medial epicondylosis anatomy

Medial epicondylosis: your console triggers may cause elbow pain

Medial epicondylosis is a tendon injury more commonly known as “golfer’s elbow.” However, with increased prevalence in gamers, this injury may end up earning a new name related to gaming similar to gamer’s thumb, mouse elbow, and mouse shoulder.

What is medial epicondylosis?

Medial epicondylosis is an overuse strain that occurs in the flexor tendons of the wrist and fingers that attach to the inside (pinky side) of the elbow. The muscles involved are the flexor muscles that close the hand and flex down the wrist.

This injury tends to be more common in console gamers. It would not be surprising if this condition earned a gamer name—perhaps along the lines of “trigger elbow” or “console elbow.”

Due to misuse and imbalance, the fiber orientation of the flexor tendons on the inside of the elbow become disrupted. This dysfunction is called a tendinosis, which is different than tendinitis—a common misnomer for this condition. We’ll discuss this difference in more detail below.

Pertinent anatomy

It’s important to know some basic anatomy of the wrist and elbow to understand medial epicondylosis.

To begin, the tendons affected in medial epicondylosis are sometimes collectively called the common flexor tendon. This tendon is made up of 5 individual muscles that converge in one spot—a projection on the inside of the humerus (arm bone) called the medial epicondyle:

  • Pronator teres: pronation (rotating downward) of your forearm
  • Flexor carpi radialis: flexion and radial deviation of your wrist
  • Palmaris longus: this muscle, if present, aids in flexor of your wrist
    • ~15% of the population will not have this muscle
  • Flexor carpi ulnaris: flexion and ulnar deviation of your wrist
  • Flexor digitorum superficialis: flexion of your fingers, not including your fingertips
muscles that make up the common flexor tendon
On their distal ends (further away from the body), each of these muscles attach to different parts of the hands or fingers, but the tendinosis occurs in the attachment at the elbow.

On their distal ends (further away from the body), each of these muscles attach to different parts of the hands or fingers, but the tendinosis occurs in the attachment at the elbow.


This injury is a tendinosis! It is NOT inflammatory in nature, and the term tendonitis is not appropriate! This is critical to determine the appropriate prevention & rehabilitation.

Medial epicondylosis occurs when there is at least one of two imbalances in muscle contraction. If one or both of these imbalances occur over time, degeneration of collagen (the protein found in connective tissue) occurs. This leads to the disruption of the tendon fiber orientation in the common flexor tendon.

The strong fibers of a tendon should line up parallel with one another. In tendinosis, these fibers will become jumbled or disorganized—commonly described as adhesion formation—causing pain and affecting the movement of the tendon and the elbow joint.

Medial epicondylosis in gamers
The fibers of the common extensor tendon become jumbled or disorganized
  • Concentric vs. eccentric imbalance
    • Concentric: the shortening phase of a muscle contraction
      • Console gaming: gripping the controller and pressing triggers & bumpers; thumb stick movement will not contribute
      • Weight lifting example: the up-phase of a biceps curl (raising the dumbbell up to your shoulder)
    • Eccentric: the lengthening phase of a muscle contraction
      • In gaming, there is no instance of an eccentric contraction, and this is the problem!
      • Weight lifting example: the down-phase of a biceps curl (controlled lowering of a dumbbell back to your hip)
  • Agonist vs. antagonist imbalance
    • Agonist: the active muscle during a particular movement
      • Console gaming: flexing the fingers to grip the controller and press triggers & buttons
    • Antagonist: the muscle that opposes the agonist; this muscle (or group of muscles) will be relaxed during agonist contraction
      • Console gaming: the antagonist muscles are the extensor muscles of the wrist and hand (i.e., opening the hand); these muscles are not challenged with any significant resistance during console gaming
eccentric contraction of the biceps muscle
A sample of eccentric contraction of the biceps muscle, lowering the arm

For PC gamers, these imbalances are not common. These imbalances in PC gaming are more likely to lead to mouse elbow.

Concentric vs. eccentric imbalance

When concentric contractions occur too frequently without the counterbalance of eccentric contraction, collagen begins to degenerate from the chronic shortening. Eccentric contraction—the lengthening of a muscle & tendon under tension—helps maintain the tendon fiber orientation.

Eccentric contraction protects tendons from overuse injury!

Agonist vs. antagonist imbalance

When agonist muscle actions occur too frequently without the counterbalance of their antagonist, there is imbalance in the strength and tension on the joints involved. When strength and tension are not balanced, the muscles can be overworked and injury becomes more common.

Signs & symptoms

If you’re affected by mouse elbow, you’re likely to experience the following symptoms:

  • Pain
    • Most often, you will experience pain at the inner portion of your elbow with wrist movements and gripping
    • Flexing your wrist and fingers (closing your hand) will likely cause pain by contracting the flexor muscles
    • Extending your wrist and fingers backwards may cause pain by stretching the flexor muscles
  • Weakness
    • Gripping may feel weak; however, your perceived weakness is more likely due to pain rather than true muscle weakness
pain on the inner portion of the elbow
The most common symptom of medial epicondylosis is pain on the inner portion of the elbow

Other common findings may include:

  • More pronounced symptoms with flexion of your wrist(s) & fingers (i.e., gripping the console controller)
  • Worsening symptoms following periods of rest
  • Relief or improvement of symptoms after warming up the flexor muscles

Note: Medial epicondylosis is considered an overuse tendinosis, and inflammation will not be present. Inflammation is categorized by pain with accompanying swelling, redness, and heat (feeling warm to the touch).

If you notice these signs of inflammation, you are experiencing something different than simple flexor tendinosis. You should consult your doctor if you are concerned about these symptoms.

Common mechanism(s) of injury

For gamers, medial epicondylosis is more common for console gamers due to the position and action of the hands using a controller. Common risks for console gamers include:

  • Poor hand position
    • Excessive flexion of your wrists while gripping the controller will create over-activation and shortening of the common flexor muscles & tendons
  • Lack of eccentric contraction
    • As described in Pathophysiology above, the actions performed in gaming do not include eccentric contraction, or lengthening of the flexor muscles
    • The imbalance of muscle shortening without lengthening under tension leads to tendon fiber disruption
  • Lack of antagonist muscle contraction
    • Also described in Pathophysiology above, gripping the controller and pressing triggers & bumpers is a stronger muscle action; taking the fingers off the triggers & bumpers is not a forceful action
    • The lack of forceful extensor muscle contraction allows for over-activity of the flexor muscles, perpetuating the shortening and fiber disruption of the tendons at the elbow
console gamer
This condition is more common for console gamers due to gripping the controller and pressing triggers & bumpers


The most common mechanisms of injury for medial epicondylosis are imbalances. Therefore, balancing muscle contraction and activation is a simple, yet extremely effective preventative measure.

For all common gamer injuries including medial epicondylosis, we’ve created a comprehensive injury prevention program. Performing this exercise routine may help reduce your risk.

Concentric vs. eccentric muscle contraction

The lengthening phase of muscle contraction is the most important! For console gamers, perform resisted flexion exercises and stretches of the wrist and fingers and control the eccentric phase.

It is absolutely essential to perform the eccentric, or “down-phase” portion of these exercises slowly and under control!

On our injury prevention video, these exercises and stretches are:

Weighted wrist curl

Weighted wrist curl
  1. Lay your forearm down on a flat surface with your palm facing upward
  2. Grab a dumbbell or other small, weighted object, and let your wrist hang over the edge
  3. Curl the dumbbell upward, and return to the low, hanging position
  4. Repeat steps 2 and 3 for a total of fifteen (15) repetitions

Post-facilitation stretch, wrist flexors

Post-facilitation stretch, wrist flexors
  1. Extend your wrists as far as you can, and place them on the ground.
  2. For 10 seconds, press your hands into the ground as hard as you can.
  3. After 10 seconds, try to lift your hands and fingers off the ground.
  4. At the same time, lean forward to stretch the flexor muscles of your forearms.
  5. Repeat steps 1-4 for a total of three (3) sets.

Agonist vs. antagonist muscle activity

Balancing the muscle activity at any joint will help keep muscles healthy. For console gamers, flexion of the wrist & fingers is the strenuous action; therefore, it is important to perform extension exercises and stretches for the wrists and fingers for balance.

On our injury prevention video, these exercises and stretches are:

Resisted finger extension

Resisted finger extension
  1. Set up the finger band around the tips of your fingers, including your thumb
  2. Begin with your finger pads together. Then, open your hand as wide as you can
  3. SLOWLY, and under control, return to the starting position
  4. Repeat steps 2-3 for a total of fifteen (15) repetitions

Weighted wrist flexion

Weighted wrist flexion
  1. Lay your forearm down on a flat surface with your palm facing downward
  2. Grab a dumbbell or other small, weighted object, and let your wrist hang over the edge
    Extend the dumbbell upward
  3. SLOWLY, and under control, return to the low, hanging position
  4. Repeat steps 2-3 for a total of fifteen (15) repetitions

Post-facilitation stretch, wrist extensors

Post-facilitation stretch, wrist extensors
  1. Flex your wrists as far as you can, and place them on the ground
  2. For 10 seconds, press your hands into the ground as hard as you can
  3. After 10 seconds, try to lift your hands and fingers off the ground
  4. At the same time, lean backwards to stretch the extensor muscles of your forearms
  5. Repeat steps 1-4 for a total of three (3) sets

In addition to these medial epicondylosis-specific preventative measures:


To effectively resolve medial epicondylosis, it is important to first identify and correct the initial cause. For example, if you’re not performing the eccentric action of the flexor muscles or exercising the extensor muscles, protocols may be ineffective because of the constant exacerbation.

In practice, rehabilitation protocols for tendinosis injuries are well-researched and highly effective. Treatment is described as a three step process.

Step 1: aggressive cross-friction massage

aggressive cross-friction massage

The provider should use a firm surface (thumb pressure or a knuckle, for example) to apply moderate pressure to the common flexor tendon and scrape perpendicularly across the tendon. Unfortunately, this maneuver tends to be moderately painful.

Note: the ulnar nerve runs near these muscles. If you feel numbness, tingling, or shooting pain along the pinky side of your forearm or in the pinky & ring finger, stop the treatment. This treatment should not irritate your ulnar nerve!

This will loosen the tendon matrix and make it more malleable for the next part of the treatment.

Step 2: Hypervolt+

In multiple case reports in practice, Esports Healthcare has found that the use of the Hypervolt+ percussion tool following cross friction and preceding heavy eccentric loading has allowed for more rapid recovery.

To your tolerance, the Hypervolt+ can be used to massage the flexor muscles and tendons on the the forearm (at the elbow).

The Hypervolt+ tool was added at this step to stimulate all the soft tissue in the region of the affected tendon to increase blood flow to the area. With increased blood flow comes oxygen and nutrients to enhance healing; there will also be more rapid removal of toxins from the healing process.

15% off all Hyperice products

Esports Healthcare utilizes the Hypervolt+ for treatment, and we wanted you to have access to this tool, as well. So, we’ve partnered with Hyperice to provide a 15% discount on ALL Hyperice products!


Step 3: heavy eccentric loading

heavy eccentric loading

Following cross-friction to loosen the tendon matrix, resistance must be added to lengthen the tendon under tension. This resistance should be moderate-to-significantly heavy in order to properly pull the tendon fibers taut.

For medial epicondylosis, this would involve holding a weight (dumbbell or other small, weighted object) in the palm of the hand with the wrist and elbow flexed. In a slow, controlled manner, allow the elbow and wrist to open—pulling the tendon.

Step 4: heat therapy

Using heat packs or other heat therapy (i.e. infrared laser) on the affected area should conclude this protocol. Generally, a heat pack should be used for 10-15 minutes.

Adding a damp towel between the heat pack and the affected area will increase its effectiveness by creating moisture that penetrates further into the body.

Generally, people think to ice their ailments to relieve the pain. However, ice relieves inflammation, and as previously discussed, inflammation is not the cause of pain.

Therefore, ice would not help this condition. In fact, icing the affected area may prolong the healing process.

Heating the area increases blood flow, thereby increasing oxygen and nutrients needed for recovery. For an overuse tendinosis, heat is more helpful than ice.

Following resolution, continuation of these protocols allows for prevention of this condition from reoccurring.

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This information is for educational purposes only and is not intended to replace the advice of your doctor. Esports Healthcare disclaims any liability for the decisions you make based on this information.

The information contained on this website does not establish, nor does it imply, doctor-patient relationship. Esports Healthcare does not offer this information for diagnostic purposes. A diagnosis must not be assumed based on the information provided.

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