eccentric one repitition maximium

hi i urgently need to know how to calculate one repitition maximum for eccentric strength training in the clinical setting without using hi tec gadgetry???

Any reason why you'd need to calculate this?

i need for a study where i would be comparing gains in eccentric and concentric strength after eccentric strength training at 2 different speeds.

You should think about the operationalisation of the question. What is the worth of a one rep eccentric test. If you shouw that it improved, so what...How is that of any benefit to someone unless they function as a human forklift once every 20 minutes??? I would look for a better measure than this and thing about what it is that is the benefit to the individual who would undertake the training that you wish to give them....lets keep research useful...sorry don't mean to be an arse!!!!