Sensing a force and/or a change in motion proximate to an arbitrarily-shaped surface via a conformal sensing element (e.g., a pressure sensor, an accelerometer) disposed on a flexible substrate and having a sufficient mechanical coupling to the surface. The conformality of the sensing element facilitates intimate proximity to the surface to ensure accurate sensing. Examples of arbitrarily-shaped surfaces include body parts of a person (e.g., a head). A processor receiving one or more signals from the sensing element may provide information relating to possible injury to a body part (e.g., head trauma) resulting from sensed forces and/or changes in motion. Such information may be conveyed by one or more output devices that provide indications of possible degrees of injury/trauma. A conformal sensing apparatus may be integrated with a protective garment or accessory, such as a helmet, wherein the conformality of the sensing apparatus also ensures sufficient comfort for the wearer.