Am I too small/weak to use thrust joint manipulation?

No, IMMT has successfully taught practitioners with a body type of close to 100 pounds to utilize thrust joint manipulation. However, it would be incorrect for anyone to say that technique can magically make up for a lack of strength. Great manipulative technique incorporates the proper application of power (strength x speed) to achieve joint cavitation. The detailed technical instruction provided by IMMT gives the smaller practitioner the tools needed to first, develop manipulative strength, and second, to utilize speed and precision to overcome the disadvantage of a smaller body type.