Architectural and biochemical adaptations in skeletal muscle and bone following rotator cuff injury in a rat model.

Background: Injury to the rotator cuff can cause irreversible changes to the structure and function of the associated muscles and bones. The temporal progression and pathomechanisms associated with these adaptations are unclear. The purpose of this study was to investigate the time course of structural muscle and osseous changes in a rat model of a massive rotator cuff tear.

Effect of supraspinatus tendon injury on supraspinatus and infraspinatus muscle passive tension and associated biochemistry.

Background: Injury to the supraspinatus and infraspinatus tendons and the associated atrophic changes to the muscle remain a common clinical problem. Specifically, increased muscle stiffness has been implicated in failure of the repair and poor functional outcomes. We present a comparison of the passive mechanical properties and associated biochemical studies from patients with and without torn supraspinatus tendons.

Skeletal muscle fibrosis and stiffness increase after rotator cuff tendon injury and neuromuscular compromise in a rat model.

Rotator cuff tears can cause irreversible changes (e.g., fibrosis) to the structure and function of the injured muscle(s).

Human skeletal muscle biochemical diversity.

The molecular components largely responsible for muscle attributes such as passive tension development (titin and collagen), active tension development (myosin heavy chain, MHC) and mechanosensitive signaling (titin) have been well studied in animals but less is known about their roles in humans. The purpose of this study was to perform a comprehensive analysis of titin, collagen and MHC isoform distributions in a large number of human muscles, to search for common themes and trends in the muscular organization of the human body. In this study, 599 biopsies were obtained from six human cadaveric donors (mean age 83 years).