A motion detection device includes an elastic film, a first strain detector, a second strain detector, and a third strain detector. The elastic film is flexible and waterproof and includes an elastic film body, a first extending portion, a second extending portion, and a third extending portion, which outward extend from the elastic film body along a first direction, a second direction, and a third direction, respectively. An angle between the second direction and the third direction is an acute angle. The first strain detector is disposed on the first extending portion to measure a strain along the first direction. The second strain detector is disposed on the second extending portion to measure a strain along the second direction. The third strain detector is disposed on the third extending portion to measure a strain along the third direction.一種動作感測裝置，包括彈性膜、第一應變感測器、第二應變感測器以及第三應變感測器。彈性膜具有彈性及防水性，並包括彈性膜本體以及自彈性膜本體分別沿著第一方向、第二方向及第三方向向外延伸的第一延伸部、第二延伸部及第三延伸部，其中第二方向與第三方向之間的夾角為銳角。第一應變感測器配置在第一延伸部上，以量測第一方向上的應變量。第二應變感測器配置在第二延伸部上，以量測第二方向上的應變量。第三應變感測器配置在第三延伸部上，以量測第三方向上的應變量。
