Hamstring tendonitis is not nearly as common as you might imagine. It is much more often the case that the muscle belly itself bears the brunt of the stress and strain of activity, hence the relative frequency of such muscle strains.
If it is to be damaged or inflamed at its tendinous regions it will either be at the origin of the muscle, from THE ISCHIAL TUBEROSITY (the boney point right at the top of the back of your thigh, just below your buttock) or behind the knee. The ischial tuberosity is where the hamstring originates from and the back of the knee is where it ends or inserts.
Inflammation can develop at either of these sites from unaccustomed activity especially if it involves muscle work in a stretched position for the muscle. Again it is much more the sporting contingent that are likely to suffer with hamstrong tendonitis. It is also relevant to know that the hamstrings has two points of insertion at the back of the knee. Both are at the back of the knee at either side (known as medially and laterally). Symptoms will normally be one side or the other, rather than both.
Unless the symptoms have been ignored and the inflammation has become chronic hamstring problems of this sort are relatively easy to resolve. Rest from aggravating activity must be implemented. Physical therapy techniques to settle the soreness, in the form of electrotherapy and/or manual techniques are helpful.
This should be followed by graduated rehabilitation of the muscle structure to full function. Once the initial soreness has resolved they tend to respond quite quickly.