What is the Mc David Carpal Tunnel Wrist Support? One size fits all basic lightweight Carpal Tunnel Syndrome wrist support. As used by Belgian goalkeeper Kristof Van Hout. When can I use it? The Mc David Carpal Tunnel Wrist Support allows full finger movement meaning its particularly useful during work related activities. Which size do I need? One size fits all. Choose left or right wrist. How does it work? In normal circumstances the pressure within the Carpal Tunnel is less than 10mm Hg, but in patients with Carpal Tunnel Syndrome this pressure rises to above 30mm Hg due to swelling. During wrist movements the pressure in the Carpal Tunnel can rise to over 90mm Hg. Increased pressure leads to increased symptoms, such as burning pain, tingling & numbness. Research has shown that using a wrist brace to prevent wrist movement is effective in relieving Carpal Tunnel Syndrome in over 80% of patients. The Mc David Carpal Tunnel Wrist Support is a basic wrist support with a supportive splint & Velcro strap to keep the wrist in a neutral position. This relieves the pressure in the Carpal Tunnel & provides relief from symptoms.