Considering I'm grumpily at about the same point I was a year ago (on the injured list due to a hamstring) the first paragraph could have been written about me.
"Athletes may show post injury structural changes in the muscle tendon unit and be at risk for reinjury for up to a year after return to sport."Reading the above in a strange way made me feel better. I'm not alone. The article suggests recurring hamstring injuries may be related to older age, muscle imbalances in the thigh, decrease in quad flexibility and of course, previous hamstring injury.
The article is science based and covers all athletes, not just runners. One study using Australian footballers (that's soccer to us Americans), showed the rate of recurrent was 12.6% during the first week returning to the sport, 8.1% during the second week and a 30.6% after 22 weeks.
Hamstring injuries are a strain or a tear, not of the muscle itself tearing from the tendon, rather is muscle tissue around that sustains the damage. Scar tissue forms as the muscle attempts to heal itself and it's the scar tissue that decreases the flexibility and increases the potential for a future injury.
All of that is nice to know, but how do you heal from it?***
The article says
"rehabilitation exercises targeting neuromuscular control of muscles in the lumbopelvic region are effective at reducing hamstring injury rates."The article also indicates people treated with a "progressive agility and trunk stabilization (PATS)" program had a reinjury rate of 0% after 2 weeks and 7.7% after a year. Compare this to the hamstring strengthening and stretching program reinjury rate of 54.5% after 2 weeks and 70% after a year. So contrary to what many doctors, PT's and Chiropractors (not all...there are a few good ones out there) prescribe of stretching and exercises to strengthen the hamstring, there may be a different solution.
Watch for an upcoming post regarding PATS.
* Article was written by Marc Sherry, Thomas Best, Amy Silder, Darryl Thelen and Bryan Heiderscheit. Subscriber login required. http://journals.lww.com/nsca-scj/Abstract/2011/06000/Hamstring_Strains__Basic_Science_and_Clinical.5.aspx
**www.nsca-lifg.org is a member site. I'm assuming joining would give you online access to the article.
***Outside of personal experience with hamstring injuries and an interest to get back to running, I have no medical, PT, or other superpower training.