Ulnar Deviation Of The Wrist Joint

Introduction

Ulnar deviation is the movement of the hand toward the little finger (ulnar) side, facilitated by the flexor carpi ulnaris and extensor carpi ulnaris. These motions are essential for grip, wrist flexibility, and functional hand movements.

Radial and ulnar deviation are wrist movements occurring in the frontal plane. Radial deviation is the movement of the hand toward the thumb (radius) side, controlled by the flexor carpi radialis and extensor carpi radialis muscles.

Rehabilitating and managing wrist injuries or conditions requires an understanding of the musculature and biomechanics behind radial and ulnar deviation. To restore normal wrist function and help with recovery, physiotherapists, occupational therapists, and other medical professionals frequently use specific exercises and therapeutic interventions.

What is the Ulnar deviation of the wrist?

The movement of the hand and wrist toward the little finger of the forearm is referred to as the ulnar deviation of the wrist. On the side of the little finger, the wrist is bent in the direction of the ulna, the smaller of the two forearm bones.

For an understanding of ulnar deviation, hold your hand palm down in front of you. At that point, bring your fingers closer to your forearm by bending your hand toward the little finger. We term this movement ulnar deviation.

One of the primary wrist joint movements, ulnar deviation is crucial for several functional tasks. As a result, the hand can move to the side of the little finger, allowing for activities like using the little finger to pick up objects, play musical instruments, type on a keyboard, and perform specific sports movements.

The opposing movement, known as radial deviation, occurs when the hand and wrist bend in the direction of the forearm’s thumb. To perform a variety of hand movements and functional tasks, complete wrist mobility and skill require both ulnar and radial deviation.

Ulnar Deviation Muscle

The forearm’s main muscles are responsible for ulnar deviation. These muscles may work together to produce and control movement. The following are the primary muscles involved in wrist ulnar deviation:

• Flexor Carpi Ulnaris: The forearm, or side of the arm, contains this muscle. It is connected to the wrist’s long bone and hamate bones and begins at the medial epicondyle of the humerus, the bony protuberance on the inside of the elbow. The wrist deviates from the ulna when the flexor carpi ulnaris contracts.
• Extensor Carpi Ulnaris: This muscle can be found on the forearm’s back side. The lateral epicondyle of the humerus is where it begins and ends at the base of the fifth metacarpal. Wrist ulnar deviation can be corrected by contracting the extensor carpi ulnaris.
• Palmaris longus: A thin muscle on the forearm is the palmaris longus if it is present. It extends to the palmar aponeurosis, or flat tendon of the palm, from the medial epicondyle of the humerus. Even while it cannot be found in everyone, when it is, it could cause wrist ulnar deviation.

These muscles are innervated by the ulnar nerve, which supplies the impulses required for wrist movement control and muscular contraction.
Note that while these muscles are mostly responsible for forearm deviation, additional forearm muscles also help to stabilize the wrist joint and coordinate different hand and finger movements.

Range of Motion of Ulnar Deviation at the Wrist

About 30 to 45 degrees is the typical range of motion for ulnar deviation of the wrist. This indicates that the hand can shift from its neutral posture to the side of the little finger by about 30 to 45 degrees if the wrist is healthy. However, it is important to remember that the range of motion can vary from person to person and is affected by anatomical variances, age, joint health, and prior injuries.

A goniometer can be used to assess the wrist’s ulnar deviation’s range of motion (ROM). Here’s how to measure this.

• Location: Request that the assessment subject sit or stand with their arm palms down on a table or lap. Throughout the measurement, make sure the forearm remains stable.
• Goniameter placement: Align the goniometer’s fixed arm with the ulnar and place it parallel to the forearm’s long axis. The goniometer’s movable arm should be oriented parallel to the hand’s long axis and the fifth metacarpal bone.
• Neutral position: Start with the subject’s wrist in a neutral posture, without any radial or ulnar deviation, and with their hand and wrist aligned with their forearm.
• Measurement: ell the subject to move their hand and wrist as close to the little finger as they can to accomplish ulnar deviation. Keep an eye on the goniometer as they move, and record where the ulnar deviation begins. Put the individual’s wrist and hand back in a neutral posture.
• Complete ulnar deviation: Tell the person to move their hand and wrist as close to the little finger as they can to repeat the ulnar deviation. Take note of the highest point attained during ulnar deviation by watching the goniometer.

Wrist Ulnar Deviation Test

The Ulnar Deviation Test is a specialized examination that evaluates the movement of the wrist’s ulnar deviation. Here’s one way to achieve this.

• Starting position: The testing subject must sit or stand with their palm facing down and their forearm resting on a table or lap.
• Completing the test: As much as possible, have the participant move their hand and wrist toward their little finger (ulnar deviation) while maintaining a stable forearm on the ground. Encourage them to move within their comfort zone to avoid pain or discomfort.
• Measurement: Visually evaluate the angle formed by the hand’s longitudinal axis and the forearm’s longitudinal axis to monitor and measure the degree of ulnar deviation. For a more accurate measurement, compare it to a reference point or utilize a goniometer, if available.
• Repeat and average: Repeat the test many times to ensure it is dependable and consistent. To obtain a more accurate estimation of the degree of an individual’s ulnar deviation, take two or three measurements. This ulnar deviation test aids in determining the wrist’s ulnar deviation’s range of motion.

A Special Test for Wrist Ulnar Deviation

Numerous specialized tests are available to evaluate wrist ulnar deviation. The following are some of the most popular tests:

Wrist deviation stress test:

Place the subject’s arm palm up on a table or their lap. To stop movement during the test, stabilize your forearm. Grab the metacarpals with your other hand and place it on the person’s arm. Apply a mild yet firm ulnar flexion force to the wrist and hand. Throughout the wrist stretch test, keep an eye out for any pain, discomfort, or instability. Compare the outcomes with the wrist that is still intact if needed.

Piano Keys Test:

The individual should have their arm palm down on a table or in their lap. Maintain forearm stability throughout the test to avoid movement. Grasp the metacarpals with your other hand while holding the person’s arm. While the person is resisting attempts to extend their wrist, apply a downward push on their wrist. Next, apply pressure on the little finger’s side (ulnar deviation) while the person responds to attempts to perform it.

Take note of any wrist pain, discomfort, or instability while taking the test. Compare the outcomes with the wrist that is still intact if required. When ulnar deviation occurs, these tests are frequently used to evaluate the wrist joint’s strength, stability, and integrity. To ascertain whether an ulnar deviation is linked to discomfort or instability, they can assist in identifying potential ligamentous or structural abnormalities.

Wrist-ulnar deviation stretching:

Place your arms palm down in front of you. Feel the stretch on the ulnar side of the wrist by gradually pulling your hand and wrist toward the little finger with the other hand. For 15 to 30 seconds, hold the same position. With the opposite arm, repeat the stretch. As you gain strength and endurance, it’s crucial to gradually increase the intensity of your exercise routine, starting with light resistance or weights.

Exercise for Ulnar Deviation

To help strengthen and correct the wrist’s ulnar deviation, try these exercises:

Resistance band wrist-ulnar deviation:

Attach the other end of the resistance band to a stationary object. Place your hand palm up on the other end of the tape. Beginning with your arms in a neutral posture, slowly turn your wrist in the direction of your little finger while overcoming the strap’s resistance. Repeat as many times as you like after returning to the beginning location. Use both hands to perform the exercise.

Ulnar Deviation with Dumbbells:

With your palm facing up, hold a stop in your hand. Against the dumbbell’s resistance, progressively twist your wrist toward your little finger while keeping your arms in a neutral position. Do as many repetitions as you like after returning to the beginning position. Use both hands to complete the exercise.

Handshake Ulnar deviation:

Maintain grip or use a grip booster. Holding your arms in a neutral stance, squeeze the handle to begin. Turn the wrist to the side of the little finger while applying pressure. Once the handle is released, return to the starting position. You are free to repeat as often as you would like. Using both hands, perform the exercise.

FAQs

References:

• Patel, D. (2023, July 4). Radial and ulnar deviation of the wrist – movement, muscles, ROM. Samarpan Physiotherapy Clinic. https://samarpanphysioclinic.com/radial-and-ulnar-deviation-of-the-wrist/