One would be amazed how many times I am asked "What is the one best thing I can do for _____." (insert your injury/painful body part here). While that is an impossible question to adequately answer (because there is no "one move" to cure all pain and injury) I do have an option... PLANKS!
Planks are one of the best things you can do for total body strength and more importantly, stability. That being said, I will always recommend variation in workout routine, frequency, duration, mode, etc for injury prevention and recovery. But, for those who are looking for 1-2 easy things to do every day in order to get them on the right track, planks are it. Here are a few reasons:
1. It's a Total Body Workout. The plank exercise uses multiple different muscle groups, starting with the shoulders. You must engage your shoulder and scapular muscles by pushing the mid back towards the ceiling and putting the humerus "in the socket." This creates stability in the shoulder joint and shoulder blade, and can help increase strength for other weight bearing upper extremity movements (ie. pushups). While performing planks, many people will say, "I just feel it in my shoulders!" which means...you have weak shoulders!
The abdominal muscles are activated by keeping your pelvis tucked and trying to take the natural curve out of the lumbar spine. The key thing here is to not let your belly bottom drop towards the floor. Pull it in toward your spine.
The lower extremities should be very active here as well, which is easy to forget. By engaging your glutes (squeezing your butt) and quads (pulling your knee caps towards your nose), as well as pushing your heels towards the opposite/back wall, you will be fulling engaging your lower extremity muscle groups.
2. Progressions for Beginners to Advanced. Many of us think of planks in one position only - on our toes and elbows. However, there is a beginner stage and ways to add variation to make planks more challenging. By starting on your knees, you are engaging the same muscles from your hips up. This puts MUCH less strain on your upper extremities, but still challenges your abdominal muscles and shoulders in the same way, just less intensely. Then, once you have mastered the true "plank" for 2 minutes, you can add in things like: alternating touching one knee down at a time, lifting one leg, followed by one arm at a time, stepping one foot out and back in, or adding jumping apart. To challenge the upper body more, army planks are great - you go up to your hands one at a time and then back to the elbows. To make the plank easier on your shoulders if you need, go onto your hands instead of your elbows.
3. You don't need ANY equipment. Activation and endurance of our "core" or abdominal musculature is much more important than power or strength. If you think about it, we need to maintain our core activation for longer periods of time (endurance), not necessarily having so much strength that we need to lift heavy things. Therefore, planks can always be increased in difficulty by increasing duration. Because you don't need to add weight to make it more challenging, planks can be done anywhere, anytime. Heck, you can even do them during lunch at your desk! Plus, plank competitions can be a great way to get your team at work active and moving.
Expanding a bit, try incorporating side planks. All the same progressions and modifications apply, like going onto your hand instead of your elbow, starting on your knees, or lifting one leg to make it more challenging. If you want to incorporate these moves into your routine at home, I like to call it the rotisserie =) Get the front/back and each side!