To present the basic concepts of normal composition and structure of tendons and indicate how they are affected by acute and chronic tendon-injury pathomechanics.
MEDLINE (1970-1999) and SPORTDiscus (1970-1999) were searched using the key words pathoanatomic, tendinitis, tendinosis, biomechanics, pathomechanics, histology, chronic, and mechanical behavior.
Acute loading modes to tendons are based on the response of tendons to tensile and compressive stress. Chronic loading modes are based on frictional forces and repetitive movement.
Conclusions and Recommendations:
With an appreciation of the pathologic changes in acute tendon injuries, the clinician can better understand injury mechanics and the healing process. Until we know more about what is happening in and around the tendon, principally in the early and late phases of chronic injury we will not be able to adequately address injury classification of structures and, hence, the pathomechanics of chronic injury