WHEN IS A HAMSTRING TRULY ‘WEAK’?
–> A weak hamstring that doesn’t respond to strength training could be related to the position of your pelvis: if the sacrum is stuck in counternutation, it will cause the sacrotuberous ligament to slacken and the hamstring to lose strength. In this case, if you passively nutate the sacrum it will in turn create more tension in the sacrotuberous ligament enabling the patient to generate more force. Hamstring ‘strength’ should return.
As Dr Ida Rolf famously said, “where you think the problem is, it is not!”