your joints in your daily life.

How to Protect Your Joints in Daily Life?

Protecting your joints involves adjusting the intensity of your activities, varying your positions, and staying active on a regular basis. When a joint is sore, taking breaks and using appropriate aids can make movements more comfortable. The goal is to continue engaging in meaningful activities at a tolerable level of duration and difficulty.

Reduce Force and Strain

Distributing the effort more evenly makes strenuous tasks more comfortable, especially when a joint is sore. Use levers to increase your mechanical strength. For example, to open a jar, use a jar opener instead of forcing it open with your hands. Distribute the load across several joints instead of just one.

Distribute the load between both hands when it helps. Bringing the object closer to your body reduces the lever arm—that is, the distance that increases the effort required of your muscles. For an object that is difficult to hold or too heavy, use a cart or ask for help.

Try these adjustments for tasks that are difficult for you and see how they work. A can opener can help if you have a sensitive hand; a cart can make carrying things easier. Stick with the solutions that improve your comfort and independence.

Avoid Prolonged Positions

Staying in one position for a long time can cause stiffness or discomfort. Alternating tasks and changing positions allows you to move in different ways. Comfort can also depend on arm support, seat height, and the duration of the task.

If your job requires you to stay in one position for long periods of time, be sure to take breaks to walk around or do some gentle stretches. You can adjust the frequency of these breaks based on your tasks and symptoms.

Keeping your head tilted while looking at a phone can become uncomfortable. You can rest your arms, move the screen closer, or change your position. You don’t have to keep your neck perfectly straight at all times.

Balance Rest and Activity

Alternating between activity and rest helps you pace yourself. Reducing your activity level can be helpful during a painful flare-up, while still performing the movements you are allowed to do. After an injury or surgery, follow the specific restrictions provided by your healthcare team.

While gardening or doing strenuous work, taking a short break can help you manage fatigue. You can also alternate between different tasks or spread the work out over several sessions. Pay attention to your symptoms during and after the activity so you can adjust your next session accordingly.

After unusual exertion, muscle soreness may develop 12 to 24 hours later, peak between 24 and 72 hours, and then gradually subside. These timeframes describe muscle soreness, not the healing time for all injuries.^{27, 28} Severe pain, significant swelling, or loss of function requires evaluation. Adjust the duration or intensity of the following activities based on your recovery.

Joint protection techniques by region

For your neck: Adjust the screen and the reading stand to find a comfortable position. Change your position regularly instead of trying to achieve perfect alignment.

For hands and wrists: Avoid repetitive movements without breaks. Use ergonomic tools that reduce strain on your fingers. Alternate between different tasks to avoid overworking the same joints.

For your knees: A cushion or knee pads can help reduce pressure when you’re working on your knees. When using the stairs, a handrail can help you manage the effort and maintain your balance. Temporarily adjust the number of steps you take if climbing them causes a sharp pain.

These adjustments can be incorporated into exercises that meet your needs.

What exercises help maintain joint health?

Mobility and strength-building exercises, as well as endurance activities, help maintain the physical abilities needed for movement. Walking, cycling, and water exercises are some options. The program should take into account your goals, your symptoms, and any medical restrictions.

Joint range of motion exercises

Mobility exercises involve moving a joint through a comfortable range of motion or the range recommended for your specific situation. They allow you to practice movements and improve flexibility without consistently pushing yourself to the limit of your range of motion.

Perform shoulder rotations, knee flexions/extensions, ankle circles, and neck rotation movements. These simple exercises can be done in the morning upon waking or during work breaks.

Consistency helps you make exercise a part of your daily routine. Start with a few exercises and adjust them based on how they affect your daily activities and symptoms.

Muscle strengthening

Strength training prepares your muscles to handle the activities that matter to you. The difficulty can be increased gradually, starting at a level you can manage with control. The choice depends, in particular, on your strength, balance, and any joint issues you may have.

Bodyweight exercises or exercises using a resistance band can serve as a starting point. A shallow squat involves bending your hips and knees slightly, as if you were about to sit down; it works the thigh and hip muscles. Arm rotations against resistance target the rotator cuff. For a glute bridge, lie on your back, bend your knees, and lift your hips in a controlled manner.

Gradually increase the resistance over the course of several weeks.

Low-Impact Activities

Walking, cycling, and water-based activities help build endurance—the ability to sustain physical effort. They place different stresses on the joints. Synovial fluid reacts to mechanical stress, as illustrated by the experiment involving ponies; the practical benefit you should aim for is an activity that is tolerable and can be done regularly.^{4, 29}

In a study of 12 people with hip or knee implants, certain exercises performed in water reduced joint forces by 36 to 55 percent compared to the same movements performed on land. The water was chest-deep. However, rapid movements or those performed against resistance could increase the forces: not all aquatic exercises relieve joint stress in the same way.²⁹ Cycling offers another way to move the knees without the impact of running.

When walking, choose a route with a surface and level of difficulty that suit your balance and comfort level. Uneven terrain requires more attention. Start with a manageable duration, then gradually increase it based on how you feel.

Recommended Frequency and Duration

To start, you can spread out targeted exercises over two or three sessions per week. Ten to fifteen minutes may be enough to practice a few movements, but this is not a universal minimum or a complete program for every issue. The duration and difficulty should be tailored to your needs.

Daily moderate physical activity is also important. This activity can be broken up into several short periods throughout the day.

A family history of osteoarthritis, being overweight, or a previous injury is not enough to rule out all high-impact sports. A review of studies found lower rates of hip or knee osteoarthritis among recreational runners than among competitive runners and non-runners. This association does not prove that running protects the joints; previous injuries and other differences between groups may explain it.³⁰ For soccer, basketball, or high-intensity running, a current injury and the demands of the sport should guide a tailored return to activity.

These preventive exercises are important, but sometimes professional intervention becomes necessary.

When should you consult a physiotherapist for your joints?

A physical therapist can evaluate persistent pain or limited range of motion that interferes with your daily activities. A warm, swollen, and painful joint requires prompt medical attention, as some causes require specific treatment. Certain signs described below warrant a visit to the emergency room, even if there is no obvious injury.¹²

Warning Signs That Require a Consultation

Pain that does not improve or recurs regularly warrants evaluation, especially if it interferes with sleep or daily activities. The fact that it persists does not mean it cannot improve; an evaluation helps determine the next steps in care.

Difficulty with daily activities is an important indicator: difficulty climbing stairs, raising your arm, walking normally, or performing your daily activities. These difficulties help clarify treatment goals.

Seek urgent medical attention on the same day if the joint becomes hot, swollen, and painful, or if the pain is accompanied by a fever, chills, or general malaise. An infection is a possible cause, even if not all of these signs are present.¹²Go to the emergency room if you can no longer walk or put weight on the joint, or if it appears deformed. After a fall or injury, severe pain, tingling, or numbness around the joint also require a visit to the emergency room.

The Preventive Role of Physiotherapy

Physical therapy can help you set a goal before an injury occurs. An evaluation assesses, among other things, your strength, balance, and the movements required for your activity. It is used to guide your training, though it cannot predict every injury.

After a long break from exercise or before starting a demanding workout, an assessment can help you determine the first steps to take. Previous injuries and health issues may affect your preparation. A family history of osteoarthritis does not mean that all movements are dangerous.

A physical therapist can teach you exercises tailored to your goals and help you adjust their difficulty. For an ankle that remains unstable after a sprain, balance and movement control exercises are particularly recommended.²¹

What a Physiotherapy Assessment Reveals

During an evaluation, the physical therapist assesses your range of motion, strength, and balance. They also observe how you walk, lift objects, or perform the movement that is causing you difficulty. These observations are compared with your medical history and symptoms to formulate hypotheses.

This assessment helps you choose a treatment plan tailored to your specific challenges. The physical therapist will also explain the results of the assessment, your potential for improvement, and helpful adjustments you can make to your daily habits.

The physical therapist may recommend a medical consultation if certain signs indicate the need for further testing. Depending on the situation, the doctor may order an X-ray, an MRI, or an analysis of the synovial fluid. These tests are performed to answer a specific question; they are not necessary for every case of pain.

What Should You Remember About Joints?

Joints connect bones and, depending on their structure, provide a combination of stability and mobility. Cartilage facilitates gliding, synovial fluid helps with lubrication and nutrient exchange, and muscles generate movement. Understanding these roles helps in choosing appropriate activities and care.

Regular, appropriate physical activity helps build strength, endurance, and flexibility. Taking breaks or adjusting your activities can make it easier to get through a painful period. However, a warm, swollen joint, a fever, or a significant loss of function requires a medical evaluation.

If pain or stiffness is limiting your activities, a physical therapy consultation can help identify your specific needs.

References

1. Thiem U, Lamsfuß R, Günther S, Schumacher J, Bäker C, Endres HG, et al. Prevalence of self-reported pain, joint complaints, and knee or hip complaints in adults aged ≥ 40 years: a cross-sectional survey in Herne, Germany. PLoS One. 2013;8(4):e60753. ↩ Back to text
2. Fransen M, McConnell S, Harmer AR, Van der Esch M, Simic M, Bennell KL. Exercise for osteoarthritis of the knee: a Cochrane systematic review. Br J Sports Med. 2015;49(24):1554-7. ↩ Back to text: 1st, 2nd, 3rd, 4th, 5th, 6th citations
3. Bora FW, Miller G. Joint physiology, cartilage metabolism, and the etiology of osteoarthritis. Hand Clin. 1987;3(3):325-36. ↩ Back to text: 1st, 2nd, 3rd citations
4. Van den Hoogen BM, van de Lest CH, van Weeren PR, Lafeber FP, Lopes-Cardozo M, van Golde LM, et al. Loading-induced changes in synovial fluid affect cartilage metabolism. Br J Rheumatol. 1998;37(6):671-6. ↩ Back to text: 1st, 2nd, 3rd, 4th, 5th citations
5. Brinjikji W, Luetmer PH, Comstock B, Bresnahan BW, Chen LE, Deyo RA, et al. Systematic literature review of imaging features of spinal degeneration in asymptomatic populations. AJNR Am J Neuroradiol. 2015;36(4):811-6. ↩ Back to text
6. Juneja P, Munjal A, Hubbard JB. Anatomy, Joints. [Updated April 21, 2024]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026. ↩ Back to text: 1st, 2nd, 3rd citations
7. Malekipour F, Whitton C, Oetomo D, Lee PV. Shock-absorbing ability of articular cartilage and subchondral bone under impact compression. J Mech Behav Biomed Mater. 2013;26:127-35. ↩ Back to text
8. Jackson A, Gu W. TRANSPORT PROPERTIES OF CARTILAGINOUS TISSUES. Curr Rheumatol Rev. 2009;5(1):40. ↩ Back to text: 1st, 2nd, 3rd citations
9. Jay GD, Torres JR, Warman ML, Laderer MC, Breuer KS. The role of lubricin in the mechanical behavior of synovial fluid. Proc Natl Acad Sci U S A. 2007;104(15):6194-9. ↩ Back to text: 1st, 2nd, 3rd citations
10. Wojtys EM, Beaulieu ML, Ashton-Miller JA. New perspectives on ACL injury: On the role of repetitive submaximal knee loading in causing ACL fatigue failure. J Orthop Res. 2016;34(12):2059-2068. ↩ Back to text
11. Salamanna F, Caravelli S, Marchese L, Carniato M, Vocale E, Gardini G, et al. Proprioception and Mechanoreceptors in Osteoarthritis: A Systematic Literature Review. J Clin Med. 2023;12(20). ↩ Back to text
12. nhs.uk. Joint pain. 2017. ↩ Back to text: 1st, 2nd, 3rd references
13. Vincent TL. Targeting mechanotransduction pathways in osteoarthritis: a focus on the pericellular matrix. Curr Opin Pharmacol. 2013;13(3):449-54. ↩ Back to text: 1st, 2nd citations
14. Palazzo C, Nguyen C, Lefevre-Colau MM, Rannou F, Poiraudeau S. Risk factors and burden of osteoarthritis. Ann Phys Rehabil Med. 2016;59(3):134-138. ↩ Back to text: 1st, 2nd references
15. Battié MC, Videman T, Kaprio J, Gibbons LE, Gill K, Manninen H, et al. The Twin Spine Study: contributions to a changing view of disc degeneration. Spine J. 2009;9(1):47-59. ↩ Back to text
16. Vincent TL. Peripheral pain mechanisms in osteoarthritis. Pain. 2020;161 Suppl 1(1):S138-S146. ↩ Back to text
17. Moseley GL. Teaching people about pain: why do we keep beating around the bush? Pain Manag. 2012;2(1):1-3. ↩ Back to text
18. Kasch R, Truthmann J, Hancock MJ, Maher CG, Otto M, Nell C, et al. Association of Lumbar MRI Findings with Current and Future Back Pain in a Population-Based Cohort Study. Spine (Phila Pa 1976). 2022;47(3):201-211. ↩ Back to text
19. Khodaee M. Common Superficial Bursitis. Am Fam Physician. 2017;95(4):224-231. ↩ Back to text: 1st, 2nd citations
20. Hubbard TJ. Ligament laxity following inversion injury with and without chronic ankle instability. Foot Ankle Int. 2008;29(3):305-11. ↩ Back to text
21. Martin RL, Davenport TE, Fraser JJ, Sawdon-Bea J, Carcia CR, Carroll LA, et al. Ankle Stability and Movement Coordination Impairments: Lateral Ankle Ligament Sprains (2021 Revision). J Orthop Sports Phys Ther. 2021;51(4):CPG1-CPG80. ↩ Back to text: 1st, 2nd citations
22. Marino C, McDonald E. Osteoarthritis and rheumatoid arthritis in elderly patients. Differentiation and treatment. Postgrad Med. 1991;90(5):237-43. ↩ Back to text
23. Zavala-González J, Pavez-Baeza F, Gutiérrez-Espinoza H, Olguín-Huerta C. The effectiveness of joint mobilization techniques for range of motion in adult patients with primary adhesive capsulitis of the shoulder: a systematic review and meta-analysis. Medwave. 2018;18(5):e7265. ↩ Back to text
24. Is exercise an effective treatment for knee osteoarthritis? | Cochrane. ↩ Back to text
25. Bialosky JE, Bishop MD, Price DD, Robinson ME, George SZ. The mechanisms of manual therapy in the treatment of musculoskeletal pain: a comprehensive model. Man Ther. 2009;14(5):531-8. ↩ Back to text
26. Murtezani A, Hundozi H, Orovcanec N, Sllamniku S, Osmani T. A comparison of high-intensity aerobic exercise and passive modalities for the treatment of workers with chronic low back pain: a randomized, controlled trial. Eur J Phys Rehabil Med. 2011;47(3):359-66. ↩ Back to text
27. Cheung K, Hume P, Maxwell L. Delayed-onset muscle soreness: treatment strategies and performance factors. Sports Med. 2003;33(2):145-64. ↩ Back to text
28. Hody S, Croisier JL, Bury T, Rogister B, Leprince P. Eccentric Muscle Contractions: Risks and Benefits. Front Physiol. 2019;10:536. ↩ Back to text
29. Kutzner I, Richter A, Gordt K, Dymke J, Damm P, Duda GN, et al. Does aquatic exercise reduce hip and knee joint loading? In vivo load measurements with instrumented implants. PLoS One. 2017;12(3):e0171972. ↩ Back to text: 1st, 2nd citations
30. Alentorn-Geli E, Samuelsson K, Musahl V, Green CL, Bhandari M, Karlsson J. The Association of Recreational and Competitive Running With Hip and Knee Osteoarthritis: A Systematic Review and Meta-analysis. J Orthop Sports Phys Ther. 2017;47(6):373-390. ↩ Back to text

Our physical therapists defined the research strategy, plan, and clinical content of this article. An AI tool assisted with the literature review and text editing to ensure consistency in content and writing style.