Could a curved spine be responsible for slumping?

Yes. Called kyphosis many types postural treatable with physical therapy other types are stiff deformities in which therapy dose little good kyphosis in growing adolescents can be braced huge deformities can be straightened surgically other types schuermans kyphosis ankylosing spondylitis traumatic after spine compression fractures kyphoscoliosis familial congenital.