Abstract: Example muscle tension relief devices are provided herein. A muscle tension relief device includes a first base portion extending in a first plane, a second base portion extending in a second plane, and a muscle engagement feature extending generally upwardly. There is a non-zero angle extending between the first plane and the second plane. The device is configured to engage with and relieve tension in a user's iliacus or psoas muscles. The device can transition from a first position resting on the first base portion to a second position resting on the second base portion to cause the muscle engagement feature to change orientation to apply pressure at the proper position on a user's psoas major muscle. The shape of an upper portion of a body of the device and the muscle engagement feature correspond to the shape of a hand, such as that of a physical therapist.