I've never been fishing, or wrestled a salmon but...I can't only imagine it feels very similar to trying to wind my 5 week old DD. 
Fortunately (
?!?) she's strong but this means I've been head butted, clawed and punched (all accidentally ofcouse!). Ive tried over the shoulder and upright on my knee gently holding her chest and chin but it's such a challenge when she's so reluctant to sit even vaguely still.
My question is - does anyone have any good tips and tricks for winding wriggly babies that doesn't require biceps to rival Popeye?