- Walk up to a straight bar - could be anything from a bo to a broomstick to a loaded Olympic barbell - and set your feet at least shoulder width apart, toes pointing out slightly.
- Pick up the bar, hands pretty far apart - not shoulder width, they have to be farther out than that, and get it overhead, either by snatching it or just lifting it (it's kind of pointless to snatch a broomstick).
- Keeping the bar directly overhead perform a full squat (keep your lower back straight or even arched a little; make sure your knees travel over or outside your toes, not caving in). I like to have a mirror to the sides to make sure I'm not letting the bar travel the the front or back. From the side your arms should be pointing straight up the entire time. If this feels like it's stretching or cramping your upper back, it's okay - you're loosening up your thoracic spine and activating lazy muscles in that region.
- Stand back up; repeat. Your arms don't bend - the distance from the bar to your head doesn't vary at all - all the motion is at your hips and knees.
People do this with higher weights and more reps as a conditioning exercise, and I'm not opposed to that in theory, it's just not how I use the movement.
The squatting movement is super important for your hips - a deep squat is probably the most important movement pattern for any athlete. Getting that full range of motion ready before your workout is a big deal for maintaining performance and hip health.
Keeping the bar overhead as your butt moves backwards requires a decent amount of thoracic mobility. Basically, your thoracic spine has to arch to keep the bar from traveling forwards and falling. Good thoracic mobility is important for good shoulder and lumbar health. Very few of us do enough thoracic mobility work in our karate workouts.
There's nothing magical about this exercise, but it's great for hitting three problem areas at once - hips, thoracic spine, and shoulders - and getting them all warmed up and prepped for the workout.
Try doing these before your next workout. The pinch in your upper back will tell you how badly you need to do more of them!