Optimal loading: key variables and mechanisms

The acronym PRICE (protection, rest, ice, compression and elevation) has traditionally been the cornerstone for treating acute soft tissue injury. Recently, its relevance in some cases has been questioned;1 of particular concern is that protection and rest may correspond with an excessively conservative approach that fails to harness the benefits of progressive tissue loading through exercise. Optimal loading may be defined as the load applied to structures that maximises physiological adaptation. Achieving optimal loading is challenging but should be driven by variables such as the tissue type, pathological presentation and the required tissue adaptation for eventual activity. Specific loading goals may include increased tensile strength, collagen reorganisation, increased muscle–tendon unit stiffness or neural reorganisation. Optimal loading works through various cellular and neural mechanisms to induce a wide range of changes (summarised in figure 1). Manipulation of loading variables can have profound effects on the nature, structure and function of the wider neuromusculoskeletal system. Figure 1 Effects of mechanical loading. One variable with …