Various implementations include an assistive hamstring device including a belt, knee sleeve, first elastic strap, second elastic strap, and third elastic strap. The first elastic strap extends between a first dorsal belt portion of the belt located adjacent a sagittal plane on a dorsal side of the person and a lateral knee portion of the knee sleeve located adjacent a lateral side of the knee. The second elastic strap extends between a side belt portion of the belt located adjacent a coronal plane of the person and a medial knee portion of the knee sleeve located adjacent a medial side of the knee. The third elastic strap extends between a second dorsal belt portion of the belt located between the first and side belt portion and an intermediate dorsal knee portion of the knee sleeve located between the lateral and medial knee portion, along the dorsal portion of the knee.