nodejs salva os campos em branco no banco mysql

const express = require("express");
const app = express();
const handlebars = require('express-handlebars')
const bodyParser = require('body-parser')
const Cadastro = require('./models/Cadastro')



// config
// tmplate Engine

app.engine('handlebars', handlebars({ defaultLayout: 'main' }))
app.set('view engine', 'handlebars')

//body Parser
app.set(bodyParser.urlencoded({ extended: false }))
app.use(bodyParser.json())


//rotas

app.get('/cad', function(req, res) {
res.render('formulario')
})

app.post('/reg', function(req, res) {
Cadastro.create({
firstname: req.body.first,
Lastname: req.body.last,
participation: req.body.participa
}).then(function() {
res.send("Successful Registration!")
}).catch(function(erro) {
res.send("Unable to register! " + erro)
})
})


app.listen(8081, function() {
console.log("servidor ok");
});