I'm sorry, I'm with JDI on this one.
Since there is absolutely nothing to be gained from this practice, other than posted a YouTube video, and the potential for harm, why do it?
Do I think the OP harmed the foal in the first video? No, I doubt it. But I think it shows questionable judgement to attempt it, and again WHY? There is no upside and there is potential for harm.
The second video made be cringe as well. The potential for that baby to have joint problems later in life because of damage to the growth plates is VERY real.