Wrist Extension

What is a Wrist Extension?

Wrist extension is a fundamental movement of the wrist joint where the hand moves upward, away from the palm, aligning the back of the hand with the forearm. This motion is primarily facilitated by the extensor muscles located in the forearm, including the extensor carpi radialis longus, extensor carpi radialis brevis, and extensor carpi ulnaris.

As the back of the hand pulls away from the forearm during wrist extension, the angle between the hand and the forearm rises. This movement mostly happens at the radiocarpal joint, which is the joint that forms between the carpal bone and the wrist’s radius, one of the forearm bones. The wrist extensor muscles, which are mostly found on the rear of the forearm, must contract to extend the wrist. Extensor carpi radialis longus, brevis, ulnar, and other extensor muscles that are involved in finger extension are among these muscles.

Activities that need the back of the hand to move away from the forearm, including pushing and lifting, require wrist extension. The overall range of motion and functionality of the hand and wrist are improved.

Extensor muscle of the wrist

The forearm’s back contains the wrist extensor muscles. When these muscles contract, the wrist is flexed backward and the back of the hand moves away from the forearm, a movement known as wrist extension.

The main extensor muscles of the wrist are as follows:

Extensor Carpi Radialis Longus: The base of the hand’s second metacarpal bone is where this muscle attaches after starting on the lateral (outside) side of the humerus, or arm bone. This facilitates radial deviation, or shifting the wrist away from the thumb, and encourages wrist extension.

Extensor Carpi Radialis Brevis: The base of the third metacarpal is where this muscle inserts, however, it also starts on the lateral side of the humerus. When combined with the extensor carpi radialis longus, it facilitates wrist extension and radial deviation.

Extensor Carpi Ulnaris: Derived from the posterior surface of the ulna, one of the forearm bones, and the lateral epicondyle of the humerus. It is situated near the base of the fifth metacarpal bone and is in charge of ulnar deviation, which causes the wrist to move to the side of the little finger, as well as wrist extension.

Extensor digitorum: Stretching down the back of the forearm from the lateral epicondyle of the humerus. It attaches itself to the extensor digitorum muscle and is principally in charge of finger and wrist extension.

Extensor tendon muscle: This muscle extends exclusively to the index finger and is a continuation of the extensor muscle. Both the wrist and the index finger can be extended with its assistance.

Lifting, pushing, and other motions that require the back of the hand to move away from the forearm are just a few of the activities that require the wrist to be extended by these muscles. When moving the arms and forearms, they offer control, strength, and stability.

Range of Motion of Wrist Extension

Each individual may have a different range of motion for wrist extension, which is the motion of bending the wrist backward. However, the typical range of motion for wrist extension is between 70 and 80 degrees.

Using a goniometer, which is frequently used to measure joint angles, you can take a quick measurement to determine the wrist’s range of motion. Here’s how to accomplish it.

• Place your forearm palm down on a level surface, such as a table, while you sit or stand comfortably. Maintain your wrists in a neutral position, neither bent nor extended, and your elbows at a 90-degree angle.
• The back of your hand should be moved away from your forearm as you slowly and smoothly extend your wrist.
• Ask someone to place the goniometer on the back of their hand while extending their wrist. After that, put one hand on the forearm and the other on the back.
• When you have extended your wrists as far as is comfortable, read and note the angle the goniometer indicates.
• Note the variations between the left and right wrists and repeat the measurement a few times to make sure it is consistent.
• Remember that this measurement is an estimate that could change depending on personal anatomy, flexibility, and any underlying conditions or injuries.

Wrist Extension Test

The “wrist extension test,” sometimes known as the “Watson test,” is a frequently used procedure to evaluate wrist extension. This can aid in the diagnosis of some ailments, like ligament injury or scapholunate instability. This is the way the test is offered.

• Start by placing your forearm palm down on a table or other level surface while you are sitting or standing comfortably.
• The examiner stabilizes the forearm to stop movement while standing close to the wrist being evaluated.
• Conversely, the examiner positions the index finger on the metatarsal bone and the thumb on the patient’s articular bone, which is found on the radial side of the wrist.
• Next, while keeping pressure on the patient’s ears and occiput, the examiner delivers a force backward to the patient’s wrist. The patient is instructed to resist the force as the examiner tries to stretch their wrist.
• A successful test is one in which the patient experiences pain, instability, or a “tired” feeling in their wrist when applying force.
• A positive test result could be a sign of instability or ligament damage.
• It is crucial to remember that there are other tests available to evaluate wrist extension and identify particular ailments, and the Watson test is just one of them.

A Special Test For Wrist Extension

There is not a single, widely used test for measuring wrist extension. Nonetheless, a few clinical tests may help assess certain wrist injuries or illnesses. Here are a few examples:

Cozen’s test (tennis elbow test):

Although wrist extension is indirectly involved, the main purpose of this test is to diagnose lateral epicondylitis, also referred to as tennis elbow. The patient is instructed to create a fist, extend their arm (palm down), and then stretch their wrists against opposition by the examiner. If the patient is unwilling to move, the examiner stops them from extending their wrist. A positive test result is defined as lateral soreness or discomfort (bony feeling on the outside of the elbow) during this movement.

Mills test:

The tendons on the thumb side of the wrist are affected by De Quervain’s tenosynovitis, which is assessed using the Mills test. The patient’s thumb is passively flexed across the palm by the examiner while they abduct the wrist ulnar, or move it to the side of the little finger. When the tendons cross the radial styloid process (the bony protrusion on the thumb side of the wrist), the test is deemed affirmative if the patient experiences pain or discomfort in that location.

Finkelstein’s test:

The Finkelstein test is another way to evaluate De Quervain’s tenosynovitis. The patient is instructed to make a fist with the thumb inside the fingers before bending the wrist to the side of the little finger (elbow deviation). In the region where the tendons cross the radial styloid process during movement, a positive test result is interpreted as pain or discomfort. Note that these tests are not all-inclusive; they are only a few instances.

Other wrist movements

Notably, the wrist joint permits not just flexion and extension but also abduction, which is the movement of the hand away from the body’s midline, and adduction, This involves the hand moving back toward the midline.

Flexibility, stability, and grip strength can all be enhanced with wrist flexor and extensor strengthening and stretching exercises. It is best to speak with a medical expert or a licensed hand therapist if you have special issues or need exercises for fitness or rehabilitation. They might provide customized guidance according to your particular needs.

Wrist Stretching Exercises

Extension of the wrist:

Hold your arms shoulder-high in front of you with your hands down. Gently hold the fingers with the other hand and draw them down so that the hand and wrist can expand. For 15 to 30 seconds, hold the stretch while pulling gently and steadily. For each arm, perform the stretch two to three times.

Stretch for Wrist Extension

Tall and Erect Standing in front of the table. Place your elbows straight, your fingers flat, and your palms down at a table. Your weight should be leaned forward. For fifteen seconds, maintain this posture. Do this three times.

Stretching the Wrist Extensors

Position of the patient is straight standing. Keep your arm palm down. Apply pressure to the affected hand’s back until the forearm’s outer muscles begin to stretch. Then Releases. do this stretching exercise 3 times.

Benefits Of The Wrist Extension Exercise

• Strengthens the forearm and wrist: Exercises involving wrist extension can help strengthen the muscles supporting the elbow and wrist.
• Enhances mobility: Wrist workouts might aid in boosting wrist range of motion and flexibility.
• Prevents injury: Exercises for the wrists can help avoid injury and soreness.
• Increases grip strength: Exercises for the wrist can assist increase grip strength, which is crucial for a variety of tasks.
• Rehabilitation: Following surgery or an injury to the wrist or elbow, wrist extension exercises may be a useful option.
• Arm size balance: You can achieve a more balanced arm size by performing wrist extension exercises.
• enables you to hold larger weights: You can hold heavier weights for extended periods by performing wrist extension workouts.

Wrist Extension Exercises

The following wrist extension exercises can help increase wrist flexibility and strengthen the relevant muscles:

Extension Curls on the Wrist:

Wrist-extension

Place your wrist over the edge of the surface and place your forearm palm down on a table or thigh if you are seated in a chair.
Hold a light dumbbell a food container or other household item. Elevate the weight toward the ceiling by slowly bending your wrist upward. Then, after a little pause at the peak, gradually lower the weight back to where you started. For each arm, perform ten to fifteen repetitions in two to three sets.

Wrist Curls in reverse:

Start with your palm facing up, just like you would for the wrist extension curl. Hold a household object or light stop. Slowly lower your wrist by bending it in the other direction. Slowly raise your wrists to the starting position after a little rest at the bottom. Two to three sets of ten to fifteen repetitions should be given to each arm.

Extension of a rubber band.

Wrap a rubber or resistance band over your thumb and fingers, palm down. Stretch your wrist and fingers as far as you can against the strap’s resistance. After a few seconds of holding the stretched position, let your arms drop back down. Throughout the task, each hand should be used ten to fifteen times. As you gain strength and comfort, gradually raise the weights or resistance from the lower starting point.

Manual Muscle Testing: Wrist Extension

One method for evaluating the strength and functionality of the muscles surrounding the wrist joint is manual wrist muscle testing. It entails introducing resistance to particular wrist movements and having the test taker attempt to sustain or overcome that resistance. This test can be used to measure muscle strength, spot imbalances or deficits, and help diagnose several wrist-related illnesses or injuries.

Assessing the muscles

• Extensors carpi radialis brevis
• Extensors carpi radialis longus
• Extensors carpi ulnaris

Grading

Normal (5): The examiner demonstrates the ability to maintain the test posture and provide it more than 95% of their effort when under extreme strain. Examiners are not permitted to “break” the test position.

Good (4+): 75–95% of the examiner’s effort is put out; they can hold the test position and endure moderate to high pressure until their muscles give out.

Good (4): The examiner exerts between 50 and 74 percent of their energy; they can maintain the test position and withstand mild pressure until their muscles fail.

Fair (3+): The examiner exerts 1-24% effort; they can withstand light pressure until their muscles become fatigued.

Fair (3): Being able to maintain gravity without the need for further force is fair.

Fair (3-): The patient gradually loses the test position as a result of their limitations in resisting gravity.

Poor (2+): While trying to maintain a *gravity eliminated (GE) posture, the individual can only perform a partial range of motion (ROM) against gravity and can only move through the entire range of motion (ROM) with resistance at the end range.

Poor (2): Unable to keep a full range of motion in a GE position and defy gravity,

Inadequate (2-): Capable of moving part of the range in a GE position, but unable to maintain an agape attitude.

Trace (1): Although no visible osteokinematic activity is present, the examiner feels a muscle or tendon contract.

Zero (0): There is no discernible contraction or osteokinematic movement of the muscles or tendons.

GE or gravity eliminated: refers to a patient’s positioning that allows them to defy gravity without the use of their muscles. This region is usually found in the horizontal plane.

Patient’s position

The patient should sit with their forearm resting on a table or armrest and their elbow flexed to a 90-degree angle.
Although the wrist should not be flexed or extended, it should be neutral when evaluating the wrist extensors.
It is necessary to prorate the patient’s forearm.

Therapist Position

• Grade 0: There is no movement
• Grade 1: the patient makes an effort to do the movement. There is a flicker contraction.
• Grade 2: The therapist should try to extend the patient’s wrist with one hand while standing behind them and supporting their forearm with the other.
• Grade 3: The therapist should stand behind the patient and use their hand to support the patient’s forearm while letting the patient extend their wrist freely and through its entire range of motion.
• Grade 4: As the patient tries to extend their wrist, the therapist should stand behind them and use one hand to support their forearm and the other to create resistance. The resistance should be just enough to keep the patient from finishing the motion, but not so much that it wears them out.
• Grade 5: As the patient tries to extend their wrist, the therapist should stand behind them and use one hand to support their forearm and the other to create resistance. The resistance should be just enough to keep the patient from finishing the motion, but not so much that it wears them out. To motivate the patient to finish the motion, the therapist should also give verbal cues.

What is the test procedure?

• Describe the process to the patient and get their consent.
• Place the patient’s arm on a table or in their lap while they are standing or sitting.
• Have the patient raise their hand toward the ceiling to lengthen their wrist. The patient performs the wrist extension themself.
• Give the dorsal side of the hand resistance in the opposite direction of extension for grades 4–5.

In addition to recording the grade, note any observations or restrictions on the patient’s capacity to complete the test correctly.

Take Precautions

• Before beginning the exam, make sure the patient is steady and at ease.
• To protect the patient from harm, avoid using too much resistance.
• During the test, pay attention to any pain or discomfort the patient may feel and stop if needed.
• Before taking the exam, look for any precautions or contraindications, such as recent surgery or wrist injuries.
• To prevent strain or injury to oneself throughout the test, use appropriate body mechanics and placement.
• To stop infections from spreading, always use gloves and sanitize your equipment as part of the recommended infection control procedures.

Summary:

• The wrist joint can move in two different ways: flexion, which involves bending the hand toward the inside of the forearm, and extension, which involves straightening the hand away from the forearm. Certain forearm muscles are responsible for these actions.
• Wrist flexion is caused by the flexor carpi radialis, flexor carpi ulnaris, and palmaris longus muscles, whereas wrist extension is caused by the extensor carpi radialis longus, extensor carpi radialis brevis, and extensor carpi ulnaris muscles.
• The flexibility, stability, and grip strength of the wrist can all be enhanced by stretching and strengthening these muscles. For individualized advice, it is advised that you speak with a medical expert or licensed hand therapist if you have particular needs or concerns.

FAQs

References

• Patel, D. (2023h, June 29). Wrist Flexion & Extension – Samarpan Physiotherapy Clinic. Samarpan Physiotherapy Clinic. https://samarpanphysioclinic.com/wrist-flexion-extension/
• Patel, D. (2023b, May 21). Manual Muscle Testing of the Wrist – Flexion, Extension, Deviations. Samarpan Physiotherapy Clinic. https://samarpanphysioclinic.com/manual-muscle-testing-of-the-wrist/