That would be one, yep. Anything that involves inducing load then holding it still. Standing calf raise then just holding it in the flexed position, calf-raise machines (seated for targeting the soleus) — I’ve even see someone sit at a table, push it up with their knees while seated, and hold it.
Tendons display plasticity and love very slow loads. Isometric exercises are basically the ultimate /very/ slow load.