Does anyone know about how to start crawlinf for a 4/5 mos old baby ona crawling track?
Hi,
You can make the infant crawling track and just begin from there! Hope this helps some. 
Autumn
At the start, the crawling track should be elevated at one end, so that the baby can use gravity to help them start moving. At the start, my dd’s track was on such an angle that even a little wiggle started her moving forward.
Not only does an elevated track help a baby be able to move forward, but it also helps them realize that they have the ability to become mobile.
We did supervise very carefully though, because a baby could flip themselves out & get injured.
Very true Kmum!
Also we use cotton fabric due to its less toxicity and it worked well for our baby to slide very easily when the track was elevated. You can also cut the costs of the crawling track expenses by building a shorter version. It works just as well plus its much more mobile then…lol! 
Good Luck!