This study focuses on the core pathology of sinew wei （痿）， which is mainly characterized by the fai-lure of qi and blood to nourish the sinews. A mechanical-biological response framework is constructed with mitochondria as a key component， explaining the modern interpretation of the disease location of sinew transmitting to qi and blood pathology. Mechanical loading， as a physical stress stimulus applied to the body， manifests primarily as passive loading formed by external forces such as massage， and active loading resulting from voluntary muscle contractions， such as dao yin （导引）. Mechanical loading can regulate mitochondrial function through two pathways， mechanical signal transduction and metabolic demand-driven regulation. Skeletal muscle mitochondrial dysfunction is regarded as the core microscopic basis of qi imbalance in sinew wei， highlighting the intrinsic connection between qi and mitochondrial energy metabolism， as well as between blood and microcirculatory efficiency. Accordingly， distinct regulatory patterns of mechanical loading are identified. Wei associated with qi stagnation may correspond to mitochondrial network fragmentation and can be treated by regulating qi through passive loading， such as tuina， to restore mitochondrial dynamics. In contrast， wei caused by qi deficiency is attributed to insufficient mitochondrial biogenesis and may be treated by tonifying qi through active loading， such as dao yin， to promote mitochondrial biogenesis. This framework reveals the biological differences in mitochondrial regulation induced by distinct mechanical loading modalities and provides a microscopic mechanism-based explanation for the principle of "treating the same disease with different methods" in sinew wei.