How does this happen? When you’re running at high speeds there’s a lot more demand to the muscles of the hip (compared to jogging). The hamstrings run from the back of your pelvis to below your knees. So when your hip is driving your leg forward, the hamstrings act as the breaks to slow down the leg in the last part of ‘swing phase’. This breaking action is called ‘eccentric contraction’ of the muscle
The most force goes through the muscle with this eccentric load. It’s why you see these injuries happen on TV with no contact to the athlete. Examples:
- Sprinters at the end of a race
- Baseball players reaching for first base
- Soccer players following through on kicks
These injuries are commonly mismanaged and a lot of times rest doesn’t help the muscle. In fact 1/3 of these injuries reoccur within 2 weeks of return to sport! (Heider 2010). We’ll get into some hamstring anatomy in the next post.