Have you had a muscle group that is weak and won’t grow from normal training? Then you should definitely give partials a try! I myself was sceptical at first- I had always believed in a full range of motion for optimum development of the musculature. However after reading Paul T Burke’s book “A new fitness paradigm for the mature male”, Pete Cisco’s info on static contraction and Steve Holman (x-rep fame) getting great benefits from using partial reps I was convinced I needed to give it a go.
Also, there are other real life examples where partial movements show that they work – look at cyclists and their calves! Or look at builders who use a hammer a lot and their meaty forearms. These are two real life examples where partial movements seem to give some real muscle growth.
Another thing I have noticed in the gym is that we have different body structures. Imagine two guys with the exact same shoulder width, muscle attachments etc, but one guy has longer forearms. His full range of motion would be a longer movement than the other guy if he took it to down to his chest. Would he be disadvantaged? I think he would be, his friend would be able to use more weight because of the shorter movement. The extra range of motion he has to perform may be stretching his shoulder joint excessively which could cause injury down the track. In this respect a partial range of motion may be more beneficial in some instances than a full range of motion. After all if your goal is to stimulate your muscles the best way you can and that means a slightly smaller range of motion to keep the tension on the right muscles then so be it.
Initially I thought I would try partials with my calves and forearms-two areas that are weaker body parts for me and feel in the joints when I use a full range of motion (this may be due to the fact that I have short muscle bellies in these areas and long tendons). I performed dumbbell wrist curls (forearm resting on bench while kneeling) but only performed the top part of the movement (from wrist being neutral to a flexed position back to neutral-no stretch). For calves I performed leg press calf raises, seated calf raises, hack raises and standing calf raises (from a neutral position to full plantar flexion-no stretch). What I got was an excellent mind muscle connection, huge pumps, no joint soreness, strength increases and some actual muscle growth!
I am now experimenting and finding positive results in other areas too. So if you have weaker body parts that haven’t grown for awhile, assess your body structure, look at your muscle bellies and tendon lengths, experiment until you find exercises that generate maximum tension on the muscles and give partial movements a try for full muscle development!