Carpal Tunnel Syndrome: Night Splinting & Physio

What is Carpal Tunnel Syndrome?

Carpal Tunnel Syndrome (CTS) is a common compressive neuropathy of the upper extremity. The carpal tunnel is a narrow, rigid passageway of ligament and bone located at the base of the wrist. Through this tunnel run nine tendons (which flex the fingers) and the median nerve (which controls sensation and movement in the thumb and first three fingers).

When the tendons become inflamed or the transverse carpal ligament thickens, the space inside the tunnel decreases. This places pressure on the median nerve, leading to pain, numbness, tingling, and weakness in the hand.

Fortunately, most cases of mild to moderate CTS do not require surgery. Utilizing a carpal tunnel night splint and engaging in targeted hand physical therapy is highly effective at reducing nerve compression and restoring grip strength.

Why Do Symptoms Flare at Night?

Patients with carpal tunnel syndrome almost always report that their symptoms are worst at night or upon waking in the morning. This nighttime increase in pain and numbness is caused by two physiological factors:

• Wrist Posture: During sleep, most people naturally flex (bend) their wrists inward. Flexing the wrist raises pressure inside the carpal tunnel from a normal 8 mmHg to over 30 mmHg, compressing the median nerve.
• Fluid Shifting: When lying flat, gravity no longer pulls fluid down the limbs. Fluid pools in the arms and wrists, increasing pressure within the closed carpal tunnel space.

Carpal Tunnel vs. Cubital Tunnel Syndrome

| Feature | Carpal Tunnel Syndrome | Cubital Tunnel Syndrome | | :--- | :--- | :--- | | Compressed Nerve | Median Nerve. | Ulnar Nerve. | | Compression Site | The wrist (carpal tunnel). | The elbow (cubital tunnel / funny bone). | | Affected Fingers | Thumb, index, middle, and half of the ring finger. | Pinky finger and the other half of the ring finger. | | Nocturnal Trigger | Sleeping with wrists bent inward. | Sleeping with elbows bent tightly. | | Physiotherapy Focus | Wrist splinting, wrist ergonomics, tendon glides. | Elbow splinting, elbow ergonomics, ulnar flossing. |

The Role of Night Splinting

A wrist night splint (or wrist orthosis) is the gold standard conservative treatment for CTS. The splint contains a rigid metal or plastic bar that holds the wrist in a neutral position (straight, or slightly extended to 15 degrees).

By holding the wrist straight, the splint:

• Prevents wrist flexion during sleep.
• Keeps the carpal tunnel at its maximum volume, minimizing pressure on the median nerve.
• Allows the inflamed tendons to rest and recover, reducing overall swelling.

Most patients notice a significant reduction in morning hand numbness and nighttime waking within 2 weeks of consistent splint use.

Hand Physiotherapy and Exercises

To complement night splinting, an occupational therapist or physiotherapist will prescribe specific exercises to keep the nerve and tendons moving smoothly:

1. Tendon Gliding Exercises

Tendons can become stuck together due to chronic inflammation. Tendon glides involve moving the hand through five distinct positions (open hand, hook fist, full fist, tabletop, straight fist) to glide the tendons relative to each other and clear out inflammation.

2. Median Nerve Flossing (Nerve Gliding)

Nerves need to slide through their tunnels during movement. Nerve flossing involves gently stretching the nerve at one joint while relaxing it at another, causing the nerve to slide back and forth through the carpal tunnel without placing too much tension on it (e.g., extending the wrist while bending the neck toward the shoulder, then reversing the movement).

3. Wrist Ergonomics

Your physical therapist will review your daytime workstation. This includes ensuring your keyboard and mouse keep your wrists straight, rather than bent upward or resting on hard desk edges.

With consistent night splinting, nerve flossing exercises, and proper hand ergonomics, you can relieve your wrist pain, eliminate finger numbness, and avoid the need for surgical carpal tunnel release.