title: Tissue adaptation to physical stress: a proposed "Physical Stress Theory" to guide physical therapist practice, education, and research.
abstract: The purpose of this perspective is to present a general theory--the Physical Stress Theory (PST). The basic premise of the PST is that changes in the relative level of physical stress cause a predictable adaptive response in all biological tissue. Specific thresholds define the upper and lower stress levels for each characteristic tissue response. Qualitatively, the 5 tissue responses to physical stress are decreased stress tolerance (eg, atrophy), maintenance, increased stress tolerance (eg, hypertrophy), injury, and death. Fundamental principles of tissue adaptation to physical stress are described that, in the authors' opinion, can be used to help guide physical therapy practice, education, and research. The description of fundamental principles is followed by a review of selected literature describing adaptation to physical stress for each of the 4 main organ systems described in the Guide to Physical Therapist Practice (ie, cardiovascular/pulmonary, integumentary, musculoskeletal, neuromuscular). Limitations and implications of the PST for practice, research, and education are presented.
authors.affiliation: Movement Science Laboratory, Program in Physical Therapy, Washington University School of Medicine, 4444 Forest Park Blvd, Campus Box 8502, St Louis, MO 63110-2212, USA. muellermi@msnotes.wustl.edu
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Mueller
authors.forename: Katrina S
authors.initials: KS
authors.lastname: Maluf
mesh_terms: D000222:Adaptation, Physiological; D001696:Biomechanical Phenomena; D006801:Humans; D008962:Models, Theoretical; D026741:Physical Therapy Modalities; D013314:Stress, Mechanical