From what you have said so far, it looks like your apples are tip-bearers on M27 stock which grows to only 5 feet high. Since they appear to be tip-bearers, if you wish to prune the main branches to an upward-facing bud, you are likely to use at least one year's crop. I would suggest using a maypole arrangement with soft string tied to the main trunk and adjusted so that the main branches are pulled upwards from the ground. As the apples form at the end of the branches and increase the strain, I would tighten the string to keep them well above the ground.