The most underestimated muscle could be the Hip Flexor ( iliopsoas ). The hip flexors main function is to help the hip joints move with full range of motion. Did you know that if you have poor Hip Flexor that it can effect posture, cause hip pain and lower back pain especially if they are too tight.
There must be a fine balance between strong , but yet flexible ( Flexor ) Hip Flexor muscle. Stretching daily and incorporating HF training 1-2 times per week will give you that balance needed .
We all have heard that having a strong core is important, well the HF is part of the equation because it connects the trunk of your body to your legs ( core ) . I know the importance of having a strong core and can show you some of the things I do to accomplish this. Try this exercise! 40 sec x 3, if 40 sec is too much start out doing 20 sec x 3.