When your muscles contract or get stretched, the physical pull they feel is the main reason they grow bigger — it's like the muscle gets a signal from the tugging to grow more muscle fibers.

In healthy adult humans, compare skeletal muscle hypertrophy after 12 weeks of resistance training with controlled mechanical tension (e.g., blood flow restriction to isolate tension without metabolic stress) versus training with matched metabolic stress but reduced tension (e.g., low-load training with slow eccentrics), using MRI-measured muscle cross-sectional area as the primary outcome.

In adult mice, determine whether genetic or pharmacological disruption of key mechanotransduction proteins (e.g., integrin β1, FAK, or YAP) abolishes muscle hypertrophy induced by mechanical stretch or overload, while preserving other growth signals.

In cultured human primary myotubes, demonstrate that direct mechanical stretch (without growth factors or metabolic stress) is sufficient to induce hypertrophy via mechanotransduction pathways, and that blocking these pathways prevents hypertrophy.

In resistance-trained humans, correlate daily mechanical tension exposure (measured via wearable force sensors and motion capture) with longitudinal muscle hypertrophy, while controlling for nutrition, sleep, and training volume.

In patients with neuromuscular disorders causing chronic muscle inactivity (e.g., spinal cord injury or prolonged immobilization), assess whether absence of mechanical tension correlates with failure of muscle hypertrophy despite anabolic stimuli (e.g., hormone replacement or protein loading).