Muscles don't develop in a neat and orderly fashion. Some grow stronger at a faster rate than others. Sometimes a muscle on the left side will be stronger than its twin on the right side or vice versa. When one muscle is weaker than others it's more at risk for injury.
Hamstrings tend to be weaker then their counterparts, the quadriceps. Because of this muscle imbalance they're one of the most commonly injured muscles, so it's important to know if yours are particularly weak.
Your hamstrings are actually four different muscles that start up in your hip and go down the back of your leg, past your knee, and attach to the top of your shin bone. There are two muscles on the inside, called medial hamstrings and two on the outside, called lateral hamstrings.
Since your hamstrings pass through your hips and knees, they're considered a two-joint muscle. That means they assist in movement of your knee and hip joints. They help your glutes extend your hip and also make your knee bend.
You use your hamstrings when you run and do other lower body exercises like squats, lunges and deadlifts. They're an incredibly important muscle because you use them in so many movements. It's important to make sure that they're strong enough to handle whatever you throw at them.
Testing Hamstring Strength
Strengthening your hamstrings is generally a good idea to prevent any injuries to the muscle. However, you can test these muscles to see if they're truly weak.
- Karen Kotila: Evidence-based testing of the hamstring muscles using EMG considering the kinematics and injury mechanisms of the hamstring muscle group
- Journal of Sports Science and Medicine: Functional and Neuromuscular Changes in the Hamstrings after Drop Jumps and Leg Curls
- British Journal of Sports Medicine: The predictive validity of a single leg bridge test for hamstring injuries in Australian Rules Football Players
- Minnesota State University, Mankato: Manual Muscle Testing
- National Institute of Health: Manual Muscle Testing Procedures