Bridges are a fundamental exercise for glute and hamstring strength. We are often dominant in the muscles in the front of our legs (hip flexors and quads), so it is really important to balance those out with strong muscles in the back of the legs (posterior chain). The more dominant your quads are and the weaker your posterior chain is, the more likely you are to get injuries.
Basic Bridge: To perform a bridge, lay on your back with your knees bent. Perform a posterior pelvic tilt and squeeze your butt as you lift your hips up into the air. You should have a straight line from your shoulders to your hips to your knees. If you do not feel your hamstrings engage, push more through your heels and they will activate. If your hamstrings cramp, thats ok! Do not give up. It means they need to be strengthened.
You can perform all of the bridge exercises shown with either your arms by your sides for support and stability OR with them straight up towards the ceiling for more of a challenge. Additionally, you can do repetitions (up and down) or simply hold the bridge position for an amount of time that you can maintain the proper alignment and muscle contraction.
Bridge with Leg Crossover: The next step is to transition from two legs supporting you to only one. The easiest way to begin this progression is to cross one leg over the other. The same sequencing for the basic bridge still applies here even though you're on on leg (posterior pelvic tilt, butt tightening, and lift).
Single Leg Bridge: The next advancement is to completely straighten one leg in the air and push up with the other leg. This is harder than the cross over because the opposite leg no longer has support and you have to hold up more weight. Again, the same basic principles apply for tight abdominals and butt, as well as alignment of shoulders to hips to knees. Make sure your hips do not tilt to one side now that you are only using one leg. Your hips should remain level.
Bridge on Ball: For a stability challenge, place your heels on a ball and perform your bridge. You can do this with your legs straight or your knees bent. You will feel it much more in your hamstrings with your knees bent than with them straight.
Hamstring curls: Keep your hips up and maintain your bridge as you pull the ball in and out (straighten and bend your knees while keeping your butt off the ground). Again, make sure you maintain level hips and keep your hips elevated. Do not let your butt drop down towards the ground, as this breaks your alignment.
Single Leg Bridge On Ball or Single Leg Hamstring Curl: Similar to the bridge without a ball, you can progress to performing the bridge on the ball with one leg. You can lift your hips up and down from the floor OR you can do you hamstring curls in and out with one leg. This is hard!
Similar to planks, bridges should be incorporated into your regular strength training routine. Along with abdominals, hamstrings and glute muscles are vital to being a strong athlete and having balanced core muscles.