I need to know if there's other mums out there having the same problem! DS recently turned 6 months and has been a great sleeper, sleeping through the night at 4 months so that's not what concerns me.
I can usually time DS's naps. Roughly he naps every two hours but this can vary with sometimes being a little earlier or later as I can tell when he's cranky. The problem is recently in the past few weeks DS refuses to nap without being rocked, he kicks up, cries, red face and tears until he's rocked but even then if it's not long enough and I set him down the cycle begins all over again, I should also mention DS is a heavy baby, he's 22 pounds but he's a long baby so not chubby, HV said he's a great weight at last weigh in which was grand but after a few minutes of rocking my arms and back are killing me! 
I've tried a softer CC for this and let him cry for roughly one or two minutes before going in to pat and comfort him/give him his dummy back and this does work, he'll roll onto his side and sleep but it distresses me so much seeing him cry and seeing his tears and he's teething (already has two bottom front teeth!) so I tend to convince myself that this also makes him fussy with naps. 
AIBU to continue rocking him and hope he grows out of it or am I creating a rod for my own back as they say? Genuinely torn with this one!