The bridge is one of the most useful exercises I know. Of the many athletes I help with fitness and rehab training from various sports, probably 80% of them will perform this exercise. Indeed, many SIB readers will most likely be familiar with it. Below is a detailed analysis of the rationale behind its use, technical coaching points for instruction and bridge progressions.
Gluteal 'inner-range' strength
Strength in specific positions and movements can be equally important for both athletic performance and injury prevention. Sometimes, this is less about the maximum weight the athlete can lift and more about the ability to recruit muscles to perform a specific function during a sporting movement. The bridge develops strength in the gluteal muscles in what is called the 'inner range', which is important for running-based sports.
The inner range for the gluteal muscles refers to the position with the hip extended and pelvis in neutral. Often athletes lack strength in this position. Norris (2000) talks about how muscle peak tension can change at specific positions. In terms of the gluteal muscles, it is common for them to become lengthened (chronically stretched), thus reducing the tension in the range around hip extension. When running, it is crucial to be strong in this range of movement, since the gluteals support the upright position of the trunk, and help maintain the pelvis and lumbar spine in a neutral position. If an athlete cannot maintain an upright trunk or has a lordotic position (pelvis tilted down at the front) while running, this is effectively the same as flexing the hip. Lack of inner-range strength in the gluteals can place greater strain on the low back, or affect the biomechanics of the lower limbs, increasing injury risks.
The gluteals must be strong in the hip-extended and neutral pelvis range of motion, and the bridge works the gluteal muscles in this position. Look at the picture. You can see how the hips are extended with the straight-line position through the knees, hips to the shoulders.
An athlete may have good gluteal strength when performing an exercise such as the squat or leg press yet at the same time be unable to use his gluteal muscles to effectively stabilise the hip extended/pelvis neutral position. This differentiation between gluteal strength depending on position is common in athletes and normal adults, and is an example of how the gluteals can act as either a prime mover or a stabiliser, depending on the task.
Start by lying on your back with your knees bent. Have your feet and knees hip width apart. Squeeze your gluteal muscles and lift your hips until you have a straight line running through your knees, hips to your mid-back. Leave your shoulder blades on the floor. Now hold the position, focusing on using the gluteal muscles. Maintain the position for 10-30 seconds, repeating for a number of sets.
It is more beneficial to perform this exercise as an isometric contraction because this mimics the stabilising role of the gluteal muscles more closely. Building up the length of time the athlete can hold the position will improve the strength endurance of the gluteals in the inner range position.
Check where the athlete is feeling the contraction. Some athletes may feel it strongly in the hamstrings or the low-back. This means the gluteals are not doing their share of the work. Encourage the athlete to focus on squeezing the gluteals more to ensure most of the support is coming from them.
If the athlete starts to feel the exercise moving out of the gluteals into the hamstrings, and maybe even cramping the hamstrings, then it's time to rest, as this is a sign that the gluteals have fatigued.
Check that the athlete does not push the hips up too far and arches the lumbar spine into a lordotic position. If this happens, lower the hips and place hands on hips to help maintain the neutral position. Check that the knees and feet are aligned at hip-width apart. No knock or bandy knees!
Once the athlete can maintain the bridge position with perfect alignment and using only the gluteals for three sets of 30 seconds, he/she is ready for some progressions.
First, try lifting the heel of one foot. This will place more load on the other side of the gluteals. Practise until the athlete can hold this position each side for 30 seconds, with a focused contraction of the gluteals.
The second progression is to bridge completely on one leg. To practise this initially, just swap from side to side by lifting each leg alternatively. When you lift the leg off the floor it is essential that the lumbar spine remains in neutral and the pelvis level. If the gluteals are not stabilising effectively, the opposite-side pelvis can drop down. In my experience, once you can bridge on one leg perfectly for three sets of 30 seconds each leg, you have developed good inner range strength.
Sometimes gluteal strength can be affected by the flexibility of the hip flexors and the ITB. Athletes may find that their ability to perform the bridge may vary. Don't worry, this is normal. Simply drop down to a less advanced progression and ensure that the gluteal muscles are recruiting correctly and the athlete can effectively maintain the neutral position on the lumbar spine. He/she will most likely return to their previous bridge level soon.
Norris, 2000. Back Stability. Human Kinetics: Champaign, IL.