350 Euro for a Sport 400 is a good deal, though that model is now superceded by the Sport Elite. Prices should continue to drop since it’s an obsolete model.
The mi-Sport 500 uses a special sensor on one of its electrode connectors. The sensor detects muscle tonus as well as your contractions, which has several benefits during use.
The unit adjusts the current for the muscle so that differing muscle groups don’t get the same intensity. For example the calves don’t need as much as the quads (not being careful without this sensor could make for an excrutiating contraction of a smaller muscle group).
The unit allows an interactive use of EMS, such that the current doesn’t begin until you contract the muscle. This is repeated every 15 seconds or so, which will give you greater motor control over your body, especially when targeting the non-primary movers, such as the lower back or erector spinae.
The sensor makes the TENS pain treatment programs more effective. The sensor is an integral part of the TENS programs, because for TENS to work properly the muscle must be relaxed. The sensor detects muscle contraction and backs off the TENS until the muscle relaxes again. The 400 does not sense muscle contraction and does not back off the current if you do contract.
So basically the mi-sensor on the 500 gives the unit a bit more directed approach to your body. But it’s quite expensive; about 750 Euros or $900 US. I’m sure you could get by without the sensor, though it’s nice.
I have the Mi Sport 500. Great product but all you really need with Compex is one that does the “explosive strenth”, “active recovery” and “Massage” programmes.
thanx a lot.
by the way: i ordered an offer from Compex: 900,- EURO (about 1100$). Here in Germany you can get it new at Ebay.de for 650,- Euro. i think thats a good price.
But i hope the sport 400 is enough for the beginning…