Pin Back Squat
Bottom-up squat, block squat, concentric squat, Anderson squat
The pin squat is a back squat
in which the barbell starts supported in a low position by a rack or blocks and the athlete begins the lift with the concentric movement rather than eccentric.
Set up a power rack or pulling blocks to place the barbell at the height at which the lift will be started. Typically this is as close to the bottom as possible while still allowing the lifter to get into position under the bar, or at approximately parallel depth. Position yourself under the bar properly, pressurize and stabilize the trunk forcefully, and lift the bar with as much upward acceleration as possible. Understand that this goal of upward acceleration does not mean that the bar should be jerked off the rack or blocks—such jerking indicates that the lifter is not tight enough under the bar prior to initiating the movement.
Establishing balance under the bar can be tricky because it’s being supported by something other than the lifter initially. Be sure to roll the bar into the correct position before beginning. Tension can be put against the bar to feel the balance first. Maximal acceleration and speed are important to truly get the most value from the exercise.
The pin squat helps train rate of force development / explosive-strength, aggression and can be used to strengthen specific ranges of motion in the squat. Most commonly, this would be around the parallel position, which is the most mechanically disadvantageous position and will create a sticking point in the lift. The pin squat differs from the pause squat because it removes much of the pre-tension of the muscles and consequently demands higher rate of force development.
Sets of 3-5 reps are typical, but 1-2 can be used periodically. The pin squat should be used as one squat variation in a given training program, combined with at least one other day of normal squatting to maintain full range of motion and training the elastic change of direction in the bottom.
Pin squats can be performed as back squats or front squats. They can be done with different eccentric variations ranging from slow eccentrics back to the pins or blocks, or even virtually no eccentric via lowing the bar back to the pins or blocks without any significant resistance.