Balancing on one leg with a club while holding the opposite foot behind the body warms up the thigh muscles, important before walking a course. Balancing also improves proprioception (orientation) in the feet so you can swing in control and read greens more accurately.
Swirling the knees around in all planes of motion helps improve mobility in the ankles. Good dorsiflexion (an upward hinging of the foot) is key to addressing the ball correctly and maintaining posture through impact--especially on bunker and deep-rough shots.
Bending the torso left or right while extending the opposite arm improves function and mobility of the oblique muscles (sides of the abdomen) and the iliotibial tract connective tissue (sides of your thighs). Side bending is crucial to swinging on plane and hitting solid shots.
Bending forward at the hips 90 degrees while extending the arms and using a club to balance lengthens most muscles along the back side of the body. This helps maintain posture during the swing and allows the arms to get the club into a good position at the top.
Dropping into a deep squat while holding a club directly overhead primes the muscles around the shoulders, thoracic spine (mid back), hips, butt and ankles. It improves core stability to swing in control. Flaring the feet challenges the outside of the hips to improve rotation.