Understanding Tendons

Understanding Tendons: How Do They Work, and Why Do They Get Injured?

Tendons transmit force from the muscles to the bones and can be injured during excessive exertion or repeated movements that exceed their current capacity. These bands of tissue connect the muscles to the skeleton. However, the forces exerted on them do not account for all problems: age, certain diseases, and the type of injury also play a role.

Achilles tendon pain can limit running, while shoulder pain can make it difficult to get dressed or work. An evaluation helps distinguish between tendinopathy—tendon pain accompanied by a decrease in function—and a tear, and helps determine the appropriate activities and treatment.

For Achilles tendinopathy and patellar tendinopathy (below the kneecap), resistance exercises can help alleviate pain and improve function. A review of 32 studies reports favorable results with several programs, but comparisons are limited. Exercises that combine lifting and lowering a load are also options; training that focuses solely on slowing the descent—known as eccentric training—is not superior in all situations.¹

Here are some helpful facts to help you better understand tendons.

• The term “tendinopathy” is broader than “tendinitis ”: it describes pain and loss of function in the tendon without assuming that inflammation—a defensive and reparative response of the tissue—alone accounts for the symptoms.
• Recovery varies: it depends on the affected tendon, the type of injury, the level of activity, overall health, and the planned activities.
• The load is increased gradually: the program can incorporate various types of contraction and must be tailored to the affected tendon, the targeted activities, and the individual’s response.
• Tendons transmit significant forces: collagen, a protein that forms strong fibers, makes up a large portion of the tendon. Type I is the primary form of collagen. The forces borne by the tendon vary depending on the tendon, the movement, and how the activity is performed.

This guide covers the anatomy of tendons, their role in movement, the problems that can affect them, and the treatment options to discuss depending on the situation. To learn more about physical therapy in general, check out our comprehensive guide to physical therapy.

What is a tendon?

A tendon is a strong band of tissue that typically connects a muscle to a bone and transmits the force needed for movement.^{2, 3} Its collagen fibers are arranged in several layers. The Achilles tendon, located behind the ankle, withstands high forces during running.⁴ In a review of 11 studies, estimates of the forces exerted while running ranged from 4.15 to 7.71 times body weight.⁵ Landing on the forefoot first places a greater load on this tendon than landing on the heel.⁶ However, the relationship between running speed and measured force varies from one study to another.⁵ The body contains many tendons of different shapes and sizes.

Differences between tendons, ligaments, and muscles:

Tendons differ from ligaments and muscles in terms of their function and composition.

• Tendons: connect a muscle to a bone, transmit force, and contain tightly packed collagen fibers.
• Ligaments : connect one bone to another and contribute to joint stability; their composition varies depending on the ligament and the region
• Muscles : generate force by contracting; they consist of muscle fibers and the tissue that connects and supports them.

This distinction is important for understanding the mechanisms of injury and the treatment approaches specific to each tissue. If you are experiencing knee pain that may involve the tendons, you can consult our guide on knee pain.

The muscle and its tendon form a single unit. The myotendinous junction connects the muscle to the tendon; the osteotendinous junction connects the tendon to the bone. These transition zones allow forces to be transmitted between different tissues.

How tendons are made

Tendons contain collagen fibers grouped into bundles, cells that maintain the tissue, and sheaths that organize the structure as a whole. Collagen, primarily type I, accounts for 65 to 80 percent of the tendon’s dry mass—that is, its mass excluding water.² The endotenon separates the bundles, the epitenon surrounds the tendon, and the paratenon surrounds certain tendons, facilitating their glide. These sheaths also contain other proteins.⁷ Cells called tenocytes maintain the matrix—the collection of fibers and the substances surrounding them.

The organization of collagen, from the smallest to the largest.

Collagen in the tendon is organized on several levels, from the basic molecule to the entire tendon.^{2, 8} Detailed descriptions also distinguish subfibrils, which lie between microfibrils and fibrils.⁹

1. Tropocollagen: basic collagen molecules.
2. Microfibrils: assemblies of tropocollagen.
3. Subfibrils: groups of microfibrils.
4. Fibrils: very fine filaments composed of collagen subunits, visible under an electron microscope.
5. Collagen fibers: groups of fibrils, visible under an optical microscope.
6. Fascicles: bundles or groups of fibers.
7. Tendon: final assembly of fascicles.

This structure allows the tendon to transmit force while stretching slightly. As tension increases, the undulations in the fibers gradually unfold.¹⁰ The tendon therefore stretches more easily at the beginning of tension, then resists stretching more. This is known as nonlinear behavior.¹¹

Protective layers.

• Epitendon: a thin membrane surrounding the tendon, connected to the internal septa and containing blood vessels and nerves.
• Endotenon: thin septa between the fascicles that allow them to slide past one another and permit the passage of blood vessels and nerves.

Cellular composition.

Tenocytes and tenoblasts produce and maintain the fibers and other components of the matrix.² Stem cells, which are capable of giving rise to different types of cells, are also present in the tendon and can develop into tenocytes.¹² The following terms traditionally distinguish between young and mature cells. Recent research, however, describes a greater diversity of cells.³

• Tenoblasts: young, active cells that produce collagen and other matrix components around the cells.
• Tenocytes: elongated, mature cells located between collagen fibers that play a role in the maintenance and repair of the tendon matrix.

Blood vessels and nerves of the tendon.

Tendons generally receive less blood than muscles. Their blood vessels still supply the cells with the oxygen and nutrients they need.¹³ For the Achilles tendon, three sources are described: the junctions with the muscle and bone, as well as the paratenon.^{14, 15} The distribution varies depending on the tendon and the method of observation. Sensory nerves, which transmit information to the nervous system, are found primarily in the sheaths. The center of a healthy tendon contains very few of them.^{16, 17} Following an injury or in cases of tendinopathy, nerve fibers may penetrate deeper into the tissue.¹⁶ Several types of sensory receptors contribute to the information coming from this region:

• Golgi tendon organs: small tension-sensitive receptors that help regulate muscle contractions.
• Exposed nerve endings: the tips of nerve fibers, some of which detect potentially harmful stimuli and transmit signals to the spinal cord, the nerve cord within the spine, and then the brain.
• Position and motion sensors: contribute to proprioception—the perception of the body's position and movement.

These signals help the nervous system control movement. Pain also depends on how this information is processed; it cannot be measured by counting nerve fibers or by looking only at the tendon’s appearance.¹⁸

What is the purpose of tendons in the body?

Tendons transmit force from the muscles to the bones, store energy during certain movements, and provide information about tension. These three roles contribute to movement and its control.

Primary function: power transmission.

When a muscle contracts, it pulls on its tendons. This pull is transmitted to the bone and contributes to joint movement. Several factors influence this transmission:

• The pennation angle (the angle between muscle fibers and the tendon): influences the maximum force that can be transmitted.
• Tendon length: The length of the tendon affects its stretch and its ability to store and release energy
• Tendon stiffness: The tendon’s resistance to elongation affects force transmission.

Secondary function: storage and release of elastic energy.

During activities such as running or jumping, certain tendons stretch under load and store energy. Some of this energy is then released during propulsion.

The Achilles tendon stores and then releases energy during walking and running.¹⁹ This release of energy can amplify the power of the movement and reduce the amount of energy the muscles must expend.

Sensory Function and Motor Control.

Receptors in the tendon provide the nervous system with information about tension and help regulate movement.

Golgi tendon organs are located at the junction of the muscle and the tendon. They detect changes in tension and help regulate muscle contractions. Depending on the task, their signals can decrease or increase the activity of certain muscles. This flow of information contributes, in particular, to weight-bearing and locomotion.²⁰

This sensory information helps us perceive, in particular:

• The state of muscle tension.
  
• Joint position.
  
• The speed and scope of the movement.

This information contributes to coordination. The perception of movement combines signals from skin sensors, neuromuscular spindles, stretch receptors in the muscles, and Golgi tendon organs. The exact contribution of each group remains difficult to isolate.²¹

What kinds of problems can affect tendons?

Tendons can develop painful tendinopathy, a partial tear, or a complete rupture. A partial tear affects only part of the tendon; a complete rupture severs it entirely. These problems can affect the Achilles tendon, the rotator cuff tendons—which help move and stabilize the shoulder—the patellar tendon, or the adductor tendons, which are the muscles that bring the thighs together.

Tendinopathy, tendinitis, and tissue changes

Tendinopathy involves pain in the tendon—often during physical activity—and a decrease in its function.²² The term “tendinitis” emphasizes inflammation. Tendinopathy may involve inflammation, but it can also involve several other changes in the tissue.²² Inflammatory processes may occur early on, though they are not absent from all persistent conditions.²³

• Collagen fibers may be less well organized, and the amount of certain substances between the fibers may increase.
• Cells, nerve fibers, and substances involved in inflammation can change.
• Small blood vessels may appear in the tendon. These findings do not directly measure pain.¹⁸
• In a study of 30 people with persistent Achilles tendinopathy despite treatment, researchers found no statistical link between the number of new blood vessels and pain or disability.²⁴
• A review of 16 studies followed athletes who were pain-free at the start. Abnormalities detected on ultrasound—a test that uses sound waves to visualize the tendon—were associated with a higher risk of future pain in the Achilles or patellar tendons. However, only about 27% of tendons with an abnormality became painful during follow-up. Therefore, an abnormal ultrasound image alone does not predict future pain.²⁵

The diagnosis is based on symptoms and a physical examination, taking into account the severity and progression of the condition. Imaging may be used to supplement this examination when it addresses a specific question.²⁶

Recognizing the Three Main Types of Problems

1. Tendinopathy: Pain may develop gradually or more rapidly. Morning stiffness and pain during physical activity are possible, though they are neither mandatory nor specific to this diagnosis. The demands of the activity and the tendon’s current capacity are factors in the evaluation.
2. Partial tear: Some of the fibers are torn, which can reduce strength or make certain movements difficult. This may be accompanied by sudden pain during physical activity. This symptom alone does not confirm a tear. A physical examination and, if necessary, imaging tests help determine the extent of the injury.
3. Complete rupture: the entire tendon is severed. A snapping sound or a sensation of a whiplash-like impact may occur, along with significant loss of function. Severe pain, a suspected rupture, or a sudden loss of strength following an injury requires urgent medical evaluation. A snapping sound is not necessary to seek medical attention²⁷.

Following a recent Achilles tendon rupture, a review of 29 studies reported fewer new ruptures with surgery: 2.3% versus 3.9% without surgery. Other complications, however, were more common: 4.9% versus 1.6%, primarily due to infections. In the subgroup where active ankle movements began within the first three weeks, the difference in new ruptures was not statistically significant; this does not prove that the two options are equivalent. Most studies that measured functional outcomes showed no clear difference between the options. The decision takes into account the type of rupture, your individual situation, and the rehabilitation program.²⁸

Tendons are often used in various activities:

• Achilles tendon: frequently strained during running and in many sports
• Rotator cuff : used in manual labor and overhead movements
• Patellar tendon: used during jumps and rapid changes in direction
• Hip adductors : used during acceleration, pivots, and changes of direction
• Tendons near the outside of the elbow : used in racquet sports and tasks that involve gripping or grasping an object

To learn more about specific tendinopathies, see our guides on Achilles tendinopathy and patellar tendinopathy.

Factors to consider during the evaluation:

• Recent increase in training volume or intensity
• Movement technique and task requirements.
• Strength and endurance relevant to the activities in question.
• Mobility available and mobility required by the job.
• Age, general health, and activity level.
• Relevant medications, including recent exposure to fluoroquinolones—a class of antibiotics associated with an increased risk of tendinitis and Achilles tendon rupture—with the risk appearing to be higher in older adults and when taken concurrently with cortisone²⁹.
• Other health issues that may affect the tendon or its treatment.

Why do tendons hurt?

Tendon pain can result from the interaction between the forces applied, the responses of tendon cells, and signals from the nervous system. The cells respond to the force, direction, frequency, and duration of the forces.³⁰ In tendinopathy, inflammatory substances and interactions between nerves and immune cells—the body’s defense cells—can make certain sensors more sensitive to potentially damaging stimuli.¹⁸ However, visible changes in the tissue alone do not determine the pain experienced. The history of the problem, the physical examination, and the progression of the condition provide a better understanding of your situation.

A tendon stretches slightly under load and then returns to its original shape. Its tolerance varies depending on the tendon, the rate of loading, and the condition of the tissue.³¹

What Can Change in a Painful Tendon

These changes can occur simultaneously. They do not constitute a mandatory sequence of increasingly severe stages.

1. Cells and fibers: Cells alter the production and turnover of the matrix. Fiber alignment and collagen proportions may change. These microscopic observations do not allow us to determine when the pain began.
2. Substances between the fibers: a more gel-like substance, called the mucoid ground substance, can accumulate. This observation is based primarily on tissue samples collected during surgery. It does not measure pain.^{32, 33}
3. Blood vessels and nerves: new blood vessels and sensory fibers may develop. Their presence alone is not sufficient to establish a diagnosis or to explain the severity of the symptoms.
4. The response to physical activity: excessive strain can perpetuate symptoms. Pain and functional ability may change even if certain tissue changes persist. Conversely, tissue changes may be present without persistent pain.

Situations that may affect symptoms:

• Repetitive Strain: Repeated exposure to a strenuous movement (running, hitting a ball, lifting)
• Insufficient capacity for the activity: potential discrepancy between the activity's requirements and current capacity
• Preparing for exercise: Starting gradually allows you to observe your body's response before increasing the intensity
• Recovery between exertions: the time available before the next strenuous activity
• Long Period of Inactivity: A Return to Work After Inactivity Should Be Gradual
• Aging: Age can influence tendon characteristics but does not alone determine symptoms

Genetics and tendons:

Studies have examined gene variants involved in two functions:

• collagen production;
• the renewal of the matrix surrounding the cells.

These genetic associations do not allow us to predict with certainty who will develop tendinopathy or how it will progress.³⁴ A recent review focused on tendon and ligament injuries in athletes. Of the four variants included in its meta-analysis, only one showed a statistically significant association: a variant of the VEGFA gene, which is associated with blood vessels, was linked to fewer injuries.³⁵ A meta-analysis combines the results of several studies; it does not transform this association into an individual test.

What factors influence the progression of a tendon injury?

The progression of a tendon injury depends, in particular, on the type of injury, the affected tendon, the person’s overall health, and the activities they hope to resume. After a recent injury, the healing process involves several overlapping mechanisms.³⁶ Three phases are described: inflammation, tissue formation, and remodeling, which reorganizes this tissue.³¹ These biological phases alone do not determine a recovery timeline.

Blood flow varies depending on the tendon and its location:

Vascularization—the presence of blood vessels—varies depending on the region and condition of the tendon. Tendons generally have poor vascularization. In chronic conditions, the formation of new blood vessels may accompany changes in the tissue, although their exact role has not been established.¹³ In a study of 30 individuals with treatment-resistant Achilles tendinopathy, the number of these vessels was not statistically associated with pain or disability.²⁴

Nutrients reach the tendon through several pathways:

• Blood delivers oxygen and nutrients to the cells.
• In certain tendons surrounded by a synovial sheath—a fluid-filled sac—nutrients also pass from this fluid into areas with poor blood supply. This transfer occurs by diffusion.¹³
• The presence of more blood vessels during repair does not automatically mean that the tendon heals better.

Not all studies describe the same distribution of blood vessels in the Achilles tendon. Some report a less vascularized central region; one study of 12 human specimens obtained postmortem found no clear difference along the tendon.^{14, 15} The method used and the region examined are important factors. This anatomy alone does not allow for predicting the duration of symptoms.

The three phases of healing following a recent injury:

1. Inflammation and cleaning of the area

• When a wound bleeds, a clot helps stop the bleeding and stabilize the area.
• Immune cells migrate to the area and help clear away damaged tissue.
• Signals between cells promote repair and the formation of new blood vessels.
• The level of protection and the range of motion permitted depend on the injury. A rupture requires a different treatment plan than tendinopathy without a rupture.

2. Production of new tissue

• Cells multiply and produce collagen as well as other matrix components.
• The new collagen is initially less well-organized than that of an intact tendon.
• Blood vessels help supply the necessary nutrients to the healing tissue.
• Exercises and weight-bearing follow guidelines specific to the injury and are adapted based on the observed response.

3. Reorganization and maturation of the tissue

• Collagen is renewed, its fibers reorient themselves, and new bonds form between them.
• The number of cells and blood vessels may decrease as the tissue matures.
• The repaired tissue may look different from the original tendon. Regaining functional movement does not require the tissue to look exactly the same.
• The intensity of the exercise is adjusted based on the activities to be resumed and the body’s response during and after exercise.⁹

Factors that may influence the outcome:

• Age: Age can influence recovery without determining its pace. As we age, the cells, matrix, and mechanical properties of the tendon change³⁷, and a review of healthy individuals found lower Achilles tendon stiffness in older adults than in young adults³⁸
• Severity of the injury: The type and extent of the problem influence decisions and follow-up care
• Location: The affected area may be a factor, though it alone does not determine the timeframe
• Mechanical load: The load is adjusted based on the function, symptoms, and observed response
• Nutrition: Nutritional needs should be discussed based on diet and overall health; no supplements are automatically required. A review of 19 studies reports improvements in pain or function with certain supplements, particularly those containing collagen peptides—small fragments of this protein. The supplements were often combined with exercise or other treatments. The studies remain too varied and of insufficient quality to recommend a specific formula, dose, or duration³⁹
• Smoking: Smoking affects overall health and can be addressed without promising a specific timeframe. After rotator cuff repair, smoking is associated with a higher rate of new tears and reoperations⁴⁰—a finding specific to this tendon that does not automatically apply to others
• Other conditions: Diabetes and other health issues can affect treatment. A review reports an association between diabetes and tendinopathy, with an odds ratio of 3.67. This calculation compares the ratio of affected to unaffected individuals in the diabetic group to that in the non-diabetic group. The association suggests a higher prevalence of tendinopathy in people with diabetes, though this does not directly imply that the condition is 3.67 times more common⁴¹. Diabetes is also associated with changes in tendon structure, function, and healing capacity⁴²

Why the growth rate is being reassessed:

A return to activities progresses as pain and functional capacity change. For Achilles tendinopathy, the Dutch guidelines recommend an initial program of education, activity modification, and gradual calf strengthening for at least 12 weeks.²⁶

• Most people with Achilles tendinopathy recover, but some continue to experience long-term symptoms.
• A symptom-free return to sports usually requires several months of active treatment.
• The follow-up focuses on functional movements, strength, and response to activities. These abilities can continue to improve after resuming sports.
• These guidelines do not automatically apply to a rupture or to all other tendons.²⁶

Resuming activity too quickly can worsen symptoms. If the reaction does not return to its usual level after reducing the workload, have your progress and diagnosis reevaluated.

What can physical therapy offer for a tendon problem?

Physical therapy involves adapting activities, progressive exercises, and training for the movements that the tendon must support. The physical therapist will work with you to develop a program based on the affected tendon, your abilities, and your goals. They may also discuss additional options, such as shockwave therapy or manual therapy—techniques performed by hand.

Mechanical load refers to the forces acting on the tendon. The cells respond to these forces and alter the tissue.⁹ A review of 61 studies, primarily on the Achilles and patellar tendons of healthy individuals, shows that training increases their resistance to stretching. The effects are generally more pronounced with resistance training.⁴³ However, the extent of the changes varies widely; the studies do not define a single “dose” that applies to everyone.⁴⁴ These findings on healthy tendons complement clinical trials involving individuals with pain.

A training option: heavy, slow resistance

Strength training with heavy, slow resistance combines a controlled lift and lower of the weight. For example, exercises designed for the patellar tendon include weighted knee bends and the leg press, a machine where you push a platform with your feet. The load should be challenging for the individual, without requiring everyone to use the same weight.¹

Principles to be tailored to individual cases:

• Choose an exercise that targets the tendon in question and that you can perform in a controlled manner.
• Perform both phases of the movement slowly, rather than focusing only on the downward phase.
• Adjust the weight, number of repetitions, and number of sets to suit your ability.
• Schedule your workouts based on your training plan, other activities, and recovery.
• Increase the requirements based on the observed response and the activities to be resumed.

Items to be adjusted in the program:

• The type of movement: for example, standing on your tiptoes to work your calves and Achilles tendons.
• Range of motion: Pain near where the Achilles tendon attaches to the heel may require starting on a flat surface, without letting the heel drop below the step.²⁶
• Intensity and frequency: For tendinopathy of the mid-portion of the Achilles tendon, above its attachment to the heel, the 2024 guidelines recommend a load as high as tolerated, provided there is no suspected tendon fragility. The guideline recommends at least three sessions per week; this specific frequency is based on theoretical or basic research rather than on clinical trials establishing an optimal frequency⁴⁵.
• Response to exercise: Symptoms experienced during and after exercise are used to adjust the training progression. Persistent deterioration requires a reassessment of the program and the diagnosis.

Comparison with eccentric training:
An eccentric exercise works the muscle as it lengthens, such as the calf muscle slowing the descent of the heel. Eccentric programs, programs combining ascending and descending movements, and heavy, slow resistance have shown improvements in pain and function. These comparisons do not indicate that any one program is superior in all situations.¹ For the mid-Achilles region, a review of 12 trials also found no clear difference between the types of loading.⁴⁶

In a study of six volleyball players with patellar tendinopathy, isometric contractions—maintained without joint movement—immediately reduced pain. The reduction was greater than that observed after contractions with movement and remained present at the 45-minute mark.⁴⁷ This favorable result comes from a very small group and does not establish a standard treatment for all tendons.

Extracorporeal shock waves:

Extracorporeal shock waves deliver mechanical pulses through the skin to the treatment area.

• Their effect depends on the tendon involved and the method used.
• These can be discussed if the initial exercise and activity modification program is not sufficient.
• The decision must take into account the observed benefits, possible side effects, and the person's preferences.

The results for shockwave therapy vary depending on the part of the Achilles tendon and the treatment with which it is compared. A 2022 review found a benefit from adding shockwave therapy to exercises for the middle portion of the tendon, with moderate certainty. It did not find a convincing benefit for injuries at the insertion site, near the heel.⁴⁸ A 2026 review, which focused on comparisons with sham treatment or no treatment, found no clinically significant overall benefit. For certain shockwave devices, however, favorable results were based on evidence of very low certainty. The authors therefore do not recommend routine use; this does not mean that a benefit is ruled out for every individual.⁴⁹

Whether shock wave therapy is appropriate depends on the affected tendon, the observed response, and the individual’s goals and preferences. For more information, visit our page on shock wave therapy.

Manual Therapy and Mobility

Manual therapy includes, among other things, guided joint movements and techniques targeting the muscles. For tendinopathy of the mid-portion of the Achilles tendon, the 2024 guidelines suggest considering this approach when limited mobility interferes with daily activities. This recommendation is based primarily on expert opinion, as comparative studies remain limited⁴⁵.

• Check whether a restriction of movement interferes with a useful action, such as climbing a step.
• Choose a technique and exercises that are appropriate for this limitation.
• Reevaluate comfort and technique after the procedure to determine its place in the program.

Joint mobilization techniques are guided movements that a physical therapist performs on a joint. They can complement exercises when they serve a specific purpose; they are not necessary in all cases.

Monitoring Guidelines for Achilles Tendinopathy

• Pain and Function: For Achilles tendinopathy, the VISA-A questionnaire can be used to monitor pain, daily function, and sports activities. A review reports sufficient reliability, meaning that the results are fairly reproducible. Its favorable conclusion regarding the detection of changes applies primarily to injuries at the insertion site following non-surgical treatment⁵⁰, whereas a study of its Danish version, involving 318 symptomatic individuals and 120 healthy individuals, criticizes its use as a standalone score⁵¹. It is therefore best to interpret it in conjunction with other measures of pain, function, and participation
• Participation: A return to the individual’s chosen activities or sports is another key indicator for follow-up
• Repeated imaging: For Achilles tendinopathy, a guideline recommends against using repeated imaging to predict the course of the condition or to monitor response to treatment²⁶. To monitor response to treatment, the key indicators remain pain, function, and participation
• Perceived recovery: A person’s reported sense of progress complements measures of pain, function, and participation

Movement training based on specific goals:

Assess the movements and skills needed for the activities:

• Running technique or athletic movement to be observed in a real-world setting.
  
• Strength or endurance, depending on the demands of the activity.
  
• Coordination that can be improved if it hinders a useful task.
  
• Mobility should be considered only if it is relevant to the activity to be resumed.

Video analysis and observation of relevant movements can help in formulating hypotheses, which must be tested in tasks and reevaluated.

Progress and Reassessment Points:

Individualized Progress Milestones:

• Starting the program: Choose a manageable load and observe the tendon's response
  
• Progression: Gradually increase the load or complexity as long as the response remains acceptable
  
• Returning to Activities: Gradually reintroduce work- or sports-specific movements based on your tolerance
  
• Maintenance: Maintain a workload appropriate for the intended activities and adjust as needed if symptoms or requirements change

Key points: Recovery progresses based on the physical demands of the sport and your response to previous stages; there is no one-size-fits-all minimum timeframe. See also our guide on returning to sports after an injury.

How to care for your tendons daily?

Regular exercise, gradually increasing the intensity of your workouts, and adequate recovery help prepare your tendons for daily activities. The program takes into account your sport, your work, and your overall health. The following guidelines are intended to help you adjust the intensity of your workouts; they do not guarantee that you will not get injured.²⁶

Gradual progression:

A rapid increase in load may exceed the tendon's current tolerance. The progression is adjusted based on symptoms, function, and the target activities.

• Change one setting at a time and observe the reaction during the activity and afterward.
  
• Example: If the distance increases, keep other changes minimal and reassess based on the tolerance
  
• Consider the distance, intensity, frequency, and total workload together

Periods of Reduced Activity:
If symptoms increase significantly and do not return to their usual level after reducing the workload, temporarily reduce your activity and have the program reevaluated.

Gradual preparation for exercise:

Four guidelines can help you prepare based on the activity and your reaction:

1. An easy start refers to a less demanding version of the planned activity.

2. The range of motion, speed, or load can be adjusted one at a time based on the observed response.

3. Preparatory movements resemble the actions of the planned activity and remain under control.

4. A new, distinct pain or difficulty controlling a movement indicates that the exercise should be modified or stopped.

Two other key points relate to aligning with the intended movement and controlling the movement:

1. Activity-specific warm-ups gradually bring your movements in line with the expected speed and intensity.
2. A gentle, controlled movement serves as a guide before increasing the effort.

The chosen treatment should be appropriate for the upcoming procedures without significantly worsening the symptoms.

Recovery between workouts:

After a demanding test, the next load is selected based on the observed response:

• Alternate, as needed, between demanding tasks and activities that are easier to handle.
  
• Adjust the intensity of the exercises based on the tendon's response.
  
• Sleep: Make sure to get enough rest to support overall health and recovery between activities.
  
• Nutrition: Aim for a sufficient and varied diet that is tailored to your health and activities.

Strengthening tailored to specific activities:

To help you structure this program, you can check out our muscle-strengthening and endurance exercises.

Strength training can prepare you for the demands of a physical activity by:

• increasing the ability to generate and control force;
  
• developing task-relevant coordination;
  
• moving toward high-impact activities if required by sports or work.

Settings to customize:

• The frequency depends on the program, other activities, and recovery.
  
• The selected muscle groups correspond to the tasks to be performed.
  
• Choose the type of contraction based on the activity, the tendon involved, and your tolerance
  
• The load is increased after reassessing tolerance and function.

Knowing when to request an evaluation:

An evaluation may be helpful if:

• The pain is still limiting the activities that matter to you;
  
• stiffness or function deteriorates significantly;
  
• symptoms worsen despite a reasonable reduction in workload;
  
• daily activities, work, or sports remain limited;
  
• An injury is accompanied by a sudden loss of strength or function, which requires urgent medical evaluation.

A medical consultation can help pinpoint the problem and tailor treatment. See a doctor right away if the pain is very severe or if you think you’ve torn a tendon, even if you didn’t hear a snap²⁷.

General Health and Related Habits:

• Smoking: Can be addressed for the sake of overall health and in accordance with the individual's priorities
• Consider your overall workload: activities, work, sports, and recent changes can all play a role
• Consider the context: stress and sleep may be discussed if they affect activities or perceived recovery
• Regular physical activity: Appropriate, regular physical activity supports overall health, though it does not guarantee the absence of injury

What should you remember about tendons?

Tendons transmit muscle force, store energy during certain movements, and provide sensory information. When a tendon becomes painful, the course of the condition varies depending on the affected tendon, the nature of the injury, the load placed on it, the person’s overall health, and the specific activities involved.

Rehabilitation—the program that helps patients regain functional abilities—often relies on progressive exercises and adjustments to daily activities. The physical therapist monitors pain levels, movement, and participation in activities, and then adjusts the exercises and complementary treatments accordingly.

For tendinopathy of the mid-portion of the Achilles tendon, above its attachment to the heel, the 2018 and 2024 guidelines recommend continuing recreational activities within the limits of pain tolerance, rather than imposing complete rest.⁵²⁴⁵ A review of 29 trials also suggests that active treatments improve symptoms more than watchful waiting alone at three months. The certainty of this finding remains low to very low, and no treatment class clearly stands out from the others.⁵³ These recommendations do not automatically apply to a rupture or to all other tendon problems.

If tendon pain is limiting your activities, a physical therapist can assess your situation, discuss your options, and work with you to develop a personalized recovery plan.

References

1. Malliaras P, Barton CJ, Reeves ND, Langberg H. Achilles and patellar tendinopathy loading programs: a systematic review comparing clinical outcomes and identifying potential mechanisms for effectiveness. Sports Med. 2013;43(4):267-86. ↩ Back to text: 1st, 2nd, 3rd citations
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