Pain in the forearm can be sudden onset (acute) and include fractures of either the radius or ulna bones. Gradual onset forearm pain can be caused by nerve impingements or from overuse of the wrist. Or from referred pain higher up the arm or shoulder.
Radius & Ulna Fracture (Broken Forearm)
A broken forearm is a fracture to either the radius or ulna bones in the forearm and is usually caused by a fall onto an outstretched arm. It is common for both bones to break, but a fracture can occur in just one bone, especially if a break occurs towards the wrist end of the bones.
They can occur at any point on the bone from the elbow to the wrist and may break the bone into two parts, or cause a fragment to be chipped off the bone such as in Olecranon fractures and fractures of the coronoid process.
Symptoms vary depending on the extent and location of the fracture but will include instant pain, swelling, tenderness over the specific site of the fracture, and there may also be a deformity. If a fractured forearm is suspected then seek medical help immediately.
An X-ray should be performed to confirm the diagnosis and determine the severity of the fracture, and whether the bone is displaced (moved). If the bones are not displaced treatment will usually involve immobilization of the arm with a cast or splint, for up to 10 weeks to allow the bones to heal.
Where the bone has become misaligned or the fractured fragment has moved away from the rest of the bone, and particularly with fractures occurring in adults, surgery may be required to realign and fix the bones back together. Again this is followed by a period of immobilization.
Gradual onset forearm pain
Radial Tunnel Syndrome
Radial tunnel syndrome, or radial nerve entrapment as it is sometimes called, occurs when the radial nerve gets compressed or restricted in the tunnel it passes through. Symptoms are very similar to those of tennis elbow but can also include pins and needles or tingling in the hand and outer forearm. Tenderness may be felt in the muscles of the upper forearm and the patient may also experience aching in the wrist and upwards into the upper arm.
Specific tests to help diagnose radial nerve entrapment will reproduce pain on resisted supination or turning the palm of the hand up and pain on extending the middle finger against resistance Treatment involves rest and avoiding any repetitive wrist movements in particular. Applying ice cold therapy to the elbow and forearm may help relieve symptoms.
Read more on Radial tunnel syndrome.
Median Nerve Injury
Injury to the median nerve at the elbow may cause symptoms to appear in the forearm, wrist, and hand. Median nerve injuries are often caused by another acute injury which traps or tears the nerve, causing numbness in the forearm.
An injury above the elbow may result in difficulty or even inability to turn the hand over or flex the wrist down. Injuries below this may cause tingling or numbness in the forearm, thumb and the three adjacent fingers. A weakness with gripping and inability to move the thumb across the palm may also be experienced along with wasting of the muscles at the base of the thumb.
The median nerve can be torn partially or fully, or compressed at the elbow. This can be from a fracture or other traumatic injury, or compression from excess fluid build up following an injury. Even relatively minor injuries, to the medial ligament, for example, may result in median nerve symptoms from pressure on the nerve.
The most common injury involving the median nerve is Carpal Tunnel Syndrome. However, this is caused by a decrease in space at the carpal tunnel in the wrist, not occur as a result of an elbow injury. Pronator Teres Syndrome is another entrapment neuropathy of the median nerve, this time as it passes between the two heads of the pronator teres muscle.
Treatment will depend on the cause, but immediate first aid of applying ice, compression, and elevation to a soft tissue injury will help to reduce swelling, in turn reducing pressure on the median nerve. Median nerve symptoms may clear up very quickly if no long-term damage was sustained. However, if the nerve was damaged, the symptoms listed above may be more long-lasting.
Read more on Median nerve injury
Forearm Splints/Compartment Syndrome
Forearm splints are similar to shin splints in the lower leg, although far less common. Forearm pain develops gradually, occurring in those who repetitively use their wrist, contracting the forearm muscles. The pain in the arm is normally dull and increases with movement, so resting from the activity is the simplest way to help this injury.
Symptoms consist of a dull forearm pain, which is minor initially, but increases as activity continues. Often pin-pointed to the dorsal or back of the hand side of the forearm, midway between the wrist and elbow. The patient may experience weakness in the wrist extensor muscles and tenderness deep in the forearm. Pain may be reproduced by attempting to bend the wrist backward against resistance.
Read more on forearm splints.
Volkmann’s Contracture is a deformity of the arm, wrist, and fingers, caused by an injury to the arm such as a fracture or a crush injury. It causes a lack of blood flow to the forearm, which can lead to muscle problems if it is not dealt with quick enough. Raising the arm and releasing the pressure in the forearm (via surgery) are two main ways to help treat this injury.
The cubital tunnel is an area on the inner elbow through which the ulnar nerve passes. Cubital tunnel syndrome is caused by compression on the nerve and may also be known as ulnar nerve compression or hitting your ‘funny bone’. There are various reasons why the nerve becomes compressed, including arthritis and repetitive bending of the arms.
Pronator teres syndrome is an entrapment of the median nerve, where it passes between the two parts of the pronator teres muscle in the arm causing pain, numbness and tingling in the forearm and hand. As the name indicates, pronating the hand (turning the hand with the palm facing down) can cause and exacerbate this arm injury.
Anterior Interosseous Syndrome
Anterior Interosseous Syndrome is an entrapment neuropathy of the anterior interosseous nerve – a branch of the Median nerve. This nerve branches off from the median nerve, just above the inner elbow. In this condition, the nerve becomes compressed, causing symptoms like pain in the upper arm and difficulty moving the thumb, index finger, and middle finger.
Causes: This nerve can be compressed within the forearm by a number of structures, or for a number of reasons. For example:
- An enlarged biceps tendon bursa.
- Fractures (in particular supracondylar fractures) or other traumatic injuries including dislocations.
- The head of Pronator Teres arising deeper than usual.
- Thrombosed radial or ulnar arteries compressing the nerve.
Treatment: Initial conservative treatment of rest, splinting and anti-inflammatory medications. Corticosteroid or nerve block injections may be used. Surgery to release the nerve is sometimes used if conservative treatment fails.