Being attached to a bigger board can have many consequences, how you are attached to your board can also come into play here.
I am currently getting over a heavy knee sprain (12 weeks now) from being attached to my SUP via a below knee leash.
Spent the first month off and on crutches and it still hurts a bit every know and then at the moment.
Back-story to wearing a knee leash in the first place, I had a bit of a dodgy ankle over summer that inflamed of an evening and kept me out of the waves for a good 4-5 weeks so I changed to a knee leash and never thought twice about going back to a regular ankle leash.
Surfing 5' waves for over 2 hrs on my backhand one day I felt my knee tweak a little bit when I bailed my board in front of me at the end section of the wave. At the time it did not hurt all that much but the next day I really felt it. Next surf, jumping over the back of a small wave I really wrenched my knee and that was it, knee seriously buggered. Spent the next day In bed with any slight movement of my leg the wrong way and I would 'yelp' in pain.
Spent half my Family Holiday in Fiji on crutches and missed an epic surf at the reef I had located as I could not walk over the ridge to get to it.
I now wear my ankle leash on my front foot and do not find it in the way or awkward whilst SUP surfing, however I am looking forward to one day wearing my leash back on my left ankle some time soon.
I like riding big boards on occasion and hope to find a good legrope that will keep my board close to me, not break easily and not hurt my body parts.
Note the legrope on my wrong foot in the image below.