 Spatially gated myosin attachment

A prescribed-velocity motor can attach only over a narrow displacement window, remain attached over a protected interval, then detach with constant rate. Converting time to displacement gives a rising attachment probability, a plateau $p_b$, and an exponential tail with spatial length $v/k_{off}$. Independent successive-site encounters require detachment before the next window, not merely a large geometric site separation. Earlier attachments can be retained in a periodic availability correction.