The phrase "concomitant increase" means that there is a simultaneous or accompanying rise or growth in something. It usually refers to two or more things that happen at the same time and get bigger or better together. Full definition
This may imply that substantial increases in muscle size of the gluteus medius are necessary in order to prevent or rehabilitate certain types of lateral hip pain successfully and that small increases in strength without concomitant increases in size may not be sufficient. (strengthandconditioningresearch.com)
At the time the former seemed a more dangerous risk than the latter — although even then massive overinvestment was China's true vulnerability — but I think by now there is a rapidly developing consensus that investment, and the unsustainable concomitant increase in debt, is China's biggest problem. (carnegieendowment.org)
Certainly universities are being encouraged to take on more students — though without concomitant increases in teaching resources, there is a danger that quality could be sacrificed on the altar of «mass - production». (newscientist.com)