Knee pads, you're going to need them.
As a student (Iaidoka) of Iaijutsu you'll soon realise that many of the core techniques (waza) are designed to teach you to handle attacks made by opponents when you are in a 'disadvantaged' positions, i.e. sitting (seiza) or relaxing (tatehiza). Whilst many of the waza have a standing variation (kae waza) you are encouraged, where possible, to practice the 'original' versions.
You'll quicky find that protecting your knees is a must, so here is some guidance on what to look for in a good set of pads drawn from our experience, recommendations only express our view and are not intended to formally endorse.
As with all things kneepads range in cost depending on the features that they offer. From additional support, alignment control through to extra thickness and Teflon coating there is much to choose from. For our art the focus should be on comfort and flexibility.
Extras are a clearly a personal preference but generally a good quality set of knee pads fit for our purposes can be found at or around the £20 price point.
'Hard-pad' kneepads have a hard plastic (or similar) layer over a pad designed to cup or cover the knee. 'Multi-pad' kneepads have a number of cells sewn into the pad. One to protect the patella (kneecap) and a number (in various designs) to protect the surrounding knee area; whereas 'single-pad' kneepads have a single pad designed to protect the whole knee area.
Sometimes with the multi-pad type the filling used to fill the cells moves around within the cells or becomes 'crushed' in the pad reducing the effectiveness of the pad over the patella where it is needed. Single pad designs work well as the protective pad cannot be pushed aside from the kneecap. Hard pads are not generally recommended.
Generally kneepads are held in place either by a sleeve (that the pad is sewn into) or straps (velcro or similar). With straps you want to make sure that the pad doesn't move about and that the straps themselves don't end up moving behind your kneecap as your train. With the sleeve type comfort is the key thing to look for, holes in the sleeve to let your skin breath and flexibility in allowing you to move freely.
Whilst strap pads can be infinitely adjusted providing a good initial fit they can have problems keeping the pads in place during vigorous training.