I like Pelvic Peels for spinal mobility.  They are also a great way to strengthen the hamstrings, back and glutes!  

Side lying clams and leg circles are are great way to strengthen the abductors. 

​I love incline push ups!  Incline push ups allow me to work my shoulders, chest and core without the strain of my whole body weight.  I can gradually increase the difficulty by increasing the incline.