This is an exercise that I often prescribe to runners during the early stages of the rehabilitation process once they are able to tolerate weight bearing through the involved region. Not only does this drill challenge the performer to maintain single leg balance in a wobble free manner, but it also starts to load the quadriceps eccentrically through a controlled range while progressing the leg over the foot (dorsiflexion). Care should be taken to assume an upright position while synchronizing the opposite arm and leg and avoiding gripping with the toes. I typically have folks perform 4, 15yd passes on firm level ground starting unshod (barefoot) before completing the exercises with shoes.
I have been spending a good deal of time as of late exploring the Redcord Sling Suspension System. Most folks naturally liken it to the TRX though it's far more robust in terms of its capabilities. This exercise features a redcord long bridge combined with a bottom's up kettlebell press using 8kg kettlebells. Make sure to maintain the position throughout the drill. I typically will perform 3 sets of 5 presses while maintaining the trunk steady. This is an advanced level exercise so most folks will probably have to work up to it. Once you master this baseline drill, you can further challenge yourself as in part two of the video by drawing the free leg towards your chest while synchronizing it with the pressing motion. Enjoy!
E-BOOK for RUNNERS
MIKE REINOLD & ERIC CRESSEY'S FUNCTIONAL STABILITY PART 4