Ulnar deviation occurs when your wrist is bent outward in the direction of your little finger. On traditional keyboards the span of your shoulders exceeds the contiguous width of the home row of keys. In order to position your hands over the home row it is necessary to bring your hands together in front of your body with your wrists deviated. This constricts the blood flow through your wrist and also requires sustained muscle tension which further reduces blood flow to the muscles. The median nerve runs through the carpal tunnel in your wrist, ulnar deviation reduces the size of the carpal tunnel and pressure on this nerve. Ulnar deviation is among the most common and potentially damaging keyboard postures.
The Freestyle2 keyboard addresses the issue of ulnar deviation in either of two ways: (1) unlimited splay – when connected together the keying modules offer unlimited splay greatly reducing ulnar deviation by placing your wrists in a more neutral position; and (2) complete separation – by removing the Pivot Tether the Freestyle’s left and right key modules can be completely separated offering up to 9 inches of separation (20 inch version also avialable) accomodating a wide-range of shoulder widths while at the same time promoting neutral wrist posture.
With wrist extension, your wrists are bent up and back such that the fingers are higher than the wrist joint. This greatly reduces blood circulation through the wrist and hand and can quickly cause pain, fatigue and numbness. Most traditional including many ergonomic keyboards have a positive 10 degree slope from front to back that promote wrist extension. Unfortunately most keyboard users do not demonstrate perfect keying technique, but rather drop their wrists into a dangerously extended posture over the front edge of the keyboard and onto the work surface.
In order to reduce/eliminate wrist extension the Kinesis Freestyle2 keyboard has a zero degree slope from front to back that greatly reduces extension. Additionally, optional padded palm supports can be purchased that attach to the front edge of the Freestyle2, thereby, positioning your wrist in a completely neutral position – at the same elevation as your forearm and hand. The VIP3 accessory also include integrated palm supports.
Pronation in the forearm and wrist occur in a typing position as the palms of your hand are turned face down and is parallel with the flat surface of the desk or floor. The majority of this turning involves the rotation of both forearm bones (the ulna and radius). Sustained pronation increases pressure on the forearm muscles and surrounding tissues and reduces blood circulation which can lead to fatigue and injury. Research demonstrates that a moderate elevation of the thumb side of the hand dramatically reduces this type of stress.
Unlike traditional flat keyboards that force your forearms and wrists into pronation, the Freestyle2 family offers three accessories that provide variable and reproducible tent settings (VIP3, V3 and Ascent accessories) to greatly reduce pronation.
Most traditional and many ergonomic keyboards have an integrated numeric 10-key which increases the overall length of the keyboard. This can force the user to over extend both their forearm and shoulder while reaching for the mouse which can lead to neck, shoulder and forearm strain.
The Freestyle2 keyboard addresses this problem by embedding the numeric keypad in the right key module, allowing close placement of any pointing device, thereby, reducing over-reach issues.