The hamstring muscle group is the workhorse of human ambulation. Just to stand upright requires a continuous effort from these muscles, making them some of the most overworked muscles in the body.

Where there is muscular overload there is trigger point activity, and the hamstrings are frequently a hotbed of both latent and active trigger points. These trigger points cause the obvious symptoms of back of the thigh and knee pain, but they also play a prominent, but less obvious, role in a whole range of musculoskeletal complaints.