Definition - What does Wrist Wedge mean?
A wrist wedge is a prop that is used to support the wrists in yoga postures where some or all of the weight of the body is placed on the hands. Wrist wedges are available as small foam or cork wedges that are sized to different hand variants or a long rectangle shape that can be used for both hands. Wrist wedges prevent yogis from placing too much weight on the wrist and helps them build strength in the wrists and hands so yogis can evenly distribute the weight through the palm and fingers.
Yogapedia explains Wrist Wedge
The traditional alignment of the hands in yoga poses such as chaturanga, downward-facing dog and upward-facing dog can lead to wrist strain or a stress fracture, unless the hands are in the proper position. When the hands are shoulder width apart, body weight can fall to the wrist and the outer edge of the hands, which is why many yoga teachers cue students to roll the hands inward and press the middle, index finger and thumb into the mat. When the weight of the body is not evenly distributed, the small muscles and ligaments in the wrists can become inflamed due to overuse, and the pisiform bone in the wrist can develop a stress fracture.
A wrist wedge teaches yogis how to place their hands properly and builds strength in the hands and wrists at the same time. To use a wrist wedge, place the wedge under the hands so that the wedge ramps up, going away from the wrists. With the fingers spread and the hands rotated out away from each other, the yogi will actively press the palm and fingers in the the wedge until the wrists lift up slightly.