Forearm pain is either sudden onset (acute) or gradual onset, overuse (chronic) pain. Acute forearm injuries include bone fractures. Gradual onset forearm pain occurs from nerve impingements, tendon inflammation, or it may be referred pain. Here we explain the causes of pain in the forearm.
A fracture is a break in a bone. Acute fractures occur suddenly from trauma. Stress fractures are hairline fractures which develop through overuse. The common forearm fractures are:
Radius & Ulna Fracture (Broken Forearm)
A broken forearm is a fracture to either the radius or ulna bones which make up the forearm. They are usually caused by a fall onto an outstretched arm. It is common for both bones to break. However, a fracture can occur in just one bone, especially near the wrist.
Acute forearm fractures occur at any point on the bone from the elbow to the wrist. Bones may break into two parts, or cause a fragment to be chipped off. For example, in Olecranon fractures and fractures of the coronoid process.
Symptoms vary depending on the extent and location of the fracture:
- Instant pain
- Tenderness over the specific site of the fracture.
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.
Acute compartment syndrome
A compartment syndrome occurs when the pressure inside a muscle or group of muscles increases, putting pressure on the surrounding sheath. An acute compartment syndrome occurs suddenly through bleeding or swelling within the compartment, often following a crush injury.
Symptoms include pain which becomes increasingly worse with numbness/tingling. If you suspect an acute compartment syndrome then seek medical advice immediately as urgent surgery is often needed to release the pressure before long term nerve damage occurs.
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.
- The patient may also experience aching in the wrist and upwards into the upper arm.
Read more on Radial tunnel syndrome.
Median Nerve Injury
Injury to the median nerve at the elbow causes symptoms 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.
- Median nerve injury above the elbow may result in difficulty or inability to turn the handover 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 elbow ligament, for example, may result in median nerve pain.
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.
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. Pain develops gradually, occurring in those who repetitively use their wrist, contracting the forearm muscles.
- 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.
Cubital Tunnel Syndrome
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.
Read more on Cubital tunnel syndrome.
Pronator Teres Syndrome
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.
Read more on Pronator teres syndrome.
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.