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  • Dr. Allison Andre, DPT

Demystifying Pulley Injuries in Rock Climbers

Rock climbing, with its blend of physical exertion, mental focus, and connection with nature, has captured the hearts of many adventure enthusiasts. However, along with the thrill comes the inherent risk of pulley injuries. As a climber, you may have already experienced or witnessed the impact of these injuries on performance and enjoyment of the sport.

As an authority in the field, I bring a unique perspective to this topic. I am not only a Doctor of Physical Therapy, well-versed in the intricacies of musculoskeletal health, but I am also an avid rock climber myself. Through personal experience and professional expertise, I have gained insights into the challenges faced by climbers and the measures necessary for a safe and successful climbing journey.

Today I want to dive into the basics of pulley injuries, exploring their causes, symptoms, and classification. By gaining a deeper understanding of the mechanics behind these injuries, climbers can make informed decisions and take necessary precautions to protect their hands while pursuing their passion.

female rock climber

Stay tuned for Part 2, where we will dive into a curated selection of exercises and rehabilitation techniques specifically designed to aid in the recovery and prevention of pulley injuries so we can climb stronger, safer and with greater resilience. In the world of rock climbing, knowledge and preparation are our most reliable companions. Let's take the first step towards understanding pulley injuries and nurturing our climbing potential to the fullest.

Function of Finger and Hand Pulleys in Rock Climbing

Pulley injuries have become increasingly prevalent among rock climbers, posing significant challenges to climbers’ performance and overall hand health. In fact, studies have reported pulley injuries accounting for 17% to 30% of all climbing related injuries.

Understanding the function of finger and hand pulleys is essential to shed light on their vital functions while emphasizing why we should care about this topic. By appreciating the role of pulleys, climbers can better understand the biomechanics behind injuries and take proactive steps towards injury prevention, rehabilitation, and long-term hand health.


The pulleys provide stability and support to the flexor tendons, helping to keep them close to the bones during finger flexion and extension movements. This stability is crucial for maintaining proper finger alignment and preventing bowstringing of the tendons.

Force Transmission

Facilitate the transfer of forces generated by the flexor tendons to the bones, allowing for efficient gripping and pulling actions during climbing. They help optimize the transmission of force from the muscles in the forearm to the fingers, enhancing grip strength.

Tendon Retention

Act as "sheaths" that hold the flexor tendons in place, preventing them from shifting or dislocating during finger movements. They help maintain the integrity and alignment of the tendons, reducing the risk of injury and ensuring smooth tendon gliding.

Grip Control

Play a vital role in controlling finger flexion and extension, allowing climbers to modulate their grip strength and adjust finger positions on holds. They enable climbers to maintain precise control and dexterity during climbing movements, aiding in balance and technique.

Injury Prevention

Help distribute forces evenly across the finger joints, reducing stress concentrations that could lead to injuries such as tendon strains, sprains, or ruptures. They play a crucial role in minimizing the risk of overloading the tendons and structures within the fingers.

Anatomy of the Hand

To fully appreciate how the pulleys are subject to injury, it’s extremely helpful to understand the anatomy of the hand. The hand is a remarkable and complex structure comprising of intricate networks of bones, joints, tendons, and ligaments that work harmoniously to enable a wide range of movements. The complex arrangement of these bones and joints allows for remarkable range of motion and dexterity of the human hand.

hand anatomy detailing all the structures

The hand consists of 27 bones. These bones include:

  • 8 carpal bones in the wrist

  • 5 metacarpal bones in the palm

  • 14 phalanges in the fingers

There are a total of 29 joints including:

  • Carpometacarpal joints Metacarpophalangeal (MP) joints

  • Proximal interphalangeal joints (PIP)

  • Distal interphalangeal joints (DIP)

Anatomy of the Flexor Tendons

Flexor tendons are robust, rope-like structures that play a vital role in finger flexion and grip strength during climbing. Originating from the muscles in the forearm, these tendons extend down the arm and pass through the palm before reaching the fingers. They are responsible for transmitting the force generated by the forearm muscles to the fingers, allowing for powerful gripping actions and precise finger movements.

The flexor tendons are organized in a layered arrangement within the fingers.

  • The deeper layer consists of the flexor digitorum profundus tendons (FDP).

  • The more superficial layer includes the flexor digitorum superficialis tendons (FDS).

  • These tendons run alongside each other and are encased in a protective pulley system.

During climbing, the flexor tendons play a crucial role in facilitating grip strength and finger flexion. As climbers grasp onto holds and pull themselves up, the flexor tendons transmit the forces generated by the muscles in the forearm, allowing for a secure grip. This grip strength is essential for maintaining control, balance, and stability while navigating various climbing routes and challenges.

The Annular Pulleys

The annular pulleys are a series of fibrous bands that encircle the flexor tendons, acting as supportive structures to maintain their close proximity to the bones. There are four primary annular pulleys, numbered from A1 to A5, each serving a specific role. The A2 and A4 are the major pulleys of the system (inserting directly to the bone) and are most prone to injury. The A1, A3, and A5 pulleys are more flexible and attach to the volar plate, a ligament that connects two phalanges together. Also, research has suggested the second Annular Pully (A2) is the strongest pulley followed by A1 and A4.

anatomical diagram of the annular pulleys


The A1 pulley is the most superficial of the annular pulleys and is positioned near the base of the finger. This pulley serves as a vital anchor point for the flexor tendons, preventing them from migrating excessively away from the bones during finger flexion and extension movements. As the fingers flex or extend, the A1 pulley acts as a supportive band, holding the tendons lose to the bones and preventing them from bowstringing or veering off course. The A1 pulley's location near the base of the finger makes it particularly susceptible to stress and injury, especially in activities that involve repetitive gripping or forceful finger movements.


The A2 pulley is located at the middle phalanx level of the finger and holds significant importance within the pulley system. In the context of rock climbing, it is one of the most injured pulleys due to the high stress and strain placed on it during gripping motions. Due to its location and the high forces and demands placed on it during climbing, the A2 pulley is prone to injury. Overuse, repetitive stress, or sudden excessive loading can lead to strain or partial tears of the A2 pulley, which are commonly referred to as "pulley injuries" in climbing.


The A3 pulley is located near the fingertip and serves an important function within the pulley system of the fingers. One of the key functions of the A3 pulley is to provide additional support to the flexor tendons as they approach the fingertip. It reinforces the attachment of the tendons to the bone, helping to anchor them firmly in place and prevent excessive movement or displacement during finger flexion and extension. While not as prone to injury as the A2 pulley, the A3 pulley can still be subjected to stress and strain, especially during intense climbing activities. The repetitive loading and dynamic movements involved in climbing can place considerable demands on the A3 pulley, potentially leading to overuse injuries or damage if proper precautions are not taken.


The A4 pulley, situated at the level of the distal interphalangeal joint (DIP joint), is the deepest pulley within the finger's pulley system. Although often overlooked, the A4 pulley plays a critical role in providing essential support and stability, especially during full finger flexion. As the deepest pulley, the A4 pulley acts as a strong fibrous band that reinforces the attachment of the flexor tendons to the bone near the fingertip. It functions to secure the tendons in place and maintain their alignment, particularly when the fingers are fully flexed. During climbing movements that require deep finger flexion, such as gripping onto small holds or crimps, the A4 pulley is subjected to significant tension and loading. It helps distribute the forces generated by the muscles in the forearm across the finger joints, preventing excessive strain on individual structures and promoting overall finger stability.


The A5 pulley lies in the region of the distal interphalangeal joints (DIP joint) and is the final pulley. The A5 pulley is flexible and attaches to the volar plate, a ligament that connects two phalanges together. It is less prone to injury compared to the other pulleys in the region.

Rock Climbing Grips and Injury Potential

In rock climbing, mastering various gripping techniques is essential for success on the wall. Different climbing grips, such as the full crimp, half crimp, and open hand, place distinct loads and stressors on the finger joints and pulleys.

In rock climbing, the A2-pulley is regularly exposed to forces up to 380 Newtons (and higher in a foot slip, for example). As a reference point, 10 Newtons is equivalent to about 1 kilogram (climbers habitually load a single finger ligament with loads around 40kg).

Let’s explore different gripping techniques in detail, examining their mechanics, applications, and the potential impact on the finger joints and pulley structures. By understanding how these grips interact with the hand anatomy, climbers can make informed decisions to optimize their climbing technique, minimize the risk of injuries, and promote long-term hand health.

Full Crimp Grip
Full Crimp Grip


The full crimp grip is a powerful grip technique used in rock climbing that involves curling the fingers tightly with the thumb pressed against the fingertips.

The MCP-joints are in 60° flexion, PIP-joints in 90° flexion and the DIP-joints are maximally hyper-extended.

This grip maximizes finger strength and provides excellent control, making it particularly useful for small holds and steep terrain.

The full crimp grip places significant stress on the finger joints, particularly the proximal interphalangeal (PIP) joint, and can exert substantial loads on the pulley system with forces on the A2 pulley up to 36 times of that of an open hand.

Half Crimp Grip
Half Crimp Grip


The half crimp grip is a modified version of the full crimp grip, where the thumb is relaxed and positioned alongside the fingers instead of pressing against them.

The MCP-joints are slightly flexed, the PIP-joints are in 90° of flexion and the DIP-joints are straight or slightly hyper-extended.

This grip offers a balance between strength and finger joint comfort, making it a popular choice for climbers.

While the half crimp grip reduces the stress on the PIP joint compared to the full crimp, it still places considerable demand on the finger flexor tendons and pulleys, especially A2 and A4.

Open Hand Grip
Open Hand Grip


The open hand grip involves maintaining an open hand position with the fingers slightly bent and the thumb relaxed.

The MCP and the PIP joints are fully extended and only the DIP joints are flexed). This grip distributes forces more evenly across the fingers, reducing the stress on the finger joints and pulleys compared to the full and half crimp grips.

The open hand grip provides greater joint comfort and allows for better blood flow, making it a preferred grip for sustained climbing and endurance.

Prevalence of Pulley Injuries

Pulley injuries are a common occurrence in rock climbing, with the A2 and A4 pulleys being the most commonly injured. Understanding the prevalence of pulley injuries in climbers can shed light on the significance of these injuries within the climbing community.

Research studies have provided valuable insights into the statistics of pulley injuries among climbers. In a study examining climbing-related injuries, it was found that three out of the four most frequent injuries were related to the fingers.

Pulley injuries accounted for approximately 20% of the reported injuries, indicating their significant prevalence in the climbing population. Tendovaginitis (inflammation of the tendon sheaths) accounted for 7% of the injuries, while joint capsular damage made up 6.1%.

To further understand the severity of pulley injuries, the pulley-injury score can be examined. This scoring system categorizes pulley injuries into four grades based on their severity. According to available data:

  • 39% of the reported pulley injuries were classified as grade 1, indicating mild damage to the pulley.

  • Grade 2 injuries accounted for 25% of the cases, representing moderate damage.

  • Grade 3 injuries were reported in approximately 30% of the cases, signifying substantial injury to the pulley.

  • The most severe cases, grade 4 injuries, made up 6% of the reported cases.

These statistics highlight the prominence of pulley injuries among rock climbers. The high percentage of pulley injuries, particularly in the fingers, underscores the importance of understanding and addressing these specific injuries within the climbing community. By recognizing the prevalence of pulley injuries, climbers can prioritize preventive measures, seek appropriate treatment, and implement effective rehabilitation strategies to promote long-term finger and pulley health.

Types of Pulley Injuries

Pulley injuries can range in type and severity depending on various factors. Understanding the different types of pulley injuries is essential for climbers to recognize symptoms, seek appropriate treatment, and implement proper rehabilitation strategies. Let's explore the various types and severity levels of pulley injuries commonly encountered in rock climbing.

1. Pulley Sprains

Sprains are the most common type of pulley injury in climbing. They occur when the pulley is stretched or partially torn due to excessive force or strain on the finger during climbing movements. They can range from mild to moderate, with symptoms including pain, swelling, and decreased finger strength and range of motion. These injuries typically require a period of rest and rehabilitation to allow the pulley to heal.

2. Pulley Tears

Tears can be partial or complete. This occurs when the pulley is fully ruptured, resulting in significant pain, swelling, and immediate loss of finger strength and function. They require medical attention, and depending on the severity, may necessitate surgical intervention to repair the torn pulley. Rehabilitation following a pulley tear is a critical step in the recovery process to restore finger strength and functionality.

3. Partial Tears

Partial tears refer to injuries in which the pulley structure sustains damage but remains partially intact. These injuries can vary in severity, with some partial tears involving minor fraying or stretching of the pulley fibers, while others may involve significant disruption or tearing. Symptoms of a partial tear can include localized pain, tenderness, swelling, and a decrease in grip strength. Climbers may also experience a popping or snapping sensation at the time of injury. Partial tears are typically classified as lower-grade injuries and may require conservative treatment approaches such as rest, splinting, and gradual rehabilitation exercises to promote healing and strengthen the affected pulley.

A2-Partial Tear and Complete Tear picture

4. Complete Tear

Complete ruptures (or tears) involve a full or near-complete tear of the pulley structure, resulting in a significant loss of integrity and function. Complete ruptures often cause more severe pain, swelling, and functional impairment compared to partial tears. Climbers may experience difficulty flexing or extending the affected finger, and in some cases, the injured finger may appear deformed or deviated from its normal position. Complete ruptures are typically classified as higher-grade injuries and may necessitate more aggressive treatment options, including surgical intervention to repair or reconstruct the damaged pulley.

3. Pulley Avulsion

An avulsion occurs when the pulley is forcibly detached from its attachment site on the bone, often resulting in a piece of bone being pulled away along with the pulley. This type of injury typically requires surgical intervention to reattach the pulley and bone fragment. The rehabilitation process following a pulley avulsion is extensive and involves a gradual progression of finger strengthening exercises.

Determining the grade of a pulley injury is a crucial step in assessing its severity and guiding appropriate treatment and rehabilitation strategies. Grading systems provide a standardized framework for categorizing pulley injuries based on their extent and impact on the finger and hand structures.

Pulley Injury Grades

Determining the grade of a pulley injury is a crucial step in assessing its severity and guiding appropriate treatment and rehabilitation strategies. Grading systems provide a standardized framework for categorizing pulley injuries based on their extent and impact on the finger and hand structures.

Grade 1

Pulley Sprain

Grade 2

Complete rupture of A4 - OR - partial rupture of A2 or A3

Grade 3

Complete rupture of A2 or A3

Grade 4

Multiple ruptures (as A2/A3, A2/A3/A4)OR single rupture (as A2 or A3) combined with lumbricalis muscle or collateral ligament trauma.

By assigning a specific grade to an injury, healthcare professionals and climbers alike can better understand the injury's implications and tailor the rehabilitation approach accordingly. The grading system takes into account factors such as the degree of tear, stability, and functional impairment. This information enables healthcare providers to develop a targeted plan that promotes optimal healing, restores strength and mobility, and minimizes the risk of reinjury.

Types of pulley injuries

Differentiating Between Acute and Chronic Injuries


Acute pulley injuries are typically the result of a single traumatic event or sudden overload placed on the pulley system. These injuries often occur during dynamic movements, such as forcefully grabbing a hold or making a quick and powerful move. They can range in severity from mild strains to complete tears, and they are characterized by immediate pain, swelling, and functional impairment. Climbers may recall a specific incident or movement that caused the injury. Prompt recognition and proper management of acute pulley injuries are crucial to prevent further damage and promote optimal healing.


On the other hand, chronic pulley injuries develop over time due to repetitive stress and strain on the pulley system. These injuries are often the result of prolonged climbing activities, improper technique, or inadequate rest and recovery. Chronic pulley injuries can manifest as gradual onset pain, discomfort, or weakness in the fingers, typically worsening with climbing and improving with rest. Climbers may not recall a specific event that caused the injury, as it develops gradually over weeks or months of climbing. It is important to address chronic pulley injuries early on to prevent progression and potential complications.


Differentiating between acute and chronic pulley injuries is essential for proper diagnosis and management. Acute injuries typically require immediate attention, including rest, ice, compression, and elevation (RICE), as well as medical evaluation to determine the extent of the injury. In some cases, more severe acute injuries may necessitate medical intervention, such as splinting or surgery, for proper healing. Chronic injuries, on the other hand, often benefit from a combination of rest, targeted rehabilitation exercises, and modifications in climbing technique or volume to alleviate strain on the pulleys and promote tissue healing.

Signs and Symptoms of a Pulley Injury

Signs and symptoms of a pulley injury can provide important clues for climbers to recognize and address potential issues. It's crucial to pay attention to any discomfort or changes in the finger region during and after climbing activities as prompt recognition and appropriate management is essential for preventing further damage while promoting recovery. The following are common indicators that may suggest a pulley injury:

1. Localized Pain: The most noticeable symptom of a pulley injury is localized pain in the finger, particularly around the injured pulley. The pain may be experienced during gripping, bending, or applying pressure to the finger. It can range from mild to severe, depending on the extent of the injury.

2. Swelling and Inflammation: Pulley injuries can cause swelling and inflammation in the affected area. The finger may appear swollen, and there might be visible redness or warmth around the injured pulley. Swelling can impede normal finger movement and contribute to discomfort.

3. Tenderness and Sensitivity: The injured pulley may be tender to touch, causing increased sensitivity in the affected area. Even gentle pressure or slight movement of the finger may elicit pain or discomfort.

4. Popping or Snapping Sensation: Some climbers may recall a popping or snapping sensation at the time of injury. This sensation could indicate a partial or complete rupture of the pulley. If this occurs, it is important to seek medical attention promptly.

5. Limited Range of Motion: A pulley injury can affect the finger's range of motion. Climbers may experience difficulty fully flexing or extending the finger. The injured finger may feel stiff or restricted in movement, impacting grip strength and overall hand dexterity.

6. Weakness in Grip Strength: Pulley injuries can lead to a noticeable decrease in grip strength. Climbers may struggle to maintain their usual grip intensity or feel weaker when holding onto climbing holds. This weakness can impact performance and climbing abilities.

7. Lump or Deformity: In some cases, a pulley injury may result in the formation of a lump or noticeable deformity near the injured pulley. This can be a result of tendon displacement or swelling. It is important to have any unusual lumps or deformities examined by a healthcare professional.

Diagnosing and Managing Pulley Injuries

When faced with a suspected pulley injury, it is essential to promptly recognize the signs and symptoms and take appropriate measures for initial treatment and management. Recognizing the injury early on and seeking medical attention can significantly impact the recovery process and minimize the potential for complications.

Common diagnostic criteria for pulley injuries include the presence of localized pain, swelling, tenderness along the affected finger, and functional limitations. In some cases, bowstringing of the flexor tendons may be observed, where the tendons become displaced from their normal anatomical position.

Medical professionals may employ various diagnostic imaging techniques such as magnetic resonance imaging (MRI), ultrasounds or X-rays to assess the extent of the injury, evaluate the condition of the pulleys and surrounding structures, and rule out other potential injuries such as fractures. Seeking medical attention and obtaining a proper diagnosis are crucial steps in developing an effective treatment plan and ensuring optimal recovery for pulley injuries in rock climbing.

The study conducted by Schöffl et al. in 2003 offers valuable insights into the occurrence of pulley injuries in rock climbers and emphasizes the significance of employing diagnostic criteria in conjunction with imaging techniques such as MRI, X-ray, and ultrasound for accurate diagnoses. As part of their research, the authors developed a diagnostic decision tree to aid in the identification of pulley injuries. This decision tree serves as a useful tool for clinicians and climbers alike, providing a systematic approach to diagnosing pulley injuries and facilitating appropriate treatment planning based on the severity and location of the injury, which can help guide rehabilitation strategies.

Flow chart of diagnostic criteria for pulley injuries

Pulley injuries are not to be taken lightly. As climbers, it is crucial to recognize the signs and symptoms of these injuries and to approach them with the seriousness they deserve. By being aware of the risk factors and understanding the mechanisms behind these injuries, we can make informed decisions to protect our hands and mitigate the chances of succumbing to pulley-related issues.

However, education is just the first step. In Part 2 of this series, we will delve into practical exercises and rehabilitation techniques specifically designed to aid in the recovery and prevention of pulley injuries. By incorporating these exercises into our training routines, we can strengthen our pulleys, improve overall hand health, and build resilience against future injuries.

Remember, the journey to becoming a stronger and safer climber is a continuous one. It requires a proactive approach to hand care, proper warm-ups, and ongoing vigilance in maintaining good climbing technique. By investing in our own well-being and taking the necessary precautions, we can continue to enjoy the thrill of climbing while minimizing the risk of pulley injuries.

Stay tuned for the next installment of this series, where we will explore practical exercises and rehabilitation techniques to support your hand health and keep you climbing stronger than ever. We will equip ourselves with a repertoire of exercises and strategies to foster healthy, robust pulleys that will propel us toward greater climbing achievements. Together, we can create a culture of injury prevention and empower climbers to pursue their passion with confidence and longevity.

Happy climbing, and remember to take care of those pulleys!


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