Seems to be a bit of confusion about partial rep training. I'm repeating something I wrote a while back, which may (or may not) throw some light on the subject. Partial training can be very rewarding. But, like any other system, it's not the be all or end all of serious training methods. The standard full ROM workout does have a certain value, but can limit a muscles potential to reach it's max strength and development. Partial reps can offer another alternatives to boost training result even more. Both systems can be used for different training cycles and different purposes. Even in the same workout. You may be shocked as to how strong you really are if never into serious partial rep, short range training. Of the size you may gain.
Just to note: Adjustable pin settings was one of the original concept when PR training was first introduced, way back in the day. It was used in partnership with partial rep training. Giving brief run down about pins here applied to partials..
Muscles have a three phase function, start, middle and finish. Acting as gears, like in a car, to transfer the strength from the weakest to strongest position. Taking the bench for example, all three phases are not trained to their max with regular BB, DB or machine training (except for most Nautilus equipment). Am referring to the start position, from off the chests, as the strongest position of the lockout above. If your starting the bench from above and than lowering it to the chest you will be usually relying on the rebound effect off the chest. Which for the most part does not require the full involvement of the lower muscle phase.
With partial pin training the lower phase will be worked as hard as it is capable of, because you will be pushing max weight for a short distance. Same holds true for the middle and top phases of the lift. This refers to most all push & pull exerciees: bench, chins, presses, squats, etc.
With the example of the bench: at the lowest start position set the pins so the bar is slightly touching the chest. Set the other two pins to about 3 to 4 inches high, so the bar will hit and stop against them. The middle start position will have the bar resting on the same position as the top pins that were used to stop the bar from the lower position. Set the other two pins to about 4 to 5 inches high, so the bar will stop against them on the way up. The top position will start from the pin settings of the stops for the middle position. You can set two top pins about an inch or two to stop a complete lockout if you wish. But some guy's do a complete lockout at the top position without any pins/stops in the way.
In any position, when hitting the stops (pins), hold there for 1 or 2 seconds than back down to the start position. Affect more strength fiber that way. Set the pins to your liking, to find the correct stop. Some guy's have short, some long, arms, etc. Used on chins, pulls, press, etc with good affect.
For power, 3 to 5 reps. And 2 to 4 sets. For BB'ing, than 8 to 10reos & 2 to 4 sets. Though this program is usually geared for power training, it can produce muscle mass. The ego may be flatten a bit when using the lower starting position. Because it is a very weak position for most guy's Can also be said for the middle range. But not to worry, you will get much stronger in a short period of time. Good Luck.
